Abstract 16382: Comparison of Provocative Maneuvers to Demonstrate Latent Obstruction in Hypertrophic Cardiomyopathy
Introduction: Exercise stress echocardiogram (ESE) is recommended for patients with hypertrophic cardiomyopathy (HCM) if a 50 mmHg gradient is not present at rest or provoked with Valsalva or amyl nitrite (amyl). Demonstrating provocable obstruction is important to direct management; however, few data compare all 3 methods of provocation.
Objectives: To compare left ventricular outflow gradients in HCM obtained via Valsalva, amyl and ESE.
Methods: A retrospective review of resting transthoracic echocardiography and ESE in patients with HCM between 2002 and 2015 in a tertiary HCM referral center was performed. Patient characteristics, echocardiographic parameters and gradients elicited by each method were compared.
Results: Of 114 HCM patients who had rest and ESE within one year (age 54.3 ± 17.4, 59% male), 91 had Valsalva maneuver and 46 amyl provocation. Median gradients were 10 mmHg (IQR 6,19) at rest, 16 mmHg (8,31) with Valsalva, 25 mmHg (13,53) with amyl and 25 mmHg (12,55) with ESE. Amyl and ESE were able to unmask obstruction (>30 mmHg) and severe obstruction (>50 mmHg) more frequently than Valsalva (figure). In patients with resting gradient <30 mmHg (n=99), provocation maneuvers unmasked obstruction in 48%; in those with Valsalva gradient <30 mmHg (n=68), amyl or ESE provoked a gradient in 41%; and in those with amyl gradient <30 mmHg (n=26), ESE provoked a gradient in 31%. ESE by treadmill (n=77) vs. supine bike (n=36) elicited median gradients of 25 vs 19 mmHg, and provoked severe obstruction (>50 mmHg) in 23 (30%) vs 8 (22%). There were no baseline echocardiographic (including wall thickness, left atrial size, systolic anterior motion of mitral valve) or demographic parameters that predicted provocable obstruction.
Conclusions: In HCM patients with suspected obstruction despite resting maneuvers, ESE is a useful method to unmask latent obstruction. All maneuvers may need to be utilized to demonstrate provocable obstruction in order to guide management.
Author Disclosures: C. Ayoub: None. J.B. Geske: None. C.M. Larsen: None. C.G. Scott: None. K.W. Klarich: None. P.A. Pellikka: None.
- © 2016 by American Heart Association, Inc.