Evaluation of myocardial microcirculation abnormalities in patients with hypertrophic cardiomyopathy by myocardial contrast echocardiography combined with exercise stress test / 中华超声影像学杂志

ABSTRACT

Objective:To detect the abnormal changes of myocardial blood perfusion in patients with hypertrophic cardiomyopathy (HCM) by myocardial contrast echocardiography(MCE) combined with exercise stress test.Methods:Twenty-seven patients with clinically diagnozed of asymmetric HCM in Fuwai Central China Cardiovascular Hospital from May 2020 to April 2021 were selected as the HCM group, and 29 healthy subjects during the same period were selected as the control group. All patients underwent routine echocardiography, resting and exercise stress MCE. The myocardial perfusion parameters of each segment of interventricular septum in the 2 groups were quantitatively analyzed the peak plateau intensity (A value), ascending slope of the curve(β value) and value of A×β. According to the end-diastolic myocardial thickness, the interventricular septum of the HCM group was divided into hypertrophic and non-hypertrophic segments, and the myocardial contrast parameters of the interventricular septum of the study group were compared with those of the control group. The myocardial blood flow reserve value of the two groups were calculated, and the correlation of myocardial blood flow reserve value with left ventricular mass index (LVMI) and left ventricular remodeling index (LVRI) were analyzed.Results:No matter at rest or under stress, the A value, β value and A×β value of ventricular septal hypertrophic and non-hypertrophic segments in the hypertrophic cardiomyopathy group were lower than those in the control group, and the differences were statistically significant (all P<0.05). Under stress, the A value, β value and A×β value of interventricular septal hypertrophic segments were lower than those in non-hypertrophic segments in the HCM group, and the differences were statistically significant (all P<0.05). The myocardial blood flow reserve in the HCM group was negatively correlated with LVMI and LVRI( r=-0.899, -0.676; all P<0.001). Conclusions:In patients with HCM under resting and exercise stress, microcirculation disorders were found in both hypertrophic and non-hypertrophic segments of the ventricular wall, and the myocardial blood flow reserve was negatively correlated with LVMI and LVRI.