The occurrence of ventricular arrhythmias of different degrees of severity correlates quantitatively with the extent of cardiac sympathetic denervation, but not with the extent of fibrosis, suggesting that myocardial sympathetic denervation plays a major role in triggering ventricular arrhythmia in CCC.

Combined myocardial analysis of the extent and location of autonomic denervation, hypoperfusion, and scarring may allow for better understanding of the pathophysiology of Chagas cardiomyopathy. Autonomic myocardial denervation may be a more sensitive marker of cardiac involvement in Chagas Disease than finding by other imaging modalities.

No abstract

No abstract

No abstract

The relationship between the myocardial tissue damage, myocardial perfusion defects and gaps in the autonomic innervation is still poorly understood. This paper proposes methods capable of providing an integrated visualization and analysis of tissue injuries through MRI images, autonomic innervations and myocardial perfusion through SPECT images. The proposed method is based on segmentation of MRI and registration between MRI images and SPECT images using 123 I-MIBG and 99m Tc-MIBI as tracers. Fibrosis segmentation in MRI images was performed based on the algorithm of maximum Tsallis entropy. Nonrigid registrations method based on B-Spline were used to align image volumes. Results show correlation between fibrosis and denervation areas in the middle short axis was obtained by Spearman correlation (r=0.571,p-value<0.05). The developed tool provides a better understanding of the relationship between myocardial tissue damage, autonomic innervations injuries and ischemia caused by Chagas disease.

No abstract

Objectives Autologous hematopoietic stem cell transplantation (AHSCT) is a disease-modifying treatment for patients with severe systemic sclerosis (SSc). Here, we aimed at assessing cardiopulmonary function outcomes of SSc patients after AHSCT. Patients and Methods Twenty-seven SSc adult patients treated with AHSCT were included in this retrospective study. Most had the diffuse cutaneous subset (93%) and pulmonary involvement (85%). Before and 12 months after AHSCT, patients underwent cardiopulmonary exercise testing (CPET), transthoracic echocardiography, pulmonary function test with diffusing capacity for carbon monoxide (DLCO), six-minute walk test (6MWT), and quality of life evaluations. Results After AHSCT, the peak VO2 increased from 954 to 1029 ml/min (p = 0.02), the percentage of predicted peak VO2 increased from 48.9 to 53.5 meters (p = 0.01), and the distance measured by the 6MWT increased from 445 to 502 meters (p = 0.01), respectively, compared to baseline. Improvements in peak VO2 correlated positively with improvements in 6MWT distance, and negatively with a decrease in resting heart rate. At baseline, patients with DLCO &gt;70% had higher peak VO2 values than those with DLCO &lt;70% (p = 0.04), but after AHSCT all patients improved VO2 values, regardless of baseline DLCO levels. Increases in VO2 levels after AHSCT positively correlated with increases in the physical component scores of the Short Form (SF)-36 quality of life questionnaire (r = 0.70; p = 0.0003). Conclusion AHSCT improves the aerobic capacity of SSc patients probably reflecting combined increments in lungs, skeletal muscle and cardiac function.