Ablation of coexisting atrial flutter and fibrillation

AUSTIN, TEXAS. Atrial fibrillation (AF) and atrial flutter (AFL) often coexist. Symptoms can be debilitating and may include palpitations, shortness of breath, chest discomfort, fatigue, dizziness and fainting; thus seriously affecting one’s quality of life (QoL). A catheter ablation for “stand alone” right atrial flutter (cavotricuspid isthmus [CTI] ablation) is relatively simple and has a high chance of being successful. However, the probability that an AFL ablation will also eliminate AF is very low and, as a matter of fact, a CTI ablation may actually “unmask” previously undetected AF.

An American/Italian research team led by Dr. Andrea Natale now reports that an AF ablation by itself or a combined AF + AFL ablation is effective in eliminating both AF and AFL, whereas an AFL ablation by itself is not. Their single-blind, randomized study involved 360 patients with documented, coexisting paroxysmal AF and AFL. The patients were randomized into Group 1 comprising 182 patients who underwent AF or AF + AFL ablation, while Group 2 comprised 178 patients who underwent only AFL ablation.

A total of 124 patients in Group 1 had only a pulmonary vein antrum isolation (PVAI) procedure with additional lesions as required. The remaining 58 patients in Group 1 underwent both a PVAI and a CTI ablation. The decision to perform the added CTI procedure was made if the patient presented with typical right atrial flutter at the start of or during the PVAI, or if flutter was provoked by the isoproterenol challenge following the PVAI.

All procedures were performed under general anesthesia. NOTE: A left atrium diameter in excess of 5 cm (50 mm) was grounds for exclusion from the study. After overnight observation, patients were prescribed their previously ineffective antiarrhythmics and discharged. A recurrence was defined as any episode or AF, AFL or tachycardia lasting 30 seconds or longer, with episodes occurring during a 12-week blanking period being ignored.

Follow-up at 3, 6, 9 and 12 months included 7-day Holter monitoring as well as extended event recording. Quality of life was assessed prior to the ablation procedure and at the 12-month follow-up using 4 different questionnaires – the Medical Outcome Study Short Form, the Hospital Anxiety and Depression Score, the Beck Depression Inventory, and the State-Trait Anxiety Inventory.

At an average of 21 months follow-up, 64% of the group having undergone PVAI only were in normal sinus rhythm (NSR) without the use of antiarrhythmics as was 66% of the group having undergone PVAI + CTI. In contrast, only 19% of Group 2 (AFL ablation only) was in NSR without the use of antiarrhythmics. Assessment of the 1-year follow-up clearly showed that study participants who had undergone a successful ablation had improved their QoL scores very significantly with particular gains in scores related to anxiety, depression, vitality, and general physical and emotional well-being. Somewhat surprisingly, the post-ablation improvement in QoL was significantly less in Group 2 even if their CTI ablation had been successful.

The researchers conclude that in coexisting AF and AFL having a stand-alone PVAI or a combined PVAI + CTI is associated with a much lower recurrence rate than having just a CTI procedure. As a matter of fact, just undergoing a PVAI may be sufficient as there is some evidence that AFL may be triggered by ectopic activity in the pulmonary veins. Furthermore, it is clear that quality of life directly correlates with freedom from arrhythmia.
Mohanty, S, et al. Results from a single-blind, randomized study comparing the impact of different ablation approaches on long-term procedure outcome in coexistent atrial fibrillation and flutter (APPROVAL). Circulation, Vol. 127, May 7, 2013, pp. 1853-60

Editor’s comment: This and previous studies clearly show that having just a right atrial flutter ablation, when both AF and AFL are present, is a waste of time. The observation that a successful ablation is associated with a greatly improved quality of life confirms the experience of afibbers who have regained permanent NSR through a successful ablation.