Mapping and ablation of left atrial roof-dependent tachycardias using an ultra-high resolution mapping system.

BACKGROUND: Left atrial roof-dependent tachycardias (LARTs) are common macroreentrant atrial tachycardias (ATs). We sought to characterize clinical LARTs using an ultra-high resolution mapping system. METHODS: This study included 22 consecutive LARTs in 21 patients who underwent AT mapping/ablation using Rhythmia systems. RESULTS: Three, 13, 4, and 2 LART patients were cardiac intervention naïve (Group-A), post-roof line ablation (Group-B), post-atrial fibrillation ablation without linear ablation (Group-C), and post-cardiac surgery (Group-D), respectively. The mean AT cycle length was 244 ± 43 ms. Coronary sinus activation was proximal-to-distal or distal-to-proximal in 16 (72.7%) ATs. The activation map revealed 13 (59.1%) clockwise and 9 (40.9%) counter-clockwise LARTs. A 12-lead synchronous isoelectric interval was observed in 10/19 (52.6%) LARTs. The slow conduction area was identified on the LA roof, anterior/septal wall, and posterior wall in 18, 6, and 2 ATs, respectively. Twenty concomitant ATs among 13 procedures were also eliminated, and peri-mitral AT coexisted in 7 of 9 non-group-B patients. In group-B, the conduction gap was predominantly located on the mid-roof. Sustained LARTs were terminated by a single application and linear ablation in 6 (27.3%) and 9 (40.9%), while converting to other ATs in 7 (31.8%) LARTs. Complete linear block was created without any complications in all, however, ablation at the mid-posterior wall was required to achieve block in 4 (18.2%) procedures. During 14.0 (6.5-28.5) months of follow-up, 17 (81.0%) and 19 (90.5%) patients were free from any atrial tachyarrhythmias after single and last procedures. CONCLUSIONS: The LART mechanisms were distinct in individual patients, and elimination of all concomitant ATs was required for the management.

Durability of a right superior pulmonary vein isolation after an inevitably interrupted single short freeze during cryoballoon ablation.

BACKGROUND: In cryoballoon ablation, applications for right superior pulmonary veins (RSPVs) inevitably need to be interrupted for some safety reasons. We retrospectively investigated the RSPV isolation durability after single interrupted short freezes. METHODS: Data from 30 patients who underwent repeat procedures 8.2 (4.1-13.8) months after an inevitably interrupted single short freeze (<180 s) for RSPVs during the index cryoballoon procedures were analyzed. It was interrupted by active deflation due to phrenic nerve injury (PNI) (Group 1: n = 14) or passive deflation due to a balloon temperature of -60°C (Group 2: n = 16). RESULTS: The freezing time was 145 (107-166) and 142 (127-160) s and nadir balloon temperature -50.7 ± 3.6 and -60°C in Groups 1 and 2, respectively. Pulmonary vein isolation was achieved after interrupted freezing in all except in one patient requiring touch-up ablation in Group 1. All PNI was asymptomatic and recovered during the follow-up. Eight/13 (61.5%) and 16/16 (100%) RSPVs were durable during the second procedure in Groups 1 and 2. In Group 1, the freezing time was significantly longer in durable than reconnected RSPVs (p = .032), and the optimal cutoff point for the freezing duration to predict the durability was 94.0 s (sensitivity 100%, specificity 60.0%). When the freezing time was ≥120 s, 80% of the RSPVs were durable. However, when the freezing time was ≤68 s, all RSPVs were reconnected. CONCLUSIONS: The feasibility of second cryoapplications for RSPVs should be discussed considering the freezing time of the interrupted initial applications in Group 1, however, it was not necessary in Group 2.

Superior vena cava isolation with 50 W high power, short duration ablation strategy.

