Voltage and calcium dynamics both underlie cellular alternans in cardiac myocytes.

ABSTRACT: Cardiac alternans, a putative trigger event for cardiac reentry, is a beat-to-beat alternation in membrane potential and calcium transient. Alternans was originally attributed to instabilities in transmembrane ion channel dynamics (i.e., the voltage mechanism). As of this writing, the predominant view is that instabilities in subcellular calcium handling are the main underlying mechanism. That being said, because the voltage and calcium systems are bidirectionally coupled, theoretical studies have suggested that both mechanisms can contribute. To date, to our knowledge, no experimental evidence of such a dual role within the same cell has been reported. Here, a combined electrophysiological and calcium imaging approach was developed and used to illuminate the contributions of voltage and c

SUBMITTER: Groenendaal W 

PROVIDER: S-EPMC4052344 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature