Cardiac beat-to-beat alternations driven by unusual spiral waves.

ABSTRACT: Alternans, a beat-to-beat temporal alternation in the sequence of heartbeats, is a known precursor of the development of cardiac fibrillation, leading to sudden cardiac death. The equally important precursor of cardiac arrhythmias is the rotating spiral wave of electro-mechanical activity, or reentry, on the heart tissue. Here, we show that these two seemingly different phenomena can have a remarkable relationship. In well controlled in vitro tissue cultures, isotropic populations of rat ventricular myocytes sustaining a temporal rhythm of alternans can support period-2 oscillatory reentries and vice versa. These reentries bear "line defects" across which the phase of local excitation slips rather abruptly by 2pi, when a full period-2 cycle of alternans completes in 4pi. In other words, th

SUBMITTER: Kim TY 

PROVIDER: S-EPMC1913880 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature