Syncope causes: Difference between revisions

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Revision as of 17:18, 31 August 2020

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vendhan Ramanujam M.B.B.S [2]

Overview

Peripheral vascular resistance and cardiac output are the two main determinants for the presentation of syncope. autonomic nervous system impairment due to drugs or an autonomic failure, can lead to a decrease in peripheral vascular resistance. Reflex activity impairment may also cause a decrease of peripheral vascular resistance, as the body normal compensation reflexes fail. Decrease in cardiac output may be due to venous pooling, cardioinhibitory reflexes, arrhythmia, hypertension, pulmonary embolism, and volume depletion leading to diminished venous return, among others.

Causes

Peripheral vascular resistance and cardiac output are the two main determinants for the presentation of syncope. autonomic nervous system impairment due to drugs or an autonomic failure, can lead to a decrease in peripheral vascular resistance. Reflex activity impairment may also cause a decrease of peripheral vascular resistance, as the body normal compensation reflexes fail. Decrease in cardiac output may be due to venous pooling, cardioinhibitory reflexes, arrhythmia, hypertension, pulmonary embolism, and volume depletion leading to diminished venous return, among others.

Life threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Hemorrhage
Hypotension
Hypoxia
Pulmonary embolism was found in 17% of patients admitted to the hospital for syncope may have pulmonary embolism according to a study of Italian hospitals.^[1] This suggests these patients should be routinely assessed with the Wells score and d-dimer test with imaging if the Wells score was more than 4 or the d-dimer test was abnormal.
Ruptured abdominal aortic aneurysm
Ventricular arrhythmia^[2]

Common Causes

Causes by Organ System

Cardiovascular	Acute coronary syndrome, acute myocardial infarction, acute myocarditis, Adams-Stokes syndrome, anomalous origins of coronary arteries, aortic aneurysm, aortic dissection, aortic stenosis, arrhythmogenic right ventricular dysplasia, atrial myxoma, atrioventricular block, AV nodal reentrant tachycardia, bifascicular block, bradyarrhythmia, brugada syndrome, cardiac tamponade, catecholaminergic polymorphic ventricular tachycardia, channelopathy, complete atrioventricular block, dehydration, dilated cardiomyopathy, epsilon wave, hemorrhage, hypertrophic cardiomyopathy, hypotension, Jervell and Lange-Nielsen syndrome, long QT syndrome, mitral stenosis,Meprobamate, orthostatic hypotension, paroxysmal ventricular tachycardia, persistent atrial flutter, preexcitation syndrome, prolonged corrected QT interval, pulmonic stenosis, retroperitoneal hemorrhage, ruptured abdominal aortic aneurysm, saddle embolus, second degree AV block, short corrected QT interval, short QT syndrome, sick sinus syndrome, significant sinus pause, subclavian steal syndrome, supraventricular tachyarrhythmia, third degree heart block, tuberculin,ventricular arrhythmia, ventricular tachycardia, Wolff-Parkinson-White syndrome
Chemical/Poisoning	Carbon monoxide, cocaine, ethanol
Dental	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	ACE inhibitor, Alfuzosin, alpha blockers, amitriptyline, Amobarbital sodium, antiarrhythmics, antidepressants, antiemetics, antihypertensive medications, antipsychotic agents, barbiturates, beta blockers, Bicalutamide, bicisate dihydrochloride,bromocriptine, calcium channel blocker, Chlordiazepoxide, chlorpheniramine, cinnarizine, Clomifene, clonidine, clozapine, desipramine, digoxin, diphenhydramine, disulfiram, diuretics, dothiepin, Dolasetron mesylate, erectile dysfunction medications, Ferric Carboxymaltose,Folinic acid, ganglionic blocker, hydralazine, Hydrocortisone, hydroxyzine, Iloperidone, Interferon-gamma, Ixabepilone, Lacosamide, Levalbuterol, L-dopa, Loxapine, Meropenem, Methocarbamol, Mitomycin, Nabilone, nabumetone, Niacin, Nilutamide, nitrates, nortriptyline, olanzapine opiates, orphenadrine, oxazepam, oxcarbazepine, Pentamidine, Pergolide, prednisolone, Isethionate, Oprelvekin, Oxaprozin, phenothiazines, rifaximin, Ritonavir, ropinirole, Rotigotine, Secobarbital sodium, sertraline, Sodium oxybate, Sodium aurothiomalate, sulindac, Tiagabine, tricyclic antidepressants, Trospium, vasodilators, zolmitriptan, zonisamide, Calcium gluconate, Cefaclor
Ear Nose Throat	No underlying causes
Endocrine	No underlying causes
Environmental	No underlying causes
Gastroenterologic	Gastrointestinal bleeding
Genetic	Channelopathy
Hematologic	No underlying causes
Iatrogenic	No underlying causes
Infectious Disease	No underlying causes
Musculoskeletal/Orthopedic	No underlying causes
Neurologic	Carotid sinus hypersensitivity, dysautonomia, Lewy body dementia, multiple system atrophy, parkinson disease, seizure, spinal cord injury, subarachnoid hemorrhage, transient ischemic attack, vagal stimulation, vertebrobasilar insufficiency
Nutritional/Metabolic	No underlying causes
Obstetric/Gynecologic	No underlying causes
Oncologic	Atrial myxoma, carcinoid syndrome
Ophthalmologic	No underlying causes
Overdose/Toxicity	No underlying causes
Psychiatric	Anorexia nervosa, anxiety, emotional stress, hysterical faint, psychogenic pseudosyncope
Pulmonary	Hypoxia
Renal/Electrolyte	Uremia
Rheumatology/Immunology/Allergy	Anaphylaxis, Takayasu's arteritis
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Miscellaneous	Breath holding spells, choking game, cough, defecation, deglutition, drop attack, hair combing, heat illness, hyperventilation, hypocapnia, hypoglycemia, implanted cardioverter defibrillator malfunction, laughing, micturition, post-exercise, postprandial hypotension, prolonged bed rest, sneeze, significant blood loss, valsalva maneuver, vomiting, weightlifting

