After CABG, what is the most concerning hemodynamic sign that may indicate cardiac tamponade?

Following coronary artery bypass grafting (CABG), cardiac tamponade is a potential complication that can compromise hemodynamics. Low blood pressure is a critical sign indicating that the heart may not be pumping effectively, which can be due to external compression caused by fluid accumulation in the pericardial space. When cardiac tamponade occurs, the heart's ability to fill properly during diastole is impaired, leading to decreased stroke volume and consequently lower cardiac output. This manifests as hypotension rather than simply a low heart rate or respiratory complications.

Additionally, low blood pressure is often accompanied by other signs of inadequate systemic perfusion, such as altered mental status or peripheral cyanosis, making it a particularly concerning indicator in this post-operative context. Prompt recognition and treatment of low blood pressure are essential to prevent further complications and stabilize the patient.