To determine if paced cycle length-dependent changes in the QRS duration correlate with the change in ventricular tachycardia (VT) cycle length after procainamide, we measured the QRS duration during sinus rhythm and during right ventricular pacing before and after procainamide (mean concentration, 9.9 micrograms/ml) in 18 patients with morphologically identical VT induced at both study periods...

Procaine and some other basic drugs reportedly induce vacuolization of various cell types. We addressed the concentration-effect and structure-activity relationships as well as the mechanism of this effect using three cell lines. Massive vacuolization occurs over several hours in primary cultures of rabbit pulmonary artery smooth muscle cells (SMCs) and COS-1 cells in response to procaine and l...

Combinations of antiarrhythmic drugs are frequently used to treat refractory ventricular tachycardia (VT), but few scientific data support this practice. We examined the efficacy and electrophysiology of 110 antiarrhythmic drug combination trials at electrophysiologic study in 74 patients with recurrent ventricular tachycardia. Lidocaine was combined with quinidine in 33 trials, procainamide in...

The effect of empiric antiarrhythmic therapy with quinidine and procainamide on long-term mortality was examined in 209 patients with coronary artery disease resuscitated after out-of-hospital cardiac arrest. The antiarrhythmic agent used was determined by the patient's private physician without knowledge of the study ambulatory electrocardiogram. Of the 209 patients, procainamide was prescribe...

A73-year-old man with mild coronary artery disease and a dilated cardiomyopathy presented to the emergency room with a hemodynamically stable wide-QRS tachycardia. His 12-lead ECG revealed episodes of ventriculoatrial block, and a diagnosis of ventricular tachycardia (VT) was made (Figure 1). Intravenous procainamide restored sinus rhythm. Tachycardia recurred, and a second bolus of intravenous...

We studied the role of the anticholinergic properties of disopyramide and quinidine in mediating the electrophysiological effects of these agents on isolated cardiac tissue. In right atria, disopyramide, quinidine, and procainamide administered alone elicited negative chronotropic responses. However, after cholinergic stimulation with physostigmine (1 X 10" M), disopyramide and quinidine produc...

Secreted Wingless type (Wnt) ligands have previously been shown to be involved in tumor developmental processes and oncogenesis. Aberrant promoter methylation of Wnt inhibitory factor-1 (WIF-1) is a fundamental mechanism of epigenetic silencing in human cancers. Procaine, a local anesthetic drug, and procainamide, a drug for the treatment of cardiac arrhythmias, have been reported as inhibitors...

We studied the role of the anticholinergic properties of disopyramide and quinidine in mediating the electrophysiological effects of these agents on isolated cardiac tissue. In right atria, disopyramide, quinidine, and procainamide administered alone elicited negative chronotropic responses. However, after cholinergic stimulation with physostigmine (1 X 10" M), disopyramide and quinidine produc...

-1. The effects of three class I antiarrhythmic drugs procainamide (class IA), tocainide (class IB) and lorcainide (class 1C) on microsomal Na+-K+-ATPase activity were compared with those of ouabain in guinea pig heart preparations. 2. All three antiarrhythmic drugs exhibited concentration-dependent inhibitory actions on the enzyme activity in a fashion similar to that of ouabain. 3. The rank o...

This study delineates the time course of procainamide accumulation in myocardium after bolus administration and its relationship to regional myocardial blood flow. The left circumflex coronary artery was ligated in 28 open-chest dogs. This was followed 40 minutes later by injection into the left atrium of labeled microspheres. C-labeled procainamide, 1.5 mg/kg, was then administered as a single...