Substernal epicardial echocardiography: A new ultrasonic window to the postoperative heart

Echocardiographic examination of the postoperative cardiac surgery patient is often problematic because of a poor acoustic window that requires imagin g by transesophageal echocardiography. Furthermore, no available echocardio graphic methods exist for simple ongoing beat-to-beat assessment of postope rative left ventricular size and function. We designed a modification of a mediastinal drain to allow a transesophageal echocardiography probe to be p laced adjacent to the epicardial surface of the heart. After chest closure in a series of 13 patients, we were able to obtain 5- and 7-MHz epicardial images of high quality in both short- and long-axis planes, which also allo wed Doppler examination of aortic, mitral, and tricuspid valves in 10 patie nts. This technique was suitable for prolonged and serial assessment of lef t ventricular size and function. Though preliminary, these observations sug gest that this new substernal epicardial echocardiographic window to the po stoperative heart offers a potential for prolonged monitoring of cardiac fu nction as well as rapid and accurate diagnosis in problematic patients.