I-123 MIBG scintigraphy demonstrated altered cardiac sympathetic modulation in chagasic patients, with 95% having a 3-hour heart-to-mediastinum uptake ratio of less than 2.19 (P<0.001).
Cross-Sectional (n=59)
Does I-123 MIBG scintigraphy detect early sympathetic neuronal dysfunction in chagasic patients with normal or borderline ECG and preserved ventricular function compared to controls?
I-123 MIBG scintigraphy demonstrates that cardiac autonomic sympathetic modulation is affected early in Chagas disease patients with preserved ventricular function and normal or borderline ECGs.
p-value: p=<0.001
PURPOSE: The indeterminate form of Chagas disease represents the most common chronic presentation. The aim of this study was to assess cardiovascular autonomic system function with I-123 metaiodobenzylguanidine (MIBG) scintigraphy in chagasic patients with normal or "borderline" electrocardiographic alterations and preserved left ventricular function evaluated by echocardiography. MATERIALS AND METHODS: A total of 40 chagasic patients and 19 control subjects were included in this study. Patients had normal echocardiogram and chest radiography; no arrhythmias or myocardial ischemia; and normal exercise performance for age, gender, and body mass index. I-123 MIBG scintigraphy was performed and the heart-to-mediastinum (H/M) uptake was used as the primary predictor in the present analysis. The data analysis was performed by using Nonparametric Regression Trees and the Survival Agreement Plot. We included only patients with preserved right and left ventricular function assessed by echocardiographic methods. RESULTS: Variables analyzed in the regression tree were age, sex, 20 minutes and 3 hours H/M uptake after injection of I-123 MIBG, washout rate, and single photon emission computed tomography imaging. The 3 hours H/M ratio was the only significant variable (P<0.001) and for 95% of chagasic patients, this value was less than 2.19. CONCLUSIONS: This study presents evidence that cardiac autonomic sympathetic modulation may be affected in chagasic subjects with preserved ventricular function evaluated by echocardiography, especially in those with "borderline" electrocardiogram.
Landesmann et al. (2011) conducted a cross-sectional in Chagas disease (n=59). I-123 metaiodobenzylguanidine (MIBG) scintigraphy vs. Control subjects was evaluated on Heart-to-mediastinum (H/M) uptake (p=<0.001). I-123 MIBG scintigraphy demonstrated altered cardiac sympathetic modulation in chagasic patients, with 95% having a 3-hour heart-to-mediastinum uptake ratio of less than 2.19 (P<0.001).