TY - JOUR
T1 - Limited myocardial contractile reserve and chronotropic incompetence in patients with chronic Chagas' disease
T2 - Assessment by dobutamine stress echocardiography
AU - Acquatella, Harry
AU - Pérez, Julio E.
AU - Condado, Jose A.
AU - Sánchez, Indira
PY - 1999/2
Y1 - 1999/2
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0033081745&partnerID=8YFLogxK
U2 - 10.1016/S0735-1097(98)00569-5
DO - 10.1016/S0735-1097(98)00569-5
M3 - Article
C2 - 9973034
AN - SCOPUS:0033081745
SN - 0735-1097
VL - 33
SP - 522
EP - 529
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
IS - 2
ER -