Familiäre Prädisposition und mikrobielle Ätiologie bei dilatativer Kardiomyopathie

Role of cardiac magnetic resonance in the evaluation of dilated cardiomyopathy: diagnostic contribution and prognostic significance

Dilated cardiomyopathy (DCM) represents the final common morphofunctional pathway of various pathological conditions in which a combination of myocyte injury and necrosis associated with tissue fibrosis results in impaired mechanical function. Recognition of the underlying aetiology of disease and accurate disease monitoring may be crucial to individually optimize therapeutic strategies and stratify patient's prognosis. In this regard, CMR has emerged as a new reference gold standard providing important information for differential diagnosis and new insight about individual risk stratification. The present review article will focus on the role of CMR in the evaluation of present condition, analysing respective strengths and limitations in the light of current literature and technological developments.

Trypanosoma cruzi in the chicken model: Chagas-like heart disease in the absence of parasitism

BACKGROUND

The administration of anti-trypanosome nitroderivatives curtails Trypanosoma cruzi infection in Chagas disease patients, but does not prevent destructive lesions in the heart. This observation suggests that an effective treatment for the disease requires understanding its pathogenesis.

METHODOLOGY/PRINCIPAL FINDINGS

To understand the origin of clinical manifestations of the heart disease we used a chicken model system in which infection can be initiated in the egg, but parasite persistence is precluded. T. cruzi inoculation into the air chamber of embryonated chicken eggs generated chicks that retained only the parasite mitochondrial kinetoplast DNA minicircle in their genome after eight days of gestation. Crossbreeding showed that minicircles were transferred vertically via the germ line to chicken progeny. Minicircle integration in coding regions was shown by targeted-primer thermal asymmetric interlaced PCR, and detected by direct genomic analysis. The kDNA-mutated chickens died with arrhythmias, shortness of breath, cyanosis and heart failure. These chickens with cardiomyopathy had rupture of the dystrophin and other genes that regulate cell growth and differentiation. Tissue pathology revealed inflammatory dilated cardiomegaly whereby immune system mononuclear cells lyse parasite-free target heart fibers. The heart cell destruction implicated a thymus-dependent, autoimmune; self-tissue rejection carried out by CD45(+), CD8γδ(+), and CD8α lymphocytes.

CONCLUSIONS/SIGNIFICANCE

These results suggest that genetic alterations resulting from kDNA integration in the host genome lead to autoimmune-mediated destruction of heart tissue in the absence of T. cruzi parasites.

[Treatment of progressive heart failure: pharmacotherapy, resynchronization (CRT), surgery]

The treatment of progressive and terminal heart failure follows the principle of causative therapy. Therefore, etiology and pathophysiology of the underlying disease and its hemodynamic conditions are indispensable. This applies to coronary artery disease, hypertension, valvular heart disease, the cardiomyopathies with and without inflammation, and microbial persistence similarly. The classic treatment algorithms both in heart failure with and without reduced ejection fraction are based on measures onloading the heart (angiotensin-converting enzyme inhibitors, angiotensin antagonists, beta-blockers, diuretics) and on antiarrhythmics and anticoagulation, when needed. Device therapy for cardiac resynchronization in left bundle branch block and permanent stimulation therapy may contribute to the hemodynamic benefit. ICD (implantable cardioverter defibrillator) therapy prevents sudden cardiac death, which is often associated with progressive heart failure. Heart transplantation and left ventricular assist devices are final options in the treatment repertoire of terminal heart failure.

Novel estrogen receptor coregulators and signaling molecules in human diseases

The steroid hormone estrogen and signaling from its receptors are increasingly recognized as critical mediators of a variety of organ-specific biological processes. Recent advances in the identification and functional characterization of novel estrogen receptor interacting proteins clearly show the complexity of hormonal signaling regulation, but may also contribute to our understanding of the roles of estrogen signaling in normal physiology and the pathobiology of human disease.