Syncope, Vasovagal
Syncope
Tilt-Table Test
Etilefrine
Autonomic Denervation
Midodrine
Bradycardia
Pacemaker, Artificial
Electrocardiography
Hypotension, Orthostatic
Unconsciousness
Exercise Movement Techniques
Sympathomimetics
Dizziness
Autonomic Nervous System
Baroreflex
Peripheral Nervous System Agents
Nitroglycerin
Head-Down Tilt
Electrocardiography, Ambulatory
Clomipramine
Vagus Nerve
Pure Autonomic Failure
Cardiac Pacing, Artificial
Lower Body Negative Pressure
Propantheline
Reflex, Abnormal
Hemodynamics
Metoprolol
Adrenergic beta-Antagonists
Postural Orthostatic Tachycardia Syndrome
Sympathetic Nervous System
Arrhythmias, Cardiac
Heart Arrest
Prospective Studies
Autonomic Nervous System Diseases
Induction of neurally mediated syncope with adenosine. (1/289)
BACKGROUND: Tilt testing is used to establish the diagnosis of neurally mediated syncope. However, applicability of the tilt test is limited by test sensitivity and length of time required to perform the test. We hypothesized that adenosine could facilitate the induction of neurally mediated syncope through its sympathomimetic effects and therefore could be used as an alternative to routine tilt testing. METHODS AND RESULTS: In protocol 1, the yield of adenosine tilt testing (12 mg while upright, followed by 60 degrees tilt for 5 minutes) and a 15-minute isoproterenol tilt test were compared in 84 patients with a negative 30-minute drug-free tilt test. In protocol 2, 100 patients underwent an initial adenosine tilt test followed by our routine tilt test (30-minute drug-free tilt followed by a 15-minute isoproterenol tilt). Six additional control patients underwent microneurography of the peroneal nerve to compare the sympathomimetic effects during bolus administration of adenosine and continuous infusion of isoproterenol. In protocol 1, the yields of adenosine (8 of 84, 10%) and isoproterenol (7 of 84, 8%) tilt testing were comparable (P=NS). In protocol 2, the yields of adenosine (19 of 100, 19%) and routine (22 of 100, 22%) tilt testing were also comparable (P=NS). Although the yield of adenosine tilt testing was comparable in both protocols, patients with a negative adenosine tilt test but a positive routine tilt test usually required isoproterenol to elicit the positive response. Microneurography confirmed discordant sympathetic activation after adenosine and isoproterenol administration. CONCLUSIONS: Adenosine is effective for the induction of neurally mediated syncope, with a diagnostic yield comparable to routine tilt testing. However, the discordant results obtained with adenosine and the isoproterenol phase of routine tilt testing suggest that adenosine and isoproterenol tilt testing may have complementary roles in eliciting a positive response. Therefore, a tilt protocol that uses an initial adenosine tilt followed, if necessary, by an isoproterenol tilt would be expected to increase the overall yield and reduce the duration of tilt testing. (+info)Effect of etilefrine in preventing syncopal recurrence in patients with vasovagal syncope: a double-blind, randomized, placebo-controlled trial. The Vasovagal Syncope International Study. (2/289)
BACKGROUND: Etilefrine is an alpha-agonist agent with a potent vasoconstrictor effect, which is potentially useful in preventing vasovagal syncope by reducing venous pooling and/or by counteracting reflex arteriolar vasodilatation. The present multicenter, randomized, placebo-controlled study was designed to evaluate the efficacy of this drug for the long-term management of patients with recurrent vasovagal syncope. METHODS AND RESULTS: In the 20 participating centers, 126 patients with recurrent vasovagal syncope (at least 3 episodes in the last 2 years) and a positive baseline head-up tilt response were randomly assigned to placebo (63 patients) or etilefrine at a dosage of 75 mg/d (63 patients) and were followed up for 1 year or until syncope recurred. The primary end-point of the study was the first recurrence of syncope. There were no differences between the 2 study groups in the patients' baseline characteristics. During follow-up, the group treated with etilefrine had a similar incidence of first syncopal recurrence to that of placebo group both in the intention-to-treat analysis (24% versus 24%) and in on- treatment analysis (26% versus 24%). Moreover, the median time to the first syncopal recurrence did not significantly differ between the 2 study groups (106 days in the etilefrine arm and 112 days in the placebo arm). CONCLUSIONS: Oral etilefrine is not superior to placebo in preventing spontaneous episodes of vasovagal syncope. Randomized controlled studies are essential to assess the real usefulness of any proposed therapy for patients with vasovagal syncope. (+info)Utility of a single-stage isoproterenol tilt table test in adults: a randomized comparison with passive head-up tilt. (3/289)
OBJECTIVES: This study was conducted to develop a time-efficient tilt table test. BACKGROUND: Current protocols of tilt table testing are quite time-consuming. This study was designed to assess the diagnostic value, tolerance and procedural time of a single-stage isoproterenol tilt table protocol. METHODS: A single-stage isoproterenol tilt table test was compared with the passive tilt table test. The study was prospectively designed in a randomized and crossover fashion. RESULTS: The study population consisted of 111 patients with a history of syncope (mean age 55 +/- 20 years). Of the total, 62 patients (56%; 95% confidence interval, 46% to 65%) had a positive vasovagal response during isoproterenol tilt table testing and 35 (32%; 23% to 41%) during passive tilt table testing (p = 0.002). The mean procedural times of the study population were 11.7 +/- 3.6 min and 36.9 +/- 13.3 min for isoproterenol and passive tilt table testing, respectively (p < 0.001). All patients tolerated single-stage isoproterenol testing. In the 23 control subjects (mean age 34 +/- 11 years), the apparent specificities were 91% (72% to 99%) and 83% (61% to 99%) for passive and single-stage tilt table testing, respectively. CONCLUSIONS: The single-stage isoproterenol tilt table test was more effective in inducing a positive vasovagal response in an adult population than the standard passive tilt table test, and it significantly reduced the procedural time. The increase in positive yield was associated with a moderate decrease in apparent specificity. These observations support the conclusion that single-stage tilt table testing could be a reasonable diagnostic option in patients undergoing syncope evaluation. (+info)Effects of paroxetine hydrochloride, a selective serotonin reuptake inhibitor, on refractory vasovagal syncope: a randomized, double-blind, placebo-controlled study. (4/289)
OBJECTIVES: The purpose of the study was to determine whether the well tolerated serotonin reuptake inhibitor paroxetine hydrochloride could prevent vasovagal syncope in patients resistant to or intolerant of previous traditional therapies. BACKGROUND: Serotonergic mechanisms play a major role in the processes leading to neurocardiogenic vasovagal syncope, and serotonin reuptake inhibitors have been reported to be effective in preventing refractory syncope. METHODS: Sixty-eight consecutive patients (26 men and 42 women, mean age 44.7+/-16.5 years) with recurrent syncope and positive head-up tilt test and in whom standard therapies with beta-adrenergic blocking agents, vagolytic, negative inotropic or mineral corticoid agents were ineffectual or poorly tolerated were referred for study. Patients randomly received either paroxetine at 20 mg once a day or a placebo. A head-up tilt test was then reperformed after one month of treatment, and the clinical effect was noted over a mean follow-up of 25.4+/-7.9 months. RESULTS: The response rates (negative tilt test) after one month of treatment were 61.8% versus 38.2% (p < 0.001) in the paroxetine and placebo groups, respectively. During follow-up spontaneous syncope was reported in six patients (17.6%) in the paroxetine group as compared to 18 patients (52.9%) in the placebo group (p < 0.0001). Only one patient (2.9%) asked to be discontinued from the drug for severe side effects. CONCLUSIONS: Paroxetine was found to significantly improve the symptoms of patients with vasovagal syncope unresponsive to or intolerant of traditional medications and was well tolerated by patients. (+info)Contribution of head-up tilt testing and ATP testing in assessing the mechanisms of vasovagal syndrome: preliminary results and potential therapeutic implications. (5/289)
BACKGROUND: In patients with vasovagal syndrome, head-up tilt testing may reproduce symptoms generally associated with vasodepression. Recent research suggests ATP testing identifies patients with abnormal vagal cardiac inhibition. This preliminary study examined the joint contribution of both tests in identifying underlying mechanisms in the general population with vasovagal syndrome. METHODS AND RESULTS: Both tests were performed in random order during 1 session and outside of predominant sympathetic periods in 72 patients hospitalized for syncope (n=56) or presyncope (n=16) for whom no cardiac or extracardiac cause was found. For passive and isoproterenol-provocative tilt testing by standard protocol, reproduction of symptoms defined a positive test. The ATP test consisted of injecting ATP 20 mg IV at bedside, continuously monitoring ECG and blood pressure; a vagal cardiac pause >10 seconds defined a positive test. For most patients (64%), >/=1 test was positive. Of the 41 patients (57%) with a positive tilt test (either passive or provoked by isoproterenol), 32% had cardiac disease; none had significant bradycardia (<50 bpm). Of the 8 patients (11%) with a positive ATP test, 62% had cardiac disease; the probability of a positive result increased with age (P=0.015). Both tests were positive in 3 patients and negative in 26 patients; the tilt and ATP test results were uncorrelated (P=0.28). CONCLUSIONS: Results suggest tilt and ATP tests individually and jointly determine the mechanism of vasovagal symptoms in most patients and that vagal cardiac inhibition increases with age. (+info)The effects of the hypothalamus on hemodynamic changes elicited by vagal nerve stimulation. (6/289)
