BACKGROUND Several distinct forms of focal ventricular tachycardia (VT) from the left ventricle (LV) have been described. We report a new syndrome of VT arising from the base of the posterior papillary muscle in the LV. METHODS AND RESULTS Among 290 consecutive patients who underwent ablation for VT or symptomatic premature ventricular complexes (PVCs) based on a focal mechanism, 7 patients w...

BACKGROUND In patients with left ventricular infarction or dilatation, leaflet tethering by displaced papillary muscles frequently induces mitral regurgitation, which doubles mortality. Little is known about the biological potential of the mitral valve (MV) to compensate for ventricular remodeling. We tested the hypothesis that MV leaflet surface area increases over time with mechanical stretch...

We compared the contractile performance of papillary muscle from a mouse model of hypertrophic cardiomyopathy [α-cardiac actin (ACTC) E99K mutation] with nontransgenic (non-TG) littermates. In isometric twitches, ACTC E99K papillary muscle produced three to four times greater force than non-TG muscle under the same conditions independent of stimulation frequency and temperature, whereas maximum...

A 33-year-old woman who reported syncope and dyspnea on exertion was diagnosed with hypertrophic cardiomy-opathy and scheduled to undergo surgical septal myectomy to relieve a severe obstruction in the left ventricular (LV) outflow tract. On transthoracic echocardiography, asymmetrical septal hypertrophy and systolic anterior motion of the mitral leaflet were noted, and the peak velocity in the...

Aim: We investigated the impact of fragmented QRS (fQRS) complexes on ECG in predicting papillary muscle dyssynchrony and functional mitral regurgitation in patients with non-ischemic dilated cardiomyopathy with narrow QRS and sinus rhythm. Methods: Thirty-one non-ischemic dilated cardiomyopathy patients with fQRS and 16 patients without fQRS were evaluated for intraventricular and papillary mu...

A patient with acute severe mitral regurgitation resulting from papillary muscle dysfunction which developed on the third day of acute myocardial infarction underwent early successful mitral valve prosthetic replacement with concomitant aortocoronary saphenous vein bypass. The concept of acute severe mitral regurgitation due to an infarcted papillary muscle which has not actually ruptured and a...

Action potential propagation from the subendocardial Purkinje network into the ventricular muscle is an essential link in cardiac activation. Studies of papillary muscles have indicated that ventricular muscle activation by the Purkinje network occurs only at discrete, localized regions near the papillary muscle base. Over the rest of the endocardial surface, however, the spatial distribution o...

A patient with acute severe mitral regurgitation resulting from papillary muscle dysfunction which developed on the third day of acute myocardial infarction underwent early successful mitral valve prosthetic replacement with concomitant aortocoronary saphenous vein bypass. The concept of acute severe mitral regurgitation due to an infarcted papillary muscle which has not actually ruptured and a...

A murmur of mitral regurgitation in patients with congestive heart failure after an acute myocardial infarction suggests a surgically correctable cause of the heart failure. Six patients who presented in this manner and who later underwent surgery have been evaluated by two-dimensional echocardiography (2DE). The underlying anatomical cause of the mitral regurgitation was correctly identified a...