Causes in Alphabetical Order

References

↑ Prandoni, Paolo; Lensing, Anthonie W.A.; Prins, Martin H.; Ciammaichella, Maurizio; Perlati, Marica; Mumoli, Nicola; Bucherini, Eugenio; Visonà, Adriana; Bova, Carlo; Imberti, Davide; Campostrini, Stefano; Barbar, Sofia (2016-10-20). "Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope". New England Journal of Medicine. 375 (16): 1524–1531. doi:10.1056/NEJMoa1602172. ISSN 1533-4406 0028-4793, 1533-4406 Check |issn= value (help). Retrieved 2016-10-21.
↑ Khoo, C.; Chakrabarti, S.; Arbour, L.; Krahn, AD. (2013). "Recognizing life-threatening causes of syncope". Cardiol Clin. 31 (1): 51–66. doi:10.1016/j.ccl.2012.10.005. PMID 23217687. Unknown parameter |month= ignored (help)
↑ Kapoor, WN. (2000). "Syncope". N Engl J Med. 343 (25): 1856–62. doi:10.1056/NEJM200012213432507. PMID 11117979. Unknown parameter |month= ignored (help)
↑ Nishida, K.; Hirota, SK.; Tokeshi, J. (2008). "Laugh syncope as a rare sub-type of the situational syncopes: a case report". J Med Case Rep. 2: 197. doi:10.1186/1752-1947-2-197. PMID 18538031.
↑ Benbadis, SR.; Chichkova, R. (2006). "Psychogenic pseudosyncope: an underestimated and provable diagnosis". Epilepsy Behav. 9 (1): 106–10. doi:10.1016/j.yebeh.2006.02.011. PMID 16697264. Unknown parameter |month= ignored (help)

Template:WikiDoc Sources

[1] Prandoni, Paolo; Lensing, Anthonie W.A.; Prins, Martin H.; Ciammaichella, Maurizio; Perlati, Marica; Mumoli, Nicola; Bucherini, Eugenio; Visonà, Adriana; Bova, Carlo; Imberti, Davide; Campostrini, Stefano; Barbar, Sofia (2016-10-20). "Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope". New England Journal of Medicine. 375 (16): 1524–1531. doi:10.1056/NEJMoa1602172. ISSN 1533-4406 0028-4793, 1533-4406 Check |issn= value (help). Retrieved 2016-10-21.