INTRODUCTION: The optimal ablation strategy is unknown regarding a superior vena cava isolation (SVCI). This study aimed to examine the feasibility and safety and to analyze the lesion characteristics of the SVCI using high-power, short-duration (HPSD) ablation. METHODS AND RESULTS: A total of 100 patients underwent an index SVCI using HPSD (n = 50, HPSD group) or conventional lower-power and longer-duration (n = 50, LPLD group) ablation, using the Thermocool Smarttouch SF. In the HPSD group, ablation was performed with a power of 50 W for 7 s, and was limited to 4 s at the lateral segment close to the right phrenic nerve. The ablation setting used in the LPLD group was 20-25 W for 20-30 s and was limited to 10-20 W for 15-30 s at the lateral segment when diaphragmatic capture was seen. An electrical SVCI was achieved in all patients. The HPSD group required a significantly shorter procedure time (10.8 ± 3.2 vs. 14.8 ± 6.4 min; p < .01), shorter radiofrequency duration (49 ± 16 vs. 282 ± 124 s; p < .01), fewer lesions (8.3 ± 2.5 vs. 10.4 ± 4.4; p < .01), and lower ablation index (316 ± 38 vs. 356 ± 62; p < .001) than the LPLD group. The incidence of a postprocedural asymptomatic mild diaphragmatic elevation was comparable (2% in the HPSD group vs. 6% in the LPLD group; p = .61). CONCLUSION: The 50-W HPSD ablation strategy allowed for a successful, fast, and safe SVCI with the fewer ablation lesions and the lower ablation index.

Features Suggesting Preferential Conduction in Pulmonary Artery Ventricular Arrhythmia for Identification of Successful Ablation Sites.

Radiofrequency catheter ablation (RFCA) for pulmonary artery ventricular arrhythmia (PAVA) can be difficult because of the occasional existence of PAVA with preferential conduction.This study described the characteristics of PAVA that demonstrate preferential conduction.We analyzed electrocardiographic and electrophysiological data from 8 patients found to have PAVAs with preferential conduction out of 183 patients (4.4%) with right ventricular outflow tract (RVOT) arrhythmias who underwent RFCA at our hospitals. The PAVA with preferential conduction were classified into two types. In type 1 PAVA, successful ablation sites (success-sites) exhibited discrete prepotentials with an isoelectric line, in which the activation time (AT) was ≥ 50 milliseconds. In type 2 PAVA, excellent pace mapping was achieved at two sites separated by ≥ 20 mm: one in the RVOT free wall and the other at the success-site in the pulmonary artery. Type 1 and 2 PAVA features were considered signs of a short and long preferential conduction pathway, respectively.There were four patients each with type 1 and 2 PAVA. Type 1 PAVA was distinguished by the isoelectric line at success-sites with the mean AT of 78 ± 25.1 milliseconds. In type 2 PAVAs, although the AT at RVOT sites was very short (18.5 ± 10.1 milliseconds), the AT at success-sites was longer than that at the RVOT by 42.3 ± 36.2 milliseconds. Type 2 PAVAs displayed distinct electrocardiogram (ECG) features (R wave in lead I, RR' in inferior leads, and transitional zone in V4) not found in typical PAVA ECGs.PAVA with preferential conduction can manifest in distinct ways on the ECG and intracardiac mapping. Knowledge of these features may facilitate successful RFCA of such PAVA cases.

The mechanisms of recurrent atrial arrhythmias after second-generation cryoballoon ablation.

BACKGROUND: In patients with paroxysmal atrial fibrillation (PAF), 10%-15% of patients require repeat procedures after second-generation cryoballoon pulmonary vein isolation (CB-PVI). We sought to explore the mechanisms of recurrences after cryoballoon ablation. METHODS: The data of 122 PAF patients who underwent second procedures for recurrent arrhythmias 7.0 (4.0-12.0) months after the CB-PVI were analyzed. During second procedures, non-PV AF foci were explored with isoproterenol, adenosine, and repetitive cardioversions. RESULTS: In total, 378/487 (77.6%) PVs remained isolated, and reconnections were not observed in any PVs in 59 (48.4%) patients. PV reconnections were associated with recurrences in 38 (31.1%) patients, of whom 33 (86.8%) had reconnections of at least 1 upper PV. In 6 (4.9%) patients, non-PV AF foci were identified in the upper PV antra where cryoballoons cannot isolate but within the circumferential radiofrequency PVI line. Non-PV AF foci were identified in the superior vena cava, right atrial body, left atrial body, and atrial septum in 28 (23.0%), 18 (14.7%), 4 (3.3%), and 5 (4.1%) patients, respectively. Twelve (9.8%) patients had multiple non-PV AF foci. Four (3.3%), 3 (2.4%), and 8 (6.5%) patients underwent second procedures for atrioventricular nodal reentrant tachycardia, atrial flutter, and atrial tachycardias. During 16.0 (8.0-24.0) months of follow-up, freedom from any atrial arrhythmia at 1 year and 2 years after the second procedure was 79.2% and 60.6%. Nineteen (15.5%) patients had antiarrhythmic drug therapy at the last follow-up. CONCLUSIONS: Our study suggested that improvement in the upper PV PVI durability, eliminating arrhythmogenic superior vena cavae and coexisting atrial arrhythmias, and bonus cryoballoon applications at PV antra might improve the single procedure outcome in cryoballoon ablation.

