Does UK-66,914 alter conduction velocity or prevent ventricular tachycardias in canine hearts with chronic myocardial infarction?
UK-66,914 is a potent Class III antiarrhythmic agent that prolongs the effective refractory period and prevents ventricular tachycardia induction without slowing conduction velocity or depressing contractility in a canine infarct model.
Antiarrhythmic Properties of UK‐ 66,914. UK‐66,914 is a potent Class III antiarrhythmic agent that has no effect on conduction velocity in normal tissue in vitro. The present study was performed to evaluate the influence of UK‐66,914 on conduction velocity in vivo in canine hearts with a previous myocardial infarction. Detailed three‐dimensional mapping of the heart in vivo was obtained using simultaneous recordings from 232 transmural sites. In dogs with a chronic anterior myocardial infarction, UK‐66,914 (50 μ g/kg) did not alter conduction velocity in regions exhibiting normal conduction (gt; 50 cm/sec) or regions with slowed conduction ( 30 cm/sec, 15‐30 cm/sec, or < 15 cm/sec, whereas procainamide significantly decreased conduction velocity at all three levels. Evaluation of the hemodynamic profile of UK‐66,914 revealed no negative ionotropic effects in conscious dogs even at doses twentyfold those required to elicit increases in the effective refractory period. Therefore, UK‐66,914 is a potent and specific Class III antiarrhythmic agent, which does not alter conduction velocity in hearts with a previous myocardial infarction and exerts no negative inotropic effects.
Onufer et al. (Mon,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: