Raised International Normalized Ratio: An Early Warning for a Late Cardiac Tamponade?

Seven consecutive cases of late cardiac tamponade after valvular surgery are reported; all were postoperatively treated with acenocoumarol and 6 had an international normalized ratio peak greater than 6.0 within 3 days preceding tamponade. It is suggested that during this excessive anticoagulation state a hemorrhagic event within the pericardial space precipitates the tamponade. In addition, it is proposed that all valve patients with a postoperative international normalized ratio peak greater than 5.0 within 6 weeks postoperatively should be considered for a transthoracic echocardiogram.