Ventricular tachycardia like ventricular parasystole is rarely observed in the absence of cardiac disease (Massie and Walsh, 1960; Scherf and Bornemann, 1961), though several cases of functional ventricular tachycardia without demonstrable heart disease have been reported by Hair, Eagan, and Orgain (1962) and others. Parasystole consists of simultaneous activity of two independent impulse-formi...

In the normal heart, an insulating barrier separates the atria and ventricles. The only way in which electrical impulses can cross this barrier is via the atrioventricular (AV) node, which delays impulse conduction to ensure the forward flow of the blood. However, in some individuals, additional muscular bundles (accessory pathways) allow rapid conduction of electrical impulses from the atria t...

This study tests the hypothesis that particulate (p) guanylyl cyclase (GC) and soluble (s) GC are involved in the distinct roles for the regulation of cGMP-PDE-cAMP signaling and of mechanical and secretory functions in the heart. Experiments were performed in perfused beating rabbit atria. C-type natriuretic peptide (CNP) and SIN-1, an NO donor, or BAY 41-2272 (BAY), a direct activator for sGC...

Atrial fibrillation is a common cardiac arrhythmia in which there is an irregular heartbeat. This paper develops a theoretical model for the intervals between successive heartbeats during atrial fibrillation based on the following ideas. There is an irregular pattern of activation of the upper chambers ~atria! of the heart. Excitation travels from the atria through the specialized conducting ti...

The presence of ventricular myosin light chains in the atria of children with congenital heart disease was demonstrated by two-dimensional polyacrylamide gel electrophoresis, peptide mapping, and Western blot analysis. Ventricular myosin light chains were present in 27% of biopsies from 91 children with different forms of congenital heart disease. Perimembranous ventricular septal defects and t...

Thyroid hormone exerts positive inotropic effects on the heart mediated in part by its regulation of calcium transporter proteins, including sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2), phospholamban (PLB), and Na(+)/Ca(2+) exchanger (NCX). To further understand the potential cardiac chamber-specific effects of thyroid hormone action, we compared the triiodo-L-thyronine (T(3)) responsiv...

BACKGROUND Structural and phenotypic changes of cardiomyocytes characterize atrial fibrillation. We investigated whether changes in the glucose-regulated protein GRP94, which is essential for cell viability, occur in the presence of chronic atrial fibrillation. METHODS AND RESULTS Samples of fibrillating atrial myocardium obtained from both goat and human hearts were analyzed for GRP94 expres...

The purpose of the present study was to investigate alpha 1-adrenergic receptors in the heart as well as the activity and the sensitivity of the phosphoinositide pathway on tissue slices of atria, ventricles, and femoral artery of hypertensive rats treated for 4 weeks with deoxycorticosterone acetate (DOCA) and 1% saline. DOCA-salt hypertensive rats were characterized by an increased sympathoad...

In 1969, the Servier Laboratoires introduced trimetazidine, 1-(2, 3, 4-trimethoxybenzyl) piperazine dihydrochloride (Vastarel®) as a medicament for angina pectoris (1). This drug is assumed to reveal its remarkable action through decreasing cardiac work and lower ing the oxygen consumption of the heart (2), but other mechanisms of its action yet await ed clarification. Since trimetazidi...

Fourteen relatively long term survivors of cardiac transplantation underwent systematic electrophysiological evaluation and ambulatory electrocardiographic monitoring. Six patients had prolonged conduction intervals during sinus rhythm. Sinus node function could be assessed in all donor atria and in 10 recipient atria. Sinus node recovery times were prolonged in four of the donor atria and in s...