Mechano-electrical feedback underlying arrhythmias: the atrial fibrillation case.
Mechanoelectrical feedback (MEF) has become firmly established as a mechanism in which mechanical forces experienced by myocardial tissue or cell membranes convey alterations in electrophysiologic characteristics of such tissue. Observations to date mainly concern mechanically induced changes in action potential duration, resting and active potential amplitude, enhanced pacemaker frequency, or afterdepolarizations. While some of these changes (i.e. after depolarizations) may give rise to premature beats, a role of MEF in explaining sustained ventricular tachyarrhythmias has so far been elusive. Here, we review recent findings showing that acute atrial dilatation facilitates atrial fibrillation (AF) and that two stretch-activated channel (SAC) blockers (gadolinium and GsMTx-4) are able to suppress stretch-facilitated AF. These findings strongly support a role of MEF and SACs in promoting sustained arrhythmias and point to a new class of antiarrhythmic drugs.
Arrhythmia Service, VA Medical Center, Georgetown University Medical Center, 50 Irving Street, NW, Washington, DC 20422, USA. michael.r.franz@verizon.net
Michael R
MR
Franz
Frank
F
Bode
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001145:Arrhythmias, Cardiac; D001281:Atrial Fibrillation; D002462:Cell Membrane; D004594:Electrophysiology; D005682:Gadolinium / Q000494:pharmacology; D006325:Heart Atria; D036341:Intercellular Signaling Peptides and Proteins; D009206:Myocardium / Q000473:pathology; D010455:Peptides / Q000494:pharmacology; D011312:Pressure; D011817:Rabbits; D013111:Spider Venoms / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D000889:Anti-Arrhythmia Agents; D036341:Intercellular Signaling Peptides and Proteins; C411249:MTx4 protein, Grammostola spatulata; D010455:Peptides; D013111:Spider Venoms; D005682:Gadolinium; D014700:Verapamil