Intravenous diltiazem worsens regional function in compromised myocardium.
The effect of intravenous diltiazem on regional myocardial function was assessed in a canine model of critical constriction of the left anterior descending coronary artery (LAD). Maintenance anesthesia with fentanyl (1.5 micrograms.kg-1.min-1), 60% inspired nitrous oxide, and 0.7% inspired halothane resulted in regional dysfunction, measured as postsystolic shortening (20.6 +/- 10.7%), which was significantly worsened after 0.1 mg/kg (48.7 +/- 12.5%, P less than 0.05) and after 0.2 mg/kg (68.8 +/- 11.7%, P less than 0.05) intravenous diltiazem. Systolic shortening in the compromised LAD territory was substantially depressed after 0.1 mg/kg diltiazem (8.2 +/- 0.6% to 5.3 +/- 1.3%, P less than 0.05) and was essentially abolished after 0.2 mg/kg diltiazem (8.2 +/- 0.6% to 0.7 +/- 2.3%, P less than 0.05). At the higher dose of diltiazem, cardiac output was substantially decreased (1.37 +/- 0.23 L/min to 0.88 +/- 0.30 L/min, P less than 0.05) and LV dP/dtmax significantly depressed (1090 +/- 90 mm Hg/sec to 744 +/- 80 mm Hg/sec, P less than 0.05). These results demonstrate significant depression of regional systolic shortening and substantial worsening of regional dysfunction in myocardium with a compromised blood supply, in association with significant depression of left ventricular performance, with intravenous diltiazem administration during anesthesia.
Leone
B J
BJ
Nuffield Department of Anaesthetics, Oxford University, Radcliffe Infirmary, United Kingdom.
Philbin
D M
DM
Lehot
J J
JJ
Wilkins
M
M
Foëx
P
P
Ryder
W A
WA
D000769:Anesthesia, Inhalation; D000777:Anesthetics / Q000633:toxicity*; D000818:Animals; D003327:Coronary Disease / Q000503:physiopathology*; D004110:Diltiazem / Q000633:toxicity*; D004285:Dogs; D004347:Drug Interactions; D005283:Fentanyl / Q000633:toxicity; D006221:Halothane / Q000633:toxicity; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D007262:Infusions, Intravenous; D009609:Nitrous Oxide / Q000633:toxicity
D000777:Anesthetics; D004110:Diltiazem; D009609:Nitrous Oxide; D005283:Fentanyl; D006221:Halothane