左室局所機能に対する肥満の影響について : 心エコー図を用いた心筋ストレインによる検討

Abstract

Background : Since the conception of "metabolic syndrome" was proposed, the relation of obesity and various diseases has been noticed. From the point of view of preventive medicine, it is important that subtle alteration of cardiac function by obesity is detected before heart failure occurs. Objectives : Myocardial strain is one of the parameters of cardiac function. Several studies reported that myocardial strain is reduced before the parameter of global left ventricular function such as left ventricular ejection fraction (LVEF) deteriorates. This study was designed to investigate whether there is correlation between myocardial strain and body mass index (BMI) in normal population who visit our echo-lab for the screening of cardiac abnormality. Methods : About 58 subjects who had no obvious cardiac disease, we investigated the correlation between myocardial strain and BMI. Tissue Doppler imaging of apical four-chamber view was obtained from all subjects. Systolic peak strain of interventricular septum was measured. In this measurement, the analysis software "QLAB" which was developed by PHILIPS Company was used. Using conventional echocardiography, LVEF was measured by modified Simpson's method. Results : There is a significant negative correlation between systolic peak strain and BMI (r=-0.38, p＜0.004). In addition, there is more close negative correlation between natural logaritim of systolic peak strain and BMI (r=-0.44, p＜0.0006). But there is no significant correlation between LVEF and Bwr (r=0.12, p=0.379). Conclusion : It is suggested that obesity is related to local latent left ventricle dysfunction.