Case 5 Cardiology

Extra Heart Sound

Work it one clue at a time. The diagnosis stays hidden until you reveal it.

Clue 1

So you hear an extra heart sound. Now what? First: Is the extra sound near S1 or S2? Each scenario is associated with a different differential. Listen to this clip. Is the extra sound here near S1 or S2?

Clue 2

Not sure you hear three sounds? To orient you, listen to normal S1 and S2. There are two sounds here.

Clue 3

Back to our patient. So is the extra sound near S1 or near S2? It is near S2. What is the differential? DDx: Split S2 S3 gallop Opening snap Pericardial knock Tumor plop Persistently split S2 and S3 gallop are most common. Let’s start there. How do you distinguish them? Split S2: best heard over BASE, with DIAPHRAGM, closer to S2 S3: best heard over APEX, with BELL, further from S2 Take a listen to this clip. There is an extra sound near S2. What is it? It is heard over the base of the heart with the diaphragm of the scope (see key in top left of video).

Clue 4

Back to our patient. So is the extra sound near S1 or near S2?

Clue 5

It is near S2. What is the differential?

DDx: Split S2, S3 gallop, Opening snap, Pericardial knock, Tumor plop

Persistently split S2 and S3 gallop are most common. Let’s start there. How do you distinguish them?

Split S2: best heard over BASE, with DIAPHRAGM, closer to S2.

S3: best heard over APEX, with BELL, further from S2.

Take a listen to this clip. There is an extra sound near S2. What is it? It is heard over the base of the heart with the diaphragm of the scope (see key in top left of video).

Clue 6

This is a persistently split S2. (S1 is also split.)

What about the the opening snap? It occurs further from S2 than the split S2, but closer to S2 than the S3 gallop and pericardial knock. It is best heard with the diaphragm and closer to the apex. Take a listen in this patient with severe mitral stenosis:

Clue 7

What about the the pericardial knock? It occurs outside the range for a split S2 and the OS of mitral stenosis, but not as far from S2 as an S3. It is best heard with the diaphragm over the LLSB/apex. Take a listen in this patient with constrictive pericarditis:

Clue 8

So back to our patient. What is the extra sound? Orienting yourself to the cardiac cycle is critical. Is the sound near S1 or near S2? How far from S2 is the sound? Is it high- or low-pitched? Is it best heard over the base or apex?

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