Plehn Gunnar, Vormbrock Julia, Butz Thomas, Christ Martin, Trappe Hans-Joachim, Meissner Axel
Department of Cardiology and Angiology, Marienhospital Herne, University of Bochum, Germany.
Int J Med Sci. 2008;5(6):333-40. doi: 10.7150/ijms.5.333. Epub 2008 Nov 4.
In patients with idiopathic dilated cardiomyopathy (IDCM) a prolongation of left ventricular (LV) systole at the expense of diastolic time was demonstrated. Our study was aimed to evaluate the effect of exercise on heart rate corrected diastolic time in controls, IDCM with and without LBBB, and patients with LBBB and normal LV function.
47 patients with IDCM, 30 without LBBB, and 17 with LBBB as well as 11 with isolated LBBB were studied during exercise using a combined hemodynamic-radionuclide angiographic approach. The phases of the cardiac cycle were derived with high temporal resolution from the ventricular time-activity curve. The loss of diastolic time per beat (LDT) was quantified using a regression equation obtained from a control group (n=24).
A significant LDT was demonstrated at rest and during peak exercise in IDCM patients with LBBB (39.1+/-32 and 37.3+/-30 ms; p < 0.001). In IDCM patients with normal activation LDT was unaffected at baseline, but elevated during peak exercise. This response was paralleled by an increase in interventricular mechanical dyssynchrony.
During exercise an abnormal shortening of LV diastolic time is a common characteristic of heart failure patients which can be explained by the high prevalence of mechanical dyssynchrony.
在特发性扩张型心肌病（IDCM）患者中，已证实左心室（LV）收缩期延长是以舒张期时间为代价的。我们的研究旨在评估运动对对照组、有无左束支传导阻滞（LBBB）的IDCM患者以及左束支传导阻滞且左心室功能正常的患者心率校正舒张期时间的影响。
采用血流动力学-放射性核素血管造影联合方法，对47例IDCM患者（30例无LBBB，17例有LBBB）以及11例孤立性LBBB患者进行运动研究。从心室时间-活性曲线以高时间分辨率得出心动周期各阶段。使用从对照组（n = 24）获得的回归方程对每搏舒张期时间损失（LDT）进行量化。
有LBBB的IDCM患者在静息和运动高峰时显示出显著的LDT（分别为39.1±32和37.3±30毫秒；p < 0.001）。激活正常的IDCM患者LDT在基线时未受影响，但在运动高峰时升高。这种反应与心室间机械不同步增加平行。
运动期间左心室舒张期时间异常缩短是心力衰竭患者的一个共同特征，这可以用机械不同步的高患病率来解释。
