Final answer:
Muffled or distant heart sounds during a physical assessment would indicate the presence of cardiac tamponade in a patient with acute pericarditis. Cardiac tamponade is diagnosed using auscultation and is due to excess fluid within the pericardial space that impedes the heart's ability to relax and fill.
Step-by-step explanation:
The assessment finding that indicates the presence of cardiac tamponade in a client with acute pericarditis would be muffled or distant heart sounds. Cardiac tamponade occurs when excess fluid, usually blood, accumulates within the pericardial cavity, putting pressure on the heart and impairing its ability to relax and fill with blood properly. This reduces the amount of blood ejected from the heart during each cycle.
Diagnosis often involves auscultation using a stethoscope. In the context of auscultation, muffled heart sounds can suggest the presence of fluid in the pericardial cavity dampening the sounds made by the heart beating, which is consistent with cardiac tamponade.
Other potential signs of cardiac tamponade, which are not mentioned in this question, might include jugular venous distension (not flat neck veins), tachycardia (not a pulse rate of 60 beats/minute), and pulsus paradoxus. Wheezing on auscultation of the lungs does not specifically indicate cardiac tamponade but rather a pulmonary issue such as asthma or other lung pathology.