Approximately 3% 11.8% of cases require permanent pacemaker implantation due to atrioventricular block (AVB) after aortic valve replacement (AVR), and determination of conduction disturbances such as left or right bundle branch block by preoperative electrocardiography is correlated with high risk postoperative permanent pacemaker implantation. Intraoperative risk factors include severe calcifi...

An unusual patient with Ebstein's anomaly of the tricuspid valve and the Wolff-Parkinson-White syndrome is presented. Ventricular pre-excitation related to conduction over both a right posterior Kent bundle and Mahaim fibers coursing from the atrioventricular node to the right ventricle. Two types of supraventricular tachycardia were demonstrable. These were due to re-entry involving antegrade ...

The conduction system of the heart initiates and coordinates the electric signal that causes the rhythmic and synchronized contractions of the atria and ventricles. In higher vertebrates, this system comprises the sinuatrial (SAN) and atrioventricular nodes (AVN) and the “wiring” of the ventricles. The latter comprises the atrioventricular bundle (AVB), the left and right bundle branches (BBs),...

BACKGROUND The electrical activity of the atrioventricular node (AVN) is functionally heterogeneous, but how this relates to distinct cell types and the 3-dimensional structure of the AVN is unknown. To address this, we have studied the expression of Na(V)1.5 and other Na+ channel isoforms in the AVN. METHODS AND RESULTS The rat AVN was identified by Masson's trichrome staining together with ...

INTRODUCTION AND OBJECTIVES Exercise-induced left bundle-branch block does not always denote the presence of underlying coronary artery disease. The aim of this study was to analyze the clinical characteristics and evolution of patients with rate-dependent left bundle-branch block. PATIENTS AND METHOD 9,318 consecutive exercise stress studies were reviewed. The clinical characteristics and ev...

Conduction of the sino-atrial impulse from the high right atrium to the ventricles was studied by intracardiac electrography in 21 unoperated patients, age 3 months to 11 years, with endocardial cushion defects (ECD). The high right atrium-to-low right atrium conduction time was prolonged in 15 of 18 subjects (mean 57 +/- 20 msec). The low right atrium-to-His bundle conduction time (LRA-H) was ...

The conduction system of the heart initiates and coordinates the electric signal that causes the rhythmic and synchronized contractions of the atria and ventricles. In higher vertebrates, this system comprises the sinuatrial (SAN) and atrioventricular nodes (AVN) and the “wiring” of the ventricles. The latter comprises the atrioventricular bundle (AVB), the left and right bundle branches (BBs),...

The conduction system of the heart initiates and coordinates the electric signal that causes the rhythmic and synchronized contractions of the atria and ventricles. In higher vertebrates, this system comprises the sinuatrial (SAN) and atrioventricular nodes (AVN) and the “wiring” of the ventricles. The latter comprises the atrioventricular bundle (AVB), the left and right bundle branches (BBs),...

We describe a 35-year-old man with idiopathic frequent premature ventricular contractions (PVCs) originating from the His-bundle region, where a low frequency ventricular potential was recorded in the bipolar recording and QR pattern in the unipolar recording. Electro-anatomical mapping revealed a confined low voltage zone (<1.2 mV) in the His-bundle region, and the activation spread out radial...