Criteria for high cardiac risk in syncope

Severe structural or coronary artery disease
Heart failure
Previous myocardial infarction
Left ventricular outflow tract obstruction
Clinical or electrocardiographic signs of arrhythmic syncope
Syncope during exertion or when supine
Palpitations at time of syncope
Family history of sudden cardiac death
Nonsustained ventricular tachycardia
Bifascicular block or intraventricular conduction
abnormality with QRS complex > 120 seconds
Inadequate sinus bradycardia or sinoatrial block
Pre-excited QRS
Prolonged or short QT interval
Right bundle branch block with Brugada pattern (ST-segment elevation in V1 –V3)
Negative T waves in precordial leads, epsilon wave, and ventricular late potentials suggestive of arrhyth mogenic right ventricular cardiomyopathy