Heterogeneity of regional systolic function detected by tissue Doppler imaging is linked to impaired global left ventricular relaxation in hypertrophic cardiomyopathy

Objective: To evaluate regional and global left ventricular (LV) function and LV wall thickness (LVWT) in patients with hypertrophic cardiomyopathy (HCM). Design and setting: Observational study at the National Cardiovascular Centre and Nagoya University Hospital in Japan. Participants: Thirty-six patients with HCM and 16 patients with hypertensive LV hypertrophy (LVH). Main outcome measures: Conventional echocardio-graphy and strain rate (SR) imaging derived from tissue Doppler imaging were performed. Systolic strain (ε _sys), peak systolic SR (SR_sys), peak early diastolic SR (SR_dia) and LVWT were obtained from eight LV segments. LV pressure was simultaneously recorded with a high-fidelity micromanometer. Results: The regional ε_sys and SR_sys were correlated with LVWT in patients with HCM (r = 0.50, p<0.001 and r = 0.63, p<0.001, respectively) but not in patients with hypertensive LVH. The standard deviations of LVWT, ε_sys and SR_sys obtained from the eight LV segments of each subject were greater for patients with HCM than for patients with hypertensive LVH. The standard deviation of LVWT was correlated with those of ε_sys and SR_sys (/- = 0.55, p<0.001 and r = 0.56, p<0.001, respectively). The standard deviations of LVWT, ε_sys and SR_sys were correlated with tau (r = 0.35, p<0.05; r = 0.47, p<O.001; and r = 0.39, p<0.005, respectively). Conclusions: Heterogeneity of regional LV systolic function detected by SR imaging is in part attributable to heterogeneity of LVH and may be linked to impaired global LV relaxation in HCM.