We examined the hemodynamic actions of clinically relevant i.v. doses (20 mg/kg and 10 mg/kg) of n-acetyl procainamide (NAPA) in conscious dogs preinstrumented with a left ventricular (LV) micromanometer, LV and aortic catheters, and ultrasonic crystals for measurement of LV internal diameter shortening (% delta D). Within 30 seconds after the 20-mg/kg dose, there were significant increases in ...

The metabolism of sulfamethazine (SMZ), which is acetylated by a binodally distributed enzyme, and procainamide (PA) was compared in 21 normal volunteers, each given a single oral dosted metabolites, N-acetyl-procainamide (NAPA) and Ac-SMZ, were measured. Subjects with less than 64% Ac-SMZ in the 0-8 hour collection were termed "slow" and those with more than 64% were termed "fast" SMZ acetylat...

In vitro and in vivo testing was performed to establish the feasibility of a totally implantable pump system to deliver antiarrhythmic agents. In vitro flow characteristics suggested predictable day to day delivery with acceptably small variations in flow with changes in reservoir volume or temperature. During 3 months of in vitro testing, procainamide and bretylium were found suitable for long...

BACKGROUND Antiarrhythmic drugs are considered to terminate atrial fibrillation by prolonging refractoriness, but direct experimental evaluation of this concept has been limited. The atria are activated rapidly during atrial fibrillation, and antiarrhythmic drugs are known to have important rate-dependent actions. The potential role of such properties in determining drug effects during atrial f...

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Procainamide, a type 1A antiarrhythmic drug, blocks sodium channels and reduces the maximum rate of rise of the cardiac action potential (Vmax) in a rate-dependent fashion. In vitro, the magnitude of this rate-dependent reduction in Vmax is greater in tissue that is partially depolarized at rest than in tissue with a normal resting potential. Reductions in Vmax produced by drugs that block sodi...

[This corrects the article on p. 213 in vol. 22, PMID: 25009702.].

We describe a single-run method for quantitating quinidine, procainamide, and N-acetylprocainamide, involving gas-liquid chromatography with a nitrogen-phosphorus selective detector. Within-run precision (CV) was 3% (x = 2 mg/L, n = 20), 6.9% (x = 4 mg/L, n = 10), and 1.5% (x = 8 mg/L, n = 8) for quinidine; 7.7% (x = 4 mg/L, n = 14), 1.6% (x = 8 mg/L, n = 16), and 2.3% (x = 12 mg/L, n = 12) for...

During the transition from a slow to rapid depolarization rhythm, rate-dependent sodium channel blockade develops progressively and increases from beat to beat under procainamide but more abruptly under lidocaine. We investigated the consequences of such differences on the dynamic course and stability of reentrant tachycardias at their onset. Procainamide and lidocaine were infused to equipoten...