Human atrial action potential and Ca2+ model: sinus rhythm and chronic atrial fibrillation.

ABSTRACT:

Rationale

Understanding atrial fibrillation (AF) requires integrated understanding of ionic currents and Ca2+ transport in remodeled human atrium, but appropriate models are limited.

Objective

To study AF, we developed a new human atrial action potential (AP) model, derived from atrial experimental results and our human ventricular myocyte model.

Methods and results

Atria versus ventricles have lower I(K1), resulting in more depolarized resting membrane potential (≈7 mV). We used higher I(to,fast) density in atrium, removed I(to,slow), and included an atrial-specific I(Kur). I(NCX) and I(NaK) densities were reduced in atrial versus ventricular myocytes according to experimental results. SERCA function was altered to reproduce human atrial myocyte Ca2+ transients. To s

SUBMITTER: Grandi E 

PROVIDER: S-EPMC3208665 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature