Characteristics of ventricular tachycardia and long-term treatment outcome in patients with dilated cardiomyopathy complicated by lamin A/C gene mutations.

Background: Dilated cardiomyopathy caused by lamin A/C gene (LMNA) mutation is complicated with atrioventricular (AV) conduction disturbances, malignant ventricular arrhythmias, and progressive severe heart failure. Radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) has been reported to be challenging due to the high recurrence rate in patients with LMNA-related cardiomyopathy. However, electrophysiological and histopathological characteristics of VT substrate remain to be fully elucidated.

Lamin A/C gene mutations in familial cardiomyopathy with advanced atrioventricular block and arrhythmia.

Lamin A and C proteins, encoded by the lamin A/C gene (LMNA), are inner nuclear membrane proteins predominantly expressed in terminally differentiated cells. Mutations in LMNA can cause various forms of cardiomyopathy with arrhythmia in an autosomal dominant manner. We collected and evaluated the clinical characteristics of unclassified familial cardiomyopathy with advanced AV block and sporadic cases with advanced AV block.

Statin ameliorates hypoxia-induced pulmonary hypertension associated with down-regulated stromal cell-derived factor-1.

Aims: Mobilization of stem cells/progenitors is regulated by the interaction between stromal cell-derived factor-1 (SDF-1) and its ligand, CXC chemokine receptor 4 (CXCR4). Statins have been suggested to ameliorate pulmonary arterial hypertension (PAH); however, the mechanisms involved, especially their effects on progenitors, are largely unknown. Therefore, we examined whether pravastatin ameliorates hypoxia-induced PAH in mice, and if so, which type of progenitors and what mechanism(s) are involved.

Endogenous erythropoietin system in non-hematopoietic lineage cells plays a protective role in myocardial ischemia/reperfusion.

Objective: Recent studies suggested that erythropoietin (Epo) receptors (EpoR) are expressed not only in the hematopoietic lineage cells but also in the heart and that the administration of recombinant human Epo elicits protective effects in myocardial ischemia and reperfusion (I/R). We tested our hypothesis that endogenous Epo signals mediated by EpoR expressed in the non-hematopoietic lineage cells play a protective role against myocardial I/R injury.

Methods: Transgene-rescued EpoR null mutant mice (RES), which express EpoR exclusively in the hematopoietic lineage cells, were subjected to 30 min left coronary artery occlusion followed by reperfusion.

Important role of endogenous erythropoietin system in recruitment of endothelial progenitor cells in hypoxia-induced pulmonary hypertension in mice.

Background: Recent studies have suggested that endogenous erythropoietin (Epo) plays an important role in the mobilization of bone marrow-derived endothelial progenitor cells (EPCs). However, it remains to be elucidated whether the Epo system exerts protective effects on pulmonary hypertension (PH), a fatal disorder encountered in cardiovascular medicine.

Methods And Results: A mouse model of hypoxia-induced PH was used for study.

Accumulation of risk markers predicts the incidence of sudden death in patients with chronic heart failure.

Background: Sudden death is common in chronic heart failure (CHF). Risk stratification is the first step for primary prevention.

Aim: To evaluate the use of risk markers for estimating sudden death risk.

Electrophysiological and histopathological characteristics of progressive atrioventricular block accompanied by familial dilated cardiomyopathy caused by a novel mutation of lamin A/C gene.

Unlabelled: Conduction defect caused by lamin A/C gene mutation.

Introduction: Mutations of lamin A/C gene (LMNA) cause dilated cardiomyopathy (DCM) with atrioventricular (AV) conduction defect, although the electrophysiological and histological profiles are not fully understood.

Methods And Results: We analyzed a large Japanese family (21 affected and 203 unaffected members) of DCM with AV block.

Prognostic value of plasma brain natriuretic peptide combined with left ventricular dimensions in predicting sudden death of patients with chronic heart failure.

Background: We evaluated a combined assessment of brain natriuretic peptide (BNP) with left ventricular dimensions as a prognostic marker for sudden death in patients with chronic heart failure (CHF). Ventricular dimensions and BNP are separately recognized as prognostic markers for sudden death in patients with CHF.

Methods And Results: CHF patients at Stage C and B were registered for a prospective study.

Characteristics and 1-year prognosis of medically treated patients with chronic heart failure in Japan.

The study was designed to characterize patients with chronic heart failure (CHF) in Japan in terms of the etiologies and prognosis. CHF was defined by ejection fraction (EF >or=50%), left ventricular diastolic dimension (LVDD >or=55 mm) or a past history of congestive heart failure. Among the 721 recruited patients, the most frequent etiology for CHF was dilated cardiomyopathy (DCM) in patients aged less than 59 years, and valvular heart disease (VHD) in those aged 70 years or more.