Association between myocardial mechanical dispersion and ventricular arrhythmogenicity in chagas cardiomyopathy.

Chagas disease is a major health concern in Latin America. Ventricular arrhythmia (VA) is a hallmark of Chagas cardiomyopathy (CCM), associated with worse prognosis. The present study aimed to verify the association between myocardial mechanical dispersion (MD) and ventricular arrhythmogenicity in CCM. In a cross-sectional study, 77 patients (55.8 ± 10.4 years) with CCM were evaluated. Global longitudinal strain (GLS) and MD were assessed by echocardiography, derived from the speckle tracking technique. Myocardial MD was measured from the onset of the Q/R wave on electrocardiogram to the peak longitudinal strain in 16 segments of the left ventricle. Frequency and complexity of ventricular extrasystoles (VES) were assessed by dynamic electrocardiography. The density and complexity of VES and the presence of non-sustained ventricular tachycardias (NSVTs) increase as MD increases. In logistic regression, MD was the only variable associated with the presence of paired VES and ventricular bigeminy. In addition, both MD and GLS were associated with the presence of NSVT (both, p < 0.01), and MD was independently associated with NSVT (OR 1.04, 95% CI 1.004-1.201, p = 0.031). In CCM, MD is associated with a higher density and complexity of VES, including NSVT.

Reversible dilated cardiomyopathy associated with amphotericin B therapy.

WHAT IS KNOWN AND OBJECTIVE: Amphotericin B (AmB) is commonly used to treat a broad spectrum of fungal infections and leishmaniasis. Its use is limited by numerous adverse effects. Reversible dilated cardiomyopathy associated with AmB is a rare disorder with only four previously reported cases, and all of them referring to patients who presented with a predisposing factor for heart failure. CASE SUMMARY: A previously healthy 45-year-old man with visceral leishmaniasis treated with AmB developed acute dilated cardiomyopathy. Other causes of heart failure as well-known predisposing factors for this condition were ruled out. As with previously reported cases, the cardiac function of our patient returned to normal shortly after. WHAT IS NEW AND CONCLUSION: We describe the first case of dilated cardiomyopathy associated with the administration of AmB in a patient without any known predisposing factor for developing cardiac dysfunction. Available evidence suggests that AmB may induce cardiotoxicity. Further investigations are needed to clarify this issue.

Foxp3+CD25(high) CD4+ regulatory T cells from indeterminate patients with Chagas disease can suppress the effector cells and cytokines and reveal altered correlations with disease severity.

Immunoregulatory mechanisms are important to control the intense immune activity induced in Chagas disease. We evaluated the phenotypic profile and the mechanisms by which Treg cells function in patients with the indeterminate (IND) and cardiac (CARD) clinical forms of Chagas disease. The frequency of Foxp3(+)CD25(high) CD4(+)-T cells is augmented and correlated with the maintenance of a better cardiac function in IND. Treg cells from IND present suppressive activity, although the mechanism is not IL-10 or CTLA-4 dependent and are able to produce augmented levels of IL-17, IL-10 and granzyme B being its frequency correlated with percentage of Annexin V(+) CD4(+)-cells. In contrast, CARD presents higher frequency of IL-6(+), IFN-gamma(+), TNF-alpha(+) and CTLA-4(+) Treg-cells than IND. Thus, our data suggest that Treg cells have an important role in controlling the exacerbated immune response and morbidity in Trypanosoma cruzi infection, probably modulating the cytokine environment and/or killing effector cells.