[Khoo-2013-2] Khoo, C.; Chakrabarti, S.; Arbour, L.; Krahn, AD. (2013). "Recognizing life-threatening causes of syncope". Cardiol Clin. 31 (1): 51–66. doi:10.1016/j.ccl.2012.10.005. PMID 23217687. Unknown parameter |month= ignored (help)

[Kapoor-2000-3] Kapoor, WN. (2000). "Syncope". N Engl J Med. 343 (25): 1856–62. doi:10.1056/NEJM200012213432507. PMID 11117979. Unknown parameter |month= ignored (help)

[Nishida-2008-4] Nishida, K.; Hirota, SK.; Tokeshi, J. (2008). "Laugh syncope as a rare sub-type of the situational syncopes: a case report". J Med Case Rep. 2: 197. doi:10.1186/1752-1947-2-197. PMID 18538031.

[Benbadis-2006-5] Benbadis, SR.; Chichkova, R. (2006). "Psychogenic pseudosyncope: an underestimated and provable diagnosis". Epilepsy Behav. 9 (1): 106–10. doi:10.1016/j.yebeh.2006.02.011. PMID 16697264. Unknown parameter |month= ignored (help)

[1]

[2]

[3]

[4]

[5]

@@ Line 4: / Line 4: @@
 ==Overview==
-More serious causes of syncope include cardiac (heart-related) causes such as an abnormal heart rhythm (an [[arrhythmia]]), where the heart beats too slowly, too rapidly or too irregularly to pump enough blood to the brain.  Other important cardio-vascular conditions that can be manifested by syncope include [[subclavian steal syndrome]] and [[aortic stenosis]].  Vasovagal (situational) syncope, one of the most common types, may occur in scary or embarrassing situations or during blood drawing, coughing, or urinating
+[[Peripheral vascular resistance]] and [[cardiac output]] are the two main determinants for the presentation of syncope. [[autonomic nervous system]] impairment due to drugs or an autonomic failure, can lead to a decrease in [[peripheral vascular resistance]]. Reflex activity impairment may also cause a decrease of [[peripheral vascular resistance]], as the body normal compensation reflexes fail. Decrease in [[cardiac output]] may be due to venous pooling, cardioinhibitory reflexes, [[arrhythmia]], [[hypertension]], [[pulmonary embolism]], and volume depletion leading to diminished venous return, among others.
 ==Causes==
@@ Line 14: / Line 14: @@
 *[[Hypotension]]
 *[[Hypoxia]]
-* [[Pulmonary embolism]] was found in 17% of patients admitted to the hospital for syncope may have pulmonary embolism according to a study of Italian hospitals.<ref>{{Cite journal| doi = 10.1056/NEJMoa1602172| issn = 0028-4793, 1533-4406| volume = 375| issue = 16| pages = 1524–1531| last1 = Prandoni| first1 = Paolo| last2 = Lensing| first2 = Anthonie W.A.| last3 = Prins| first3 = Martin H.| last4 = Ciammaichella| first4 = Maurizio| last5 = Perlati| first5 = Marica| last6 = Mumoli| first6 = Nicola| last7 = Bucherini| first7 = Eugenio| last8 = Visonà| first8 = Adriana| last9 = Bova| first9 = Carlo| last10 = Imberti| first10 = Davide| last11 = Campostrini| first11 = Stefano| last12 = Barbar| first12 = Sofia| title = Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope| journal = New England Journal of Medicine| accessdate = 2016-10-21| date = 2016-10-20| url = http://www.nejm.org/doi/10.1056/NEJMoa1602172}}</ref> This suggests these patients should be routinely assessed with the [[Pulmonary embolism assessment of clinical probability and risk scores|Wells score]] and [[d-dimer]] test with imaging if the Wells score was more than 4 or the d-dimer test was abnormal.
