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Intravenous diltiazem worsens regional function in compromised myocardium
B J Leone1, D M Philbin, J J Lehot
1Nuffield Department of Anaesthetics, Oxford University, Radcliffe Infirmary, United Kingdom.
Anesthesia and Analgesia
|March 1, 1988
Summary
Intravenous diltiazem worsened regional myocardial dysfunction and reduced systolic shortening in a canine model with a constricted left anterior descending coronary artery (LAD). The drug also decreased cardiac output and left ventricular performance.
Area of Science:
- Cardiology
- Pharmacology
- Anesthesiology
Background:
- Regional myocardial dysfunction can occur during anesthesia.
- The effects of diltiazem on myocardial function under anesthesia are not fully understood.
Purpose of the Study:
- To assess the impact of intravenous diltiazem on regional myocardial function in a canine model with a critically constricted left anterior descending coronary artery (LAD).
Main Methods:
- A canine model was used with critical LAD constriction.
- Anesthesia was maintained with fentanyl, nitrous oxide, and halothane.
- Intravenous diltiazem was administered at doses of 0.1 mg/kg and 0.2 mg/kg, and its effects on regional dysfunction, systolic shortening, cardiac output, and LV dP/dtmax were measured.
Main Results:
- Diltiazem significantly worsened postsystolic shortening, indicating increased regional dysfunction.
- Systolic shortening in the LAD territory was substantially depressed and nearly abolished at higher diltiazem doses.
- Cardiac output and LV dP/dtmax were significantly decreased at the higher diltiazem dose.
Conclusions:
- Intravenous diltiazem significantly depresses regional systolic shortening and worsens myocardial dysfunction in areas with compromised blood supply.
- Diltiazem administration during anesthesia also leads to significant depression of overall left ventricular performance.