Abstract
Chronic Chagas' disease, a leading cause of cardiomyopathy in Latin America induces left ventricular aneurysm formation despite normal coronary arteries. We have previously described abnormal coronary vasomotor response to acetylcholine in patients with Chagas'. To determine whether myocardial contractile reserve may be reduced in Chagas', we evaluated global and segmental left ventricular (LV) response to dobutamine in 18 patients with positive serology. Patients underwent dobutamine stress echocardiograpy with quantitation of LV cavity area (cm2) fractional area change (FAC, %) and coronary arteriography. Patients without LV aneurysm (n = 6) had normal baseline contraction (FAC = 43.4 ± 10.8%) but exhibited a blunted response to peak dobutamine (FAC= 48.9 ± 10.1%). The contractile response in patients with apical akinesis (n = 4), or aneurysms (n = 8) was similarly blunted (up to 36.5 ± 18.3%, and up to 31.6 ± 9.2%, respectively). Analysis of 192 myocardial segments in the 12 patients with abnormal wall motion (but with normal coronary anatomy) yielded: No Change Improved Worse Low dose dobutamine (LD) 167 22 3 Peak dose dobutamine (PD) 67 106 19 In five of these 12 patients a Diphasic response was noted (improvement in wall motion at LD, but worsening at PD). Thus, chronic Chagas' disease limits myocardial contractile reserve and induces a segmental dysfunction behavior similar to that seen in patients with coronary artery disease.
Original language | English |
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Pages (from-to) | 426 |
Number of pages | 1 |
Journal | Journal of the American Society of Echocardiography |
Volume | 10 |
Issue number | 4 |
State | Published - 1997 |