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
Continuous murmur is found in- 
Select and explain. 
A. Cardiomyopathy, B. Systemic A V fistula, C. Mitral stenosis, D. cardiac tamponade
B: Systemic A V fistula
Answer: B: Systemic A V fistula 
Explanation: A continuous murmur is predicated ona pressure gradient that persists betweentwo cardiac chambers or blood vesselsacross systole and diastole. The murmurstypically begin in systole, envelop thesecond hea sound (S 2 ), and continuethrough some poion of diastole. Theycan often be difficult to distinguish fromindividual systolic and diastolic murmursin patients with mixed valvular hea disease.The classic example of a continuousmurmur is that associated with a patentductus aeriosus, which usually is heardin the second or third interspace at a slightdistance from the sternal border. Othercauses of a continuous murmur includea ruptured sinus of Valsalva aneurysmwith creation of an aoic-right atrialor right ventricular fistula, a coronaryor great vessel aeriovenous fistula, andan aeriovenous fistula constructed toprovide dialysis access. Harrison's principle of internal medicine,20 edition,pg no.1445