To investigate the means by which neurogenic shock or syncope occur in dentistry, we determined the hemodynamic response to the activation of vagal tone in cats while they were under emotional stress. The hypothalamus and the vagal nerve were electrically stimulated to produce emotional stress and to activate vagal tone, respectively. Hemodynamic changes were recorded during vagal stimulation (Va group) and during vagal stimulation preceded by hypothalamic stimulation (AH + Va group). Although blood pressure decreased in both groups, the degree of hypotensive response in the AH + Va group was greater than the response in the Va group. Total peripheral resistance (TPR) was reduced in the AH + Va group but was increased in the Va group. The blood flow to the skeletal muscles in the AH + Va group was greater than that of the Va group. Reduced TPR, which could be due to vasodilation in the skeletal muscles, was the cause of intensified hypotension in the AH + Va group. Clearly, the hypotension produced by vagal stimulation was worsened when it was preceded by hypothalamic stimulation; this occurrence could be related to the tendency of blood to flow to the skeletal muscles. (+info)Accurate diagnosis of convulsive syncope: role of an implantable subcutaneous ECG monitor. (7/289)
Convulsive syncope due to transient bradycardia is recognized as a cause of treatment-resistant seizures. However, the diagnosis may be difficult to make with conventional electrocardiographic devices if attacks are infrequent. We present a case of apparent epilepsy in which a new implantable electrocardiographic event recorder (the 'Reveal' insertable loop recorder) was used to show that attacks were caused by prolonged asystole of up to 36 s in duration. The insertable loop recorder may have an important role in the investigation of patients with treatment-resistant seizures, particularly where there is a strong suspicion of an underlying cardiac arrhythmia. (+info)Serum prolactin levels after seizure and syncopal attacks. (8/289)
Loss of consciousness and falling are the key features of syncope. Common accompaniments include tonic and myoclonic muscle activity, eye deviations, automatisms, vocalizations and hallucinations that may render the distinction from epileptic seizures difficult. The frequently increased levels of serum prolactin (SPRL) were observed immediately after generalized and complex partial seizures. Presumably, the hormone release is caused by the propagation of epileptic activity, usually from the temporal lobe to the hypothalamic pituitary axis. Numerous reports have demonstrated that the post-ictal SPRL level may be used to differentiate between epileptic and syncopal, non-epileptic attacks. In order to confirm the hypothesis, the SPRL levels were measured in patients with complex partial seizures (CPS) and patients with vaso-vagal syncopal attacks (VVS). The SPRL levels were prospectively measured for each patient as soon as possible after the event (within 1 hour), then 1 hour after the first determination and finally blood was sampled 24 hours later. During the study period (18 months), 18 patients with CPS and 15 patients with VVS were investigated in total. The mean values of SPRL levels in both groups were increased immediately after the event (CPS group: 1142 +/- 305 mIU/l; VVS group: 874 +/- 208 mIU/l). The elevated SPRL levels were found in 14 (78%) patients immediately after CPS and in 9 (60%) patients immediately after VVS. After examining the results of the present study we conclude that the elevated serum prolactin level after an epileptic attack is of no significant value in differential diagnosis between epileptic and vaso-vagal syncopal attacks. (+info)Vasovagal syncope is a type of fainting (syncope) that occurs when the body overreacts to certain triggers, such as the sight of blood or extreme emotional distress. This reaction causes the heart rate and blood pressure to drop, leading to reduced blood flow to the brain and loss of consciousness. Vasovagal syncope is usually not a cause for concern and does not typically indicate a serious underlying medical condition. However, it can be dangerous if it occurs during activities such as driving or operating heavy machinery. If you experience frequent episodes of vasovagal syncope, it is important to speak with a healthcare provider for evaluation and treatment options.
Syncope is a medical term defined as a transient, temporary loss of consciousness and postural tone due to reduced blood flow to the brain. It's often caused by a drop in blood pressure, which can be brought on by various factors such as dehydration, emotional stress, prolonged standing, or certain medical conditions like heart diseases, arrhythmias, or neurological disorders.
During a syncope episode, an individual may experience warning signs such as lightheadedness, dizziness, blurred vision, or nausea before losing consciousness. These episodes usually last only a few minutes and are followed by a rapid, full recovery. However, if left untreated or undiagnosed, recurrent syncope can lead to severe injuries from falls or even life-threatening conditions related to the underlying cause.
A tilt-table test is a diagnostic procedure used to evaluate symptoms of syncope (fainting) or near-syncope. It measures your body's cardiovascular response to changes in position. During the test, you lie on a table that can be tilted to change the angle of your body from horizontal to upright. This simulates what happens when you stand up from a lying down position.
The test monitors heart rate, blood pressure, and oxygen levels while you're in different positions. If you experience symptoms like dizziness or fainting during the test, these can provide clues about the cause of your symptoms. The test is used to diagnose conditions like orthostatic hypotension (a sudden drop in blood pressure when standing), vasovagal syncope (fainting due to an overactive vagus nerve), and other heart rhythm disorders.
Etilefrine is a synthetic, sympathomimetic amine drug that acts as a direct-acting adrenergic agonist. It primarily stimulates alpha-1 and beta-1 adrenergic receptors, leading to increased heart rate, cardiac contractility, and blood pressure. Etilefrine is used clinically as a vasopressor agent to treat hypotension (low blood pressure) in certain conditions, such as shock or during surgical procedures. It should be administered under the supervision of a healthcare professional due to its potential serious side effects, including cardiac arrhythmias and hypertension.
Autonomic denervation is a medical term that refers to the interruption or loss of nerve supply to the autonomic nervous system. The autonomic nervous system is the part of the nervous system that controls involuntary actions, such as heart rate, blood pressure, digestion, and pupil dilation.
Autonomic denervation can occur due to various reasons, including surgical procedures, trauma, degenerative diseases, or medical conditions such as diabetes. The interruption of nerve supply can lead to a range of symptoms depending on the specific autonomic functions that are affected.
For example, autonomic denervation in the heart can lead to abnormal heart rhythms or low blood pressure. In the digestive system, it can cause problems with motility and secretion, leading to symptoms such as bloating, constipation, or diarrhea. Autonomic denervation in the eyes can result in pupil abnormalities, dry eyes, or light sensitivity.
Treatment for autonomic denervation depends on the underlying cause and the specific symptoms that are present. In some cases, medication may be used to manage symptoms, while in others, surgical intervention may be necessary to repair or restore nerve function.
Midodrine is a medication that belongs to a class of drugs called vasoconstrictors. It works by narrowing the blood vessels and increasing blood pressure. The medical definition of Midodrine is:
A synthetic derivative of the imidazole compound, adrenergic agonist, which is used in the treatment of orthostatic hypotension. Midodrine is a prodrug that is rapidly metabolized to its active form, desglymidodrine, after oral administration. It selectively binds to and activates alpha-1 adrenergic receptors, causing vasoconstriction and an increase in blood pressure. The drug's effects are most pronounced on the venous side of the circulation, leading to increased venous return and cardiac output. Midodrine is typically administered orally in divided doses throughout the day, and its use is usually reserved for patients who have not responded to other treatments for orthostatic hypotension.
