Which of the following findings is indicative of cardiac tamponade?

Cardiac tamponade is a condition characterized by the accumulation of fluid in the pericardial space, leading to increased pressure on the heart. One of the hallmark findings of cardiac tamponade is a narrow pulse pressure, which is the difference between systolic and diastolic blood pressure. When the heart is compressed, its ability to fill and eject blood is compromised, often resulting in a reduced stroke volume. This reduced volume leads to a lower systolic blood pressure while diastolic blood pressure may remain relatively stable, thereby narrowing the pulse pressure.

In addition, the other findings mentioned do not point to cardiac tamponade. Elevated troponin levels can indicate myocardial injury but are not specific for tamponade. Increased cardiac output would be unlikely in this condition due to the impaired ventricular filling and contraction. A wide QRS complex generally points to conduction abnormalities or ventricular problems, which are not directly indicative of cardiac tamponade. Thus, the presence of a narrow pulse pressure is a significant clinical indicator of cardiac tamponade.