Echocardiographic assessment of ventricular performance following induction with two anesthetics

Echocardiographic studies were made of 20 healthy patients scheduled for minor surgical procedures to determine whether this technique could be used routinely in the operating room and to evaluate the effects of halothane and enflurane on left ventricular performance. Thirteen minutes following induction of anesthesia with halothane in ten patients (mean end-tidal halothane concentration 0.93 per cent), mean arterial blood pressure, left ventricular (LV) diastolic dimension, LV fractional shortening, mean velocity of circumferential fiber shortening and systolic thickening of the posterior LV wall were significantly decreased. LV systolic dimension was increased significantly. These data indicate that halothane caused decreased contractility in the presence of a decreased afterload. Twelve minutes following induction of anesthesia with enflurane in ten patients (mean delivered enflurane concentration 2.4 per cent), mean arterial blood pressure and LV systolic and diastolic dimensions were decreased, while heart rate was increased significantly, indicating that enflurane caused vasodilatation and may have had some depressant effect on contractility. Echocardiography is a non-invasive, safe and relatively rapid method that can be used in the perioperative period to assess cardiac function and to evaluate the effects of pharmacologic agents on the heart.