TABLE 7-4 ■ Extra Heart Sounds in Systole
Extra heart sounds in systole are of two kinds: and late systole.
1) early ejection sounds, and (2) clicks, most commonly heard in mid-
Early Systolic Ejection Sounds ll
I lull I
Early systolic ejection sounds occur shortly after the first heart sound, coincident with the opening of the aortic and pulmonic valves. They are relatively high in pitch, have a sharp, clicking quality, and are heard better with the diaphragm of the stethoscope. An ejection sound indicates cardiovascular disease.
An aortic ejection sound is heard at both base and apex and may be louder at the apex. It does not usually vary with respiration. An aortic ejection sound may accompany a dilated aorta or aortic valve disease, such as congenital stenosis or a bicuspid valve.
A pulmonic ejection sound is heard best in the 2nd and 3rd left interspaces. When the first heart sound, usually relatively soft in this area, appears to be loud, you may instead be hearing a pulmonic ejection sound. Its intensity often decreases with inspiration. Causes include dilatation of the pulmonary artery, pulmonary hypertension, and pulmonic stenosis.
Systolic clicks are usually due to mitral valve prolapse—an abnormal systolic ballooning of part of the mitral valve into the left atrium. The clicks are usually mid- or late systolic. Prolapse of the mitral valve is a common cardiac condition, affecting about 5% of the general population. It is now felt to have equal prevalence in men and women. The click is usually single, but more than one may be heard. A click is heard best at or medial to the apex but may also be heard at the lower left sternal border. It is high-pitched and heard better with the diaphragm. The click is often followed by a late systolic murmur, which usually represents mitral regurgitation—a flow of blood from left ventricle to left atrium. The murmur usually crescendos up to S2. Systolic clicks may also be of extracardial or mediastinal origin.
Auscultatory findings are notably variable. Most patients have only a click, some have only a murmur, and some have both. Findings vary from time to time and often change with body position. Several positions are recommended to identify the syndrome: supine, seated, squatting, and standing. Squatting delays the click and murmur; standing moves them closer to S^
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