Circulatory dynamics changes are an additional predictor of successful pulmonary vein isolation during cryoballoon ablation.

The association between circulatory dynamics changes during cryoballoon applications and a successful pulmonary vein isolation (PVI) is unknown. Seventy atrial fibrillation patients who underwent PVI with 28-mm second-generation cryoballoons and single 3-min freezes were included. Intra-procedural parameters including circulatory dynamics changes during cryoapplications, were compared between 113 successful applications (30 left superior PVs[LSPVs], 30 left inferior PVs[LIPVs], 25 right superior PVs[RSPVs], and 28 right inferior PVs[RIPVs]) and 47 failed applications (10 LSPVs, 9 LIPVs, 8 RSPVs, and 20 RIPVs). In all individual PVs, lower nadir balloon temperatures (MinTemps) and longer thawing times (ThawTimes) significantly predicted a successful PVI. In addition, greater systolic blood pressure drops following releasing the PV occlusion (SBP-drops) significantly predicted a successful right PV PVI, and longer elapse times during SBP-drops significantly predicted a successful RIPV PVI. Composite parameters incorporating MinTemps and ThawTimes, SBP-drops, and ThawTimes showed the highest area under the curve to predict a successful left PV (0.876 for LSPVs, 0.851 for LIPVs) and right PV (0.927 for RSPVs, 0.980 for RIPVs) PVI, respectively. If the ThawTime (≥ 30 s) and SBP-drop (≤ - 21 mmHg) cutoff values were achieved for the RIPVs, the positive predictive value was 100%. In contrast, if both criteria were not achieved for the RIPVs, the negative predictive value was 100%. In the second-generation cryoballoon PVI, the MinTemp and ThawTime were significantly associated with acute success for all four PVs. In addition, SBP-drops further improved the accuracy of predicting a successful right PV PVI, especially of the RIPV.

Perfect pace-mapping with different latencies from adjacent sites in bilateral outflow tract leading to successful sequential unipolar ablation.

A 77-year-old man with frequent monomorphic ventricular premature contractions (VPCs) was referred for catheter ablation. Detailed mapping just above the pulmonary valve (PV) revealed tiny fragmented potentials earlier than the VPC onset. Perfect pace-mapping was obtained using high voltage pacing just above the PV and the left aortic sinus of Valsalva, whose stimulus-to-VPC latencies differed by 20 ms. While the ablation at the pulmonary valve could not completely eliminate the VPCs, unipolar sequential ablation on both sides of the outflow tracts led to their successful abolition that was guided by perfect pace-mapping.

Extent of Atrial Deformation in Catheter Ablation of Atrial Fibrillation.

Anatomical atrial distortion during catheter mapping and ablation has not been elucidated in atrial fibrillation (AF) ablation. This study aimed to characterize the regional anatomical distortion in common ablation areas according to different contact forces (CFs) with radiofrequency and cryoballoon catheters.Ten patients underwent distortion mapping with low (5-10 g) and high CFs (10-30 g) at the pulmonary vein (PV) antra, left atrial (LA) roof line, mitral isthmus line, cavotricuspid isthmus line, and superior vena cava (SVC)-right atrial (RA) junction. Fifteen patients underwent distortion mapping with a 28-mm second-generation cryoballoon surrounded by a decapolar catheter at each PV antrum following creating the LA geometry. High CFs distorted the PV antra as compared to low CFs and the extent was greater at the anterior PV aspect, and the catheter was located more inside the PVs. The inflated cryballoon stretched the PV surface in the postero-superior direction in the upper PVs and posterior direction in the lower PVs. High CFs as compared to low CFs distorted the LA roof and cavotricuspid isthmus in the postero-inferior and inferior directions, respectively, but not the mitral isthmus line even with deflectable sheaths. High CFs distended the SVC-RA junction as compared to low CFs, and the extent was greatest at the lateral side and smallest at the antero-septal side.Human atria significantly distend during radiofrequency and cryoballoon ablation, and there are regional heterogeneities of the extent of the distortion. This information might aid operators in performing safe and effective AF ablation procedures.

