Transesophageal Echocardiography for Monitoring Segmental Wall Motion During Off-Pump Coronary Artery Bypass Surgery

In Brief In this prospective, observational study, we evaluated whether transesophageal echocardiography allows for monitoring left ventricular segmental wall motion during cardiac displacement for off-pump coronary artery bypass (OPCAB) surgery. On the basis of a pilot study that showed frequent loss of transgastric views during OPCAB surgery, we analyzed only midesophageal views. The midesophageal 4-chamber view, 2-chamber view, and long-axis view were recorded in 60 patients after opening the chest and placing an epicardial stabilizer on the displaced heart. Using the 16-segment model, 2 echocardiographers independently performed offline analysis of segmental wall motion. The percentage of patients in whom ≥14 left ventricular segments were readable was calculated at baseline and after cardiac displacement and placement of an epicardial stabilizer. At baseline, ≥14 segments were readable in 59 (98%) of 60 patients. After cardiac displacement, ≥14 segments were readable during 58 (76%) of 76 revascularizations of the left anterior descending coronary artery (P < 0.01 versus baseline), during 33 (83%) of 40 revascularizations of the left circumflex coronary artery (P < 0.01 versus baseline), and during 29 (94%) of 31 revascularizations of the right coronary artery (not significant). We conclude that the number of readable segments decreased after cardiac displacement but that availability of ≥14 readable segments allowed for reliable monitoring of segmental wall motion in 4 of 5 patients during OPCAB surgery. IMPLICATIONS: Our study found that transesophageal echocardiography provided reliable visualization of left ventricular segmental wall motion during off-pump coronary artery bypass surgery in most patients—a prerequisite for echocardiographic monitoring for ischemia. Future studies are needed to evaluate whether such monitoring improves patient outcome.