Administration of milrinone before ischemia, in the presence of beta-blockade, to treat metabolic impairment and myocardial stunning in pigs.

Abstract

BACKGROUND:

We examined effects of phosphodiesterase type III inhibition on regional myocardial metabolism and global left ventricular function, during ischemia, in the presence of beta-blockade.

METHODS:

Twenty-three pigs were randomized and studied to completion in four groups: C, did not receive drugs; M, received 50 microg/kg milrinone; E, received esmolol (150 microg/kg/min); E+M, received both. The left anterior descending artery (LADa) was then occluded for 15 min, followed by a 60-min reperfusion. Left ventricular (LV) function data obtained included LV pressures, cardiac output (CO), slope of end-systolic pressure-volume relationship (Emax), and dP/dT. Blood lactate concentrations were obtained from the aorta, LADa, and vein at baseline, end of occlusion, and during early (5 min) and late (1 h) reperfusion.

RESULTS:

During ischemia, occlusion produced significant depression in LV dP/dT, Emax and concomitant elevation of LVEDP that persisted over early reperfusion in groups not treated with milrinone. After ischemia, measurements of CO were higher, with lower LVEDP and SVR; LV dP/dT and the Emax were higher, with lower LVEDP in the E+M group vs. the E group. Ischemic region lactate extraction during ischemia was better with E group vs. C group. Esmolol without or with milrinone was associated with nonsignificant lactate ischemic production during early reperfusion from baseline values.

CONCLUSION:

We demonstrated that the pre-emptive administration of milrinone before ischemia was associated with less ischemic hemodynamic effects, without worsening the ischemic metabolic process. The combination E+M diminished ischemic metabolic impairment, and preserved left ventricular function and baseline hemodynamics.

• Authors: A Sidi, J D Muehlschlegel, D S Kirby, E B Lobato
• Journal: Acta anaesthesiologica Scandinavica (Acta Anaesthesiol Scand) Vol. 52 Issue 3 Pg. 397-405 (Mar 2008) ISSN: 1399-6576 [Electronic] England
• PMID: 18269389 (Publication Type: Journal Article)

Chemical References

• Adrenergic beta-Antagonists
• Cardiotonic Agents
• Propanolamines
• Lactic Acid
• Milrinone
• esmolol

Topics

• Adrenergic beta-Antagonists (pharmacology)
• Animals
• Blood Pressure (drug effects)
• Cardiac Output (drug effects)
• Cardiotonic Agents (pharmacology)
• Coronary Stenosis (complications)
• Disease Models, Animal
• Heart Rate (drug effects)
• Lactic Acid (metabolism)
• Milrinone (pharmacology)
• Myocardial Reperfusion
• Myocardial Stunning (drug therapy, etiology, metabolism)
• Propanolamines (pharmacology)
• Random Allocation
• Swine
• Time Factors
• Vascular Resistance (drug effects)
• Ventricular Dysfunction, Left (drug therapy, etiology)