The development of congestive heart failure (CHF) is associated with left ventricular (LV) dilation and myocardial remodeling. However, fundamental mechanisms that contribute to this remodeling process with the progression of CHF remain unclear. The matrix metalloproteinases (MMPs) have been demonstrated to play a significant role in tissue remodeling in a number of pathological processes. The ...

Components of excitation-contraction (EC)-coupling were compared at 37 degrees C and 22 degrees C to determine whether hypothermia altered the gain of EC coupling in guinea pig ventricular myocytes. Ca(2+) concentration (fura-2) and cell shortening (edge detector) were measured simultaneously. Hypothermia increased fractional shortening (8.3+/-1.7 vs. 2.6+/-0.3% at 37 degrees C), Ca(2+) transie...

BACKGROUND Transient atrial contractile dysfunction ("atrial stunning") follows conversion of atrial fibrillation (AF) to sinus rhythm and has significant clinical implications; however, the underlying mechanisms are poorly understood. We investigated the hypothesis that rapid atrial activation (as during AF) impairs cellular contractility and affects cellular Ca2+ handling. METHODS AND RESUL...

To perform cardiac imaging in mice without having to invest in expensive dedicated equipment, we adapted a clinical 1.5 Tesla (T) magnetic resonance imaging (MRI) scanner for use in a murine ischemia/reperfusion model. Phase-sensitive inversion recovery (PSIR) sequence facilitated the determination of infarct sizes in vivo by late gadolinium enhancement. Results were compared to histological in...

Hypertrophy: What Is the Effective Role of Heat Shock Transcription Factor 1? To the Editor: In the recent interesting article by Sakamoto et al,1 the authors found that rats undergoing exercise training showed lower degree of left ventricular (LV) hypertrophy, higher expression and activity of heat shock transcription factor 1 (HSF1), and preserved LV systolic function in comparison with rats ...

BACKGROUND: Bone marrow-derived mesenchymal cellscan transdifferentiate into Cardiomyocyte cells and improveheart function after transplantation. Since biomaterials canimprove the cell retention in the site, cell survival and differentiation,heart tissue engineering is now being explored as anapplied solution to support cell-based therapies and increasetheir efficacy for myocardial diseases. Ch...

BACKGROUND Noninvasive predictors of important outcomes after valve replacement for mitral regurgitation have not been examined in a rheumatic population (in whom the results of valve repair are suboptimal) in the era of chordal preservation. Timing of valve replacement thus remains a difficult question in rheumatic mitral regurgitation. METHODS AND RESULTS Of 278 patients followed after valv...