Evaluation of myocardial perfusion abnormalities in patients with hypertrophic cardiomyopathy by myocardial contrast echocardiography

Objective To evaluate the microcirculation abnormalities in the patients with hypertrophic cardiomyopathy(HCM). Methods Twenty patients with HCM and 20 healthy volunteers were included in the study. Two-dimensional images on the apical four-chamber, two-chamber and long-axis views, including 5 cardiac cycles before 'flash' and 15 cardiac cycles after 'flash', were reeorded and stored for off-line analysis in EchoPAC workstation. Then,contrast time-intensity curves were obtained for each available left ventrieular segment. Results There were significant differences in the A,k and the product A×k between the hypertrophic wall segments (P = 0.01, P<0.001, P = 0.036,respectively) and nonhypertrophic wall segments (P<0.001,respectively) and healthy subjects. A,k and the product A×k in hypertrophic wall segments were significantly different from those in nonhypertrophic wall segments in patients with HCM (P = 0.021, P = 0.016, P = 0. 001,respectively). Accordingly,the normalized value of A and the product A × k were lower in hypertrophied wall segments (P = 0.031, P<0.001, respectively) and nonhypertrophied wall segments(P = 0.002, P<0.001,respectively) in patients with HCM than those in normal segments of healthy controls. The normalized value of A and the product A × k were lower in hypertrophic wall segments than nonhypertrophic wall segments in patients with HCM(P = 0.045, P = 0.021,respectively). Conclusions Myocardial contrast echocardiography is a useful method to investigate myocardial perfusion abnormalities in patients with HCM. Key words: Echocardiography;  Microbubbles;  Cardiomyopathy, hypertrophic;  Coronary circulation