BACKGROUND During development, AV conduction switches from base-to-apex to apex-to-base conduction after emergence of the conduction system. We hypothesize that after this transition, the bulk of the AV ring, although no longer required for AV conduction, remains transiently able to conduct, providing a potential arrhythmia substrate. We studied AV conduction during this transition and its sens...

Previous studies of reentrant arrhythmias in the heart have been performed in computer models and tissue experiments. We hypothesized that confluent monolayers of cardiac cells can provide a simple, controlled, and reproducible experimental model of reentry. Neonatal rat ventricular cells were cultured on 22-mm-diameter coverslips and stained with the voltage-sensitive dye RH-237. Recordings of...

Received February 28, 2005; accepted May 4, 2005. The transition from the period of diagnosis and medical treatment of cancer to survivorship (i.e., the reentry phase) is an understudied phase in the cancer trajectory. The objectives of this report were 1) to illustrate several adaptive tasks of the reentry phase, 2) to provide examples of research on factors that predict positive adjustment du...

BACKGROUND The pathophysiological mechanisms leading to acceleration of ventricular tachycardia (VT) are still unclear. METHODS AND RESULTS High-resolution epicardial mapping was used to study the mechanisms of VT acceleration by programmed electrical stimulation (PES) in a model of sustained reentrant VT in Langendorff-perfused rabbit hearts (n = 40). Three different mechanisms responsible f...

BACKGROUND Knowledge of cycle-to-cycle changes in isthmus geometry is of potential importance for radiofrequency catheter ablation to stop reentrant ventricular tachycardia. It was hypothesized that isthmus geometry often undergoes continuous evolution throughout reentry and that cycle-length variability measurements could be used to segment reentry into distinct phases and to predict changes i...

Cardiac fibrosis is a well-known arrhythmogenic condition which can lead to sudden cardiac death. Physically, be viewed as large number of small obstacles in an excitable medium, may create nonlinear wave turbulence or reentry. The relation between the specific texture and onset reentry great theoretical practical importance. Here, we present conceptual framework combines functional aspects pro...

The importance of activation sequence of an atrioventricular junctional reentrant (AVJRe) circuit, before delivery of an extrastimulus, has received little attention in studies concerned with clinical tachycardias. In this study a change in activation sequence was accomplished using bidirectional activation (V-A sequential pacing) during the basic drive (V1A1-V1A1). It was noted that, compared ...

curves on atrial extrastimulus testing. Stimulation was performed from the right atrium in all cases. The left atrium was stimulated from the coronary sinus in 13 patients and directly through a patent foramen ovale in two patients. Baseline fast-AVN-pathway AH intervals were significantly shorter with left atrial stimulation. Maximum AH intervals for conduction over the fast or slow AVN pathwa...

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. It can occur at any age but is very rare in children and becomes extremely common in the elderly, with a prevalence approaching 20% in patients 85 years of age.1 AF is associated with a wide range of potential complications and contributes significantly to population morbidity and mortality. Present therapeutic approac...