TITLE: REAL-TIME VS OFF-LINE EVALUATION OF INTRAOPERATIVE REGIONAL WALL MOTION ABNORMALITIES (RWMA) WITH TRANSESOPHAGEAL ECHOCARDIOGRAPHY (TEE) DURING DOBUTAMINE STRESS TEST

AUTHORS: Louis Bolduc, MD, Pierre Couture, MD, Jean- Claude Tardif, MD, Andre Denault, MD, Michel Pellerin, MD, Jean-François Hardy, MD
AFFILIATION: Montreal Heart Institute, Montreal, Quebec, Canada.

INTRODUCTION: Stress TEE using dobutamine (dobu) in anesthetized patients could be useful to stratify cardiac risk in patients undergoing urgent non-cardiac surgery or to assess the results of a CABG (1) provided RWMA can be detected on-line in the OR. We compared real-time vs off-line interpretations of RWM during dobu infusion.
METHODS: Twelve patients scheduled for elective CABG were enrolled. Hemodynamic data, ST segment (D2-V5), and TEE were recorded. After anesthesia, dobu infusion was started at 10 mg• kg^-1• min^-1 and increased to 20-30 and 40 mg• kg^-1• min^{- 1} at 3 min intervals. Hemodynamic data and TEE were recorded at the end of each level and 5min after the infusion. End-points for stopping dobu were: 1mm ST depression, reaching sub- maximal heart rate, ventricular arrythmia, systolic pressure>180mmHg, diastolic pulmonary artery pressure >20mmHg or TEE detection of new RWMA. Real-time analysis of TEE images was performed using 16 ventricular segments (2). Off-line analysis was done several weeks later by the same investigator blinded to real-time results RWMA was assessed according to a 4 point scale (normal=I hypokinesis=II, akinesis=III, dyskinesis=IV) and related RWMA was defined as change in one segmental score. Chi-square was used for data analysis.
RESULTS: Baseline images and those obtained at peak dose of dobu were included. 384 segments were analyzed of which 14 were excluded due to inadequate imaging. Ten of 12 patients had ischemia detected by ST segment and/or TEE analysis. More segments were graded as normal with the real-time analysis and more segments were considered hypokinetic when analyzed off- line, both during baseline and at peak dobu dose (table 1). More segments differed by one grade or more between assessments at peak dobu dose compared to baseline (53/184 vs 35/186) (P< 0.05).

* P< 0.05, **P<0.01when compared to real-time analysis

DISCUSSION: Real-time analysis overestimated the number of segments with normal RWM and underestimated the number of hypokinetic segments compared to the off-line analysis. This discrepancy was greater at peak dobu dose when new RWMA are more likely to occur.
REFERENCES:

1.)Anesth Analg 1995;80:S422.

2.) J Am Soc Echocardiogr 1989;2:358-67.