Watch Out for Midventricular Obstruction in HCM

A single-center study provides prevalence and outcomes data for a disorder that appears to be more common — and dangerous — than previously thought.

Left ventricular (LV) obstruction in hypertrophic cardiomyopathy (HCM) typically occurs at the subaortic level and results from systolic anterior motion of the anterior mitral valve leaflet. However, in some patients, an obstruction occurs in the midventricle, with marked septal hypertrophy coming into contact with the LV free wall. In this observational study, investigators identified midventricular obstruction (MVO; peak gradient, >30 mm Hg) without outflow tract obstruction (OTO) in 46 of 490 patients with HCM (a hypertrophied, nondilated left ventricle without a cardiac or systemic etiology) at a single center in Japan.

Compared with patients with OTO (110 of 490), those with MVO were similar in age but had a lower mean gradient (46 mm H…

Reviewing Author

Howard C. Herrmann, MD

Disclosures

Consultant/Advisory BoardAffluent Medical; Artedrone; Caranx; Johnson & Johnson; Medtronic; Prolifagen; Wells Fargo

EquityMicrointerventional Devices, Inc.

RoyaltiesUniversity of Pennsylvania

Grant/Research SupportAbbott Vascular; Edwards Lifesciences; Johnson & Johnson; Medtronic

Editorial BoardsCatheterization and Cardiovascular Interventions; Journal of the American College of Cardiology; Circulation: Cardiovascular Interventions; JACC Cardiovascular Interventions; JACC Case Reports; JSCAI