The present study was designed to investigate mechanisms of adenosine (ADO)-mediated prolongation of conductivity through the atrioventricular (AV) node during myocardial ischemia. Using the Langendorff preparation of the guinea pig heart, we tested the hypothesis that extracellular potassium concentration elevated due to ischemia could augment ADO effect. Exposure of the heart preparation to e...

OBJECTIVES The objective of this study was to correlate electrocardiographic (ECG) PR interval changes during normal sinus rhythm with recent observations regarding the anatomy and physiology of the dual, slow and fast atrioventricular (AV) pathways. BACKGROUND The least common manifestation of dual AV conduction is an abrupt PR interval change in the setting of sinus rhythm. Whereas isolated...

Introduction: Despite extensive studies about effects of Crataegus monogyna on cardiovascular diseases yet, a few study has been undertaken antiarrhythmic property of this plant. Aims of the present study were: 1) To determine the protective role of methanolic extract of C.monogyna on the rate-dependent model and the concealed conduction . 2) To explore the role of Na+-K+ A TPase in the protect...

We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontane...

The Tako-tsubo cardiomyopathy, also known as transient apical dysfunction, transient apical dyskinesia, stress-induced cardiomyopathy or broken heart syndrome, is a type of nonischemic cardiomyopathy in which there is a sudden temporary weakening of the myocardium. The PR interval reflects the time the electrical impulse takes to travel from the sinus node through the AV node and entering the v...

Nineteen procedures were performed in 17 children, aged 10 months to 17 years, using catheter radiofrequency applications for the management of malignant or drug-resistant supraventricular tachyarrhythmias. Diagnoses were junctional ectopic tachycardia in 1 patient, atrioventricular (AV) node reentrant tachycardia in 4 and accessory pathway-mediated tachycardia in 12. Accessory pathway location...

First-degree atrioventricular (AV) block is a delay within the AV conduction system and is defined as a prolongation of the PR interval beyond the upper limit of what is considered normal (generally 0.20 s). Up until recently, first-degree AV block was considered an entirely benign condition. In fact, some complain that it is a misnomer since there is only delay and no actual block in the AV co...

OBJECTIVE To assess the incidence of arterial embolic events in patients with high rate, drug resistant, severely symptomatic paroxysmal and chronic atrial fibrillation who have undergone atrioventricular (AV) node ablation and permanent pacing. DESIGN Multicentre retrospective cohort study. PATIENTS AND MANAGEMENT: From May 1987 to January 1997, AV node ablation was performed in 585 severely...

background: potassium, as an extracellular ion, plays an important role in the electrophysiologic function of the myocardium and any change in extracellular concentration of this ion might have a marked impression upon myocyte electrophysiologic gain. high serum potassium levels are thought to impair pulse conduction in purkinje fibers and ventricles more than that in the atrioventricular (av) ...