Q: Pulmonary edema may occur after synchronized cardioversion in atrial fibrillation. What is the mechanism behind it?


Answer: With cardioversion in atrial fibrillation, the return of atrial systole causes a significant elevation in left atrial pressure which consequently may cause pulmonary edema. This is more common in atrial fibrillation associated with valvular heart disease or left ventricular dysfunction.



Reference: 

Gowda RM, Misra D, Khan IA, Schweitzer P. Acute pulmonary edema after cardioversion of cardiac arrhythmias. Int J Cardiol 2003; 92:271.