Long-Term Evolution of Patients Treated for Paroxysmal Atrial Fibrillation with First and Second Generation Cryoballoon Catheter Ablation with a Prospective Protocol Guided by Complete Bidirectional Left Atrium-Pulmonary Veins Disconnection after Adenosine as Main Target end Point to achieved. Seven Years Follow-up of Patients with a rough estimation profile of Low ALARMEc Score. A Single Center Report

Abstract

Introduction: Cryoballoon ablation (CB) has proven effective for treating patients with paroxysmal atrial fibrillation (PAF). We analyzed our seven year follow-up of patients, treated for PAF with first (CB1) and second generation (CB2), with demonstration of LA-PV disconnection with bidirectional block (BB) after adenosine (AD).

Methods: Since November 2008 to May 2015, 128 patients, 97 male (58±7 years), without heart disease, highly symptomatic, refractory to antiarrhythmic drugs (AAD) were treated, and follow-up (1411 ±727 days). Left atrial size: 37±6 mm.

Results: A total of 439 PV were successfully isolated (91.9%). Acute reconduction: 44 PV (9%): 16 after CB; 16 unmasked by AD; 12 extrapulmonary muscular connections (EMC). Main complication was phrenic nerve palsy (PNP): 9 (7 %). On follow-up, 114 patients (89%) remain asymptomatic in sinus rhythm (SR), free of medication. Fourteen patients (11%) had arrhythmia recurrence: 12 male (52±8 years). Early recurrences occurred in 9 male. Late recurrences presented 3 male at 24, 27 and 60 months, and 2 female at 7 and 40 months respectively. All recurrence patients were Redo, and remain in SR without medication during follow-up.

Conclusions: CB alone is very effective and safe for the definitive treatment of patients suffering PAF with 72.6% success rate, increasing up to 89.1% when this protocol is applied in a single procedure. After Redo, all population group (100%), remain in sinus rhythm, freedom of arrhythmia, without AAD, in this very long term follow-up. Checking for BB, AD protocol, and ruling out EMC allowed-us to identified 14.8% of patients with underlying substrate for potential arrhythmia recurrence. CB2 applications entail a highest risk of PNP. Patients with a rough estimated profile of low ALARMEc score (≤ 1) have an excellent long term outcome, being this series the largest follow-up described so far, for patients treated for PAF with CB.

Keywords: Ablation; Cryoballoon; Paroxysmal Atrial Fibrillation.

Figure 1:. Endoluminal and CT Scan reconstruction anatomical approach, to assess diameter/ shape and sizes of PV/LA-PV junction level and interpulmonary ridge, in relation to the size of CB to be used and the orientation for better PV-LA wedging

Figure 2A:. Atrial far-field and synchronous PV electrical activity as recorded with the circular catheter mapping at the PV-LA junction antral level

Figure 2B:. Asynchronous atrial far-field (Af) and PV electrical potential (PVP) as recorded on circular catheter mapping by pacing CS

Figure 3:. Diagram flow showing the type of balloon used for different group of pts, occlusion degree, and temperature reached

Figure 4:. A.Upper panel: Left side: pacing proximal antrum (circular 13-14) showing exit block (right side). B. Lower panel: Left side (same patient): pacing distal vein (circular 13-14), 1:1 PV/LA conduction resumed (right side)

Figure 5:. Same patient as figure 4 A, B. Upper panel right side: pacing gap (red circle) distal vein with RF catheter (left side) with: 1:1 PV/LA conduction (third and fourth paced beat) demonstration at the right side recording. Lower panel (left side): pacing gap RF catheter, 1:1 PV/LA conduction is evident (three paced beat). After stop pacing, RC gap is evident (red circle), followed by RF application. After focal RF, exit block is demonstrated (right side)

Figure 6:. Diagram flow showing total acute reconnected PV and number of patients. AR: acute reconnection

Figure 7:. A, Residual conduction gap (red circle) evident after incomplete CB occlusion (B, C) (degree III) with contrast leakage evident (arrow) as compare with PV/LA electrical activity recording in the same patient before the incomplete CB application (D)

Figure 8A:. Upper panel: showing PV electrical activity recorded at the 10 bipoles of the circular catheter mapping (left side) placed at the PV-LA junction antral level (right side).Lower panel: after CB application occlusion degree IV (left side), PV electrical activity is no more recording at circular catheter mapping (right side)

Figure 8B:. Same patient as in Figure A. Upper panel: (left side): pacing (circular 1-2) at PV-LA junction antral level (right side), demonstrated exit block. Lower panel: dormant tissue unmasked by AD (red circle), at the time of complete A-V conduction block, and 1:1 PV-LA conduction demonstrated (second and third paced beats), by pacing gap

Figure 8C:. Same patient as in [Figure 8A] and [8B]B. By placing RF catheter (lower right side figure) on PV dormant tissue location unmasked by AD, and pacing gap from RF catheter (upper side recording) 1:1 PV-LA conduction showed on first and second (left side) paced beats during AD effect, as evident with completed A-V conduction block, followed by RF application

Figure 9:. CT Scan slides showing pulmonary infiltrate (red circles)

Figure 10:. Diagram representation for the different number of RC found in the different segment location

Figure 10A:. Segment distribution appearance of RC gaps

Figure 10B:. Reconduction was shown at first procedure in 6 pts with 23 PV including 1 TC. Left side upper figure showed number of gaps after CB, and unmasked by AD (lower left figure), as compared to number and distribution of gaps showing at Redo (right figure) on the same pts