Let us tune in on the acoustic events at the upper left sternal edge by tuning out those prominent murmurs. At the time of the first sound, listen carefully to the acoustic events and pay particular attention to the character of the second heart sound. We'll again use the diaphragm of the stethoscope, we'll use the carotid vessel for timing of systole... Everyone listen together.[Cut-away]
What we heard at the upper left sternal edge was a prominent ejection sound. The ejection sound occurs just after the first heart sound. It is high in frequency and as the patient breathed out, the ejection sound became more prominent. The cause of this is related to the dilated pulmonary artery. As the pulmonary valve opens up in that larger pulmonary artery. We also heard another very important acoustic event, and that was the second heart sound. It wasn't [sounds], it was [sounds]. A very prominent second sound, undoubtedly in the context of our patient, a loud pulmonary sound due to significant pulmonary hypertension.
Osciloscopic image
By viewing an oscilloscopic image and simultaneously listening, we can further appreciate these auscultatory events.
Ejection sounds (ES)
Ejection sounds are early systolic, high-frequency events that occur at the onset of systolic flow into the great vessels and are best heard at the aortic and pulmonary areas. They result from doming of a stenotic but mobile semilunar valve or from the initial systolic distention of a dilated great vessel. In general, aortic ejection sounds are best heard at the upper right sternal edge, while pulmonary ejection sounds are best heard at the upper left sternal edge. A pulmonary ejection sound may diminish with inspiration, as in our patient.
Differentiate ES
One must differentiate ejection sounds from other heart sounds that occur near the time of the first heart sound. Split first heart sounds are best heard at the lower left sternal edge, are more closely apposed, and are of similar high frequency. Fourth heart sounds are best heard at the apex and lower left sternal edge, precede the first heart sound and are low in frequency. Systolic clicks are best heard at the apex and lower left sternal edge, occur later during systole and are of similar high frequency.
Loud pulmonary sound
A loud pulmonary second sound suggests pulmonary hypertension with a dilated pulmonary artery. The pulmonary sound often fuses with and obscures the aortic second sound, so that the second sound is single.