Epicardial-endocardial breakthrough site ablation: Demonstration of alternative target for perimitral atrial tachycardia.

A 62-year-old man underwent the catheter ablation for persistent atrial tachycardia (AT) with a cycle length of 357 milliseconds. An ultrahigh resolution mapping revealed that this tachycardia was a clockwise perimitral AT despite the conduction was apparently blocked across the lateral mitral isthmus line both at the endocardium and within the coronary sinus. The AT was terminated by the single radiofrequency application at the site below the mitral isthmus line where the endocardial activation breakout was seen. This case suggests that the epicardial-endocardial conduction breakthrough site may be an alternative ablation target in a difficult ablation case of perimitral AT.

Impact of electrical connections between ipsilateral pulmonary veins on the second-generation cryoballoon ablation procedure.

BACKGROUND: Electrical connections between ipsilateral pulmonary veins (PVs) have been reported histologically and electrophysiologically. This study investigated the impact of electrical connections between ipsilateral PVs on PV isolation using second-generation cryoballoons (CB2-PVI). METHODS: Five hundred eleven atrial fibrillation patients, without any PV anomalies, underwent CB2-PVI using one 28-mm balloon and a single 3-minute freeze strategy without any bonus applications. RESULTS: Overall, 1966 of 2044 (96.2%) PVs were isolated exclusively by using 28-mm cryoballoons. Among them, 13 left superior PV (LSPVs) and two right superior PV were not persistently isolated by the first application despite a complete vein occlusion, but were isolated by subsequent applications targeting other ipsilateral PVs. Among the 13 LSPVs, six were transiently isolated by 87 (62-146) second time-to-isolation LSPV applications, but were immediately reconnected after the application. The nadir balloon temperature during the LSPV application was similar between the 13 LSPVs not isolated by the LSPV application but were not so by subsequent left inferior PV (LIPV) applications and the 488 LSPVs persistently isolated by LSPV applications (-49.4℃ ± 4.3℃ vs -50.8℃ ± 5.1℃; P = 0.328). In 59 patients in whom the initial LSPV application failed despite a complete occlusion, LIPVs were targeted for the second applications in 31 patients, and both the LSPV and LIPV were simultaneously isolated in 13 of 31 (41.9%). CONCLUSIONS: Electrical connections between ipsilateral PVs could have an impact on the CB2-PVI procedure. When the vein isolation failed despite a complete occlusion, especially for left ipsilateral PVs, it was reasonable to target the other ipsilateral PV instead of repeatedly targeting the same vein.

A case of bidirectional conduction block within the superior vena cava induced by cryoballoon pulmonary vein isolation.

A 53-year-old male underwent a pulmonary vein isolation (PVI) of atrial fibrillation (AF) with a second-generation cryoballoon (CB). Although the patient maintained sinus rhythm after the PVI, a superior vena cava (SVC) fibrillation was recorded by a circular-multipolar-electrode catheter positioned inside the SVC that suggested conduction block between the right atrium (RA)-SVC connection. An adenosine triphosphate intravenous injection induced a dormant reconnection of the SVC myocardial sleeve and converted sinus rhythm to an AF rhythm. This case demonstrated that a CB application for the isolation of a right superior pulmonary vein could induce an electrical conduction block between the RA-SVC connection.

Utility of low-dose adenosine triphosphate sensitivity in slow-fast atrioventricular nodal reentrant tachycardia.

PURPOSE: Low-dose adenosine triphosphate (LD-ATP) is useful for diagnosing ATP-sensitive atrial tachycardia. However, the clinical implications of the sensitivity of LD-ATP in atrioventricular nodal reentrant tachycardia (AVNRT) still remain unknown. This study aimed to evaluate the mechanism of LD-ATP sensitivity in slow-fast AVNRT. METHODS: We estimated the sensitivity of LD-ATP in slow-fast AVNRT by a 2-4-mg ATP intravenous injection during the tachycardia. We evaluated the atrial-His (A-H) interval, tachycardia termination mode, prevalence of a lower common pathway (LCP), and successful ablation site in slow-fast AVNRT with LD-ATP sensitivity. LCPs were defined as His-atrial interval differences of at least 5 ms between that during ventricular pacing at the tachycardia cycle length and that during the tachycardia. RESULTS: Twenty-eight patients (mean age = 58 ± 11 years old, 18 females) with slow-fast AVNRT, who underwent catheter ablation of the antegrade slow pathway, were enrolled. Seventeen of 28 (61%) patients had LD-ATP sensitivity defined as termination of the tachycardia and/or a prolongation of the A-H interval of over 30 ms after an LD-ATP injection. The patients with LD-ATP sensitivity had a significantly higher prevalence of an LCP than those without (15/17 vs0/11, P < 0.0001). The successful ablation site in the LD-ATP sensitive group was significantly closer to the His bundle area than that in the LD-ATP nonsensitive group (13.3 ± 3.8 vs 20.5 ± 5.4 mm; distance to His bundle area in the left anterior oblique fluoroscopic view, P < 0.0001). CONCLUSIONS: LD-ATP sensitivity in slow-fast AVNRT may suggest the existence of an LCP. The successful ablation site in patients with LD-ATP sensitivity could be closer to the His bundle region.

