Effects of acute decrease in systemic afterload on accuracy of Doppler-derived left ventricular rate of pressure rise measurement in anesthetized patients.
OBJECTIVE
This study was designed to describe exactly the effects of acute decrease in systemic afterload on the accuracy of Doppler-derived left ventricular rate of pressure rise (LV DeltaP/Delta(t)) measurements compared with other routinely used indices of systolic function.


METHODS
Twelve patients scheduled for coronary artery bypass grafting were studied. After induction of anesthesia (T0), afterload was modified by incremental administrations of nicardipine (T1-4). At each step of the procedure, thermodilution-derived cardiac index, left ventricular (LV) fractional area change, and LV DeltaP/Delta(t) were measured, and systemic vascular resistances were calculated.


RESULTS
During the procedure, the systemic vascular resistances decrease averaged 13.4%. Systemic vascular resistances were correlated with LV DeltaP/Delta(t) (r = 0.843, P =.003) but inversely correlated with cardiac index (r = -0.782, P =.005) and LV fractional area change (r = -0.887, P =.003).


CONCLUSIONS
In conclusion, and inversely to cardiac index or LV fractional area change, LV DeltaP/Delta(t) does not overestimate LV contractility in the presence of an acute decrease in systemic afterload.
Broka
S M
SM
Department of Anesthesiology, University Clinics U.C.L. of Mont-Godinne, Yvoir, Belgium. broka@anes.ucl.ac.be
Dubois
P E
PE
Jamart
J
J
Joucken
K L
KL
D000368:Aged; D000758:Anesthesia; D018686:Anesthetics, Intravenous; D002302:Cardiac Output; D001026:Coronary Artery Bypass; D017548:Echocardiography, Transesophageal; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D013599:Systole / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*; D017725:Ventricular Pressure
D018686:Anesthetics, Intravenous