Effects of propafenone associated with propofol on myocardial contractility, heart rate, coronary flow, and the incidence of arrhythmia in isolated hearts of rats.
OBJECTIVE
To study the influence of propafenone associated with propofol on myocardial contractility (dP/dt and heart rate), coronary flow, and the incidence of arrhythmia in isolated rat hearts.


METHODS
Forty albino rats were anesthetized with sulfuric ether, a modified Langendorff method was performed, and the rats were fed with Krebs-Henseleit (K-H) solution, (95% O2, 5% CO2, pH 7.4+/-0.1, perfusion pressure between 90 and 100cm of water, and temperature 37+/- 0.5 masculine C). Control records were obtained after a stabilization period and rats were distributed into the following 4 groups: I (control), II (100mcg propafenone), III (25mcg propofol), and IV (propafenone-propofol).


RESULTS
A decrease (P<0.05) in the heart rate in groups II and IV was observed, with a greater decrease in group II. A decrease was noted in the dP/dt ratio (P< 0.05) in groups II and IV, during all periods. Group III experienced depression from the 1st to the 3rd minute. Coronary flow had a decrease (P<0.05) in all groups, compared with the control group, especially in group IV with a decrease from 14mL/min to 11mL/min. Arrhythmogenic effects of propafenone (pro-arrhythmia) were verified in 50% of group II. In the association with propofol (group IV), no significant difference occurred, and arrhythmias (pro-arrhythmic effect) were observed in 40% of the hearts.


CONCLUSIONS
The association propafenone-propofol was not harmful to the use of propafenone solely, regarding the effects observed in myocardial contractility, coronary flow, and in the incidence of arrhythmias.
Assis
Nilcéa Leal de Moraes
NL
Serviço do Coração, Fundação Cardiovascular São Francisco de Assis, Belo Horizonte, MG, Brasil. nilcealm@cardiol.br
Gomes
Otoni Moreira
OM
Garcia
Silvério Leonardo Macedo
SL
do Valle
Guilherme Gustavo
GG
D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D003326:Coronary Circulation / Q000187:drug effects; D004338:Drug Combinations; D004347:Drug Interactions; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D011405:Propafenone / Q000008:administration & dosage / Q000494:pharmacology*; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D018686:Anesthetics, Intravenous; D000889:Anti-Arrhythmia Agents; D004338:Drug Combinations; D011405:Propafenone; D015742:Propofol