Perioperative echocardiographic evaluation of cardiovascular function: assessment of changing hemodynamic state.

Abstract

To evaluate echocardiographic assessment of ventricular function in a changing hemodynamic situation, 20 infants and children undergoing open heart surgery were examined preoperatively and 1,4 and 24 hours postoperatively by this technique. Clinical evaluation and measurements of cardiac output were obtained simultaneously with each echocardiogram. On the basis of their clinical course and cardiac output, the patients were divided into two groups: group 1 - cardiac index > 2.3 1/min/m2 without inotropic support (n = 9); and group 2 - cardiac index less than or equal to 2.3 1/min/m2 and/or need for inotropic support (n = 11). Of the echocardiographic measurements obtained, the left ventricular systolic time interval ratio (left ventricular preejection period/left ventricular ejection time ([LVPEP/LVET] correlated significantly with the clinical course, separating the two groups of patients completely at each determination. The aortic root velocity (AoV), a new index defined as the anterior excursion (in degrees) of the aortic root from the horizontal plane with systole, also correlated with the clinical course, although this was not statistically significant. Serial change in LVPEP/LVET and AoV crrrelated with changes in clinical status and cardiac output for individual patients. Using a formula based on the opening slope of the mitral valve, echocardiographic estimations of cardiac output correlated well with those determined by dye dilution. The results indicate that selected echocardiographic indexes can be used for serial assessment of cardiac performance in patients with a changing hemodynamic state.