Which of the following symptoms is NOT part of Beck's triad for cardiac tamponade?

Beck's triad for cardiac tamponade consists of hypotension, muffled heart sounds, and jugular venous distension. These signs are indicative of the underlying pathology associated with fluid accumulation in the pericardial space, leading to compromised cardiac function.

Hypotension occurs due to decreased cardiac output as the heart's diastolic filling is impaired. Muffled heart sounds arise from the sound-dampening effect of the fluid surrounding the heart, and jugular venous distension reflects elevated central venous pressure resulting from impeded venous return.

Pulsus paradoxus, although significant in cardiac tamponade, is not part of Beck's triad. It refers to a drop in blood pressure during inspiration and is not included in the classic triad. Bradycardia is not characteristic of cardiac tamponade, as the heart rate may actually vary; it does not reflect the hallmark signs related to cardiac compression due to fluid accumulation.

Thus, the symptom that is not part of Beck's triad is bradycardia.