慢性恰加斯病患者心肌收缩储备受限和变时性功能不全：经多巴酚丁胺负荷超声心动图评估

Limited myocardial contractile reserve and chronotropic incompetence in patients with chronic Chagas' disease: assessment by dobutamine stress echocardiography.

作者信息

Acquatella H, Pérez J E, Condado J A, Sánchez I

机构信息

Centro de Investigaciones J.F. Torrealba, Hospital Universitario de Caracas, Venezuela.

出版信息

J Am Coll Cardiol. 1999 Feb;33(2):522-9. doi: 10.1016/s0735-1097(98)00569-5.

DOI:10.1016/s0735-1097(98)00569-5

PMID:9973034

Abstract

OBJECTIVES

To determine whether dobutamine stimulation in patients with Chagas' disease may uncover abnormal contractile responses as seen in ischemic myocardium.

BACKGROUND

Segmental left ventricular (LV) dysfunction in the absence of coronary atherosclerosis is frequently seen in patients with chronic Chagas' heart disease. Myocardial ischemia and coronary microcirculation abnormalities have been found in animal models and in humans with Chagas' disease. In addition, chagasic sera may contain autoantibodies against human beta-adrenergic receptors.

METHODS

Two groups of patients with Chagas' disease were studied by echocardiography: group 1 (n = 12) without and group 2 (n = 14) with LV segmental wall motion abnormalities (mostly apical aneurysm). Ten normal subjects served as control subjects. We performed qualitative assessment of wall motion and quantitative evaluation of LV cavity under baseline conditions and after dobutamine stimulation.

RESULTS

Patients with Chagas' disease exhibited a blunted inotropic and chronotropic response to dobutamine stimulation. After dobutamine, fractional area change in Chagas' group 1 (54.7+/-6.6%; SD) and in group 2 (35.1+/-12.1%) were significantly lower than control group (66.7+/-2.5%; p < 0.001). In addition, in 6 of 14 group 2 patients, dobutamine induced a biphasic response with improvement at low dose and deterioration at peak dose, as seen in patients with coronary artery disease. Although the three groups had similar basal mean heart rates and attained a similar mean peak dobutamine doses, both groups of patients with Chagas' disease had a significantly blunted mean heart rate effect after dobutamine (p < 0.0001).

CONCLUSIONS

Thus, dobutamine stimulation unmasks a chronotropic incompetence and a blunted myocardial contractile response in chagasic patients, even in those with no overt manifestation of heart disease.

摘要

目的

确定恰加斯病患者接受多巴酚丁胺刺激时是否会出现如缺血性心肌所见的异常收缩反应。

背景

慢性恰加斯心脏病患者常出现无冠状动脉粥样硬化情况下的节段性左心室（LV）功能障碍。在恰加斯病的动物模型和人类中已发现心肌缺血和冠状动脉微循环异常。此外，恰加斯病血清可能含有抗人β - 肾上腺素能受体的自身抗体。

方法

通过超声心动图对两组恰加斯病患者进行研究：第1组（n = 12）无LV节段性壁运动异常，第2组（n = 14）有LV节段性壁运动异常（主要是心尖部动脉瘤）。10名正常受试者作为对照。我们在基线条件下以及多巴酚丁胺刺激后对壁运动进行定性评估，并对LV腔进行定量评估。

结果

恰加斯病患者对多巴酚丁胺刺激表现出变力性和变时性反应减弱。多巴酚丁胺刺激后，第1组恰加斯病患者（54.7±6.6%；标准差）和第2组（35.1±12.1%）的面积变化分数显著低于对照组（66.7±2.5%；p < 0.001）。此外，在第2组的14名患者中有6名，多巴酚丁胺诱导出双相反应，低剂量时改善，峰值剂量时恶化，这与冠心病患者所见相同。尽管三组的基础平均心率相似，且达到的平均多巴酚丁胺峰值剂量相似，但两组恰加斯病患者在多巴酚丁胺刺激后的平均心率效应均显著减弱（p < 0.0001）。