Standardized Goal-Directed Valsalva Maneuver for Assessment of Inducible Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy

Abstract

The Valsalva maneuver is widely used to provoke left ventricular outflow tract obstruction in hypertrophic cardiomyopathy (HCM). Whereas early experiments used a standardized, goal-directed approach by maintaining an intraoral pressure >40mm Hg for >10sec, current practice depends on patients' understanding and effort. The aim of this study was to evaluate the clinical effectiveness of the goal-directed Valsalva maneuver (GDV) in HCM as a method to provoke left ventricular outflow tract obstruction. In this prospective study, patients blew into a syringe barrel connected to a manometer with rubber tubing and maintained an intraoral pressure of >40mm Hg for >10sec (GDV). Using Doppler echocardiography, peak left ventricular outflow tract gradient (pLVOTG) was measured at rest and using the provocative maneuvers of the self-directed Valsalva maneuver (SDV), GDV, and exercise. A total of 52 patients were included. Mean pLVOTG with GDV was higher compared with SDV (48vs 38mm Hg, P=.001, n=52) and was similar to exercise (GDV, 52mm Hg; exercise, 58mm Hg; P=.42; n=43). Reclassification to obstructive HCM (pLVOTG≥30mm Hg) with GDV was significantly higher than with SDV (38% vs 16.6%, P=.016) and comparable with exercise (50%, P=.51). Reclassification to severe obstruction (pLVOTG≥50mm Hg) was higher with GDV compared with SDV (28.3% vs 13.5%, P=.045) and was similar to exercise (29.7%). Furthermore, GDV identified two patients with occult severe obstruction in isolation. GDV is an objective, practical, and effective physiologic method of provoking left ventricular outflow tract obstruction. It can significantly alter patient management by reclassifying disease severity and should be incorporated in the routine clinical evaluation of patients with HCM.