Quantitative Analysis of Isolation Area and Rhythm Outcome in Patients With Paroxysmal Atrial Fibrillation After Circumferential Pulmonary Vein Antrum Isolation Using the Pace-and-Ablate Technique

Abstract

Background-We sought to determine the relationship between the size of the left atrial isolated surface area (ISA) after pulmonary vein antrum isolation for paroxysmal atrial fibrillation (AF) and rhythm outcome during a 12-month follow-up. Methods and Results-One hundred one consecutive patients with paroxysmal AF (mean age, 59±11 years; median [range] AF history, 36 months; mean left atrial size, 42±6 mm) were enrolled. The ISA was defined as the ratio of the total isolated antral surface area excluding the pulmonary veins to the sum of the total isolated antral surface area and the left atrial posterior wall surface area, while considering the individual characteristics of antral anatomy. All surface areas were assessed using the NavX system. Patients were divided into 4 groups according to ISA (group I: <50%; group II: 50 to <60%; group III: 60 to <70%; group IV: ≥70%). The average ISA for all patients was 59.2±11.6%. Subgroup analysis showed that ISA was 42.8±4.2% in group I (n=23), 54.2±3.0% in group II (n=23), 64.3±3.0% in group III (n=33), and 73.9±3.6% in group IV (n=22). After a 12-month follow-up period, 70% of patients in group I, 78% in group II, 97% in group III, and 100% in group IV were free from AF and atrial macroreentrant tachycardia. There was a significant difference between groups I and III, I and IV, II and III, and II and IV but not groups I and II and groups III and IV (logrank test P=0.024, 0.016, 0.037, 0.044, 0.584, and 0.500, respectively). Receiver operating characteristic curve analysis yielded an optimal cutoff value of 55% for ISA. Conclusions-After Methods Patient SelectionThe study was conducted on 101 consecutive patients with highly symptomatic, medically refractory paroxysmal AF, who had been treated with PVAI between January and December 2009. Paroxysmal AF was defined as a self-terminating AF of <1 week duration. Mapping and Ablation ProcedureBefore the procedure, transesophageal echocardiography was performed to exclude thrombus formation. Patients were studied under deep propofol sedation, breathing spontaneously. Standard electrode catheters were placed in the right ventricular apex and the coronary sinus, after which a single transseptal puncture was made. Unfractionated heparin was administered in bolus form immediately after the transseptal puncture to maintain an activated clotting time of >250 s. If AF occurred an external electrical cardioversion was performed to restore sinus rhythm. Mapping and ablation were performed using the NavX system (St. Jude Medical, Inc, St. Paul, MI) as a guide after integration of a 3-dimensional model of the left atrium (LA) and PV anatomy obtained from preinterventional computed tomography (CT), as described previously. 10 Before the ablation, the circular mapping catheter-reconstructed PV anatomies were aligned with the CT-PVs. Furthermore, the multipolar mapping catheter was replaced by a 4-mm M-curve irrigated tip ablation catheter (IBI Therapy Cooled Path; St Jude Medical, Inc). Fine adjustment of image integration was ach...

What Is the Acute Antral Lesion Size After Pulmonary Vein Isolation Using Different Balloon Ablation Technologies?

“…11, 13 It is notable that the IASAs found in this study were larger than in previously published studies. 13,21 This may be the result of different LA sizes and/or differences in the analyses.…”

“…11, 13 It is notable that the IASAs found in this study were larger than in previously published studies. 13,21 This may be the result of different LA sizes and/or differences in the analyses. Kiuchi et al calculated the IASA based on 3D markers arbitrarily taken during the ablation, 13 but in the present study we used electroanatomical voltage mapping to truly demarcate the acute ablation lesion size.…”

“…Considering the multiple angulations of the electroanatomical map, the PV to LA junction (e.g., PV ostium) was defined by points at the maximal inflection between the PV and the LA wall. 13 The level of ablation scar was quantitatively assessed offline by measuring the LVAs using the NavX TM system. The following parameters were measured with an implemented software tool allowing for exact determination of the map's surface area within an area of manually selected points (Figure 1).…”

“…To assess if ISA and the clinical success rate were linked, we divided the study population into 2 groups according to ISA size (ISA <55%; ISA ≥55%), 13 and outcomes in both groups were assessed and compared by means of Chi-square analysis.…”

“…11, 12 A recent study found a correlation between the area of isolated peri-ostial myocardium and clinical outcome in patients treated with irrigated radiofrequency current (RF) ablation. 13 Although novel ablation devices such as the cryoballoon (CB; Arctic Front Advance TM , Medtronic) and the laser balloon (LB; HeartLight TM , CardioFocus) have shown favorable rates of acute and durable PVI, data on the area of isolated atrial antral myocardium following a balloonbased PVI approach are scarce. 14- 16 We therefore investigated the size of the isolated antral surface area (IASA) Antral Lesion Size After PVI LB-Guided PVI In the LB group, the sizeable balloon (HeartLight TM , CardioFocus, MA, USA) was navigated to the individual PV by the steerable sheath and inflated to obtain optimal PV occlusion.…”