Evaluation of left ventricular function in coronary bypass surgery

OBJECTIVES: To evaluate non-invasive indexes measuring systolic and diastolic ventricular function. Eleven coronary artery bypass grafting (CABG) patients were investigated in order to assess the ability of preoperative ejection fraction (EF) and end diastolic pressure (EDP) to predict left ventricular function determined non-invasively at surgery. DESIGN: End-systolic elastance (Ees) was assessed perioperatively using transoesophageal echocardiographic area estimation and arterial pressure monitoring during preload variations (caval balloon). Diastolic function was evaluated using three different echo/Doppler indexes. RESULTS: EF correlated positively to Ees (r = 0.69, p = 0.03). No correlations were found between EDP and the perioperative diastolic indexes. Ees fell from pre-bypass to post-bypass (from 9.0 +/- 2.7 to 4.7 +/- 1.7 mmHg/cm2, mean +/- SD, p < 0.001), but no alterations in diastolic parameters occurred. CONCLUSIONS: A positive correlation was found between preoperative EF and Ees at surgery. The semi-invasive Ees detected a systolic "stunning" after cardiopulmonary bypass and is promising as a surveillance tool for left ventricular perioperative function and treatment. No correlations between preoperative EDP and non-invasive diastolic indexes were found, and assessment of perioperative diastolic function needs further refinement.