+*[[Pulmonary embolism]] was found in 17% of patients admitted to the hospital for syncope may have pulmonary embolism according to a study of Italian hospitals.<ref>{{Cite journal| doi = 10.1056/NEJMoa1602172| issn = 0028-4793, 1533-4406| volume = 375| issue = 16| pages = 1524–1531| last1 = Prandoni| first1 = Paolo| last2 = Lensing| first2 = Anthonie W.A.| last3 = Prins| first3 = Martin H.| last4 = Ciammaichella| first4 = Maurizio| last5 = Perlati| first5 = Marica| last6 = Mumoli| first6 = Nicola| last7 = Bucherini| first7 = Eugenio| last8 = Visonà| first8 = Adriana| last9 = Bova| first9 = Carlo| last10 = Imberti| first10 = Davide| last11 = Campostrini| first11 = Stefano| last12 = Barbar| first12 = Sofia| title = Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope| journal = New England Journal of Medicine| accessdate = 2016-10-21| date = 2016-10-20| url = http://www.nejm.org/doi/10.1056/NEJMoa1602172}}</ref> This suggests these patients should be routinely assessed with the [[Pulmonary embolism assessment of clinical probability and risk scores|Wells score]] and [[d-dimer]] test with imaging if the Wells score was more than 4 or the d-dimer test was abnormal.
 *[[Ruptured abdominal aortic aneurysm]]
 *[[Ventricular arrhythmia]]<ref name="Khoo-2013">{{Cite journal  | last1 = Khoo | first1 = C. | last2 = Chakrabarti | first2 = S. | last3 = Arbour | first3 = L. | last4 = Krahn | first4 = AD. | title = Recognizing life-threatening causes of syncope. | journal = Cardiol Clin | volume = 31 | issue = 1 | pages = 51-66 | month = Feb | year = 2013 | doi = 10.1016/j.ccl.2012.10.005 | PMID = 23217687 }}</ref>
 ===Common Causes===
 *[[Arrhythmia]]
 *[[Medication]]
@@ Line 26: / Line 27: @@
 ===Causes by Organ System===
-{|style="width:80%; height:100px" border="1"
+{| style="width:80%; height:100px" border="1"
-|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
+| style="width:25%" bgcolor="LightSteelBlue" ; border="1" |'''Cardiovascular'''
-|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | [[Acute coronary syndrome]], [[acute myocardial infarction]], [[acute myocarditis]], [[Adams-Stokes syndrome]], [[anomalous origins of coronary arteries]], [[aortic aneurysm]], [[aortic dissection]], [[aortic stenosis]], [[arrhythmogenic right ventricular dysplasia]], [[atrial myxoma]], [[atrioventricular block]], [[AVNRT|AV nodal reentrant tachycardia]], [[bifascicular block]], [[bradyarrhythmia]], [[brugada syndrome]], [[cardiac tamponade]], [[catecholaminergic polymorphic ventricular tachycardia]], [[channelopathy]], [[AV block|complete atrioventricular block]], [[dehydration]], [[dilated cardiomyopathy]], [[epsilon wave]], [[hemorrhage]], [[hypertrophic cardiomyopathy]], [[hypotension]], [[Jervell and Lange-Nielsen syndrome]], [[long QT syndrome]], [[mitral stenosis]],[[Meprobamate]], [[orthostatic hypotension]], [[paroxysmal ventricular tachycardia]], [[Atrial flutter|persistent atrial flutter]], [[preexcitation syndrome]], [[QT prolongation|prolonged corrected QT interval]], [[pulmonic stenosis]], [[retroperitoneal hemorrhage]], [[ruptured abdominal aortic aneurysm]], [[Pulmonary embolism classification|saddle embolus]], [[second degree AV block]], [[Short QT syndrome|short corrected QT interval]], [[short QT syndrome]], [[sick sinus syndrome]], [[Sinoatrial arrest|significant sinus pause]], [[subclavian steal syndrome]], [[Supraventricular tachycardia|supraventricular tachyarrhythmia]], [[third degree heart block]], [[tuberculin]],[[ventricular arrhythmia]], [[ventricular tachycardia]], [[Wolff-Parkinson-White syndrome]]
