Abstract Introduction: Isolated perfused heart models such as perfusion and superfusion are commonly used for mammalian heart research. However, there are several fundamental limitations in the current techniques. In perfusion model, a suitable cannula is connected to the aorta and the perfusion is retrogradely performed. But, electrode displacement is a potential unwanted event resulted fr...

introduction: developmental changes in atrioventricular nodal conduction time and refractoriness have been shown in several studies. prevalence of atrioventricular nodal reentrant tachycardia (avnrt) is clearly age-dependent. the purpose of this study was to determine developmental changes of basic and frequency-dependent electrophysiological properties of the atrioventricular node (av-node) in...

OBJECTIVE To study the intracellular pathways which mediate the inhibitory actions of adenosine on isoprenaline-stimulated calcium current (ICa) in atrioventricular (AV) nodal myocytes. METHODS The whole-cell patch-clamp technique was used to record ICa from rabbit AV nodal cells, isolated by enzymatic and mechanical dispersion. RESULTS Isoprenaline, 0.1 microM, increased peak ICa from 0.58...

We used intracellular microelectrodes to study the effects of hypoxia on the isolated, superfused sinoatrial (SA) node, atrium, and atrioventricular (AV) node of the rabbit heart. Hypoxia decreased the rate of spontaneous impulse initiation in SA nodal fibers by decreasing the slope of diastolic depolarization. With gradually decreasing Po2, the sinus rate was reduced; concomitantly, the correc...

The atrioventricular (AV) node is permanently damaged in approximately 3% of congenital heart surgery operations, requiring implantation of a permanent pacemaker. Improvements in pacemaker design and in alternative treatment modalities require an effective in vivo model of complete heart block (CHB) before testing can be performed in humans. Such a model should enable accurate, reliable, and de...

Inhibition of proliferative neointima formed by vascular smooth muscle cells is a potential target in preventing angioplasty-induced restenosis. We have created a potent antiproliferative by fusing the active regions of the p27 and p16 cell cycle inhibitors. Intravascular delivery of a replication-deficient adenoviral vector (AV) encoding this p27-p16 fusion protein, named W9, inhibited balloon...

Dual atrioventricular (AV) nodal pathway physiology is described as two different wave fronts that propagate from the atria to the His bundle: one with a longer effective refractory period [fast pathway (FP)] and a second with a shorter effective refractory period [slow pathway (SP)]. By using His electrogram alternance, we have developed a mathematical model of AV conduction that incorporates ...

BACKGROUND The atrioventricular (AV) node is insensitive to changes in extracellular potassium concentration, [K+]o, because of the absence of the inward rectifier potassium current (IK1). However, we propose that in the presence of adenosine, elevated [K+]o should increase the adenosine-activated inward rectifier potassium current (IK,ADO) in AV nodal myocytes and hence augment the negative dr...

We discuss in this paper the strong convergence for weighted sums of negatively orthant dependent (NOD) random variables by generalized Gaussian techniques. As a corollary, a Cesaro law of large numbers of i.i.d. random variables is extended in NOD setting by generalized Gaussian techniques.

During failure of the sinoatrial node, the heart can be driven by an atrioventricular (AV) junctional pacemaker. The position of the leading pacemaker site during AV junctional rhythm is debated. In this study, we present evidence from high-resolution fluorescent imaging of electrical activity in rabbit isolated atrioventricular node (AVN) preparations that, in the majority of cases (11 out of ...