Relationships among exercise capacity, hypertrophy, and left ventricular diastolic function in nonobstructive hypertrophic cardiomyopathy

Aim The aim of this study was to analyze the relationships among exercise capacity (EC), hypertrophy, and diastolic function in nonobstructive hypertrophic cardiomyopathy (NOHCM). Methods and Results Twenty-seven patients with NOHCM were studied. Left ventricular hypertrophy (LVH) was determined by appropriate echocardiographic indexes. For diastolic function evaluation, the following were measured: the early (E) and late (A) waves, E/A, and deceleration time of E of the mitral flow; the systolic (S), diastolic (D), and atrial reversal (AR) waves, S/D, and the atrial systolic filling fraction of the pulmonary vein flow; and the early (Ea), late (Aa) waves, Ea/Aa, and E/Ea by tissue Doppler imaging. The difference between the duration of AR and A waves (DurAR − DurA), the peak V˙o2, and anaerobic threshold (AT) were also determined. In these patients, the E/Ea ratio was 8.9 ± 3.2 and DurAR − DurA was 22.6 ± 32.6 milliseconds. The peak V˙o2 and AT correlated with D (r = 0.55, P = .003 and .51, P = .007, respectively) and Ea/Aa (r = 0.56, P = .007 and .45, P = .03, respectively). There was no correlation between EC and LVH. Conclusions Patients with NOHCM demonstrated evidences of elevated left ventricular (LV) end-diastolic pressure with normal filling pressure. EC compromise may be attributed to relaxation changes with inadequate filling of the left ventricle.