Early signs of tamponade include tachycardia and elevated central venous pressure, followed by hypotension and decreased cardiac output. Beck’s triad describes the classic findings of jugular venous distention, muffled heart sounds, and hypotension. If a pulmonary artery catheter is present, the equalization of filling pressures may be evident with right atrial pressure = right ventricular end-diastolic pressure = pulmonary artery diastolic pressure = pulmonary artery wedge pressure = left ventricular end diastolic pressure. It should be noted that pressure equalization may not be evident postcardiac surgery because the pericardium has invariably been opened. Pulsus paradoxicus, the decrease in systolic blood pressure of greater than 10 to 15 mm Hg on inspiration, is also observed in tamponade. Pulsus paradoxicus is a result of systemic venous return during inspiration causing rapid right ventricular filling, which compresses and impairs left ventricular filling.