This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Atrial fibrillation occurs in all except 
Select and explain. 
A. Mitral stenosis, B. Hypothyroidism, C. Dilated cardiomyopathy, D. Mitral regurgitation
B: Hypothyroidism
Answer: B: Hypothyroidism 
Explanation: Atrial fibrillation can occur in hypehyroidism, not hypothyroidism. Other causes are: CAD Valvular hea diseases Hypeension Sinoatrial disease Alcohol Cardiomyopathy Congenital hea disease Chest infection Pulmonary embolism Pericardial disease Idiopathic Reference Harrison 20th edition pg 1433