Posture is the position or alignment of body parts supported by the muscles, especially the spine and head in relation to the vertebral column. It can be described as static (related to a stationary position) or dynamic (related to movement). Good posture involves training your body to stand, walk, sit, and lie in positions where the least strain is placed on supporting muscles and ligaments during movement or weight-bearing activities. Poor posture can lead to various health issues such as back pain, neck pain, headaches, and respiratory problems.
Bradycardia is a medical term that refers to an abnormally slow heart rate, typically defined as a resting heart rate of less than 60 beats per minute in adults. While some people, particularly well-trained athletes, may have a naturally low resting heart rate, bradycardia can also be a sign of an underlying health problem.
There are several potential causes of bradycardia, including:
* Damage to the heart's electrical conduction system, such as from heart disease or aging
* Certain medications, including beta blockers, calcium channel blockers, and digoxin
* Hypothyroidism (underactive thyroid gland)
* Sleep apnea
* Infection of the heart (endocarditis or myocarditis)
* Infiltrative diseases such as amyloidosis or sarcoidosis
Symptoms of bradycardia can vary depending on the severity and underlying cause. Some people with bradycardia may not experience any symptoms, while others may feel weak, fatigued, dizzy, or short of breath. In severe cases, bradycardia can lead to fainting, confusion, or even cardiac arrest.
Treatment for bradycardia depends on the underlying cause. If a medication is causing the slow heart rate, adjusting the dosage or switching to a different medication may help. In other cases, a pacemaker may be necessary to regulate the heart's rhythm. It is important to seek medical attention if you experience symptoms of bradycardia, as it can be a sign of a serious underlying condition.
An artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart. It is typically used when the heart's natural pacemaker, the sinoatrial node, is not functioning properly and the heart rate is too slow or irregular. The pacemaker consists of a small generator that contains a battery and electronic circuits, which are connected to one or more electrodes that are placed in the heart.
The generator sends electrical signals through the electrodes to stimulate the heart muscle and cause it to contract, thereby maintaining a regular heart rhythm. Artificial pacemakers can be programmed to deliver electrical impulses at a specific rate or in response to the body's needs. They are typically implanted in the chest during a surgical procedure and can last for many years before needing to be replaced.
Artificial pacemakers are an effective treatment for various types of bradycardia, which is a heart rhythm disorder characterized by a slow heart rate. Pacemakers can significantly improve symptoms associated with bradycardia, such as fatigue, dizziness, shortness of breath, and fainting spells.
Recurrence, in a medical context, refers to the return of symptoms or signs of a disease after a period of improvement or remission. It indicates that the condition has not been fully eradicated and may require further treatment. Recurrence is often used to describe situations where a disease such as cancer comes back after initial treatment, but it can also apply to other medical conditions. The likelihood of recurrence varies depending on the type of disease and individual patient factors.
Electrocardiography (ECG or EKG) is a medical procedure that records the electrical activity of the heart. It provides a graphic representation of the electrical changes that occur during each heartbeat. The resulting tracing, called an electrocardiogram, can reveal information about the heart's rate and rhythm, as well as any damage to its cells or abnormalities in its conduction system.
During an ECG, small electrodes are placed on the skin of the chest, arms, and legs. These electrodes detect the electrical signals produced by the heart and transmit them to a machine that amplifies and records them. The procedure is non-invasive, painless, and quick, usually taking only a few minutes.
ECGs are commonly used to diagnose and monitor various heart conditions, including arrhythmias, coronary artery disease, heart attacks, and electrolyte imbalances. They can also be used to evaluate the effectiveness of certain medications or treatments.
Orthostatic hypotension is a type of low blood pressure that occurs when you stand up from a sitting or lying position. The drop in blood pressure causes a brief period of lightheadedness or dizziness, and can even cause fainting in some cases. This condition is also known as postural hypotension.
Orthostatic hypotension is caused by a rapid decrease in blood pressure when you stand up, which reduces the amount of blood that reaches your brain. Normally, when you stand up, your body compensates for this by increasing your heart rate and constricting blood vessels to maintain blood pressure. However, if these mechanisms fail or are impaired, orthostatic hypotension can occur.
Orthostatic hypotension is more common in older adults, but it can also affect younger people who have certain medical conditions or take certain medications. Some of the risk factors for orthostatic hypotension include dehydration, prolonged bed rest, pregnancy, diabetes, heart disease, Parkinson's disease, and certain neurological disorders.
If you experience symptoms of orthostatic hypotension, it is important to seek medical attention. Your healthcare provider can perform tests to determine the underlying cause of your symptoms and recommend appropriate treatment options. Treatment may include lifestyle changes, such as increasing fluid intake, avoiding alcohol and caffeine, and gradually changing positions from lying down or sitting to standing up. In some cases, medication may be necessary to manage orthostatic hypotension.
Unconsciousness is a state of complete awareness where a person is not responsive to stimuli and cannot be awakened. It is often caused by severe trauma, illness, or lack of oxygen supply to the brain. In medical terms, it is defined as a lack of response to verbal commands, pain, or other stimuli, indicating that the person's brain is not functioning at a level necessary to maintain wakefulness and awareness.
Unconsciousness can be described as having different levels, ranging from drowsiness to deep coma. The causes of unconsciousness can vary widely, including head injury, seizure, stroke, infection, drug overdose, or lack of oxygen supply to the brain. Depending on the cause and severity, unconsciousness may last for a few seconds or continue for an extended period, requiring medical intervention and treatment.
Heart rate is the number of heartbeats per unit of time, often expressed as beats per minute (bpm). It can vary significantly depending on factors such as age, physical fitness, emotions, and overall health status. A resting heart rate between 60-100 bpm is generally considered normal for adults, but athletes and individuals with high levels of physical fitness may have a resting heart rate below 60 bpm due to their enhanced cardiovascular efficiency. Monitoring heart rate can provide valuable insights into an individual's health status, exercise intensity, and response to various treatments or interventions.
"Exercise movement techniques" is a general term that refers to the specific ways in which various exercises are performed. These techniques encompass the proper form, alignment, and range of motion for each exercise, as well as any breathing patterns or other instructions that may be necessary to ensure safe and effective execution.
The purpose of learning and practicing exercise movement techniques is to maximize the benefits of physical activity while minimizing the risk of injury. Proper technique can help to ensure that the intended muscles are being targeted and strengthened, while also reducing strain on surrounding joints and connective tissues.
Examples of exercise movement techniques may include:
* The correct way to perform a squat, lunge, or deadlift, with attention to foot placement, knee alignment, and spinal positioning.
* The proper form for a push-up or pull-up, including how to engage the core muscles and maintain stability throughout the movement.
* Breathing techniques for yoga or Pilates exercises, such as inhaling on the expansion phase of a movement and exhaling on the contraction phase.
* Techniques for proper alignment and posture during cardiovascular activities like running or cycling, to reduce strain on the joints and prevent injury.
Overall, exercise movement techniques are an essential component of any safe and effective fitness program, and should be learned and practiced under the guidance of a qualified instructor or trainer.
Sympathomimetic drugs are substances that mimic or stimulate the actions of the sympathetic nervous system. The sympathetic nervous system is one of the two divisions of the autonomic nervous system, which regulates various automatic physiological functions in the body. The sympathetic nervous system's primary function is to prepare the body for the "fight-or-flight" response, which includes increasing heart rate, blood pressure, respiratory rate, and metabolism while decreasing digestive activity.
Sympathomimetic drugs can exert their effects through various mechanisms, including directly stimulating adrenergic receptors (alpha and beta receptors) or indirectly causing the release of norepinephrine and epinephrine from nerve endings. These drugs are used in various clinical settings to treat conditions such as asthma, nasal congestion, low blood pressure, and attention deficit hyperactivity disorder (ADHD). Examples of sympathomimetic drugs include epinephrine, norepinephrine, dopamine, dobutamine, albuterol, pseudoephedrine, and methylphenidate.
It is important to note that sympathomimetic drugs can also have adverse effects, particularly when used in high doses or in individuals with certain medical conditions. These adverse effects may include anxiety, tremors, palpitations, hypertension, arrhythmias, and seizures. Therefore, these medications should be used under the close supervision of a healthcare provider.
