Feb 26, 2003

Cx43 and dual-pathway electrophysiology of the atrioventricular node and atrioventricular nodal reentry

Circulation Research
Vladimir P NikolskiI R Efimov

Abstract

Fluorescent imaging has revealed that posterior nodal extensions provide the anatomical substrate for the dual-pathway electrophysiology of the atrioventricular (AV) node during normal conduction and reentry. The reentry can be intranodal, or as well as the posterior nodal extensions, it can involve an endocardial layer of atrial/atrial-nodal (A/AN) cells as part of the AV nodal reentry (AVNR) circuit. Using fluorescent imaging with a voltage-sensitive dye and immunolabeling of Cx43, we mapped the electrical activity and structural substrate in 3 types of AVNR induced by premature atrial stimulation in 8 rabbit hearts. In 6 cases, the AVNR pathway involved (1) a fast pathway (FP), (2) the A/AN layer, and (3) a slow pathway (SP). In 4 cases, reentry took the path (1) SP, (2) A/AN layer, and (3) FP. In 2 cases, reentry was intranodal, propagating between the 2 posterior nodal extensions. Immunolabeling revealed that the FP and SP are formed by Cx43-expressing bundles surrounded by tissue without Cx43. Cx43-expressing posterior nodal extensions are the substrate of AVNR during both intranodal and extranodal reentry.

Mentioned in this Paper

Biochemical Pathway
GJA1 gene
Electrical Activity of Brain
Immunocytochemistry
Insulin Resistance
Atrial Fibrillation
Fluorescent stain
Endocardium
Cardiac Conduction System
Structure of Atrioventricular Node

Related Feeds

Atrial Fibrillation

Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.

Atrial Filbrillation

Atrial fibrillation refers to the abnormal heart rhythm characterized by rapid and irregular beating of the atria. Here is the latest research.

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Cardiac Conduction System

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.