Marin-Neto J A, Bromberg-Marin G, Pazin-Filho A, Simões M V, Maciel B C
Cardiology Division, University of São Paulol Medical School in Ribeirão Preto, Brazil.
Int J Cardiol. 1998 Aug;65(3):261-9. doi: 10.1016/s0167-5273(98)00132-6.
Cardiac autonomic impairment and right side heart failure are prominent features in patients with Chagas' disease, but no causal relationship between these phenomena has been disclosed and the pathophysiology of such manifestations is unclear. Aim of study was to assess the cardiac autonomic control and biventricular function in chagasic patients in early stages of the disease, using radionuclide angiography, Valsalva manoeuvre, head-up tilt and baroreflex sensitivity evaluation. Thirty-one chagasic patients with no clinical signs of Chagas' heart disease-16 in the indeterminate phase and 15 with sole organic digestive involvement-were studied, and results compared with those obtained in 14 normal volunteers. No significant differences were observed among the three groups, in regard to any systolic or diastolic parameter of LV function, including ejection fraction, peak ejection and filling rates and correspondent times, time to end-systole, and the standard deviation of phase values. The indeterminate and digestive groups of chagasics had significantly lower right ventricular ejection fraction (45.7 +/- 6.3 and 46.2 +/- 10.1 respectively) and peak ejection rate (respectively 2.8 +/- 0.6 and 2.9 +/- 0.6) and higher right ventricular phase standard deviation (22.4 +/- 5.9 and 20.1 +/- 5.6 degrees, respectively), as compared with the control group (53.6 +/- 4.3, 3.5 +/- 0.5, and 15.8 +/- 3.8 respectively for right ventricular ejection fraction, peak ejection rate and phase standard deviation). No significant differences were found between the results of autonomic evaluation in the control and indeterminate groups of chagasic patients. The group of digestive disease patients showed abnormally lower Valsalva ratio (1.5 +/- 0.15), baroreflex sensitivity (8.85 +/- 2.05 ms/mmHg) and parasympathetically-dependent heart rate response to tilt (8.85 +/- 8.42 beats/mm) and higher Valsalva delay (15.67 +/- 1.35 s) values, compared with the control group (respectively 1.85 +/- 0.49, 20.23 +/- 12.66 ms/mmHg, 21.61 +/- 5.77 beats/mm and 10.1 +/- 2.5 s). Thus, cardiac autonomic impairment is a prominent feature in chagasic patients with the digestive but not the indeterminate form of Chagas' disease. It bears no causative relationship to the early myocardial damage that is apparent only regarding right ventricular function, in both groups of patients. Early right ventricular dysfunction is a likely mechanism for the marked predominance of systemic over pulmonary congestion when heart failure supervenes in patients with Chagas' disease.
心脏自主神经功能障碍和右侧心力衰竭是恰加斯病患者的突出特征，但这些现象之间的因果关系尚未明确，此类表现的病理生理学也不清楚。本研究的目的是使用放射性核素血管造影、瓦尔萨尔瓦动作、头高位倾斜和压力反射敏感性评估，来评估恰加斯病早期患者的心脏自主神经控制和双心室功能。研究了31例无恰加斯心脏病临床症状的恰加斯病患者——16例处于疾病不确定期，15例仅有器质性消化系统受累——并将结果与14名正常志愿者的结果进行比较。在左心室功能的任何收缩期或舒张期参数方面，包括射血分数、射血峰值和充盈率及相应时间、收缩末期时间以及相位值的标准差，三组之间均未观察到显著差异。与对照组相比（右心室射血分数、射血峰值率和相位标准差分别为53.6±4.3、3.5±0.5和15.8±3.8），恰加斯病不确定期组和消化系统受累组的右心室射血分数（分别为45.7±6.3和46.2±10.1）和射血峰值率（分别为2.8±0.6和2.9±0.6）显著降低，右心室相位标准差（分别为22.4±5.9和20.1±5.6度）更高。恰加斯病患者对照组和不确定期组的自主神经评估结果之间未发现显著差异。与对照组相比（瓦尔萨尔瓦比值、压力反射敏感性、倾斜时副交感神经依赖性心率反应和瓦尔萨尔瓦延迟分别为1.85±0.49、20.23±12.66毫秒/毫米汞柱、21.61±5.77次/毫米和10.1±2.5秒），消化系统疾病患者组的瓦尔萨尔瓦比值（1.5±0.15）、压力反射敏感性（8.85±2.05毫秒/毫米汞柱）和倾斜时副交感神经依赖性心率反应（8.85±8.42次/毫米）异常降低，瓦尔萨尔瓦延迟（15.67±1.35秒）值更高。因此，心脏自主神经功能障碍是恰加斯病消化系统受累而非疾病不确定期患者的突出特征。在两组患者中，它与仅在右心室功能方面明显的早期心肌损伤无因果关系。当恰加斯病患者发生心力衰竭时，早期右心室功能障碍可能是全身充血明显多于肺充血的主要机制。
