Troponin I isoform expression in human and experimental atrial fibrillation.

Background: Atrial fibrillation (AF) is accompanied by re-expression of fetal genes and activation of proteolytic enzymes. In this study both aspects were addressed with respect to troponin I (TnI) isoform expression.

Methods And Results: Western blotting and real-time reverse transcription-polymerase chain reaction were used to study TnI isoform expression in patients with paroxysmal or chronic AF and in goats after 1, 2, 4, 8, and 16 weeks of AF.

Reverse structural and gap-junctional remodeling after prolonged atrial fibrillation in the goat.

Background: Prolonged atrial fibrillation (AF) results in electrical, structural, and gap-junctional remodeling. We examined the reversibility of the changes in (ultra)structure and gap junctions.

Methods And Results: Four groups of goats were used: (1) sinus rhythm (SR), (2) 4 months' AF (4 mo AF), (3) 2 months' SR after 4 mo AF (2 mo post-AF), and (4) 4 months' SR after 4 mo AF (4 mo post-AF).

Analysis of altered gene expression during sustained atrial fibrillation in the goat.

Objective: Atrial fibrillation (AF) is characterised by electrical, gap junctional and structural remodelling. However, the underlying molecular mechanisms of these phenomena are largely unknown. To get more insight into atrial remodelling at the molecular level we have analysed changes in gene expression during sustained AF in the goat.

Cardiac gap junctions and connexins: their role in atrial fibrillation and potential as therapeutic targets.

In the heart, changes in velocity and in patterns of conduction of myocardial electrical activity can affect cardiac rhythm and the coordination of contraction. Abnormal electrical coupling between cardiomyocytes through gap junctions is, therefore, considered an important factor in various pathophysiologic conditions. In the present report we summarize the literature on gap junctions and their structural proteins, the connexins, in the normal and fibrillating atrium.

Atrial fibrillation in the goat induces changes in monophasic action potential and mRNA expression of ion channels involved in repolarization.

Introduction: Sustained atrial fibrillation (AF) is characterized by a marked shortening of the atrial effective refractory period (AERP) and a decrease or reversal of its physiologic adaptation to heart rate. The aim of the present study was to investigate whether the AF-induced changes in AERP in the goat are associated with changes in the atrial monophasic action potential (MAP) and whether an abnormal expression of specific ion channels underlies such changes.

Methods And Results: Following thoracotomy, MAPs were recorded from the free wall of the right atrium both before induction of AF (control) and after cardioversion of sustained AF (>2 months) in chronically instrumented goats.