Changes in biomechanical parameters during heart perfusion and after midazolam pre-medication--experimental pilot study.
BACKGROUND
Midazolam is a frequently used benzodiazepine in anaesthesiology and intensive care.


OBJECTIVE
The aim of pilot study was to monitor its effect during heart perfusion in the laboratory rat.


METHODS
The same groups of animals (n = 10). The 1(st) group was treated with midazolam in a dose of 0.5mg/kg i.p. The 2(nd) group was a placebo. After i.p. administration of heparine injection of 500 IU dose, the hearts were excised and perfused (modified Langendorf's method). Working schedule: stabilization/ischaemia/reperfusion proceed at intervals of 20/30/60 min. Monitored parameters in isolated heart: left ventricle pressure (LVP), end-diastolic pressure (LVEDP), contractility (+dP/dt(max)).


RESULTS
The treated hearts showed improved postischemic recovery, reaching LVP values of 92 +/- 6 % at the end of the reperfusion, placebo only 61 +/- 7 %. In placebo hearts LVEDP rose from 10.0 +/- 0.5 mmHg to 43 +/- 4 mmHg after, in treated animals only about 25 mmHg. The treated hearts improved +dP/dt(max) recovery during reperfusion to 91 +/- 8 %. These values were significantly greater than those obtained from the placebo hearts.


CONCLUSIONS
Positive changes in monitored parameters were found in this experimental pilot study. We conclude that the administration of midazolam in laboratory rats has a cardioprotective potential against ischemia-reperfusion induced injury.
Bartosikova
Lenka
L
Department of Physiology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic. bartosil@tunw.upol.cz
Necas
Jiri
J
Bartosik
Tomas
T
Frana
Petr
P
Pavlik
Martin
M
D000818:Animals; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008874:Midazolam / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D011229:Preanesthetic Medication; D051381:Rats; D017208:Rats, Wistar; D016277:Ventricular Function, Left / Q000187:drug effects
D006993:Hypnotics and Sedatives; D008874:Midazolam