Continuous murmur is found in -a) AS combined with ARb) Systemic A V fistulac) PDA with reversal of shuntd) Aortopulmonary windowe) Rupture of sinus valsalva
**Core Concept**
A continuous murmur is a type of cardiac murmur that is heard throughout systole and diastole, indicating continuous blood flow between two chambers of the heart or between the heart and a great vessel. This murmur is often associated with abnormal connections or communications between the heart and its surrounding vessels.
**Why the Correct Answer is Right**
Continuous murmurs are typically caused by abnormal connections between the aorta and a systemic artery or between the pulmonary artery and a pulmonary artery branch. These connections allow for continuous blood flow between the chambers, resulting in a continuous murmur. The correct answer, **Systemic A V fistula**, is a type of abnormal connection between the aorta and a systemic artery, which would lead to a continuous murmur.
**Why Each Wrong Option is Incorrect**
**Option A:** AS combined with AR would not typically produce a continuous murmur, as the murmur of AS is usually a harsh, crescendo-decrescendo systolic murmur, and the murmur of AR is typically a blowing, pansystolic murmur. The combination of these murmurs would not result in a continuous sound.
**Option C:** PDA with reversal of shunt would produce a continuous murmur, but it is not the most specific or correct answer. PDA typically produces a continuous murmur due to the abnormal connection between the aorta and pulmonary artery, but the reversal of shunt would not be a characteristic feature of this condition.
**Option D:** Aortopulmonary window would produce a continuous murmur, similar to a systemic A V fistula, but it is a more specific type of abnormal connection between the aorta and pulmonary artery.
**Option E:** Rupture of sinus Valsalva would not typically produce a continuous murmur, as this condition would more likely result in a systolic ejection murmur due to the turbulent blood flow.
**Clinical Pearl / High-Yield Fact**
Remember that continuous murmurs are often associated with abnormal connections or communications between the heart and its surrounding vessels. When encountering a continuous murmur, consider the possibility of a systemic A V fistula or other abnormal connections.
**Correct Answer:** B. Systemic A V fistula