Dizziness is a term used to describe a range of sensations, such as feeling lightheaded, faint, unsteady, or a false sense of spinning or moving. Medically, dizziness is often described as a non-specific symptom that can be caused by various underlying conditions or factors. These may include:
1. Inner ear disorders (such as benign paroxysmal positional vertigo, labyrinthitis, vestibular neuronitis, or Meniere's disease)
2. Cardiovascular problems (like low blood pressure, arrhythmias, or orthostatic hypotension)
3. Neurological issues (such as migraines, multiple sclerosis, or stroke)
4. Anxiety disorders and panic attacks
5. Side effects of medications
6. Dehydration or overheating
7. Infections (like viral infections or bacterial meningitis)
8. Head or neck injuries
9. Low blood sugar levels (hypoglycemia)
It is essential to consult a healthcare professional if you experience persistent dizziness, as it can be a sign of a more severe underlying condition. The appropriate treatment will depend on the specific cause of the dizziness.
The Autonomic Nervous System (ANS) is a part of the peripheral nervous system that operates largely below the level of consciousness and controls visceral functions. It is divided into two main subdivisions: the sympathetic and parasympathetic nervous systems, which generally have opposing effects and maintain homeostasis in the body.
The Sympathetic Nervous System (SNS) prepares the body for stressful or emergency situations, often referred to as the "fight or flight" response. It increases heart rate, blood pressure, respiratory rate, and metabolic rate, while also decreasing digestive activity. This response helps the body respond quickly to perceived threats.
The Parasympathetic Nervous System (PNS), on the other hand, promotes the "rest and digest" state, allowing the body to conserve energy and restore itself after the stress response has subsided. It decreases heart rate, blood pressure, and respiratory rate, while increasing digestive activity and promoting relaxation.
These two systems work together to maintain balance in the body by adjusting various functions based on internal and external demands. Disorders of the Autonomic Nervous System can lead to a variety of symptoms, such as orthostatic hypotension, gastroparesis, and cardiac arrhythmias, among others.
The baroreflex is a physiological mechanism that helps regulate blood pressure and heart rate in response to changes in stretch of the arterial walls. It is mediated by baroreceptors, which are specialized sensory nerve endings located in the carotid sinus and aortic arch. These receptors detect changes in blood pressure and send signals to the brainstem via the glossopharyngeal (cranial nerve IX) and vagus nerves (cranial nerve X), respectively.
In response to an increase in arterial pressure, the baroreceptors are stimulated, leading to increased firing of afferent neurons that signal the brainstem. This results in a reflexive decrease in heart rate and cardiac output, as well as vasodilation of peripheral blood vessels, which collectively work to reduce blood pressure back towards its normal level. Conversely, if arterial pressure decreases, the baroreceptors are less stimulated, leading to an increase in heart rate and cardiac output, as well as vasoconstriction of peripheral blood vessels, which helps restore blood pressure.
Overall, the baroreflex is a crucial homeostatic mechanism that helps maintain stable blood pressure and ensure adequate perfusion of vital organs.
Peripheral nervous system (PNS) agents are a category of pharmaceutical drugs that act on the peripheral nervous system, which includes all the nerves outside the central nervous system (the brain and spinal cord). These agents can be further classified into various subgroups based on their specific mechanisms of action and therapeutic effects. Here are some examples:
1. Local anesthetics: These drugs block nerve impulses by inhibiting the sodium channels in the neuronal membrane, thereby preventing the generation and transmission of nerve impulses. They are commonly used to provide local or regional anesthesia during surgical procedures or to manage pain. Examples include lidocaine, bupivacaine, and prilocaine.
2. Neuropathic pain agents: These drugs are used to treat neuropathic pain, which is caused by damage or dysfunction of the peripheral nerves. They can act on various targets, including sodium channels, N-methyl-D-aspartate (NMDA) receptors, and voltage-gated calcium channels. Examples include gabapentin, pregabalin, duloxetine, and amitriptyline.
3. Muscle relaxants: These drugs act on the skeletal muscle to reduce muscle tone and spasticity. They can be classified into two main categories: centrally acting muscle relaxants (e.g., baclofen, tizanidine) and peripherally acting muscle relaxants (e.g., cyclobenzaprine, carisoprodol).
4. Cholinergic agents: These drugs act on the cholinergic receptors in the PNS to modulate nerve impulse transmission. They can be further classified into muscarinic and nicotinic agonists or antagonists, depending on their specific mechanism of action. Examples include neostigmine, pyridostigmine, and physostigmine.
5. Sympathomimetic agents: These drugs stimulate the sympathetic nervous system, which is part of the PNS that regulates the "fight or flight" response. They can be used to treat various conditions, such as hypotension, bronchospasm, and nasal congestion. Examples include epinephrine, norepinephrine, phenylephrine, and pseudoephedrine.
6. Sympatholytic agents: These drugs block the sympathetic nervous system to reduce its activity. They can be used to treat various conditions, such as hypertension, tachycardia, and anxiety. Examples include beta-blockers (e.g., propranolol, metoprolol), alpha-blockers (e.g., prazosin, doxazosin), and combined alpha-beta blockers (e.g., labetalol, carvedilol).
7. Neuropathic pain agents: These drugs are used to treat neuropathic pain, which is caused by damage or dysfunction of the nervous system. They can act on various targets in the PNS, such as sodium channels, N-methyl-D-aspartate (NMDA) receptors, and opioid receptors. Examples include lidocaine, capsaicin, tramadol, and tapentadol.
8. Antiepileptic drugs: These drugs are used to treat epilepsy, which is a neurological disorder characterized by recurrent seizures. They can act on various targets in the PNS, such as sodium channels, calcium channels, and GABA receptors. Examples include phenytoin, carbamazepine, valproate, lamotrigine, topiramate, and levetiracetam.
9. Antidepressant drugs: These drugs are used to treat depression, which is a mental disorder characterized by persistent low mood and loss of interest in activities. They can act on various targets in the PNS, such as serotonin receptors, norepinephrine receptors, and dopamine receptors. Examples include selective serotonin reuptake inhibitors (SSRIs) (e.g., fluoxetine, sertraline), serotonin-norepinephrine reuptake inhibitors (SNRIs) (e.g., venlafaxine, duloxetine), tricyclic antidepressants (TCAs) (e.g., amitriptyline, imipramine), and monoamine oxidase inhibitors (MAOIs) (e.g., phenelzine, selegiline).
10. Antipsychotic drugs: These drugs are used to treat psychosis, which is a mental disorder characterized by hallucinations, delusions, and disordered thought processes. They can act on various targets in the PNS, such as dopamine receptors, serotonin receptors, and histamine receptors. Examples include typical antipsychotics (e.g., haloperidol, chlorpromazine) and atypical antipsychotics (e.g., clozapine, risperidone).
11. Anxiolytic drugs: These drugs are used to treat anxiety disorders, which are mental disorders characterized by excessive fear, worry, or nervousness. They can act on various targets in the PNS, such as GABA receptors and benzodiazepine receptors. Examples include benzodiazepines (e.g., diazepam, alprazolam), buspirone, and hydroxyzine.
12. Sedative drugs: These drugs are used to induce sleep or reduce excitement. They can act on various targets in the PNS, such as GABA receptors and histamine receptors. Examples include barbiturates (e.g., phenobarbital, secobarbital), benzodiazepines (e.g., diazepam, temazepam), and antihistamines (e.g., diphenhydramine, doxylamine).
13. Hypnotic drugs: These drugs are used to induce sleep. They can act on various targets in the PNS, such as GABA receptors and benzodiazepine receptors. Examples include benzodiazepines (e.g., triazolam, flunitrazepam) and non-benzodiazepine hypnotics (e.g., zolpidem, eszopiclone).
14. Antidepressant drugs: These drugs are used to treat depression, which is a mental disorder characterized by persistent feelings of sadness, hopelessness, or worthlessness. They can act on various targets in the PNS, such as serotonin receptors and norepinephrine transporters. Examples include selective serotonin reuptake inhibitors (e.g., fluoxetine, sertraline), tricyclic antidepressants (e.g., amitriptyline, imipramine), and monoamine oxidase inhibitors (e.g., phenelzine, selegiline).
15. Anxiolytic drugs: These drugs are used to reduce anxiety, which is a feeling of fear, worry, or unease. They can act on various targets in the PNS, such as GABA receptors and benzodiazepine receptors. Examples include benzodiazepines (e.g., alprazolam, lorazepam), buspirone, and hydroxyzine.
16. Antipsychotic drugs: These drugs are used to treat psychosis, which is a mental disorder characterized by hallucinations, delusions, or disordered thinking. They can act on various targets in the PNS, such as dopamine receptors and serotonin receptors. Examples include typical antipsychotics (e.g., haloperidol, chlorpromazine) and atypical antipsychotics (e.g., risperidone, olanzapine).
