Atrial fibrillation may occur in all of the following conditions, except?: (A) Mitral stenosis, (B) Hypothyroidism, (C) Dilated cardiomyopathy, (D) Mitral regurgitation
Answer is B. Causes of Atrial fibrillation: Rheumatic heart disease (MS and MR), Nonrheumatic mitral valve disease, Hypertensive cardio-vascular disease, dilated cardiomyopathy, atrial septal defect, Coronary heart disease, Thyrotoxicosis, Acute alcohol excess and alcohol withdrawal.