[Nibentan -- a drug for pharmacological cardioversion of persistent atrial fibrillation].

AIM: To assess efficacy of a potassium channel blocker nibentan for pharmacological cardioversion of persistent atrial fibrillation. Method. Nibentan (1% solution) was infused intravenously after 3 weeks of warfarin pretreatment to 31 patients with duration of atrial fibrillation from 4 weeks to 15 months. RESULTS: Sinus rhythm was restored in 24 patients. Mean dose of nibentan was 0.119+/-0.02 mg/kg. Proarrhythmic effects (paroxysmal or nonsustained polymorphic ventricular tachycardia) and substantial suppression of sinus rhythm automatism were registered in 3 and 3 patients, respectively. CONCLUSION: Nibentan is highly effective in persistent atrial fibrillation. It can be recommended for inhospital use in intensive care facilities.

[Heart rate control with nebivolol in patients with tachysystolic atrial fibrillation]. / Kontrol' chastoty serdechnykh sokrashchenii u bol'nykh s takhisistolicheskoi fibrilliatsiei predserdii s pomoshch'iu nebivolola.

AIM: To find out whether selective beta-adrenoblocker nebivolol can be used for heart rate (HR) control in patients with chronic tachysystolic atrial fibrillation. MATERIAL: Patients (n=20, 7 men, 13 women, age 47-79 years) with ischemic heart disease and permanent atrial fibrillation (duration 2.5 months - 11 years) admitted to a specialized clinic for diagnosis and treatment of cardiac arrhythmias. All patients had tachycardia throughout 24 hours despite therapy. METHODS: Dosing of nebivolol: week 1 - 2.5 mg/day, week 2 7 5 mg/day. If after 2 weeks HR was considered inadequate the dose was increased up to 7.5 mg/day. Holter ECG was registered at baseline and in the end of weeks 1 and 2 of treatment. RESULTS: After 1 week of nebivolol (2.5 mg/day) HR decreased: day-time average - from 116.3+/-13.4 to 97.2+/-14.5, day-time minimal - from 78.1+/-13,5 to 71.4+/-8.2, day-time maximal - from 154.4+/-18.1 to 142.1+/-15.5; night-time average - from 83.6+/-7.1 to 76.3+/-7.14, night-time minimal - from 61.2+/-6.7 to 56.6+/-5.1, night-time maximal - from 93.5+/-10.5 to 88.2+/-10.8 bpm. After week 2 when patients received 5 mg/day of nebivolol their HR was: day-time average - 79.6+/-9,8, day-time minimal -65.2+/-7.7, day-time maximal - 128.7+/-12,2, night-time average - 69.9+/-7.6, night-time minimal - 53.1+/-4,7, night-time maximal - 80.8+/-10.1 bpm. In 2 patients (10%), interruption of nebivolol was required because of atrioventricular block in evening and nocturnal periods. CONCLUSION: Nebivolol effectively controlled HR in hospitalized patients with chronic atrial fibrillation due to ischemic heart disease. In most patients 5 mg /day was sufficient for attainment of acceptable HR.

[Electrophysiological criteria for efficacy of different antiarrhythmics classes in patients with paroxysmal reciprocal atrioventricular nodal tachycardia]. / Elektrofiziologicheskie kriterii éffektivnosti antiaritmicheskikh preparatov raznykh klassov u bol'nykh s paroksizmal'noi retsiproknoi atrioventrikuliarnoi uzlovoi takhikardiei.

Clinical and electrophysiological studies of 510 patients with different paroxysmal reciprocal atrioventricular nodal tachycardias identified criteria for resistance of paroxysmal nodal tachycardia. Examination of changes in major electrophysiological parameters due to different antiarrhythmics established the specific features of their electrophysiological action and thereof criteria for the efficacy of antiarrhythmic therapy.

[Criteria for a pathogenetic approach to antiarrhythmic therapy in paroxysmal supraventricular reciprocal tachycardia]. / Kriterii patogeneticheskogo podkhoda k antiaritmicheskoi terapii pri paroksizmal'nykh nadzheludochkovykh retsiproknykh takhikardiiakh.

An electrophysiological study using programmed transesophageal atrial pacing was performed in 106 patients with abnormalities in the myocardial conduction system, of whom 102 suffered from paroxysmal supraventricular reciprocal tachycardia and/or paroxysmal atrial fibrillation. The electrophysiological properties of the myocardial conduction system were demonstrated to be labile. The factors determining the frequency and length of palpitations were outlined. The conditions for an onset of supraventricular reciprocal tachycardiac paroxysm and for existence of a reentrant chain were found to be minimal in the effective refractory period of the accessory pathway, which was less or equal to the effective refractory period of the atrioventricular junction. An approach to antiarrhythmic therapy was proposed, which was based on modifying the ratio of the effective refractory periods of normal and abnormal excitation pathways.