Table 3.

Risk Factors for Sudden Cardiac Death in Patients With HCM

Major risk factors
 Previous episode of cardiac arrest (aborted SCD)
 Family history of SCD (more than one family member)
 Reflective of the causal mutations, including double mutations, and the modifier genes
 History of recurrent syncope (caused by arrhythmias)
 Sustained and repetitive nonsustained ventricular tachycardia
Intermediary risk factors
 Severe cardiac hypertrophy
 Extensive late gadolinium enhancement on cardiac MRI
Questionable risk factors
 Severe LVOT obstruction (LVOT gradient >80 mm Hg)
 Abnormal blood pressure response to exercise
 Severe myocyte disarray
 Early onset of clinical manifestations (young age)
 Presence of myocardial ischemia
  • HCM indicates hypertrophic cardiomyopathy; LVOT, left ventricular outflow tract; MRI, magnetic resonance imaging; and SCD, sudden cardiac death.