17. Mood stabilizers: These drugs are used to treat mood disorders, such as bipolar disorder or major depressive disorder. They can act on various targets in the PNS, such as sodium channels and GABA receptors. Examples include lithium, valproic acid, and carbamazepine.
18. Stimulants: These drugs are used to treat attention deficit hyperactivity disorder (ADHD) or narcolepsy. They can act on various targets in the PNS, such as dopamine transporters and norepinephrine transporters. Examples include amphetamine, methylphenidate, and modafinil.
19. Antihistamines: These drugs are used to treat allergies or symptoms of the common cold. They can act on various targets in the PNS, such as histamine receptors and muscarinic acetylcholine receptors. Examples include diphenhydramine, loratadine, and cetirizine.
20. Antiemetics: These
The supine position is a term used in medicine to describe a body posture where an individual is lying down on their back, with their face and torso facing upwards. This position is often adopted during various medical procedures, examinations, or when resting, as it allows for easy access to the front of the body. It is also the position automatically assumed by most people who are falling asleep.
It's important to note that in the supine position, the head can be flat on the surface or raised with the use of pillows or specialized medical equipment like a hospital bed. This can help to alleviate potential issues such as breathing difficulties or swelling in the face and head.
Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:
1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.
Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.
Nitroglycerin, also known as glyceryl trinitrate, is a medication used primarily for the treatment of angina pectoris (chest pain due to coronary artery disease) and hypertensive emergencies (severe high blood pressure). It belongs to a class of drugs called nitrates or organic nitrites.
Nitroglycerin works by relaxing and dilating the smooth muscle in blood vessels, which leads to decreased workload on the heart and increased oxygen delivery to the myocardium (heart muscle). This results in reduced symptoms of angina and improved cardiac function during hypertensive emergencies.
The drug is available in various forms, including sublingual tablets, sprays, transdermal patches, ointments, and intravenous solutions. The choice of formulation depends on the specific clinical situation and patient needs. Common side effects of nitroglycerin include headache, dizziness, and hypotension (low blood pressure).
Head-down tilt (HDT) is a positioning technique often used in medical settings, particularly during diagnostic procedures or treatment interventions. In this position, the person lies down on a specially designed table with their head tilted below the horizontal plane, typically at an angle of 6 degrees to 15 degrees, but sometimes as steep as 90 degrees. This posture allows for various medical evaluations such as carotid sinus massage or intracranial pressure monitoring. It is also used in space medicine to simulate some effects of weightlessness on the human body during spaceflight. Please note that prolonged exposure to head-down tilt can have physiological consequences, including changes in blood pressure, heart rate, and eye function, which should be monitored and managed by healthcare professionals.
Ambulatory electrocardiography, also known as ambulatory ECG or Holter monitoring, is a non-invasive method of recording the electrical activity of the heart over an extended period of time (typically 24 hours or more) while the patient goes about their daily activities. The device used to record the ECG is called a Holter monitor, which consists of a small, portable recorder that is attached to the patient's chest with electrodes.
The recorded data provides information on any abnormalities in the heart's rhythm or electrical activity during different stages of activity and rest, allowing healthcare providers to diagnose and evaluate various cardiac conditions such as arrhythmias, ischemia, and infarction. The ability to monitor the heart's activity over an extended period while the patient performs their normal activities provides valuable information that may not be captured during a standard ECG, which only records the heart's electrical activity for a few seconds.
In summary, ambulatory electrocardiography is a diagnostic tool used to evaluate the electrical activity of the heart over an extended period, allowing healthcare providers to diagnose and manage various cardiac conditions.
Clomipramine is a tricyclic antidepressant drug that is primarily used to treat obsessive-compulsive disorder (OCD). It works by increasing the levels of certain neurotransmitters, such as serotonin and norepinephrine, in the brain. These neurotransmitters are involved in regulating mood and behavior.
Clomipramine is also used off-label to treat other conditions, including panic disorder, depression, chronic pain, and sleep disorders. It is available as a tablet or capsule and is typically taken one to three times a day. Common side effects of clomipramine include dry mouth, constipation, blurred vision, dizziness, and drowsiness.
As with all medications, clomipramine should be used under the close supervision of a healthcare provider, who can monitor its effectiveness and potential side effects. It is important to follow the dosage instructions carefully and to report any unusual symptoms or concerns to the healthcare provider promptly.
The vagus nerve, also known as the 10th cranial nerve (CN X), is the longest of the cranial nerves and extends from the brainstem to the abdomen. It has both sensory and motor functions and plays a crucial role in regulating various bodily functions such as heart rate, digestion, respiratory rate, speech, and sweating, among others.
The vagus nerve is responsible for carrying sensory information from the internal organs to the brain, and it also sends motor signals from the brain to the muscles of the throat and voice box, as well as to the heart, lungs, and digestive tract. The vagus nerve helps regulate the body's involuntary responses, such as controlling heart rate and blood pressure, promoting relaxation, and reducing inflammation.
Dysfunction in the vagus nerve can lead to various medical conditions, including gastroparesis, chronic pain, and autonomic nervous system disorders. Vagus nerve stimulation (VNS) is a therapeutic intervention that involves delivering electrical impulses to the vagus nerve to treat conditions such as epilepsy, depression, and migraine headaches.
Pure Autonomic Failure (PAF) is a rare neurological disorder characterized by the progressive loss of function of the autonomic nervous system, which regulates involuntary bodily functions such as heart rate, blood pressure, sweating, digestion, and bladder control. In PAF, there is no evidence of any other underlying disease or neurological condition that could explain these symptoms.
The primary feature of PAF is orthostatic hypotension, a sudden drop in blood pressure when standing up from a sitting or lying down position, which can lead to dizziness, lightheadedness, and even fainting. Other common symptoms include:
* Anhidrosis (inability to sweat) or hyperhidrosis (excessive sweating)
* Constipation or diarrhea
* Urinary incontinence or retention
* Sexual dysfunction
* Tachycardia (rapid heart rate) or bradycardia (slow heart rate)
* Difficulty regulating body temperature
The exact cause of PAF is unknown, but it is believed to be related to the degeneration of nerve cells in the autonomic nervous system. There is no cure for PAF, and treatment is focused on managing symptoms and preventing complications. This may include lifestyle changes such as increasing fluid and salt intake, wearing compression stockings, and avoiding prolonged periods of standing or sitting. Medications may also be prescribed to help regulate blood pressure, heart rate, and other autonomic functions.
Artificial cardiac pacing is a medical procedure that involves the use of an artificial device to regulate and stimulate the contraction of the heart muscle. This is often necessary when the heart's natural pacemaker, the sinoatrial node, is not functioning properly and the heart is beating too slowly or irregularly.
The artificial pacemaker consists of a small generator that produces electrical impulses and leads that are positioned in the heart to transmit the impulses. The generator is typically implanted just under the skin in the chest, while the leads are inserted into the heart through a vein.
There are different types of artificial cardiac pacing systems, including single-chamber pacemakers, which stimulate either the right atrium or right ventricle, and dual-chamber pacemakers, which stimulate both chambers of the heart. Some pacemakers also have additional features that allow them to respond to changes in the body's needs, such as during exercise or sleep.
Artificial cardiac pacing is a safe and effective treatment for many people with abnormal heart rhythms, and it can significantly improve their quality of life and longevity.
Lower Body Negative Pressure (LBNP) is a medical term that refers to the application of a negative pressure (below atmospheric pressure) to the lower body, while the upper body remains at normal atmospheric pressure. This is typically achieved through the use of an air-tight chamber or suit that covers the lower body from the waist down.
The negative pressure causes fluid to be drawn towards the lower body, which can simulate the effects of weightlessness or reduced gravity on the cardiovascular system. LBNP is often used in research settings to study the physiological responses to changes in gravitational forces, as well as in clinical settings to help prevent or treat various medical conditions, such as orthostatic intolerance, venous ulcers, and chronic wounds.
Propantheline is an anticholinergic drug, which means it blocks the action of acetylcholine, a neurotransmitter in the body. The specific action of propantheline is to inhibit the muscarinic receptors, leading to a decrease in glandular secretions and smooth muscle tone. It is primarily used as a treatment for peptic ulcers, as it reduces gastric acid secretion.
