Left ventricular TEI index: comparison between flow and tissue Doppler analyses and its association with postoperative atrial fibrillation in cardiopulmonary bypass surgery

Introduction

The TEI index (myocardial performance index), an indicator of combined ventricular systolic and diastolic function, is defined as the ratio of the sum of the isovolumic relaxation time and the isovolumic contraction time. The TEI index is independent of ventricular geometry, and is not significantly affected by heart rate or blood pressure. We sought to determine whether there was association with postoperative atrial fibrillation (AF) after cardiopulmonary bypass surgery.

Methods

We performed a preoperative and the postoperative first hour comparison between flow and tissue Doppler imaging analyses in patients who underwent cardiopulmonary bypass surgery. The Doppler sample volume was placed at the tips of the mitral leaflets to obtain the left ventricular inflow waveforms from the apical four-chamber view and just below the aortic valve to obtain the left ventricular outflow waveforms from the apical long-axis view, sequentially. All sample volumes were positioned with ultrasonic beam alignment to flow. Tissue Doppler imaging was obtained with the sample volume placed at the lateral and septal corner of the mitral annulus from the apical four-chamber view. We analyzed the mean of five consecutive measures. We compared the result according to the presence of postoperative atrial fibrillation. SPSS version 15 was used.

Results

We studied 166 patients, 50 (30.1%) women and 116 (69.9%) men, mean age 67 ± 1 years. Surgical procedures were 92 (55.4%) coronary artery bypass grafting, 55 (33.1%) valvular, 16 (9.5%) combined surgery and three (1.8%) other procedures. The onset of postoperative AF was 38 ± 5 hours. We observed a higher preoperative lateral-mitral tissue Doppler TEI index (0.87 ± 0.43 versus 0.68 ± 0.32, P = 0.017) and preoperative septal-mitral tissue Doppler (0.96 ± 0.45 versus 0.67 ± 0.31, P = 0.004) in patients who developed postoperative AF. The flow Doppler TEI index showed no differences between both groups. The postoperative tissue Doppler TEI index showed no differences: lateral-mitral, 0.76 ± 0.42 versus 0.71 ± 0.43 and septal-mitral, 0.76 ± 0.45 versus 0.78 ± 0.44, and the postoperative flow TEI index showed similar values, 0.66 ± 0.30 versus 0.64 ± 0.27.

Conclusion

Higher values of the preoperative tissue Doppler TEI index, which reflects a worse global ventricular function, were associated with postoperative AF.