Tissue Discontinuities Affect Conduction Velocity Restitution
نویسندگان
چکیده
منابع مشابه
Tissue discontinuities affect conduction velocity restitution: a mechanism by which structural barriers may promote wave break.
BACKGROUND The mechanism by which structural barriers promote wave break and fibrillation is unclear. Conduction velocity (CV) restitution is an important determinant of wave break. Abnormal CV restitution is associated with ventricular fibrillation in patients with heart disease and arises preferentially in fibrotic myocardium. We hypothesize that tissue discontinuities imposed by structural b...
متن کاملSuppression of alternans and conduction blocks despite steep APD restitution: electrotonic, memory, and conduction velocity restitution effects.
We examine the utility of the action potential (AP) duration (APD) restitution curve slope in predicting the onset of electrical alternans when electrotonic and memory effects are considered. We develop and use two ionic cell models without memory that have the same restitution curve with slope >1 but different AP shapes and, therefore, different electrotonic effects. We also study a third cell...
متن کاملAsymptotics of conduction velocity restitution in models of electrical excitation in the heart.
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...
متن کاملThe role of short term memory and conduction velocity restitution in alternans formation.
Alternans is the periodic beat-to-beat short-long alternation in action potential duration (APD), which is considered to be a precursor of ventricular arrhythmias and sudden cardiac death. In extended cardiac tissue, electrical alternans can be either spatially concordant (SCA, all cells oscillate in phase) or spatially discordant (SDA, cells in different regions oscillate out of phase). SDA gi...
متن کاملConduction velocity costs energy
Hodgkin and Adrian’s 1975 hypothesis that the squid axon is optimized for maximum conduction velocity is flawed by (i) the inaccurate value of its prediction for channel density, and (ii) the prohibitive energetic expense entailed by their prediction. Here we investigate the metabolic cost of conduction velocity. By manipulating ion channel density or by manipulating the Nernst battery voltages...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Circulation
سال: 2003
ISSN: 0009-7322,1524-4539
DOI: 10.1161/01.cir.0000081766.16185.28