Assessment of regional left ventricular filling dynamics using color kinesis in patients with hypertrophic cardiomyopathy

Objectives. Using color kinesis, we evaluated regional left ventricular filling dynamics in patients with hypertrophic cardiomyopathy (HCM). Methods. In all, 20 patients (14 men and 6 women) and 20 age-matched healthy control subjects (10 men and 10 women) were studied. From color kinesis diastolic images in a left ventricular short-axis view, we generated regional time curves (6 segments) of left ventricular filling. The percent filling fraction at 25%, 50%, and 75% of filling time was averaged for all segments in each patient, and the SD of its mean was used as an asynchrony index at each particular filling time. The mean filling time for each segment was also measured. Results. The asynchrony index was increased significantly in mid (50%) to late (75%) diastole in patients with HCM as compared with control subjects. Patients with HCM had regional mean filling times prolonged even in the nonhypertrophic segments. Moreover, there was significant correlation between the asynchrony index at mid and late diastole, and the global mean filling time. Conclusions. Color kinesis is useful in evaluating regional filling dynamics in patients with HCM. Our data reinforce the notion that HCM is a functionally heterogeneous disorder.