The occurrence of dysrhythmias after the Mustard operation for transposition of the great arteries was compared in 70 patients operated upon before and 58 patients operated upon after January 1972 when surgical modifications aimed at preserving the sino-atrial node and its arterial supply were initiated. The surgical modifications included changing the site of the superior vena cava (SVC) cannu...

The architecture of the sinus node, the atrioventricular conduction axis, and the internodal atrial myocardium R. H. Anderson and S. Y. Ho Multicentric origin of the atrial depolarization wave: the pacemaker complex. Relation to dynamics of atrial conduction, P-wave changes and heart rate control – J. P. Boineau and others Voltage-clamp investigations of membrane currents underlying pace-maker ...

A large number of studies in healthy and asymptomatic subjects, as well as patients with already established cardiovascular disease (CAD) have demonstrated that heart rate (HR) is a very important and major independent cardiovascular risk factor for prognosis. Lowering heart rate reduces cardiac work, thereby diminishing myocardial oxygen demand. Several experimental studies in animals, includi...

Experiments with electrophysiology of the heart have been essential for the progress in diagnostics and pharmacotherapy of cardiovascular diseases. The aim of the study was to establish the influence of a new propranolol analogue on mechanical and bioelectrical activity of the rabbit heart in vitro. In the experiment, propranolol (1-isopropylamino-3-[1-naphthoxy]-2-propanol hydrochloride) and i...

BACKGROUND Recent reports suggest that adenosine, in addition to terminating supraventricular tachycardia involving the atrioventricular (AV) node, may have antiarrhythmic effects on atrial tachycardia. The electrophysiological effects of adenosine on supraventricular tissue include shortening of action potential duration in atrial myocytes mediated by the potassium current, IKACh,Ado; shorteni...

HASHIMOTO , K., SUZUKI, Y. and CHIBA, S. Influence of Calcium and Magne sium Ions on the Sino-atrial Node Pacemaker Activity of the Canine Heart. Tohoku J. exp. Med., 1974, 113 (2), 187-196 •\ Using constant pressure perfusion technique of the canine sinus node artery, effects of changing concentrations of calcium and magnesium ions were investigated on the sino-atrial (SA) pacemaker activity. ...

Genetically modified mice provide a number of models for studying cardiac channelopathies related to cardiac Na(+) channel (SCN5A) abnormalities. We review key pathophysiological features in these murine models that may underlie clinical features observed in sinus node dysfunction and progressive cardiac conduction disease, thereby providing insights into their pathophysiological mechanisms. We...

In one patient reprodncibk episodes of sMal tachyear(200 msec, control; 70 msec, atropine) and sustained dia conld be elicited via programmed atrial premature atrial tachycardia no longer could be elicited. These dcpoluizations. Evllodion of the elechpphysiologic studies mpport the concept that h a t t i a l reciprocation shldks suggested that the most tikely mechanism was can be a mechanism re...

Patients carrying the heterozygous A414G mutation in HCN4 gene, which encodes protein, demonstrate moderate to severe bradycardia of heart. Tetramers subunits compose ion channels sinus node that carry hyperpolarization-activated ‘funny’ current (If), also named ‘pacemaker current’. If plays an essential modulating role pacemaker activity. To assess mechanism by results bradycardia, we first pe...