The nurse is performing a cardiac assessment on a 65-year-old patient 3 days after her myocardial infarction (MI) . Heart sounds are normal when she is supine, but when she is sitting and leaning forward, the nurse hears a high-pitched, scratchy sound with the diaphragm of the stethoscope at the apex. It disappears on inspiration. What does the nurse suspect?

A) Another MI
B) Increased cardiac output
C) Inflammation of the precordium
D) Ventricular hypertrophy resulting from muscle damage

Inflammation of the precordium gives rise to a friction rub. The sound is high pitched and scratchy, similar to sandpaper being rubbed. A friction rub is best heard with the diaphragm of the stethoscope, with the person sitting up and leaning forward, and with the breath held in expiration. A friction rub can be heard any place on the precordium. Usually, however, the sound is best heard at the apex and left lower sternal border, which are places where the pericardium comes in close contact with the chest wall.