2025 – PAGE 128 – CARDIOLOGY

CONTINUOUS MURMURS

Continuous murmurs include:

• VENOUS HUM: This is a continuous, vibratory, right subclavicular murmur. It is present when sitting and resolves when supine or the head is turned. It is a benign murmur, so no interventions are needed.
• PATENT DUCTUS ARTERIOSUS(PDA): A continuous “machine-like” or “rumbling” murmur heard best below the left clavicle.

BOUNDING PULSE

A bounding pulse can be associated with aortic regurgitation (AKA aortic insufficiency) or large LEFT to RIGHT shunts, such as a patent ductus arteriosus (PDA) or truncus arteriosus.

WIDE PULSE PRESSURE

Subtracting the diastolic BP from the systolic BP gives you your pulse pressure. A pulse pressure of 33% – 50% of the systolic BP is normal, and anything over 50% of the systolic BP is considered wide. A wide pulse pressure can be noted in:

• Aortic regurgitation (AKA aortic insufficiency)
• Patent ductus arteriosus (PDA).
• MNEMONIC: Since these are “relatively valve-less” disorders, there is nothing to prevent backflow of the blood during diastole. This results in a very low diastolic blood pressure and wide pulse pressure!

CRANIAL BRUITS

Cranial bruits can be due to intracranial arteriovenous malformations. Watch out for signs of high output congestive heart failure (CHF).

CAROTID BRUITS

Carotid bruits are benign in children.

FIXED SPLIT S2

A fixed split S2 is almost always due to an Atrial Septal Defect (ASD). It occurs due to persistent L to R shunting, which results in persistently higher volumes across the pulmonary valve, and thus delayed closure.

WIDELY SPLIT S2

A widely split S2 can be found with a RBBB or Pulmonic Stenosis (PS). The normal A2—–P2 changes to A2———-P2 due to delayed closure of the pulmonic valve. The P2 is also softer than normal and may be missed, causing the S2 to sound single.

PARADOXICAL SPLIT OF S2

The paradoxical split of S2 occurs with a LBBB and Aortic Stenosis. S2 splits during EXPIRATION instead of inspiration. A2 is so delayed that it overlaps P2, resulting in a single S2 on inspiration. The S2 then splits on expiration.