Introduction: Endorphins are produced by cardiomyocytes, and exert different effects on the heart. The aim of the present study is to assess morphine effects on extracellular atrioventricular (AV) node field potential pattern and ventricular rhythm of isolated rabbit heart during experimental atrial fibrillation (AF). Methods: Effects of different concentrations of morphine (10, 20, 50 and 1...

His bundle ablation was performed in a 48 year old man with drug refractory orthodromic atrioventricular reentrant tachycardia and paroxysmal atrial fibrillation. Reentry was caused by a left free wall concealed accessory pathway. Interruption of the His bundle by low energy direct current shock (25 J) was quickly followed by anterograde conduction via the accessory pathway, with various forms ...

T he occurrence of a premature beat between two consecutive conducted sinus beats is termed an interpolated premature systole or extrasystole.1 An interpolated premature ventricular systole can effect the conduction of the subsequent sinus beat by concealed retrograde penetration into the His-Purkinje system or AV node or both. This retrograde concealed penetration can result in a prolongation ...

  Introduction : The aim of this study is to obtain new insight into possible relation between functional properties of slow concealed pathway and rate-dependent properties of AV-node.   Methods : Rate-dependent nodal properties of recovery, facilitation, and fatigue were characterized by stimulation protocols in one groups of (N=7) isolated superfused AV-Nodal rabbits. Small miniature lesions ...

THE TERM "concealed conduction" was introduced by Langendorfl to describe the phenomenon of entry of an electrical impulse into the A-V node without complete transmission but with modification of conduction of a subsequent impulse. This concept unified diverse observations of earlier years concerning disturbances of A-V transmission2-4 and clarified the mechanisms of many arrhythmias.5 6 Subseq...

In the course of electrophysiological evaluation of six patients with sick sinus syndrome, two patients with chronic conduction system disease and four patients with paroxysmal supraventricular tachycardia or atrial flutter-fibrillation, the phenomenon of concealed conduction within the atrium (At) was repeatedly observed. One pair of intracardiac electrodes was used to deliver electrical stimu...

as an accepted method of treatment of StokesAdams disease, it became feasible to produce in the human heart conditions prone to reveal the phenomenon of concealed conduction. Simple experimental procedures can be applied at the bedside without danger or discomfort to the patient and various disturbances of cardiac rhythm can be reproduced at will. Such observations, some of which shed new light...

Electrophysiological and epicardial mapping studies are described in a patient without pre-excitation who had intractable recurrent paroxysmal supraventricular tachycardia. Electrophysiological studies revealed fixed VA conduction times during both rapid ventricular pacing and coupled ventricular stimulation. Catheter mapping of atrial activation during retrograde conduction and during induced ...

BACKGROUND The term "concealed conduction" is used in electrocardiography when a proximal (atrial or ventricular) impulse penetrates the atrioventricular (AV) node but fails to traverse it completely. Its penetration into the node is inferred by its after effects on the propagation of succeeding impulses. Concealed AV nodal conduction is a well-established phenomenon, but its precise cellular a...