Effects of Na+ channel blockers on the restitution of refractory period, conduction time, and excitation wavelength in perfused guinea-pig heart.
- Oleg E Osadchii
PLoS One 2017 23;12(2):e0172683. Epub 2017 Feb 23.
Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
Na+ channel blockers flecainide and quinidine can increase propensity to ventricular tachyarrhythmia, whereas lidocaine and mexiletine are recognized as safe antiarrhythmics. Clinically, ventricular fibrillation is often precipitated by transient tachycardia that reduces action potential duration, suggesting that a critical shortening of the excitation wavelength (EW) may contribute to the arrhythmic substrate. This study examined whether different INa blockers can produce contrasting effects on the rate adaptation of the EW, which would explain the difference in their safety profile. Read More