We extend a non-Tikhonov asymptotic embedding, proposed earlier, for calculation of conduction velocity restitution curves in ionic models of cardiac excitability. Conduction velocity restitution is the simplest non-trivial spatially extended problem in excitable media, and in the case of cardiac tissue it is an important tool for prediction of cardiac arrhythmias and fibrillation. An idealized...

Recent experimental results regarding the action potential duration restitution curve have explained the transition from ventricular tachycardia (VT) to fibrillation (VF) in terms of spiral wave (SW) meandering and breakup. However, it remains unclear whether VF always has a steep restitution curve. The present study was designed to test the hypothesis that afterdepolarizations occur at excitab...

BACKGROUND The restitution of the action potential duration (APDR) and conduction velocity (CVR) are mechanisms whereby cardiac excitation and repolarization adapt to changes in heart rate. They modulate the vulnerability to dangerous arrhythmia, but the mechanistic link between restitution and arrhythmogenesis remains only partially understood. METHODS This paper provides an experimental and...

Rao JN, Rathor N, Zou T, Liu L, Xiao L, Yu T, Cui Y, Wang JY. STIM1 translocation to the plasma membrane enhances intestinal epithelial restitution by inducing TRPC1-mediated Ca signaling after wounding. Am J Physiol Cell Physiol 299: C579–C588, 2010. First published July 14, 2010; doi:10.1152/ajpcell.00066.2010.—Early epithelial restitution is an important repair modality in the gut mucosa and...

The spatial variation in restitution properties in relation to varying stimulus site is poorly defined. This study aimed to investigate the effect of varying stimulus site on apicobasal and transmural activation time (AT), action potential duration (APD) and repolarization time (RT) during restitution studies in the intact human heart. Ten patients with structurally normal hearts, undergoing cl...

We present numerical simulations of surface waves in vibrated granular systems. For the simulations we use an event driven (ED) procedure with a non-constant restitution coeecient. The important advantage of a non-constant restitution coeecient is that it allows to circumvent the \inelastic collapse", i.e. the divergence of collision frequency, usually observed in ED simulations of dense and di...

Spatial heterogeneity of repolarization can provide a substrate for reentry to occur in myocardium. This heterogeneity may result from spatial differences in action potential duration (APD) restitution. The restitution portrait (RP) measures many aspects of rate-dependent restitution: the dynamic restitution curve (RC), S1-S2 RC, and short-term memory response. We used the RP to characterize ep...

Small bowel epithelium is at the frontline of intestinal barrier function. Restitution is considered to be the major determinant of epithelial repair, because function recovers in parallel with restitution after acute injury. As such, studies of intact mucosa have largely been replaced by migration assays of cultured epithelia. These latter studies fail to account for the simultaneous roles pla...

Upon ligand binding, epidermal growth factor (EGF) receptor (R) autophosphorylates on COOH-terminal tyrosines, generating docking sites for signaling partners that stimulate proliferation, restitution, and chemotaxis. Specificity for individual EGFR tyrosines in cellular responses has been hypothesized but not well documented. Here we tested the requirement for particular tyrosines, and associa...

BASS, kz G. htitution of the action potential in cat papillary muscle. Am. J. Physiol. Z%(6) : 17 17-l 724. 1975.-Membrane recovery (electrical restitution) following an action potential (AP) was studied in isolated, electrically driven cat papillary muscle by interpolation of test extrasystoles at various delays in the interval between two AP’s (recorded with glass microelectrodes). Curves des...