+| style="width:75%" bgcolor="Beige" ; border="1" |[[Acute coronary syndrome]], [[acute myocardial infarction]], [[acute myocarditis]], [[Adams-Stokes syndrome]], [[anomalous origins of coronary arteries]], [[aortic aneurysm]], [[aortic dissection]], [[aortic stenosis]], [[arrhythmogenic right ventricular dysplasia]], [[atrial myxoma]], [[atrioventricular block]], [[AVNRT|AV nodal reentrant tachycardia]], [[bifascicular block]], [[bradyarrhythmia]], [[brugada syndrome]], [[cardiac tamponade]], [[catecholaminergic polymorphic ventricular tachycardia]], [[channelopathy]], [[AV block|complete atrioventricular block]], [[dehydration]], [[dilated cardiomyopathy]], [[epsilon wave]], [[hemorrhage]], [[hypertrophic cardiomyopathy]], [[hypotension]], [[Jervell and Lange-Nielsen syndrome]], [[long QT syndrome]], [[mitral stenosis]],[[Meprobamate]], [[orthostatic hypotension]], [[paroxysmal ventricular tachycardia]], [[Atrial flutter|persistent atrial flutter]], [[preexcitation syndrome]], [[QT prolongation|prolonged corrected QT interval]], [[pulmonic stenosis]], [[retroperitoneal hemorrhage]], [[ruptured abdominal aortic aneurysm]], [[Pulmonary embolism classification|saddle embolus]], [[second degree AV block]], [[Short QT syndrome|short corrected QT interval]], [[short QT syndrome]], [[sick sinus syndrome]], [[Sinoatrial arrest|significant sinus pause]], [[subclavian steal syndrome]], [[Supraventricular tachycardia|supraventricular tachyarrhythmia]], [[third degree heart block]], [[tuberculin]],[[ventricular arrhythmia]], [[ventricular tachycardia]], [[Wolff-Parkinson-White syndrome]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Chemical/Poisoning'''
+|'''Chemical/Poisoning'''
-|bgcolor="Beige"| [[Carbon monoxide]], [[cocaine]], [[ethanol]]
+| bgcolor="Beige" |[[Carbon monoxide]], [[cocaine]], [[ethanol]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Dental'''
+|'''Dental'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Dermatologic'''
+|'''Dermatologic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Drug Side Effect'''
+|'''Drug Side Effect'''
-|bgcolor="Beige"| [[ACEI|ACE inhibitor]], [[Alfuzosin]], [[alpha blockers]], [[amitriptyline]],  [[Amobarbital sodium]],  [[antiarrhythmics]], [[antidepressants]], [[antiemetics]], [[Antihypertensive|antihypertensive medications]], [[antipsychotic agents]], [[barbiturates]], [[beta blockers]], [[Bicalutamide]], [[bicisate dihydrochloride]],[[bromocriptine]], [[calcium channel blocker]], [[Chlordiazepoxide]], [[chlorpheniramine]], [[cinnarizine]], [[Clomifene]], [[clonidine]], [[clozapine]], [[desipramine]], [[digoxin]], [[diphenhydramine]], [[disulfiram]], [[diuretics]], [[dothiepin]], [[Dolasetron mesylate]], [[Erectile dysfunction medical therapy|erectile dysfunction medications]], [[Ferric Carboxymaltose]],[[Folinic acid]], [[Ganglionic blocker|ganglionic blocker]], [[hydralazine]], [[Hydrocortisone]], [[hydroxyzine]], [[Iloperidone]], [[Interferon-gamma]], [[Ixabepilone]], [[Lacosamide]], [[Levalbuterol]], [[L-dopa]], [[Loxapine]], [[Meropenem]], [[Methocarbamol]], [[Mitomycin]],  [[Nabilone]], [[nabumetone]], [[Niacin]], [[Nilutamide]], [[nitrates]], [[nortriptyline]], [[olanzapine]] [[opiates]], [[orphenadrine]], [[oxazepam]], [[oxcarbazepine]], [[Pentamidine]], [[Pergolide]], [[prednisolone]], [[Isethionate]], [[Oprelvekin]], [[Oxaprozin]], [[phenothiazines]], [[rifaximin]], [[Ritonavir]], [[ropinirole]], [[Rotigotine]], [[Secobarbital sodium]], [[sertraline]], [[Sodium oxybate]], [[Sodium aurothiomalate]], [[sulindac]], [[Tiagabine]], [[tricyclic antidepressants]], [[Trospium]], [[vasodilators]], [[zolmitriptan]], [[zonisamide]], [[Calcium gluconate]],  [[Cefaclor]]
