Kang Soo-Jin, Lim Hong-Seok, Hwang Jungwon, Choi Jung-Hyun, Seo Kyoung-Woo, Choi Byung-Joo, Choi So-Yeon, Hwang Gyo-Seung, Yoon Myeong-Ho, Shin Joon-Han, Tahk Seung-Jea
Division of Cardiology, Ajou University Hospital, Suwon, South Korea.
Echocardiography. 2008 Apr;25(4):394-400. doi: 10.1111/j.1540-8175.2007.00621.x.
We evaluated the myocardial contractile reserve related to exercise-induced changes in functional mitral regurgitation (MR) by tissue Doppler imaging (TDI).
Supine bicycle exercise was performed in 35 patients with nonischemic cardiomyopathy (age 51 +/- 12 years; EF < 40%) and resting, and peak exercise 2D echocardiographic parameters, and TDI data were obtained. V(avg) was defined as the average of peak systolic velocities of six basal LV segments by TDI. Myocardial contractile reserve, which was calculated by [peak exercise V(avg)- baseline V(avg)], was represented as DeltaV(avg). Dyssynchrony index was derived from the standard deviation of the time to the peak systolic velocity of 12 LV segments.
During exercise (9.7 +/- 2.4 minutes), the mean V(avg) increased from 4.0 +/- 0.8 cm/s to 5.5 +/- 1.0 cm/s. The effective regurgitant orifice area (ERO) and the ratio of MR jet area to the left atrial area (JLA%) were 1.9 +/- 2.9 mm(2) and 12 +/- 12%, respectively. During exercise, ERO and JLA% significantly increased to 6.2 +/- 6.4 mm(2) and 21 +/- 13% (P < 0.05), respectively, with individually variable changes. Tenting area was found to be an independent factor that showed a relationship with the baseline severity of MR (r = 0.561, P < 0.001). Dyssynchrony index and DeltaV(avg) were found to correlate with both maximal MR severity at peak exercise and changes in MR during exercise. By multivariate analysis, DeltaV(avg) was found to be an independent determinant of exercise-induced changes in ERO (DeltaERO; r =-0.707, P< 0.001) and changes in JLA% (DeltaJLA%; r =-0.663, P< 0.001).
In patients with nonischemic cardiomyopathy, impaired contractile reserve assessed by TDI velocity data may be an independent determinant affecting exercise-induced changes in dynamic MR.
我们通过组织多普勒成像（TDI）评估了与运动诱发的功能性二尖瓣反流（MR）变化相关的心肌收缩储备。
对35例非缺血性心肌病患者（年龄51±12岁；射血分数<40%）进行仰卧位自行车运动，并获取静息及运动高峰时的二维超声心动图参数和TDI数据。V(avg)定义为通过TDI测得的左心室六个基底节段收缩期峰值速度的平均值。心肌收缩储备通过[运动高峰V(avg)-基线V(avg)]计算得出，用ΔV(avg)表示。不同步指数由12个左心室节段收缩期峰值速度到达时间的标准差得出。
运动期间（9.7±2.4分钟），平均V(avg)从4.0±0.8厘米/秒增加到5.5±1.0厘米/秒。有效反流口面积（ERO）和MR射流面积与左心房面积之比（JLA%）分别为1.9±2.9平方毫米和12±12%。运动期间，ERO和JLA%分别显著增加至6.2±6.4平方毫米和21±13%（P<0.05），且个体变化各异。发现帐篷面积是与MR基线严重程度相关的独立因素（r = 0.561，P<0.001）。发现不同步指数和ΔV(avg)与运动高峰时的最大MR严重程度以及运动期间MR的变化均相关。通过多变量分析，发现ΔV(avg)是运动诱发的ERO变化（ΔERO；r = -0.707，P<0.001）和JLA%变化（ΔJLA%；r = -0.663，P<0.001）的独立决定因素。
在非缺血性心肌病患者中，通过TDI速度数据评估的收缩储备受损可能是影响运动诱发的动态MR变化的独立决定因素。
