The science of uncertainty and the art of probability: syncope and its consequences in hypertrophic cardiomyopathy.

In this edition of Circulation, Spirito and coworkers present a retrospective study of a large cohort of patients with hypertrophic cardiomyopathy in which they compare the prognostic significance of neurally mediated (vasovagal) faints and unexplained syncope.1 Although neither symptom was significantly associated with sudden-death risk, subgroup analysis revealed that unexplained syncope was associated with a higher mortality in patients who had experienced their symptom within 6 months of their initial evaluation and in those aged 18 years. The authors conclude that recent unexplained syncope in all age groups “may justify consideration for prophylactic implantation of a cardioverterdefibrillator.” The challenge for clinicians is the translation of this message into everyday clinical management.