This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ECG and Arrhythmias 1, Subject name: Medicine
All of the following lead to AV block except? 
Select and explain. 
A. Hypothyroidism, B. Ankylosing spondylitis, C. Lyme disease, D. Lev's disease
B: Ankylosing spondylitis
Answer: B: Ankylosing spondylitis 
Explanation: Myxedema AV node can block Ankylosing spondylitis will not cause av block Lyme disease caused by Borrelia burgdorferi, transmitted by Tick Bite & causes Myocarditis & AV block. Lev's disease= Idiopathic fibrosis of conduction system.