Electrophysiological predictors of propafenone efficacy in prevention of atrioventricular nodal re-entrant and atrioventricular re-entrant tachycardia

Abstract

AimTo assess the efficacy of propafenone in prevention of atrioventricular nodal reentrant tachycardia (AVNRT) and orthodromic atrioventricular tachycardia (AVRT) based on the clinical results of arrhythmia recurrence and find the electrophysiological predictor of propafenone effectiveness.MethodsThis retrospective study included 44 participants in a 12-month period, who were divided in two groups: group A – in which propafenone caused complete ventriculo-atrial block and group B – in which propafenone did not cause complete ventriculo-atrial block.ResultsGroup A had significantly lower incidence of tachycardia than group B (95% vs 70.8%, P = 0.038), and complete ventriculo-atrial block predicted the efficacy of propafenone oral therapy in the prevention of tachycardia (sensitivity 87.5%, specificity 52.8%, positive predictive value 95%, negative predictive value 29.2%). Patients with AVNRT in group B who did not experience the recurrences of tachycardia had significantly shorter echo zone before intravenous administration of propafenone than the patients who experienced episodes of sustained tachycardia (median 40 ms [range 15-60 ms] vs 79 ms [range 50-180 ms], P = 0.008).ConclusionIn patients with non-inducible tachycardia, complete ventriculo-atrial block can be used as an electrophysiological predictor of the efficacy of propafenone oral therapy in the prevention of tachycardia. In patients with non-inducible AVNRT, but without complete ventriculo-atrial block, propafenone was more effective in patients with shorter echo zone of tachycardia.

The effects of cardiac drugs on human erythrocyte carbonic anhydrase I and II isozymes

“…It works by blocking the activity of particular electrical signals in the heart that can cause arrythmias. It is used to restore a normal heart rhythm and maintain regular beats in supraventricular tachyarrhythmias 18 . The effect of these cardiovascular drugs on CA has not been studied; however, the effects of some of these agents on aldehyde oxidase were studied.…”

Patients with drug-refractory atrioventricular nodal reentrant tachycardia: Clinical features, electrophysiological characteristics, and predictors of medication failure

“…Another important factor in the inducibility of AVNRT is the echo zone, which is indirectly related to the critical AH interval. The echo zone is defined as the zone in which atrial extrastimuli induce atrial echo beats with or without AVNRT [17,20]. The outer and inner limits of this zone are the longest and shortest A 1 -A 2 stimuli followed by an atrial echo beat, respectively.…”

Methods and techniques Atrioventricular nodal reentrant tachycardia ablation with radiofrequency energy during ongoing tachycardia: is it feasible?

“…Another prerequisite to the inducibility of AVNRT is the echo zone. The echo zone is defined as the zone in which atrial extrastimuli induce atrial echoes with or without AVNRT [ 8 ]. The outer and inner limits of this zone are the longest and shortest A1–A2 stimuli followed by an atrial echo, respectively.…”