Catheter ablation of paroxysmal atrial fibrillation in patients with sick sinus syndrome.

Sick sinus syndrome (SSS) frequently coexists with atrial fibrillation (AF). The results of AF ablation in patients with SSS have not been fully evaluated. We retrospectively investigated 65 patients with paroxysmal AF (PAF) and SSS who underwent AF ablation using either radiofrequency (n = 50) or cryoballoon ablation (n = 15) in our institute. Forty-nine (75.4%) patients had a median of 5.6 (4.8-6.0) s of documented sinus pauses prior to the procedure (42 patients on antiarrhythmic drugs), and were observed when AF terminated in 47 patients. Successful pulmonary vein isolation was achieved in all, and substrate modification was added in 3 patients. Freedom from recurrent atrial arrhythmias after single procedures was 58.7, 45.2, and 38.9% at 1, 2, and 3 years after the initial procedure. During a 23.4 (11.1-40.7) month median follow-up and after 1.4 ± 0.6 sessions, 80.6% of patients were free from arrhythmia recurrence; however, permanent pacemaker implantations were required in 9 (13.8%) patients at a median of 5.3 (2.9-21.0) months after initial procedures. The average heart rate did not significantly differ before or a median of 2.5 (1.2-5.3) months post-procedure (76.7 ± 17.4 vs. 73.5 ± 14.6 bpm, p = 0.90). Multivariate analyses revealed that larger left atrial diameters [odds ratio (OR) 1.21, 95% confidential interval (CI) 1.01-1.45, p = 0.042] were independent predictor of AF recurrence, and SSS type 1 was the sole predictor of pacemaker implantations (OR 10.30, 95% CI 1.38-76.7, p = 0.023), respectively. AF ablation obviated permanent pacemaker implantations in the majority of the patients with SSS and PAF, and SSS type 1 was a sole factor predicting pacemaker implantations.

Electrocardiographic morphology of multiple ventricular arrhythmias originating from the right ventricular outflow tract: inverse correlation of the amplitude in the inferior leads and anatomic height of the origin.

It is unclear whether the electrocardiogram amplitude in the inferior leads (Amp-I) can always predict the height of the origin of right ventricular outflow tract arrhythmias (RVOT-VAs). We analyzed patients who received catheter ablation of multiple RVOT-VAs in the same session in our hospital from 2011 to 2016. Two distinguished RVOT-VAs, those with anatomically higher origins (HOs) and lower origins (LOs), were identified and compared to measure the longitudinal distance. Amp-I was uniquely determined for each OTVA as the highest amplitude in leads II, III, and aVF and compared between the HO-VAs and LO-VAs. In total, out of 187 patients who underwent catheter ablation of RVOT-VAs, 9 (4.8%) had multiple right OTVAs successfully treated. Four cases (Group A) had HO-VAs (10.8 ± 5.3 mm from an LO) with a lower Amp-I (1.28 ± 0.46 mV) than the LO-VAs (1.81 ± 0.59 mV), whereas the other 4 patients (Group B) had HO-VAs with a higher Amp-I (1.91 ± 0.23 mV) than the LO-VAs (1.26 ± 0.35 mV). In Group A, all HO-VAs originated from the lateral free wall and had notched R waves in the inferior leads, whereas all LOs with higher Amp-Is were located on the septum. In one patient, the HO and LO were at almost the same height, while a VA from a lateral origin had lower notched R waves in the inferior leads. A divided excitation from high lateral origins may result in not only QRS notching, but also a reduction in the QRS amplitude. In patients harboring multiple RVOT-VAs, VAs arising from the high lateral free wall could have lower Amp-Is than VAs from low septal origins.

