Myocardial contractility impairment with racemic bupivacaine, non-racemic bupivacaine and ropivacaine. A comparative study.
OBJECTIVE
To study racemic bupivacaine, non-racemic bupivacaine and ropivacaine on myocardial contractility.


METHODS
Isolated Wistar papillary muscles were submitted to 50 and 100 mM racemic bupivacaine (B50 and B100), non-racemic bupivacaine (NR50 and NR100) and ropivacaine (R50 and R100) intoxication. Isometric contraction data were obtained in basal condition (0.2 Hz), after increasing the frequency of stimulation to 1.0 Hz and after 5, 10 and 15 min of local anesthetic intoxication. Data were analyzed as relative changes of variation.


RESULTS
Developed tension was higher with R100 than B100 at D1 (4.3 ± 41.1 vs -57.9 ± 48.1). Resting tension was altered with B50 (-10.6 ± 23.8 vs -4.7 ± 5.0) and R50 (-14.0 ± 20.5 vs -0.5 ± 7.1) between D1 and D3. Maximum rate of tension development was lower with B100 (-56.6 ± 38.0) than R50 (-6.3 ± 37.9) and R100 (-1.9 ± 37.2) in D1. B50, B100 and NR100 modified the maximum rate of tension decline from D1 through D2. Time to peak tension was changed with NR50 between D1 and D2.


CONCLUSIONS
Racemic bupivacaine depressed myocardial contractile force more than non-racemic bupivacaine and ropivacaine. Non-racemic and racemic bupivacaine caused myocardial relaxation impairment more than ropivacaine.
Department of Anesthesiology, Botucatu School of Medicine, Universidade Estadual de São Paulo, São Paulo, Brazil.
Matheus Fécchio
MF
Pinotti
Department of Anesthesiology, Botucatu School of Medicine, UNESP, Botucatu, SP, Brazil.
Adriana
A
Hepner
Department of Internal Medicine, Botucatu School of Medicine, UNESP, Botucatu, SP, Brazil.
Dijon Henrique Salomé
DH
Campos
Department of Anesthesiology, Botucatu School of Medicine, UNESP, Botucatu, SP, Brazil.
Leopoldo Muniz
LM
Silva
Department of Internal Medicine, Botucatu School of Medicine, UNESP, Botucatu, SP, Brazil.
Antonio Carlos
AC
Cicogna
Department of Anesthesiology, Botucatu School of Medicine, UNESP, Botucatu, SP, Brazil.
Eliana Marisa
EM
Ganem
D000577:Amides / Q000494:pharmacology*; D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D002045:Bupivacaine / Q000737:chemistry / Q000494:pharmacology*; D003864:Depression, Chemical; D008297:Male; D009129:Muscle Tonus / Q000187:drug effects / Q000502:physiology; D009200:Myocardial Contraction / Q000187:drug effects* / Q000502:physiology; D010210:Papillary Muscles / Q000187:drug effects / Q000502:physiology; D017208:Rats, Wistar; D012016:Reference Values; D000077212:Ropivacaine; D013237:Stereoisomerism; D013997:Time Factors
D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D002045:Bupivacaine