First Human Experience With Pulmonary Vein Isolation Using a Through-the-Balloon Circumferential Ultrasound Ablation System for Recurrent Atrial Fibrillation

Abstract

Background-Standard mapping and ablation of focal sources of atrial fibrillation are associated with very long procedure times and low efficacy. An anatomic approach to complete pulmonary vein isolation could overcome these limitations. Methods and Results-Fifteen patients with atrial fibrillation refractory to medication underwent circumferential isolation of the pulmonary veins by using a novel catheter, with an ultrasound transducer (8-MHz) mounted near the tip, in a saline-filled balloon. Twelve atrial foci and/or atrial fibrillation triggers were identified in 9 patients (pulmonary vein locations: left upper, 3; right upper, 6; right middle, 1; right lower, 1; and left inferior, 1). In 5 patients, lesions were placed in the absence of any mapped triggers. Irrespective of trigger mapping, circumferential isolation of both upper pulmonary veins was attempted in all patients. The lower pulmonary veins were ablated when sinus rhythm activation mapping revealed evidence of a sleeve of atrial muscle in the vein. The median number of lesions per patient required to isolate 1 pulmonary vein was 4 (range, 1 to 29). After ablation, no evidence of narrowing was seen with repeat venography or follow-up computed tomography scan. After a mean follow-up of 35Ϯ6 weeks, 5 patients had recurrence of atrial fibrillation. Three responded to drugs that were previously ineffective, and 2 remained in atrial fibrillation. Conclusions-This novel ultrasound ablation system can successfully isolate multiple pulmonary veins. At early follow-up, this approach seems to be effective in preventing recurrent atrial fibrillation in a significant number of patients.

Utilidade do Ultrassom intracardíaco no isolamento de veias pulmonares usando cateter-balão a laser

“…Alternatively, different energy sources have been used for circumferential ablation through radial energy delivery. Natale et al 7 reported the use of ultrasound balloon catheter to isolate PV from the left atrium, which was accomplished in 60% 7 . In the present study, PV isolation was achieved in 64% after mean energy delivery duration of 280 ± 177 sec, which is very similar to that reported by Natale et al 7 However, our rates of PV isolation increased to 79% when no blood flow leaks were observed.…”

“…In order to decrease recurrence of AF and avoid PV stenosis, PV isolation has been proposed as the endpoint for ablation, either with RF or alternative energy such as ultrasound and laser [7][8][9] . A novel laser balloon catheter ablation (LBCA) strategy was recently developed to electrically isolate the PV from the left atrium by creating circumferential lesions at the PV ostium 10 .…”

Treatment of Paroxysmal Atrial Fibrillation by Pulmonary Vein Isolation

“…18 Although electrical isolation also can be achieved by circumferential ablation of the entire ostium, 19 segmental ostial ablation targets only the ostial sites at which electrical connections are present, which often is 50-60% of the entire ostial circumference. 13,17 Therefore, segmental ostial ablation avoids unnecessary injury to the pulmonary veins.…”

Catheter ablation of atrial fibrillation

“…18 To overcome these limitations, researchers have recently developed a novel catheter ablation approach that involves circumferential lesions created around the ostia of each PV, with the aim of isolating these veins electrically from the left atrium while reducing the risk of PV stenosis. 31,32 This approach eliminates the need for mapping, while it also has the advantage of being able to deal with multiple foci in the PVs, which possibly would not all have been mapped or ablated if the focal ablation approach had been employed.…”

“…Instead of delivering multiple, contiguous point applications of RF energy in a circumferential fashion as carried out by Pappone et al, the circumferential ablation approach has recently been tested using ultrasound energy delivered through a balloon in the pulmonary vein by Natale et al 32 In their recent study of 15 patients refractory to medication, a novel catheter (Atrionix catheter system, Atrionix, Palo Alto, Calif., USA), with an ultrasound transducer (8 MHz) mounted near the tip, in a saline-filled balloon, was used to produce circumferential isolation of the pulmonary veins. The safety of this technique was supported by their preliminary results showing no evidence of narrowing when assessed by repeat venography or follow-up computed tomography scan.…”