+| bgcolor="Beige" |[[ACEI|ACE inhibitor]], [[Alfuzosin]], [[alpha blockers]], [[amitriptyline]],  [[Amobarbital sodium]],  [[antiarrhythmics]], [[antidepressants]], [[antiemetics]], [[Antihypertensive|antihypertensive medications]], [[antipsychotic agents]], [[barbiturates]], [[beta blockers]], [[Bicalutamide]], [[bicisate dihydrochloride]],[[bromocriptine]], [[calcium channel blocker]], [[Chlordiazepoxide]], [[chlorpheniramine]], [[cinnarizine]], [[Clomifene]], [[clonidine]], [[clozapine]], [[desipramine]], [[digoxin]], [[diphenhydramine]], [[disulfiram]], [[diuretics]], [[dothiepin]], [[Dolasetron mesylate]], [[Erectile dysfunction medical therapy|erectile dysfunction medications]], [[Ferric Carboxymaltose]],[[Folinic acid]], [[Ganglionic blocker|ganglionic blocker]], [[hydralazine]], [[Hydrocortisone]], [[hydroxyzine]], [[Iloperidone]], [[Interferon-gamma]], [[Ixabepilone]], [[Lacosamide]], [[Levalbuterol]], [[L-dopa]], [[Loxapine]], [[Meropenem]], [[Methocarbamol]], [[Mitomycin]],  [[Nabilone]], [[nabumetone]], [[Niacin]], [[Nilutamide]], [[nitrates]], [[nortriptyline]], [[olanzapine]] [[opiates]], [[orphenadrine]], [[oxazepam]], [[oxcarbazepine]], [[Pentamidine]], [[Pergolide]], [[prednisolone]], [[Isethionate]], [[Oprelvekin]], [[Oxaprozin]], [[phenothiazines]], [[rifaximin]], [[Ritonavir]], [[ropinirole]], [[Rotigotine]], [[Secobarbital sodium]], [[sertraline]], [[Sodium oxybate]], [[Sodium aurothiomalate]], [[sulindac]], [[Tiagabine]], [[tricyclic antidepressants]], [[Trospium]], [[vasodilators]], [[zolmitriptan]], [[zonisamide]], [[Calcium gluconate]],  [[Cefaclor]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Ear Nose Throat'''
+|'''Ear Nose Throat'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Endocrine'''
+|'''Endocrine'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Environmental'''
+|'''Environmental'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Gastroenterologic'''
+|'''Gastroenterologic'''
-|bgcolor="Beige"| [[Gastrointestinal bleeding]]
+| bgcolor="Beige" |[[Gastrointestinal bleeding]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Genetic'''
+|'''Genetic'''
-|bgcolor="Beige"| [[Channelopathy]]
+| bgcolor="Beige" |[[Channelopathy]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Hematologic'''
+|'''Hematologic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Iatrogenic'''
+|'''Iatrogenic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Infectious Disease'''
+|'''Infectious Disease'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Musculoskeletal/Orthopedic'''
+|'''Musculoskeletal/Orthopedic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Neurologic'''
+|'''Neurologic'''
-|bgcolor="Beige"| [[Carotid sinus hypersensitivity]], [[dysautonomia]], [[Lewy body dementia]], [[multiple system atrophy]], [[parkinson disease]], [[seizure]], [[spinal cord injury]], [[subarachnoid hemorrhage]], [[transient ischemic attack]], [[vagal stimulation]], [[vertebrobasilar insufficiency]]
