ECHOCARDIOGRAPHIC EVALUATION OF GLOBAL LEFT-VENTRICULAR FUNCTION DURING HIGH THORACIC EPIDURAL-ANESTHESIA

Objectives: To assess the effects of high thoracic epidural anesthesia on left ventricular (LV) diastolic filling and systolic function in p atients without heart disease. Design: Prospective study. Setting: Uni versity hospital. Participants: 24 ASA physical status I and II patien ts scheduled for elective noncardiac surgery. Interventions: Patients received high thoracic (HTE; n = 12) or low thoracic (LTE; n = 12) epi dural anesthesia. Measurement and Main Results: Left ventricular diast olic filling was noninvasively determined by precordial echocardiograp hy using a pulsed Doppler technique and with a newly developed acousti c quantification (AQ) method that automatically detects endocardial bo rders and measures cavity area. All measurements were performed in awa ke premedicated patients. In the HTE group, the extent of sensory bloc kade of T-1-T-5, at the least, was induced with 2% lidocaine 5 ml. Dur ing HTE, systolic blood pressure (119 +/- 16 vs. 108 +/- 14 mmHg, p < 0.01), heart rate (73 +/- 9.8 vs. 63 +/- 6.8 beats/min, p < 0.01), car diac output (CO; 4.5 +/- 1.1 vs. 3.8 +/- 1.2 L/min, p < 0.05), and fra ctional area change (50 +/- 11 vs. 37 +/- 11%, p < 0.01) decreased sig nificantly, whereas end diastolic area (9.4 +/- 1.4 vs. 10.3 +/- 1.1 c m(2) p < 0.01) and end systolic area (4.8 +/- 1.3 vs. 60 +/- 1.1 cm(2) , p < 0.05) showed a significant increase. As a result, stroke volume was kept constant (63 +/- 14 vs. 60 +/- 19 ml). Pulsed Doppler derives indices such as peak velocity during the early filling (E) and the at rial contraction (A) phases, peak early to atrial velocity ratio (E/A) , and acceleration time remained unchanged. AQ derived peak dA/dt duri ng the early diastolic (D1) and the atrial contraction phases (D2) and D1/D2 also remained unchanged. In contrast, in the LTE group, no sign ificant differences were noted in all systolic and diastolic indices o btained by poised Doppler and AQ method. Conclusions: High thoracic ep idural anesthesia causes a decrease in CO without changing LV ejection and diastolic filling performance in healthy subjects. (C) 1997 by El sevier Science Inc.