069 CASE SERIES OF ATRIAL FLUTTER WITH 1:1 CONDUCTION: A COMPARATIVE ANALYSIS AMONG GROUPS OF PATIENTS SUFFERING SPONTANEOUS VERSUS DRUG INDUCED 1:1 CONDUCTING ATRIAL FLUTTER:

Abstract

Background Atrial flutter with 1:1 (AFL 1:1) conduction may be spontaneous or secondary to anti-arrhythmic drug (AAD) use. This group of patients are not well characterised. We aimed to compare various characteristics between patients suffering 9spontaneous9 AFL 1:1 (the development of 1:1 Atrioventricular conducting Atrial Flutter in the absence of concomitant AAD use) and 9Drug-induced9 AFL 1:1. Methods This is a retrospective study of patients referred to our institution over an 8 year period. Sixty-eight patients had confirmed and documented atrial flutter with 1:1 conduction. Results Baseline clinical characteristics and differences between the study populations are summarised in Table. Patients with spontaneous AFL 1:1 had a significantly higher flutter rate and were less likely to have concomitant AF. Drug-induced AFL 1:1 was mainly secondary to Class 1 AAD9s despite the use of AV blocking agents in a third of these patients. Sixty-three patients underwent a successful cavotricuspid isthmus ablation with no recurrence. Conclusions We have reported the largest series of patients with atrial flutter and 1:1 conduction. Patients suffering spontaneous AFL 1:1 had a significantly faster flutter rate compared to the drug-induced population.