Out of 60 patients included in our study, 9 patients had post operative atrial fibrillation. According to our results, Left Atrial Volume was the most significant factor associated to post operative atrial fibrillation, but this volume showed no significant association to post operative atrial fibrillation when indexed to body surface area. Left atrial volume (LAV) can be measured easily before surgery, other studies agree with our study that, increased LAV has been shown to predict the development of AF 14, but its utility in the prediction of post operative atrial fibrillation is unknown. The increase in LAV is hemodynamically closely related to the chronic burden of elevated ventricular filling pressure and diastolic dysfunction 197.