The medical definition of 'Propantheline' can be stated as:
A belladonna alkaloid with parasympatholytic effects, used as an antispasmodic and in the treatment of peptic ulcer to reduce gastric acid secretion. It inhibits the action of acetylcholine on muscarinic receptors, leading to decreased glandular secretions and smooth muscle tone. Common side effects include dry mouth, blurred vision, and constipation.
An abnormal reflex in a medical context refers to an involuntary and exaggerated response or lack of response to a stimulus that is not expected in the normal physiological range. These responses can be indicative of underlying neurological disorders or damage to the nervous system. Examples include hyperreflexia (overactive reflexes) and hyporeflexia (underactive reflexes). The assessment of reflexes is an important part of a physical examination, as it can provide valuable information about the functioning of the nervous system.
Sublingual administration refers to a route of delivering medication or other substances through placement under the tongue, allowing for rapid absorption into the bloodstream through the mucous membranes located there. This method can allow for quick onset of action and avoids first-pass metabolism in the liver that may occur with oral administration. Common examples of sublingual medications include nitroglycerin for angina pectoris and certain forms of hormone replacement therapy.
Hemodynamics is the study of how blood flows through the cardiovascular system, including the heart and the vascular network. It examines various factors that affect blood flow, such as blood volume, viscosity, vessel length and diameter, and pressure differences between different parts of the circulatory system. Hemodynamics also considers the impact of various physiological and pathological conditions on these variables, and how they in turn influence the function of vital organs and systems in the body. It is a critical area of study in fields such as cardiology, anesthesiology, and critical care medicine.
Metoprolol is a type of medication known as a beta blocker. According to the US National Library of Medicine's MedlinePlus, metoprolol is used to treat high blood pressure, angina (chest pain), and heart conditions that may occur after a heart attack. It works by blocking the action of certain natural chemicals in your body, such as epinephrine, on the heart and blood vessels. This helps to reduce the heart's workload, lower its blood pressure, and regulate its rhythm.
Metoprolol is available under various brand names, including Lopressor and Toprol-XL. It can be taken orally as a tablet or an extended-release capsule. As with any medication, metoprolol should be used under the supervision of a healthcare provider, who can monitor its effectiveness and potential side effects.
It is important to note that this definition is intended to provide a general overview of the medical use of metoprolol and should not be considered a substitute for professional medical advice.
Adrenergic beta-antagonists, also known as beta blockers, are a class of medications that block the effects of adrenaline and noradrenaline (also known as epinephrine and norepinephrine) on beta-adrenergic receptors. These receptors are found in various tissues throughout the body, including the heart, lungs, and blood vessels.
Beta blockers work by binding to these receptors and preventing the activation of certain signaling pathways that lead to increased heart rate, force of heart contractions, and relaxation of blood vessels. As a result, beta blockers can lower blood pressure, reduce heart rate, and decrease the workload on the heart.
Beta blockers are used to treat a variety of medical conditions, including hypertension (high blood pressure), angina (chest pain), heart failure, irregular heart rhythms, migraines, and certain anxiety disorders. Some common examples of beta blockers include metoprolol, atenolol, propranolol, and bisoprolol.
It is important to note that while beta blockers can have many benefits, they can also cause side effects such as fatigue, dizziness, and shortness of breath. Additionally, sudden discontinuation of beta blocker therapy can lead to rebound hypertension or worsening chest pain. Therefore, it is important to follow the dosing instructions provided by a healthcare provider carefully when taking these medications.
Postural Orthostatic Tachycardia Syndrome (POTS) is a condition characterized by an abnormally rapid heart rate (tachycardia) that occurs upon standing, leading to symptoms such as dizziness, lightheadedness, and fainting. The diagnostic criteria for POTS include:
1. A heart rate increase of 30 beats per minute or more within the first 10 minutes of standing or a heart rate of 120 beats per minute or more within the first 10 minutes of standing, measured by a heart rate monitor.
2. The presence of symptoms such as lightheadedness, dizziness, blurred vision, weakness, fatigue, headache, shortness of breath, or chest pain upon standing that are relieved by lying down.
3. Symptoms must be present for at least three months and occur in the absence of other medical conditions that could explain them.
POTS is thought to be caused by a dysfunction of the autonomic nervous system, which controls involuntary functions such as heart rate and blood pressure. Treatment may include lifestyle modifications, such as increasing fluid and salt intake, wearing compression stockings, and avoiding prolonged standing or sitting. Medications that help regulate blood pressure and heart rate may also be prescribed.
The sympathetic nervous system (SNS) is a part of the autonomic nervous system that operates largely below the level of consciousness, and it functions to produce appropriate physiological responses to perceived danger. It's often associated with the "fight or flight" response. The SNS uses nerve impulses to stimulate target organs, causing them to speed up (e.g., increased heart rate), prepare for action, or otherwise respond to stressful situations.
The sympathetic nervous system is activated due to stressful emotional or physical situations and it prepares the body for immediate actions. It dilates the pupils, increases heart rate and blood pressure, accelerates breathing, and slows down digestion. The primary neurotransmitter involved in this system is norepinephrine (also known as noradrenaline).
Cardiac arrhythmias are abnormal heart rhythms that result from disturbances in the electrical conduction system of the heart. The heart's normal rhythm is controlled by an electrical signal that originates in the sinoatrial (SA) node, located in the right atrium. This signal travels through the atrioventricular (AV) node and into the ventricles, causing them to contract and pump blood throughout the body.
An arrhythmia occurs when there is a disruption in this electrical pathway or when the heart's natural pacemaker produces an abnormal rhythm. This can cause the heart to beat too fast (tachycardia), too slow (bradycardia), or irregularly.
There are several types of cardiac arrhythmias, including:
1. Atrial fibrillation: A rapid and irregular heartbeat that starts in the atria (the upper chambers of the heart).
2. Atrial flutter: A rapid but regular heartbeat that starts in the atria.
3. Supraventricular tachycardia (SVT): A rapid heartbeat that starts above the ventricles, usually in the atria or AV node.
4. Ventricular tachycardia: A rapid and potentially life-threatening heart rhythm that originates in the ventricles.
5. Ventricular fibrillation: A chaotic and disorganized electrical activity in the ventricles, which can be fatal if not treated immediately.
6. Heart block: A delay or interruption in the conduction of electrical signals from the atria to the ventricles.
Cardiac arrhythmias can cause various symptoms, such as palpitations, dizziness, shortness of breath, chest pain, and fatigue. In some cases, they may not cause any symptoms and go unnoticed. However, if left untreated, certain types of arrhythmias can lead to serious complications, including stroke, heart failure, or even sudden cardiac death.
Treatment for cardiac arrhythmias depends on the type, severity, and underlying causes. Options may include lifestyle changes, medications, cardioversion (electrical shock therapy), catheter ablation, implantable devices such as pacemakers or defibrillators, and surgery. It is essential to consult a healthcare professional for proper evaluation and management of cardiac arrhythmias.
Cardiac arrest, also known as heart arrest, is a medical condition where the heart suddenly stops beating or functioning properly. This results in the cessation of blood flow to the rest of the body, including the brain, leading to loss of consciousness and pulse. Cardiac arrest is often caused by electrical disturbances in the heart that disrupt its normal rhythm, known as arrhythmias. If not treated immediately with cardiopulmonary resuscitation (CPR) and defibrillation, it can lead to death or permanent brain damage due to lack of oxygen supply. It's important to note that a heart attack is different from cardiac arrest; a heart attack occurs when blood flow to a part of the heart is blocked, often by a clot, causing damage to the heart muscle, but the heart continues to beat. However, a heart attack can sometimes trigger a cardiac arrest.
Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.
The Autonomic Nervous System (ANS) is a part of the nervous system that controls involuntary actions, such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. It consists of two subdivisions: the sympathetic and parasympathetic nervous systems, which generally have opposing effects and maintain homeostasis in the body.
Autonomic Nervous System Diseases (also known as Autonomic Disorders or Autonomic Neuropathies) refer to a group of conditions that affect the functioning of the autonomic nervous system. These diseases can cause damage to the nerves that control automatic functions, leading to various symptoms and complications.
Autonomic Nervous System Diseases can be classified into two main categories:
1. Primary Autonomic Nervous System Disorders: These are conditions that primarily affect the autonomic nervous system without any underlying cause. Examples include:
* Pure Autonomic Failure (PAF): A rare disorder characterized by progressive loss of autonomic nerve function, leading to symptoms such as orthostatic hypotension, urinary retention, and constipation.
