2025 – PAGE 125 – CARDIOLOGY

AV CANAL DEFECT

In AV canal defect, there is a left to right shunt. The condition refers to the presence of both an ASD and a VSD. This has a strong association with DOWN SYNDROME (Trisomy 21) and DIGEORGE SYNDROME. Physical exam findings include a LOUD S1 AND S2 and possibly a HOLOSYSTOLIC APICAL MURMUR (due to either the associated mitral regurgitation or due to regurgitation at the combined AV valve). Increased pulmonary flow results in BIVENTRICULAR HYPERTROPHY (BVH). The EKG shows BVH + LAD, and the CXR shows the increased pulmonary vasculature and BVH (or RVH + “cardiomegaly”).

IMAGE: www.pbrlinks.com/AVCANAL1

AV CANAL DEFECT & VSD

Both AV canal defects and VSDs are left to right shunts and can present with symptoms of CONGESTIVE HEART FAILURE (CHF) after a few weeks or months.

MURMURS & SPLITS

PATHOLOGIC MURMURS

The following terms are usually used to refer to a high-grade, or pathologic murmur. If any of these are included in an ABP vignette, a “wait and watch” approach is probably not the answer:

• Click
• Harsh
• Grade III, or “loud”
• Diastolic
• Pansystolic
• Late systolic
• S4 or 4^th heart sound
• S3 or 3^rd heart sound that remains after changing positions from supine to sitting.

MURMUR TERMINOLOGY

• RUSB = Right 2^nd intercostal space = 2^nd RICS
• LUSB = Left 2^nd intercostal space = 2nd LICS
• LLSB = Left 4^th intercostal space = 4^th LICS
• APICAL: Left 4^th intercostal space near the apex = 4^th LICS near the apex

PEARLS:

• • “STENOSIS” murmurs generally start in the middle of a cycle (mid-systolic or mid-diastolic). Stenotic means something is only “half” way open!
  • “REGURGITATION” murmurs generally start at the beginning of a cycle (early systolic or early diastolic). Mitral valve prolapse is an exception (this is different from MV regurgitation).

MNEMONICS:

• • PASS = Pulmonary/Aortic Stenosis is Systolic
  • PAID = Pulmonary/Aortic Insufficiency is Diastolic
  • Opposite is true for Mitral/Tricuspid valves