Acute effects of diltiazem on regional left ventricular diastolic filling dynamics in patients with hypertrophic cardiomyopathy as assessed by color kinesis.

ABSTRACT

BACKGROUND: The effect of calcium antagonists on regional left ventricular (LV) filling dynamics in patients with hypertrophic cardiomyopathy (HCM) is not well known, so the present study evaluated the results of echocardiography with color kinesis (CK) analysis during diltiazem infusion. METHODS AND RESULTS: Nineteen patients (16 men, 3 women; mean age 55+/-15 years) underwent echocardiography with CK analysis during intravenous diltiazem (10 mg/2 min). Using the quantitative CK software the LV short-axis image was divided into 6 segments and the percent endocardial expansion at the early, mid- and late-diastolic filling time was averaged for all segments, with the standard deviation of the mean used as an index of diastolic asynchrony (asynchrony index). The regional mean filling time was also measured for the corresponding segments. As global diastolic parameters, the global filling time, peak filling rate, and the time-to-peak filling were calculated. After the administration of diltiazem, the asynchrony index was decreased for all three diastolic filling times. Diltiazem shortened the mean filling time overall, especially in the posterior and lateral wall segments. These findings were associated with significant improvement in the CK-derived global diastolic parameters. CONCLUSIONS: Diltiazam has a favorable effect on LV diastolic asynchrony, which may account for the acute changes in global LV relaxation.