Primary cardiac electrical disturbances |
Long QT syndrome* |
Brugada syndrome* |
Familial catecholaminergic polymorphic ventricular tachycardia* |
Short QT syndrome* |
Preexcitation syndromes (such as Wolff-Parkinson-White)* |
Bradyarrhythmias (complete atrioventricular block, sinus node dysfunction)* |
Structural cardiac abnormalities |
Hypertrophic cardiomyopathy* |
Coronary artery anomalies* |
Arrhythmogenic right ventricular dysplasia/cardiomyopathy* |
Valvar aortic stenosis* |
Dilated cardiomyopathy* |
Pulmonary hypertension* |
Acute myocarditis* |
Congenital heart disease* |
Heat illness* |
Anaphylaxis* |
Vasovagal (neurocardiogenic) syndrome, including situational syncope (eg, cough, micturition, hair combing, blood draw, intramuscular injection, or emotional stress)¶ |
Breath-holding spell¶ |
Orthostatic hypotension due to volume depletion (hemorrhage, dehydration, pregnancy, anorexia nervosa)¶ |
Drug effects or toxic exposure (eg, clonidine, typical antipsychotic agents, carbon monoxide, ethanol intoxication)*¶ |
Hypoglycemia* |
Conditions that mimic syncope |
Seizure |
Migraine syndromes |
Somatization or conversion disorder |
Hyperventilation |
Intentional strangulation (eg, the "choking game") |
Narcolepsy |
* Potentially life-threatening causes.
¶ Common causes.