Continuous murmur is found in all, except -: (A) Mitral stenosis with mitral regurgitation, (B) Patent ductus aeriosus, (C) Rupture of sinus of Valsalva, (D) Systemic aeriovenous (AV) fistula
Answer is A. 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,20edition,pg no.1436