COMPARATIVE EFFECTS OF LIDOCAINE AND PROCAINAMIDE ON ACUTELY IMPAIRED HEMODYNAMICS

Controversy exists regarding the relative safety of i.v. administered lidocaine and procainamide to patients with acutely impaired hemodynamics. Accordingly, their effects were studied in 15 such patients, 14 with acute myocardial infarction and 1 with cardiomyopathy and severe congestive heart failure. All had elevated levels of pulmonary capillary wedge pressure (> 15 mm Hg) and/or low cardiac index (< 2.5 l/min per m2). Patients were given lidocaine, a 100 mg bolus followed by a 3 mg/min infusion and, after at least a 30 min recovery period, procainamide, a 100 mg bolus over 2 min followed by a 20 mg/min infusion for 20-25 min. Hemodynamic measurements were compared early and late in the infusion of each drug. Small, clinically insignificant differences were observed in the hemodynamic responses to the drugs, and no clinically significant deterioration occurred with either. Conventional therapeutic doses of i.v. procainamide can be administered by this regimen, to patients with acute myocardial infarction complicated by cardiac failure or low cardiac output, without producing deleterious hemodynamic effects.