Cardioprotective effects of various class I antiarrhythmic drugs in canine hearts

Postrepolarization refractoriness versus conduction slowing caused by class I antiarrhythmic drugs: antiarrhythmic and proarrhythmic effects.

BACKGROUND Conduction block may be both antiarrhythmic and proarrhythmic. Drug-induced postrepolarization refractoriness (PRR) may prevent premature excitation and tachyarrhythmia induction. The effects of propafenone and procainamide on these parameters, and their antiarrhythmic or proarrhythmic consequences, were investigated. METHODS AND RESULTS In 11 isolated Langendorff-perfused rabbit h...

Effects of class I antiarrhythmic drugs on mitochondrial ATPase activity in guinea pig heart preparations.

1. The effects of three class I antiarrhythmic drugs quinidine, lidocaine and lorcainide on undamaged myocardial mitochondrial ATPase [ATP: phosphohydrolase, EC 3.6.1.3] activity were evaluated in guinea pig heart preparations. 2. All three drugs inhibited the enzyme activity in a concentration-dependent fashion. 3. Lorcainide was the most potent, exerting inhibitory effects in the range of les...

Antiarrhythmic and cardioprotective effects of remifentanil in anesthetized dogs.

OBJECTIVE To study the antiarrhythmic effect of remifentanil in experimental arrhythmias in dogs. METHODS We used dogs weighing 12 kg-18 kg anesthetized with 30 mg/kg sodium pentobarbital given intravenously. Ventricular arrhythmia, ventricular fibrillation and death were induced with digoxin (9 microg/kg/min). In another model, two types of arrhythmia were induced in the right atrium, one of...

Class 1: Sodium Channel Blockers – Antiarrhythmic Drugs

Antagonism by class I antiarrhythmic drugs of levcromakalim-induced relaxation in isolated rat aorta.

We have analyzed the effects of several class I antiarrhythmic drugs (propafenone, quinidine, its enantiomer quinine, disopyramide, flecainide and mexiletine), tetraethylammonium (TEA) and glibenclamide on the vasodilator effects of the adenosine 5'-triphosphate-dependent K+ channels channel opener levcromakalim in isolated rat aorta precontracted by 30 mM KCl. TEA (>1 mM) and disopyramide (>/=...