Question

In which of the following congenital heart disease of cats, a continuous murmur that is loudest at the left heart base and hyperkinetic femoral pulse are heard on auscultation?

• A. Patent ductus arteriosus
• B. Aortic insufficiency
• C. Endocardial fibroelastosis
• D. Vascular ring stricture

Hint:

A "continuous machinery murmur" coupled with "bounding/hyperkinetic femoral pulses" is a classic diagnostic signature for Patent Ductus Arteriosus (PDA) in both dogs and cats.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Patent Ductus Arteriosus (PDA) is a common congenital cardiac anomaly resulting from the failure of the fetal ductus arteriosus to close after birth, leading to a persistent shunt between the aorta and the pulmonary artery.

Step 2: Detailed Explanation:
The physiological consequences of a persistent PDA create highly characteristic clinical findings:
1. Continuous Murmur: Because the pressure in the aorta is consistently higher than that in the pulmonary artery during both systole and diastole, blood shunts continuously from left to right. This continuous flow produces a pathognomonic "machinery" or continuous murmur, which is heard loudest over the left cranial heart base.
2. Hyperkinetic Femoral Pulse: Due to the rapid runoff of blood from the aorta into the low-pressure pulmonary artery during diastole, the diastolic blood pressure drops significantly. This creates a wide arterial pulse pressure (systolic minus diastolic pressure), which clinically manifests as bounding or hyperkinetic femoral pulses (also known as "water-hammer" pulses).
Other options like aortic insufficiency, endocardial fibroelastosis, and vascular ring anomalies do not present with this specific combination of a continuous murmur and hyperkinetic pulses.
Therefore, these findings are diagnostic for PDA.

Step 3: Final Answer:
The congenital heart disease described is Patent ductus arteriosus, corresponding to option (A).