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...

Dilated cardiomyopathy (DCM) is one of the most common types of cardiomyopathy worldwide. It is characterized by progressive chamber dilatation and myocardial systolic dysfunction and diagnosed by finding left ventricular (LV) enlargement and impaired systolic LV function (LV ejection fraction less than 50% or fractional shortening of less than 25-30%). Angiotensin-converting enzyme inhibitors ...

OBJECTIVE To assess the effect of acute alterations in afterload by aortoiliac clamping, during peripheral vascular surgery, on left ventricular function. DESIGN Prospective examination of the left ventricular long axis and transmitral Doppler flow preoperatively and intraoperatively; before aortic clamping, during clamping and 5 min, 15 min, and 5 days after unclamping. SETTING A tertiary ...

BACKGROUND Regional performance of the hypertrophied left ventricle (LV) in hypertrophic cardiomyopathy (HCM) is still incompletely characterized with studies variably reporting that the hypertrophied myocardium is hypokinetic, akinetic, or has normal function. Different imaging modalities (M-mode or two-dimensional echocardiography) and methods of analysis (fixed or floating frame of reference...

BACKGROUND Systolic shortening is known to produce muscle deactivation. The present study was designed to analyze whether the velocity and the timing of ejection play a role on end-systolic pressure-volume relations (ESPVR). METHODS AND RESULTS In isolated rabbit hearts, left ventricular pressure and volume were recorded and digitized, and left ventricular volume was controlled by a servosyst...

Hyperthyroidism has been reported to affect all of the major determinants of left ventricular performance in a manner that would augment ventricular shortening characteristics. The hypothesis tested in this study is that reduced afterload in conjunction with increased preload and heart rate, rather than augmented contractility, accounts for much of the increase in left ventricular performance n...