Effects of halothane and isoflurane on left ventricular diastolic function during surgical stress in patients with coronary artery disease.
BACKGROUND
The effects of inhalation anesthetics on left ventricular (LV) systolic function are well documented, while the effects of these agents on LV diastolic function have mainly been evaluated in animal studies, with conflicting results.


METHODS
We investigated the effects of halothane and isoflurane, when used to control the stress response to sternotomy in 33 patients with coronary artery disease (CAD). LV early diastolic relaxation and end-diastolic stiffness were evaluated from mitral Doppler flow profiles, transesophageal two-dimensional echocardiography, and central hemodynamic measurements. Measurements were performed a) after induction of anesthesia, b) after volume loading, c) prior to surgery and d) during surgery, 10 min after introduction of the inhalation anesthetic. The effects of the anesthetics on Doppler indices reflecting early diastolic relaxation, and on the left ventricular end-diastolic pressure-area (LVED P/A) relationship, were studied.


RESULTS
When data obtained during surgical stress were compared to the control situation, we found an increase in the LV filling pressures in both groups, while only the isoflurane group showed an increase in heart rate. An increase in end-systolic LV area and decreased fractional area change was present in the halothane group, while an increase in LV end-diastolic area, and similar changes in the mitral Doppler indices (decreases of deceleration rate and time of early diastolic filling), indicating an impairment of early diastolic relaxation, was present in both groups. Isoflurane induced a displacement of the LVED P/A relationship leftwards from the baseline LVED P/A curve.


CONCLUSIONS
Both halothane and isoflurane impair early diastolic relaxation in patients with CAD, when used to control intraoperative surgical stress. In contrast to halothane, isoflurane induced a change in the LVED P/A relationship, suggestive of an increased LVED stiffness.
Houltz
E
E
Department of Anesthesia, Sahlgrenska University Hospital, Gothenburg, Sweden.
Caidahl
K
K
Adin
C
C
Gustavsson
T
T
Ricksten
S E
SE
D000328:Adult; D000368:Aged; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D003327:Coronary Disease / Q000503:physiopathology*; D003971:Diastole / Q000187:drug effects*; D004452:Echocardiography; D005260:Female; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D007530:Isoflurane / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D013249:Sternum / Q000601:surgery; D016277:Ventricular Function, Left / Q000187:drug effects*
D018685:Anesthetics, Inhalation; D007530:Isoflurane; D006221:Halothane