Adenosine was administered intravenously to 17 patients undergoing intracardiac electrophysiologic studies. At a mean dose of 179 +/- 88 micrograms/kg (+/- SD), adenosine suppressed sinus node automaticity and depressed atrioventricular (AV) nodal conduction. These effects were less than 20 sec in duration and were not influenced by muscarinic blockade with atropine (0.02 to 0.03 mg/kg). Adenos...

tive examination. Internal morphology of the left appendage revealed a smooth endocardium without a crista terminalis and was of the left atria1 type. The presence of left atria1 isomerism associated with a common atrium led to the diagnosis of ambiguous AV connection. Surgical correction involved rerouting the systemic venous return to the tricuspid valve. This was achieved with a “mirror imag...

Electrical stimulation of the carotid sinus nerves was applied during diagnostic catheterization of two patients who had coronary artery disease. The immediate reflex prolongation of the atrioventricular (AV) interval was due to prolongation of the AH interval only and was roughly parallel to the reflex RR interval prolongation evoked without atrial pacing. After cholinergic block, the reduced ...

BACKGROUND Atrioventricular nodal reentry tachycardia (AVNRT) represents the most commonly encountered type of regular paroxysmal supraventricular tachycardia. This study determined whether administration of adenosine-5'-triphosphate (ATP) during sinus rhythm may be useful in the noninvasive diagnosis of dual AV nodal pathways. METHODS AND RESULTS During electrophysiological study, we intrave...

BACKGROUND Atrioventricular (AV) nodal reentry is a relatively common cause of regular, narrow QRS tachycardia. The underlying basis for this arrhythmia is functional (and anatomic) duality of pathways in the region of the AV node, although the exact boundaries of the reentrant circuit have not been convincingly defined. During the more common type of AV nodal reentry (seen in approximately 90%...

BACKGROUND Familial preexcitation syndrome is linked to mutations in PRKAG2. Previous studies on the R302Q mutation have provided evidence for a remarkably high proportion of otherwise rare accessory pathways with atrioventricular (AV) node-like conduction properties (Mahaim fibers). Yet, histopathologic proof is still lacking. We aimed to provide such proof. METHODS AND RESULTS We retrospect...

Twin AV nodal reentrant tachycardia most commonly occurs in patients with complex congenital heart disease who have two distinct AV nodes, His bundles, and non-preexcited QRS morphologies. Catheter ablation of the weaker AV node may be hindered by anatomical complexities. In such cases, remote magnetic guidance offers a potentially effective solution.

Recent work has shown that alterations in the dynamic atrioventricular (AV) nodal response to changes in heart rate can significantly modify AV nodal function. The present study was designed to evaluate the nature and potential importance of sympathetic regulation of the rate-dependent properties of the AV node. Selective stimulation protocols and mathematical formulations were used to independ...

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...