Ultrastructural and Functional Remodeling of the Coupling Between Ca ²⁺ Influx and Sarcoplasmic Reticulum Ca ²⁺ Release in Right Atrial Myocytes From Experimental Persistent Atrial Fibrillation

Abstract

In persistent AF, reduced SR Ca(2+) release despite preserved SR Ca(2+) content is a major factor in contractile dysfunction. Fewer Ca(2+) channel-RyR couplings and reduced efficiency of the coupling at subsarcolemmal sites, possibly related to increased Na(+)/Ca(2+) exchanger, underlie the reduction in Ca(2+) release.