+| bgcolor="Beige" |[[Carotid sinus hypersensitivity]], [[dysautonomia]], [[Lewy body dementia]], [[multiple system atrophy]], [[parkinson disease]], [[seizure]], [[spinal cord injury]], [[subarachnoid hemorrhage]], [[transient ischemic attack]], [[vagal stimulation]], [[vertebrobasilar insufficiency]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Nutritional/Metabolic'''
+|'''Nutritional/Metabolic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Obstetric/Gynecologic'''
+|'''Obstetric/Gynecologic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Oncologic'''
+|'''Oncologic'''
-|bgcolor="Beige"| [[Atrial myxoma]], [[carcinoid syndrome]]
+| bgcolor="Beige" |[[Atrial myxoma]], [[carcinoid syndrome]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Ophthalmologic'''
+|'''Ophthalmologic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Overdose/Toxicity'''
+|'''Overdose/Toxicity'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Psychiatric'''
+|'''Psychiatric'''
-|bgcolor="Beige"| [[Anorexia nervosa]], [[anxiety]], [[emotional stress]], [[Hysteria|hysterical faint]], [[Psychogenic non-epileptic seizures|psychogenic pseudosyncope]]
+| bgcolor="Beige" |[[Anorexia nervosa]], [[anxiety]], [[emotional stress]], [[Hysteria|hysterical faint]], [[Psychogenic non-epileptic seizures|psychogenic pseudosyncope]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Pulmonary'''
+|'''Pulmonary'''
-|bgcolor="Beige"| [[Hypoxia]]
+| bgcolor="Beige" |[[Hypoxia]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Renal/Electrolyte'''
+|'''Renal/Electrolyte'''
-|bgcolor="Beige"| [[Uremia]]
+| bgcolor="Beige" |[[Uremia]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Rheumatology/Immunology/Allergy'''
+|'''Rheumatology/Immunology/Allergy'''
-|bgcolor="Beige"| [[Anaphylaxis]], [[Takayasu's arteritis]]
+| bgcolor="Beige" |[[Anaphylaxis]], [[Takayasu's arteritis]]
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Sexual'''
+|'''Sexual'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Trauma'''
+|'''Trauma'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Urologic'''
+|'''Urologic'''
-|bgcolor="Beige"| No underlying causes
+| bgcolor="Beige" |No underlying causes
 |-
-|-bgcolor="LightSteelBlue"
+|- bgcolor="LightSteelBlue"
-| '''Miscellaneous'''
+|'''Miscellaneous'''
-|bgcolor="Beige"| [[Breath-holding spells|Breath holding spells]], [[choking game]], [[cough]], [[defecation]], [[deglutition]], [[drop attack]], [[Hair-grooming syncope|hair combing]], [[heat illness]], [[hyperventilation]], [[hypocapnia]], [[hypoglycemia]], [[Implantable cardioverter defibrillator|implanted cardioverter defibrillator malfunction]], [[Laughter-induced syncope|laughing]], [[micturition]], [[post-exercise]], [[Food coma|postprandial hypotension]], [[Bed rest|prolonged bed rest]], [[sneeze]], [[Hypovolemia|significant blood loss]], [[valsalva maneuver]], [[vomiting]], [[Physical exercise|weightlifting]]
+| bgcolor="Beige" |[[Breath-holding spells|Breath holding spells]], [[choking game]], [[cough]], [[defecation]], [[deglutition]], [[drop attack]], [[Hair-grooming syncope|hair combing]], [[heat illness]], [[hyperventilation]], [[hypocapnia]], [[hypoglycemia]], [[Implantable cardioverter defibrillator|implanted cardioverter defibrillator malfunction]], [[Laughter-induced syncope|laughing]], [[micturition]], [[post-exercise]], [[Food coma|postprandial hypotension]], [[Bed rest|prolonged bed rest]], [[sneeze]], [[Hypovolemia|significant blood loss]], [[valsalva maneuver]], [[vomiting]], [[Physical exercise|weightlifting]]
 |-
 |}