This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
Propranolol is useful in the treatment of all of the following except 
Select and explain. 
A. Angina, B. Paial atrioventricular block, C. Idiopathic hyperophic subaic cardiomyopathy, D. Familial tremor
B: Paial atrioventricular block
Answer: B: Paial atrioventricular block 
Explanation: Ref-KDT 6/e p142,143 Beta blockers are contraindicated in hea block because this can conve paial AV block to complete AV block. These agents are the drugs if choice for HOCM