Borow K M, Neumann A, Arensman F W, Yacoub M H
Circulation. 1985 May;71(5):866-72. doi: 10.1161/01.cir.71.5.866.
Limited data are available concerning left ventricular contractility and contractile reserve in the chronically denervated, transplanted human heart. This is primarily because of the inability of traditional tests of left ventricular performance to distinguish changes in contractility from alterations in ventricular loading conditions. In this study, load-independent end-systolic indexes of left ventricular contractility were measured by echocardiography and calibrated carotid pulse tracings in 10 patients who had undergone orthotopic cardiac transplant (age 48 +/- 4 years; interval from operation to study 1.2 +/- 0.8 years) and in 10 normal control subjects (age 25 +/- 4 years) matched for donor heart age (25 +/- 6 years). None of the transplant patients had evidence of rejection as determined by endomyocardial biopsy. Baseline left ventricular contractility was assessed over a wide range of afterload generated by infusion of methoxamine. Contractile reserve was measured as the response to an infusion of dobutamine plus methoxamine. Before afterload challenge, baseline left ventricular percent fractional shortening was higher for the transplant patients than for the control subjects (36.5 +/- 5.7% vs 32.1 +/- 2.1%; p less than .05). These differences occurred at a time that end-systolic wall stress (a measure of afterload) was significantly lower for the transplant patients (38 +/- 16 vs 50 +/- 9 g/cm2; p less than .05). When the left ventricular end-systolic pressure-dimension and stress-shortening relationships were determined for the transplant and control subjects, no differences in contractility or contractile reserve were noted. Thus the chronically denervated, transplanted, nonrejecting human left ventricle demonstrates normal contractile characteristics and reserve.
关于慢性去神经支配的移植人类心脏的左心室收缩力和收缩储备，可用的数据有限。这主要是因为传统的左心室功能测试无法区分收缩力的变化与心室负荷条件的改变。在本研究中，通过超声心动图和校准的颈动脉脉搏描记法，对10例接受原位心脏移植的患者（年龄48±4岁；手术至研究的间隔时间1.2±0.8年）和10名与供体心脏年龄匹配（25±6岁）的正常对照受试者（年龄25±4岁）测量了左心室收缩力的负荷独立型收缩末期指标。经心内膜活检确定，所有移植患者均无排斥反应迹象。通过输注甲氧明产生广泛的后负荷范围来评估基线左心室收缩力。收缩储备通过对输注多巴酚丁胺加甲氧明的反应来测量。在进行后负荷挑战之前，移植患者的基线左心室缩短分数百分比高于对照受试者（36.5±5.7%对32.1±2.1%；p<0.05）。这些差异出现时，移植患者的收缩末期壁应力（后负荷的一种测量指标）显著更低（38±16对50±9 g/cm2；p<0.05）。当确定移植患者和对照受试者的左心室收缩末期压力-维度和应力-缩短关系时，未发现收缩力或收缩储备有差异。因此，慢性去神经支配、移植且无排斥反应的人类左心室表现出正常的收缩特性和储备。
