Characterization of the in vivo cardiac electrophysiologic effects of high-dose cocaine in closed-chest, anesthetized dogs with normal hearts

Characterization of the in vivo cardiac electrophysiologic effects of high-dose cocaine in closed-chest, anesthetized dogs with normal hearts

Author Fenelon, Guilherme Autor UNIFESP Google Scholar
Uchoa, Júlio Autor UNIFESP Google Scholar
Otobone, José Roberto Autor UNIFESP Google Scholar
Reis, Marcos Autor UNIFESP Google Scholar
Amaral, José Luiz Gomes do Autor UNIFESP Google Scholar
De Paola, Angelo Amato Vincenzo Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract OBJECTIVE: To characterize the cardiac electrophysiologic effects of cocaine. METHODS: In 8 dogs (9-13 kg), electrophysiologic parameters and programmed stimulation were undertaken using transvenous catheters at baseline, and after cocaine intravenous infusion (12 mg/kg bolus followed by 0.22 mg/kg/min for 25 minutes). RESULTS: Cocaine plasma levels (n=5) rose to 6.73± 0.56 mg/mL. Cocaine did not affect sinus cycle length and arterial pressure. Cocaine prolonged P wave duration (54±6 vs 73±4 ms, P<0.001), PR interval (115±17 vs 164±15 ms, P<0.001), QRS duration (62±10 vs 88±14 ms, P<0.001), and QTc interval (344±28 vs 403±62 ms, P=0.03) but not JT interval (193±35 vs 226±53 ms, NS). Cocaine prolonged PA (9±6 vs 23±8 ms, P<0.001), AH (73±16 vs 92±15 ms; P=0.03), and HV (35±5 vs 45±3ms; P<0.001) intervals and Wenckebach point (247±26 vs 280±28 ms, P=0.04). An increase occurred in atrial (138±8 vs 184± 20 ms; P<0.001) and ventricular (160±15 vs 187±25 ms; P=0.03) refractoriness at a cycle length of 300 ms. Atrial arrhythmias were not induced in any dog. Ventricular fibrillation (VF) was induced in 2/8 dogs at baseline and 4/8 dogs after cocaine. CONCLUSION: High doses of cocaine exert significant class I effects and seem to enhance inducibility of VF but not of atrial arrhythmias.
Keywords cocaine
electrophysiology
ventricular fibrillation
Language English
Date 2003-07-01
Published in Arquivos Brasileiros de Cardiologia. Sociedade Brasileira de Cardiologia - SBC, v. 81, n. 1, p. 29-34, 2003.
ISSN 0066-782X (Sherpa/Romeo)
Publisher Sociedade Brasileira de Cardiologia - SBC
Extent 29-34
Origin http://dx.doi.org/10.1590/S0066-782X2003000900002
Access rights Open access Open Access
Type Article
SciELO ID S0066-782X2003000900002 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/1776

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