* Multiple System Atrophy (MSA): A degenerative neurological disorder that affects both the autonomic nervous system and movement coordination. Symptoms may include orthostatic hypotension, urinary incontinence, sexual dysfunction, and Parkinsonian features like stiffness and slowness of movements.
* Autonomic Neuropathy associated with Parkinson's Disease: Some individuals with Parkinson's disease develop autonomic symptoms such as orthostatic hypotension, constipation, and urinary dysfunction due to the degeneration of autonomic nerves.
2. Secondary Autonomic Nervous System Disorders: These are conditions that affect the autonomic nervous system as a result of an underlying cause or disease. Examples include:
* Diabetic Autonomic Neuropathy: A complication of diabetes mellitus that affects the autonomic nerves, leading to symptoms such as orthostatic hypotension, gastroparesis (delayed gastric emptying), and sexual dysfunction.
* Autoimmune-mediated Autonomic Neuropathies: Conditions like Guillain-Barré syndrome or autoimmune autonomic ganglionopathy can cause autonomic symptoms due to the immune system attacking the autonomic nerves.
* Infectious Autonomic Neuropathies: Certain infections, such as HIV or Lyme disease, can lead to autonomic dysfunction as a result of nerve damage.
* Toxin-induced Autonomic Neuropathy: Exposure to certain toxins, like heavy metals or organophosphate pesticides, can cause autonomic neuropathy.
Autonomic nervous system disorders can significantly impact a person's quality of life and daily functioning. Proper diagnosis and management are crucial for improving symptoms and preventing complications. Treatment options may include lifestyle modifications, medications, and in some cases, devices or surgical interventions.
Reflex syncope
Tunnel vision
Orthostatic syncope
Fear of needles
Hypotension
Tami Farrell
2023 in American television
Urination
Bezold-Jarisch reflex
Postural orthostatic tachycardia syndrome
Vagus nerve
Syncope (medicine)
Julia Newton
Anti-predator adaptation
Vein
The Canon of Medicine
Circulatory system
Cardioneuroablation
Hysterosalpingography
Reflex asystolic syncope
Panayiotopoulos syndrome
Hyuna
Blood phobia
Micturition syncope
Blair Grubb
Jessie Ward
Blood-injection-injury type phobia
Vagotonia
Bhagwat Karad
Vasodilation
Neurocardiogenic Syncope: A Focus on the Management of Vasovagal Episodes
Vasovagal syncope
What Is Vasovagal Syncope And How To Prevent It?
Situational vs vasovagal syncope : one but different? | Lund University Publications
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Serval - Cardiovascular and Cerebral Responses During a Vasovagal Reaction Without Syncope.
Sudden drop of heart rate (vasovagal syncope) is associated with lower vitamin D - several studies | VitaminDWiki
7 possible reasons for passing out after an orgasm
Association of Vitamin B12 and Folate Deficiency with Vasovagal Syncope: A Case-Control Study - Authorea
Malignant vasovagal syncope due to blood phobia | Syncopedia
Baroreflex sensitivity in patients with vasovagal syncope - UEA Digital Repository
Orthostatic Intolerance: Background, Pathophysiology, Etiology
dealing with vasovagal syncope fainting in tweens • A Family Lifestyle & Food Blog
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Syncope | Fainting | MedlinePlus
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Ganglionated Plexus Ablation Procedures to Treat Vasovagal Syncope. | Int J Mol Sci;24(17)2023 Aug 26. | MEDLINE
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Syncope: Evaluation and Differential Diagnosis | AAFP
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Thieme E-Journals - Arquivos Brasileiros de Neurocirurgia: Brazilian Neurosurgery / Full Text
Neurocardiogenic syncope5
- Neurocardiogenic syncope is the most common type of syncope among children and adults, accounting for up to 50% of cases. (uspharmacist.com)
- Neurocardiogenic syncope is a self-limiting condition caused by an abnormal or exaggerated autonomic response to certain stimuli. (uspharmacist.com)
- therefore, it is commonly used synonymously with the term neurocardiogenic syncope . (uspharmacist.com)
- However, it is believed that 50% to 66% of these patients actually experience neurocardiogenic syncope. (uspharmacist.com)
- Tilt table testing produces maximal venous pooling, which can trigger vasovagal (neurocardiogenic) syncope and reproduce the symptoms and signs that accompany it (nausea, light-headedness, pallor, hypotension, bradycardia). (msdmanuals.com)
Episode of vasovagal syncope1
- A single episode of vasovagal syncope might not be alarming. (spts.org)
Recurrent vasovagal syncope1
- Methods Fourteen women (aged 18-30) suffering from recurrent vasovagal syncope and 15 age-matched healthy women were included. (diva-portal.org)
Loss of consciousn4
- Syncope is a transient loss of consciousness associated with a loss of postural tone due to decreased cerebral perfusion. (uspharmacist.com)
- Vasovagal syncope is defined as a momentary loss of consciousness. (spts.org)
- Syncope is an abrupt and transient loss of consciousness caused by cerebral hypoperfusion. (aafp.org)
- Syncope is a brief loss of consciousness and muscle tone that can occur when not enough blood gets to the brain. (stlouischildrens.org)
Postural3
- Cerebral Blood Flow (CBF) velocity is shown in the image below for two common forms of OI, vasovagal syncope (VVS) and postural tachycardia syndrome (POTS). (medscape.com)
- 2015 heart rhythm society expert consensus statement on the diagnosis and treatment of postural tachycardia syndrome, inappropriate sinus tachycardia, and vasovagal syncope. (nih.gov)
- 30 beats/minute) with little change in BP (postural orthostatic tachycardia syndrome), and report of syncope with no hemodynamic changes (psychogenic syncope). (msdmanuals.com)
Faint2
- Sometimes, especially if you are standing still, the body's calming response can prompt a faint, also known as vasovagal syncope. (discovermagazine.com)
- People with vasovagal syncope will faint when exposed to certain triggers like pain, emotional stress, fear of needles or even just the sight of blood. (rojakpot.com)
Carotid4
- Further classifications of this particular type of syncope include situational, carotid sinus, and vasovagal syncope. (uspharmacist.com)
- Carotid sinus syncope is defined as syncope due to the manipulation of the carotid sinuses (i.e., rotation/turning of the head or pressure placed on the carotid sinuses) that may be reproduced by carotid sinus massage. (uspharmacist.com)
- Do not perform imaging of the carotid arteries for simple syncope without other neurologic symptoms. (aafp.org)
- This type of syncope can happen when something pinches or constricts the carotid artery in your neck. (clevelandclinic.org)
Situational2
- Situational syncope refers to neurally mediated syncope commonly associated with cough, micturition, and defecation. (uspharmacist.com)
- Situational vs vasovagal syncope : one but different? (lu.se)
Anaphylaxis4
- See Table 1 for a side by side comparison of presenting features of anaphylaxis and vasovagal syncope. (canada.ca)
- Table 1 lists clinical features that differentiate fainting due to vasovagal syncope from anaphylaxis. (canada.ca)
- Table 1: Key distinguishing features of anaphylaxis and vasovagal syncope. (canada.ca)
- The answer is a qualified "yes": it's entirely possible to experience vaccine injuries from an immunization, including brain damage such as encephalitis and encephalopathy as well as anaphylaxis, arthritis, vasovagal syncope, Guillain-Barré Syndrome, and SIRVA (Shoulder Injury Related to Vaccine Administration). (vaccineinjuryhelpcenter.com)
Allergic2
- Special emphasis is done to discuss recommendations to cope with undesirable events that may arise during anesthesia (vasovagal syncope, anesthetic toxicity, anaphylactic and allergic reactions). (intechopen.com)
- We obtained a total of 3.89% complications: 2.33% reflection vasovagal, 0.56% allergic skin reaction, anaphylactic shock 0.07%, 0.27% femoral hematoma, 0.26% transient neurological deficit, 0.12% permanent neurological deficit and no case of death. (thieme-connect.de)
Fainting11
- Vasovagal syncope is a medical term for a common fainting episode. (spts.org)
- Vasovagal syncope is all about fainting, but why does it happen? (spts.org)
- Vasovagal syncope is the most common type of fainting. (medicalnewstoday.com)
- Mercury poisoning (especially methylmercury) Sleep deprivation Usher Syndrome Syncope (fainting) Eyeglass users experience tunnel vision to varying degrees due to the corrective lens only providing a small area of proper focus, with the rest of the field of view beyond the lenses being unfocused and blurry. (wikipedia.org)
- Fainting during Urination (Micturition Syncope): What Causes It? (medlineplus.gov)
