Increased atrial effectiveness of flecainide conferred by altered biophysical properties of sodium channels

Atrial fibrillation (AF) affects over 1% of the population and is a leading cause of stroke and heart failure in the elderly. A feared side effect of sodium channel blocker therapy, ventricular pro-arrhythmia, appears to be relatively rare in patients with AF. The biophysical reasons for this relative safety of sodium blockers are not known.Our data demonstrates intrinsic differences between atrial and ventricular cardiac voltage-gated sodium currents (INa), leading to reduced maximum upstroke velocity of action potential and slower conduction, in left atria compared to ventricle.

Source: Journal of Molecular and Cellular Cardiology - January 31, 2022 Category: Cytology Authors: Sian O' Brien, Andrew P. Holmes, Daniel M. Johnson, S. Nashitha Kabir, Christopher O' Shea, Molly O' Reilly, Adelisa Avezzu, Jasmeet S. Reyat, Amelia W. Hall, Clara Apicella, Patrick T. Ellinor, Steven Niederer, Nathan R. Tucker, Larissa Fabritz, Paulus K Source Type: research