Role of Left Ventricular Regional Diastolic Abnormalities for Global Diastolic Dysfunction in Patients with Hypertrophic Cardiomyopathy

Background: The usefulness of Doppler strain rate imaging for assessment of left ventricular regional diastolic function has not been fully determined. Objective: We aimed to clarify the relationships between diastolic strain rates and global diastolic function and find a useful index for regional diastolic function in patients with hypertrophic cardiomyopathy (HCM). Methods: Strain rate curves were obtained using an apical approach at 12 different sites of the left ventricular myocardium in 25 patients with HCM and 20 control subjects, and peak early diastolic strain rate (E_SR), peak late diastolic strain rate, and the time from QRS to E_SR were measured. The flow propagation velocity was measured using color M-mode Doppler echocardiography as a global diastolic index. Results: Each of the spatially averaged values of E_SR and E_SR/peak late diastolic strain rate and the coefficients of variation of time from QRS to E_SR was significantly correlated with flow propagation velocity, but the best correlation was observed in E_SR. Although both E_SR and peak late diastolic strain rate of each myocardial segment of patients with HCM tended to decrease as the wall thickness increased, only E_SR significantly decreased even in the segments without apparent hypertrophy. Conclusions: In patients with HCM, the reduction of E_SR was more closely associated with global diastolic dysfunction than asynchrony, and E_SR may be a useful and sensitive index for regional diastolic function.