Doppler tissue velocity, strain, and strain rate imaging with transesophageal echocardiography in the operating room: a feasibility study.

OBJECTIVE: Transesophageal echocardiography (TEE) is increasingly used to monitor regional myocardial function during cardiac operation. Doppler myocardial imaging (DMI) indices can potentially provide new information on regional radial and longitudinal myocardial motion and local deformation. This study examined the feasibility of TEE acquisition of regional radial and longitudinal velocity, displacement (D), strain, and strain rate data during cardiac operation and evaluated the effects of sternotomy and pericardial opening on these indices.
METHODS: After a baseline transthoracic echocardiographic study, TEE was performed in 22 patients (age 64 +/- 7 years) before sternotomy, after sternotomy with intact pericardium, and after pericardial opening. Regional DMI velocity analysis was performed for the transgastric anterior and inferior walls midpapillary segment (radial function) and the 4-chamber septum and 2-chamber inferior walls basal, mid, and apical segments (longitudinal function). For each segment, systolic and diastolic velocity were derived and D, strain, and strain rate calculated.
RESULTS: Transthoracic echocardiographic study and TEE provided similar data from an equivalent number of interpretable segments. In the basal and mid septum, maximum longitudinal systolic D decreased with pericardial opening (basal septum pericardium closed: 6.6 +/- 1.5 mm, open: 4.6 +/- 1.8 mm, P =.007; midseptum pericardium closed: 4.7 +/- 2.5 mm, open: 2.7 +/- 1.5 mm, P =.028). No changes were evident in systolic or diastolic DMI indices in all other segments.
CONCLUSION: DMI with TEE is feasible during cardiac operation. During pericardial opening, longitudinal D decreases in the septum, but not in the inferior wall. DMI requires further evaluation in the assessment of ventricular function and the detection of ischemia in the operating room.