Mechanoelectrical Feedback as Novel Mechanism of Cardiac Electrical Remodeling

Mechanoelectrical feedback as novel mechanism of cardiac electrical remodeling.

BACKGROUND Altered electrical activation of the heart by pacing or disease induces profound ventricular electrical remodeling (VER), manifested electrocardiographically as T-wave memory and ultimately as deleterious mechanical remodeling from heterogeneous strain. Although T-wave memory is associated with altered expression of sarcolemmal ion channels, the biophysical mechanisms responsible for...

Feedback remodeling of cardiac potassium current expression: a novel potential mechanism for control of repolarization reserve.

BACKGROUND Inhibition of individual K(+) currents causes functionally based compensatory increases in other K(+) currents that minimize changes in action potential duration, a phenomenon known as repolarization reserve. The possibility that sustained K(+) channel inhibition may induce remodeling of ion current expression has not been tested. Accordingly, we assessed the effects of sustained inh...

Feedback Mechanisms for Cardiac-Specific microRNAs and cAMP Signaling in Electrical Remodeling Running title: Myers et al.; Roles of Cardiac MicroRNA in Electrical Remodeling

Feedback mechanisms for cardiac-specific microRNAs and cAMP signaling in electrical remodeling.

BACKGROUND Loss of transient outward K(+) current (Ito) is well documented in cardiac hypertrophy and failure both in animal models and in humans. Electrical remodeling contributes to prolonged action potential duration and increased incidence of arrhythmias. Furthermore, there is a growing body of evidence linking microRNA (miR) dysregulation to the progression of both conditions. In this stud...

Electrical remodeling in pressure-overload cardiac hypertrophy: role of calcineurin.

BACKGROUND Myocyte hypertrophy accompanies many forms of heart disease, but its contribution to electrical remodeling is unknown. METHODS AND RESULTS We studied mouse hearts subjected to pressure overload by surgical thoracic aortic banding. In unbanded control hearts, action potential duration (APD) was significantly longer in subendocardial myocytes compared with subepicardial myocytes. Hyp...