Background: Functional mitral regurgitation(MR) is one of the common and severe complications in patients with dilated cardiomyopathy. The detailed mechanisms that cause functional MR remain to be elucidated. Using tw...Background: Functional mitral regurgitation(MR) is one of the common and severe complications in patients with dilated cardiomyopathy. The detailed mechanisms that cause functional MR remain to be elucidated. Using two-dimensional transthoracic echocardiography, we inves- tigated the differences in major determinants of MR severity between ischemic cardiomyopathy(ICM) and non-ICM patients. Methods: We enrolled 103 patients(91 males; age 64± 12 years) with significant left ventricular(LV) dilatation. They were divided into ICM group(n=69) with significant coronary disease, and non-ICM(n=34) group without coronary disease. We devised a novel and simple parameter; the short-axis sphericity index(SI), to evaluate global LV remodeling, and used coaptation depth(CD) and tenting area(TA) to evaluate mitral deformity. Results: In all cases, CD, TA and left atrium diameter(LAD) correlated positively with maximum regurgitation area(MRA)(r=0.54, 0.57, 0.57; P< 0.0001). A negative correlation was observed between MRA and SI(r=-0.33, P=0.0008). There was no significant relationship between MRA and LV ejection fraction(EF). In non-ICM cases, SI tended to be lower with reduced EF.Multivariate stepwise linear regression analysis showed the following equations; ICM: MRA=-9.4 + 0.81CD + 0.21LAD(r2=0.47, P< 0.0001), non-ICM: MRA=-7.2 + 0.17LVDs(LV end systolic diameter)-8.7SI + 0.27LAD(r2=0.63, P< 0.0001). Conclusions: The strongest determinants of functional MR severity differ in ICM and non-ICM. While LV diameter and SI(global LV remodeling index) mainly determine the severity in non-ICM, CD that reflects mitral deformity is the major determinant in ICM.展开更多
文摘Background: Functional mitral regurgitation(MR) is one of the common and severe complications in patients with dilated cardiomyopathy. The detailed mechanisms that cause functional MR remain to be elucidated. Using two-dimensional transthoracic echocardiography, we inves- tigated the differences in major determinants of MR severity between ischemic cardiomyopathy(ICM) and non-ICM patients. Methods: We enrolled 103 patients(91 males; age 64± 12 years) with significant left ventricular(LV) dilatation. They were divided into ICM group(n=69) with significant coronary disease, and non-ICM(n=34) group without coronary disease. We devised a novel and simple parameter; the short-axis sphericity index(SI), to evaluate global LV remodeling, and used coaptation depth(CD) and tenting area(TA) to evaluate mitral deformity. Results: In all cases, CD, TA and left atrium diameter(LAD) correlated positively with maximum regurgitation area(MRA)(r=0.54, 0.57, 0.57; P< 0.0001). A negative correlation was observed between MRA and SI(r=-0.33, P=0.0008). There was no significant relationship between MRA and LV ejection fraction(EF). In non-ICM cases, SI tended to be lower with reduced EF.Multivariate stepwise linear regression analysis showed the following equations; ICM: MRA=-9.4 + 0.81CD + 0.21LAD(r2=0.47, P< 0.0001), non-ICM: MRA=-7.2 + 0.17LVDs(LV end systolic diameter)-8.7SI + 0.27LAD(r2=0.63, P< 0.0001). Conclusions: The strongest determinants of functional MR severity differ in ICM and non-ICM. While LV diameter and SI(global LV remodeling index) mainly determine the severity in non-ICM, CD that reflects mitral deformity is the major determinant in ICM.
