Real-time compared to off-line evaluation of segmental wall motion abnormalities with transesophageal echocardiography using dobutamine stress testing

Abstract

Objective: To compare real-time (on-line) monitoring of myocardial ischemia with transesophageal echocardiography (TEE) with off-line reviewing during a dobutamine stress test in patients undergoing coronary artery bypass grafting (CABG).

Design: Prospective observational study.

Setting: Tertiary care university hospital.

Patients: Seventeen patients undergoing CABG.

Interventions: TEE and electrocardiographic monitoring of myocardial ischemia during dobutamine stress testing.

Measurements and main results: Sixteen of 17 patients developed myocardial ischemia as diagnosed by TEE or electrocardiographic monitoring. On-line and off-line TEE detected myocardial ischemia in 11/17 and 12/17 patients, respectively. In total, 532 myocardial segments were analyzed at baseline and at peak dobutamine dose. The concordance between on-line and off-line assessments of segmental wall motion was poor at baseline and at peak dobutamine dose (κ = 0.28 and 0.29, respectively). The concordance for detecting myocardial ischemia (worsening in regional wall motion by ≥1 class or a biphasic response in any segment) was better between on-line and off-line analysis (κ = 0.60). There was no agreement between ST-segment monitoring and on-line TEE (κ = -0.27) and between 12-lead electrocardiogram and on-line TEE (-0.11). There was no agreement between ST-segment monitoring and off-line TEE (κ = -0.15) and between 12-lead electrocardiogram and off-line TEE (κ = -0.27).

Conclusions: Only a fair agreement exists between on-line and off-line analysis of myocardial ischemia during dobutamine stress testing in patients undergoing CABG. However, TEE misses up to one third of ischemic episodes and the present observations suggest using continuous electrocardiographic methods to complement TEE monitoring.