- Vasovagal syncope is otherwise known as fainting and is the most common example of dysautonomia. (healthline.com)
- Syncope is remarkably common: about one-third of people report having at least one episode of fainting during their lifetime. (harvard.edu)
- This type of syncope involves fainting because of a heart problem. (clevelandclinic.org)
- The exact frequency of fainting post-immunization is not known but the majority of syncope adverse event reports involve adolescents or adults. (canada.ca)
- Syncope is commonly called fainting. (stlouischildrens.org)
- Fainting, known to doctors as syncope (SIN-kuh-pee), is what happens when a disruption occurs in the blood flow to the brain. (discovermagazine.com)
Pediatric patients1
- There is some clinical evidence of the association between vitamin B12 deficiency and vasovagal syncope (VVS) in pediatric patients. (authorea.com)
Sudden drop in blood pressure1
- Anxiety may also cause vasovagal syncope, which causes a sudden drop in blood pressure. (medicalnewstoday.com)
Occur3
- Although the exact mechanism of this type of syncope is not fully understood, it is believed to occur as a result of reflex-mediated changes in vascular tone and/or heart rate. (uspharmacist.com)
- A vasovagal collapse can occur after certain triggers (emotional or prolonged standing) which cause a reduction in sympathetic outflow to the systemic circulation and augmentation of efferent vagal activity. (syncopedia.org)
- How often does syncope occur? (stlouischildrens.org)
Diagnosis2
Symptoms3
- Patients with syncope who are at low risk of adverse events (e.g., those with symptoms consistent with vasovagal or orthostatic hypotension syncope, no history of heart disease, no family history of sudden cardiac death, and normal electrocardiographic findings) may be safely followed without further intervention or treatment. (aafp.org)
- Did your child had any symptoms before the syncope? (stlouischildrens.org)
- If vasovagal symptoms develop, vasovagal syncope is confirmed. (msdmanuals.com)
Neurally3
- Syncope is classified as neurally mediated, cardiac, and orthostatic hypotension. (aafp.org)
- Neurally mediated syncope is the most common type and has a benign course, whereas cardiac syncope is associated with increased morbidity and mortality. (aafp.org)
- The treatment of neurally mediated and orthostatic hypotension syncope is largely supportive, although severe cases may require pharmacotherapy. (aafp.org)
Autonomic1
- Aims: To investigate the association of vitamin D deficiency with cardiovascular autonomic nervous system function in children and adolescents with vasovagal syncope (VVS). (vitamindwiki.com)
Onset1
- Usually vasodilatation is the most important cause of hypotension in syncope, while bradycardia is often moderate and of late onset. (syncopedia.org)
Reflex3
- Introduction Vasovagal reflex is the most common type of syncope but its etiology is not fully elucidated. (diva-portal.org)
- Reflex syncope in children and adolescents. (vitamindwiki.com)
- The stressful event stimulates a bodily reflex called the vasovagal reaction. (clevelandclinic.org)
Refers1
- Vasovagal syncope (VVS) refers to a heterogeneous group of conditions whereby the cardiovascular reflexes normally controlling the circulation are interrupted irregularly in response to a trigger, resulting in vasodilation , bradycardia , or both. (bvsalud.org)
Ablation3
- Ganglionated Plexus Ablation Procedures to Treat Vasovagal Syncope. (bvsalud.org)
- The novel procedure of ganglionated plexus (GP) ablation has emerged rapidly in the past two decades, and has been proven successful in treating syncope . (bvsalud.org)
- Cardiac syncope may require cardiac device placement or ablation. (aafp.org)
Benign1
- Vasovagal syncope is a frightening but usually benign condition. (syncopedia.org)
Head Up Tilt1
- In this case-control study, we included adult patients with VVS who presented to our tertiary syncope unit for a head-up tilt table test as the case group. (authorea.com)
Cerebral1
- Cardiovascular and Cerebral Responses During a Vasovagal Reaction Without Syncope. (unil.ch)
Venous1
- The results emphasize the importance of venous return and cardiac output in the pathogenesis of vasovagal syncope. (diva-portal.org)
Presyncope2
Adolescents1
- Zhang Q, Du J, Wang C, Du Z, Wang L, Tang C. The diagnostic protocol in children and adolescents with syncope: a multi-centre prospective study. (vitamindwiki.com)
Temporary1
- Vasovagal syncope results from a temporary drop in blood pressure. (spts.org)
CARDIOVASCULAR1
- The aim of the study was to assess cardiovascular biomarkers and echocardiographic measures at rest and during hypovolemia in women with and without a history of vasovagal syncope. (diva-portal.org)
Structural1
- Patients with syncope and evidence of congestive heart failure or structural heart disease, abnormal electrocardiographic findings, or a family history of sudden death should be admitted to the hospital for emergent evaluation. (aafp.org)
Hospital admissions3
- Syncope accounts for 1% to 6% of hospital admissions and 3% of emergency departments visits. (uspharmacist.com)
- A standardized approach to syncope evaluation reduces hospital admissions and medical costs, and increases diagnostic accuracy. (aafp.org)
- Syncope accounts for 1% to 1.5% of all emergency department visits, 250,000 annual hospital admissions, and a median hospital cost of $8,500. (aafp.org)
Blood pressure3
- Similar to vasovagal syncope, it can cause blood pressure to drop very low suddenly. (medicalnewstoday.com)
- Patients presenting with syncope should have orthostatic blood pressure measurements and standard 12-lead electrocardiography. (aafp.org)
- With vasovagal syncope, heart rate and blood pressure (BP) usually decrease. (msdmanuals.com)
Common1
- This is the most common cause of syncope and can follow periods of extreme emotion. (stlouischildrens.org)
Mortality1
- Although syncope is associated with serious risks, short-term mortality is low (i.e., 0.7% at 10 days and 1.6% at 30 days). (aafp.org)
Assessment1
- The initial assessment for all patients presenting with syncope includes a detailed history, physical examination, and electrocardiography. (aafp.org)
Emotional1
- Chronic stress and sudden emotional shocks can trigger a vasovagal response. (spts.org)
Trauma1
- Avoid computed tomography of the head in asymptomatic adult patients in the emergency department with syncope, insignificant trauma, and a normal neurologic evaluation. (aafp.org)
Patients6
- In most cases (up to 50%), patients who experience syncope have no exact cause despite comprehensive evaluation. (uspharmacist.com)
- 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines and the heart rhythm society. (vitamindwiki.com)
- In the present study, we tested the hypothesis that baroreflex sensitivity is reduced in patients with vasovagal syncope compared with normal control subjects. (uea.ac.uk)
- Low-risk patients with a single episode of syncope can often be reassured with no further investigation. (aafp.org)
- Laboratory and imaging studies should be ordered for patients with syncope only if clinically indicated by the history and physical examination. (aafp.org)
- Approximately 25% of patients with syncope will experience another event within two years. (aafp.org)
Response3
- Syncope due to an emotionally-evoked vasovagal response with extreme bradycardia was diagnosed. (syncopedia.org)
- This young patient is unique in 3 ways: First, only thinking of venipuncture was enough to induce a vasovagal response. (syncopedia.org)
- Missy has had a vasovagal response to emesis. (aspcapro.org)
Interventions1
- Vasovagal syncope (VVS) is the most prevalent type of syncope and its management includes pharmacologic and non-pharmacologic interventions. (vitamindwiki.com)
Heart rate1
- Vasovagal" comes from the vagus nerve, which controls our heart rate. (spts.org)
History2
- We selected age- and sex-matched individuals without any history of syncope from the population-based Tehran Cohort Study as the control group. (authorea.com)
- Rule number one: In vasovagal syncope, history rules. (discovermagazine.com)
Keywords1
- International databases including Scopus, Web of Science, PubMed, and Embase were searched with keywords related to "vasovagal syncope" and "vitamin D." Studies were screened and the data were extracted from them. (vitamindwiki.com)
Brain3
- I just assumed it was a symptom of panic disorder, but after a doctor at a university hospital examined my brain waves, I was diagnosed with vasovagal syncope. (koreaboo.com)
- In the evaluation of simple syncope and a normal neurologic evaluation, do not obtain brain imaging studies (computed tomography or magnetic resonance imaging). (aafp.org)
- It's an apt expression, because syncope occurs due to a sudden reduction in blood flow to the brain. (harvard.edu)