Vali-Asr Ave, Mellat Park, Tehran, Iran.
Background- Atrial fibrillation (AF) is a common complication of heart surgery. This unwanted sequel leads to an increased risk of thromboembolism and necessitates further often costly health care. Advanced age, previous AF rhythm, and valvular heart disease are the most consistently identified risk factors for the development of this rhythm after cardiac surgical procedures. Dispersion of repolarization leading to reentry is believed to be the mechanism of postoperative AF. Treatment is aimed at controlling heart rate, preventing thromboembolic events, and converting to sinus rhythm.
Material- 500 consecutive patients who were undergoing cardiac surgical procedures consisting of coronary artery bypass, valve procedures and combined coronary-valve procedures were prospectively evaluated to determine the predisposing factors relating to the development of postoperative AF rhythm.
Results- In this series of 500 patients undergoing cardiac operations at our center, we found the incidence of AF to be 13% after coronary artery bypass grafting (CABG), 24% after mitral valve replacement, 23% after aortic valve replacement, and 32% after combined CABG and valve replacement procedures. Patient age, valvular heart disease, preoperative AF rhythm, and discontinuation of beta-blockers were shown to be statistically significant in determining the development of postoperative AF rhythm in our group of patients.
Conclusion- The only firm conclusion that can be drawn concerning preventive measures is that beta-blocker withdrawal is to be avoided after heart operations and to consider beta-blocker therapy for other patients who may tolerate these drugs in order to reduce the chances of developing AF rhythm