Substrate Leading to Atrial Arrhythmia May Be Reversed
Mitral commissurotomy can reverse atrial abnormalities resulting from chronic stretch
MONDAY, March 22 (HealthDay News) -- The use of mitral commissurotomy may reverse the substrate that contributes to atrial arrhythmia due to chronic atrial stretch, according to research published in the March 23 issue of the Journal of the American College of Cardiology.
Bobby John, M.D., of the University of Adelaide in Australia, and colleagues analyzed data from 21 patients with mitral stenosis who underwent mitral commissurotomy. Patients underwent electrophysiological evaluation of both atria before and directly after the procedure, and 14 patients underwent right atrium studies at least six months after the procedure.
The researchers report that, immediately after the procedure, mitral valve area increased and left atrial volume and pressure and pulmonary arterial pressure decreased. This was associated with a decrease in P-wave duration and an increase in conduction velocity and voltage, with no change in effective refractory period. At follow-up, subjects' mitral valve area remained unchanged, while P-wave duration and right atrial effective refractory period decreased and conduction velocity and voltage increased.
"Structural remodeling and the associated conduction abnormalities are increasingly recognized as important precursors for the substrate predisposing to atrial fibrillation. Thus, reversal of these changes could potentially have important implications for the prevention of atrial fibrillation. The present study demonstrates such marked reversal by treatment directed at reversing chronic atrial stretch. It lends weight to a strategy of treatment of the predisposing condition to modify the atrial fibrillation substrate to prevent arrhythmogenesis," the authors conclude.
A co-author reported financial relationships with several medical device companies.