Table 6.

Summary of Clinical Outcomes of the 3 HCM Hemodynamic Spectrums

Outcomes	Nonobstructive HCM	Labile HCM	Obstructive HCM
Need for SRT	−	+	++
Clinical outcomes
AF	+	+	+++
VT/VF	+++	++	+
Heart failure	++	+	++
Death	+	+/−	+
Overall risk	Intermediate	Low	High

The left ventricular outflow tract pressure gradients were as follows: nonobstructive HCM, at rest, <30 mm Hg, and provoked, <30 mm Hg; labile HCM, at rest, <30 mm Hg, and provoked, ≥30 mm Hg; and obstructive HCM, at rest, ≥30 mm Hg, and provoked, ≥30 mm Hg. + indicates low risk; ++, intermediate risk; +++, high risk; −, not applicable; AF, atrial fibrillation; HCM, hypertrophic cardiomyopathy; SRT, septal reduction therapy; and VT/VF, ventricular tachycardia/ventricular fibrillation.