Alteration of Time Intervals in Patients With Hypertrophic Cardiomyopathy During an Exercise Echocardiography

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is often associated with diastolic dysfunction. Theoretically, a more marked alteration of diastolic function is revealed during exercise. METHODS AND RESULTS: We studied 84 persons: 1) 25 patients with HCM, 2) 25 patients with essential arterial hypertension (AH) and 3) 34 healthy controls. Each person performed a treadmill echocardiography. Before and after work, the following parameters were measured: the time interval between the QRS complex and the onset of mitral early diastolic filling velocity (TE), the interval between the QRS complex and the onset of peak early tissue mitral annular velocity (Te’), the isovolumetric relaxation time over the difference of TE and Te’ ratio (IVRT/(TE-Te’)), and changes of the time parameters during the stress test. In comparison with hypertensive and control groups, HCM patients at rest showed a significantly longer TE (448 ± 55 vs. 423 ± 33 vs. 417 ± 24 ms, P < 0.04) and Te’ (446 ± 48 vs. 403 ± 44 vs. 416 ± 38 ms, P < 0.003). After stress the HCM group had a longer Te’ (355 ± 59 vs. 299 ± 40 vs. 292 ± 30 ms, P < 0.000004) and a higher IVRT/(TE-Te’) ratio (3.1 ± 1.5 vs. 0.9 ± 2.4 vs. 1.7 ± 1.2, P < 0.002). CONCLUSIONS: HCM patients show an alteration in the time parameters not only compared to healthy persons but to hypertensive patients as well.