Evaluation of a cardiac murmur

What it is

Timing comes first. Ejection systolic: AS, PS, ASD, HOCM. Pansystolic: VSD, MR, TR. Early diastolic: AR, PR. Mid-diastolic: MS, TS. Continuous, machinery: PDA. Said the other way, systolic heart sounds include aortic and pulmonic stenosis, mitral and tricuspid regurgitation, VSD and MVP; diastolic heart sounds include aortic and pulmonic regurgitation and mitral and tricuspid stenosis. Two mnemonics hold it: MR, TR and VSD are holosystolic — MR. TRiumphed over the VSD; MS and AR are diastolic — MS. ARrested in Diastole.

How it presents

AS: a crescendo then decrescendo ejection murmur at the right 2nd ICS radiating to the carotids, with parvus et tardus, a weak delayed pulse; from calcification in the elderly or a congenital bicuspid valve. MR: blowing holosystolic murmur at the apex, 5th ICS midclavicular line, radiating to the axilla, often with a thrill and a soft S1; an S3 with a soft S1 and a widely split S2 goes with worse MR. TR: blowing holosystolic murmur at the lower left sternal border that increases with inspiration, the Carvallo's sign. AR: decrescendo diastolic murmur at the left sternal border, best heard when the patient leans forward, with bounding pulses, wide pulse pressure, water hammer pulse, the Duroziez sign over the femoral arteries, and an Austin-Flint murmur. MS: opening snap and a low-pitched rumbling diastolic murmur at the apex, in the left lateral decubitus position. MVP: mid-to-late systolic click followed by a late systolic murmur at the apex. Where the murmur radiates is the next thing to note, and three directions carry most of the weight: aortic stenosis radiates to the carotid arteries, mitral regurgitation radiates to the left axilla with the patient in the left lateral recumbent position, and pulmonary stenosis radiates to the interscapular region. So a systolic murmur that radiates to the carotids is read as aortic stenosis, the same timing to the axilla is mitral regurgitation, and to the interscapular region it is pulmonary stenosis. Two more radiate toward the back and should not be taken for those: coarctation of the aorta gives a systolic murmur that is loud in the back, and with upper limb hypertension and a murmur between the scapulae the first answer is coarctation, while PDA gives a continuous murmur that can also radiate toward the back. Congenital lesions have their own murmur map, and what sits beside the murmur is what settles it:

• VSD: harsh pansystolic murmur at the LLSB, with a possible thrill and a loud P2 if there is pulmonary HTN.
• ASD: wide fixed split of S2 with a systolic ejection murmur in the pulmonary area, and a possible pulmonary flow murmur.
• PDA: continuous machinery murmur at the LUSB, with a bounding pulse and wide pulse pressure.
• Tetralogy of Fallot: harsh systolic murmur from the pulmonary stenosis component, with cyanosis and a boot-shaped heart on CXR.
• Transposition of the great arteries: usually no murmur and a single loud S2, with cyanosis in the newborn.
• Tricuspid atresia: holosystolic murmur related to the VSD, with cyanosis and LAD on ECG.
• Coarctation of the aorta: systolic murmur best heard at the back or scapula, or left infraclavicular, with a differential BP and radio-femoral delay.
• Congenital aortic stenosis: systolic ejection murmur at the RUSB radiating to the neck, with weak pulses and a delayed carotid upstroke.
• Pulmonary stenosis: systolic ejection murmur at the LUSB, with an ejection click and a possible RV heave.
• Ebstein anomaly: holosystolic murmur of TR with a loud S1, with cyanosis and WPW on ECG.
• TAPVR: variable murmur, and there may be a fixed split S2, with the snowman sign on CXR in the supracardiac type.