Key result
Combined infusion of lidocaine and propafenone reversed the prolongation in atrial and ventricular refractoriness produced by propafenone alone, with mild additive negative inotropic effects.
Why the study?
Does the combined infusion of lidocaine and propafenone alter hemodynamic and electrophysiologic parameters compared to either drug alone in patients with ventricular arrhythmia?
Does the combined infusion of lidocaine and propafenone alter hemodynamic and electrophysiologic parameters compared to either drug alone in patients with ventricular arrhythmia?
The combination of lidocaine and propafenone attenuates the electrophysiologic refractoriness prolongation seen with propafenone alone, potentially altering its antiarrhythmic efficacy, while causing additive negative inotropic effects.
Answers are grounded in this paper and cite their sources.
May blunt propafenone's refractoriness effects with additive negative inotropy; leaves open impact on antiarrhythmic efficacy.
The hemodynamic and electrophysiologic effect of a combined intravenous infusion of lidocaine (100 mg bolus followed by 2 mg/min infusion) and propafenone (1 or 2 mg/kg) in patients with a history of ventricular arrhythmia was studied. Lidocaine infusion alone significantly increased the mean pulmonary artery (+28%) and pulmonary capillary wedge (+17%) pressure, with no effect on cardiac index. Lidocaine alone produced no consistent change in any measured electrophysiologic parameter, except slight QTc shortening (-2%, P less than .05). Propafenone alone, particularly at the higher dose (2 mg/kg), produced significant increases in mean blood pressure (+14%), right atrial pressure (+78%), pulmonary artery pressure (+50%), pulmonary capillary wedge pressure (+65%), systemic vascular resistance (+29%), and pulmonary vascular resistance (+61%) and a decrease in cardiac index (-12%). Significant prolongation of PR (+9%), AH (+29%), and HV (+23%) intervals, atrial functional refractory period (+12%), ventricular effective (+7%) and functional (+6%) refractory period, and Wenckebach cycle length (+13%) also occurred after the administration of propafenone alone. Only the effects on atrioventricular (AV) node were observed at the lower dose of propafenone (1 mg/kg). Combined infusion of lidocaine with propafenone produced a mild, statistically insignificant additional negative inotropic effect but reversed the prolongation in atrial and ventricular refractoriness produced by propafenone alone. Thus, the data show that lidocaine attenuates certain electrophysiologic effects of propafenone, which might alter its antiarrhythmic efficacy, while producing mild additive negative inotropic effects that may be of hemodynamic significance.
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Feld et al. (1987) studied Ventricular arrhythmia. Combined infusion of lidocaine and propafenone vs. Lidocaine alone and propafenone alone was evaluated on Hemodynamic and electrophysiologic effects. Combined infusion of lidocaine and propafenone reversed the prolongation in atrial and ventricular refractoriness produced by propafenone alone, with mild additive negative inotropic effects.
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