Background: The PiCCO system provides different variables of cardiac function: the cardiac function index (CFI), the global ejection fraction (GEF) and the maximal pressure developed by the left ventricle (dP/dtMax). The purpose of this study was to investigate the ability of these variables to predict impaired left ventricular ejection fraction (LVEF) derived by transesophageal echocardiography during acute myocardial ischemia.
Methods: In this prospective experimental study, fifteen pigs (28-34 kg) were anesthetized, mechanically ventilated and subjected to left anterior descending (LAD) coronary artery occlusion. PiCCO-derived variables and LVEF were obtained 5, 10, 15, and 20 minutes after LAD occlusion. Receiver operating characteristics analysis was performed to assess the ability of PiCCO-derived parameters to estimate LVEF ≤40% and ≤50%.
Results: LAD occlusion induced a decrease in PiCCO-derived variables and LVEF (P<0.001 for each). Significant correlations were found between LVEF and CFI (r=0.59, P<0.001), GEF (r=0.64, P<0.001), dP/dtMax (r=0.36, P<0.001), and cardiac output (r=0.25, P=0.028). The area under the receiver operating characteristics curve for the estimation of LVEF ≤40% and ≤50% was 0.80 and 0.79 for CFI (P=0.009, P<0.001), 0.86 and 0.78 for GEF (P=0.002, P<0.001), 0.76 and 0.68 for dP/dtMax (P=0.033, P=0.012), and 0.57 and 0.58 for cardiac output (P=0.554, P=0.259).
Conclusion: Cardiac function indices permit the bedside quantification of left ventricular systolic function during acute myocardial ischemia in pigs. Therefore, the PiCCO system may represent a valuable technique for cardiovascular monitoring, particularly for detecting acute left ventricular systolic dysfunction due to myocardial ischemia.