Early Tissue Reaction After Second-Generation Cryoballoon Ablation Evaluated with Intracardiac Echocardiography.

Radiofrequency energy applications immediately produce tissue edema. This study aimed to investigate the acute tissue reaction immediately after second-generation cryoballoon applications using 3-dimensional intracardiac echocardiography (ICE) imaging technology.This study consisted of 10 patients with paroxysmal atrial fibrillation who underwent pulmonary vein isolation (PVI) using second-generation cryoballoons. Ablation was performed with a single 3-minute freeze strategy and exclusively 28-mm balloons. The left atrial and right pulmonary vein (PV) antra geometries were created with 3-dimensional ICE technology before and immediately after the PVI.Out of 20 right PVs, 19 were isolated exclusively with cryoballoons, and one right inferior PV (RIPV) required touch-up ablation. All 10 right superior PVs (RSPVs) were isolated by single cryoballoon applications, and RIPVs were isolated by a mean of 1.2 ± 0.4 applications. The total application time was 171 ± 19 and 203 ± 71 seconds, and nadir balloon temperature was -56.0 ± 4.9 and -53.8 ± 5.4°C for the RSPVs and RIPVs, respectively. In all patients, diffuse wall thickening of the antra and ostium of the right PVs was observed as compared to baseline. The wall thickening was 0-0.25 mm in 3 patients, and 0.25-0.5 mm in the remaining 7. During the median follow-up of 13 [10.2-17.2] months, 8 (80%) patients were free from arrhythmia recurrences. Nine (90%) patients underwent repeat cardiac computed tomography at a median of 6.0 [4.5-12.0] months after the initial procedure, and no PV stenosis was observed in all.Tissue edema and wall thickening appeared in the human left atrium immediately after second-generation cryoballoon ablation.

Transcranial measurement of cerebral microembolic signals during left-sided catheter ablation with the use of different approaches- the potential microembolic risk of a transseptal approach.

Aims: Subclinical brain damage due to microembolization could occur during catheter ablation procedures. We evaluated the microembolic signals (MESs) detected by transcranial Doppler during ablation of supraventricular tachycardias (SVTs) or idiopathic ventricular arrhythmias (VAs) with the use of different approaches. Methods and results: This study included 36 patients (23 men, 49 ± 21 years) who underwent catheter ablation of SVTs (n = 27) or idiopathic VAs (n = 9). Left-sided ablation was performed by either a transaortic (Group 1, n = 11) or transseptal approach (Group 2, n = 9). A sole right-sided ablation was performed in the remaining 16 patients (Group 3). The MESs were counted throughout the procedure, and then analysed offline with a frequency analysis. The mean number of radiofrequency applications, total energy delivery time, total application energy, and total procedure time were 5.8 ± 5.0, 4.3 ± 3.3 min, 6625 ± 4633 J, and 81 ± 40 min, respectively, and there was no significant difference in the parameters between the three groups. The mean total number of MESs was 3.8 ± 3.1 in Group 1, 75 ± 58 in Group 2, and 0.3 ± 0.6 in Group 3 (P = 0.001). Few MESs were detectable during the radiofrequency energy deliveries in all groups. In Group 2, 19 ± 18 MESs were detected during the transseptal puncture period, and subsequently a relatively even distribution of emboli formation was observed. A frequency analysis suggested that 99, 91, and 100% of MESs were gaseous, in Group 1, Group 2, and Group 3, respectively. No neurological impairment was observed in any patients after the procedure. Conclusion: The retrograde aortic approach might potentially have a lower risk of subclinical brain damage than the transseptal approach during left-sided catheter ablation.

Management of cardiac tamponade in catheter ablation of atrial fibrillation: single-centre 15 year experience on 5222 procedures.

Aims: Cardiac tamponade during atrial fibrillation (AF) ablation is infrequent but potentially fatal. This study aimed to retrospectively investigate the incidence, management, and outcomes of tamponade in large patient series. Methods and results: The study analysed 5222 AF ablation procedures in 3483 patients between 2002 and 2016 under a heparin-bridge anticoagulation protocol. Cardiac tamponade occurred in 51 procedures/patients, and the incidence was 0.98% per procedure and 1.46% per patient and was noted during the procedure in 42 patients and in the ward in the remaining 9 patients. No clinical factors were associated with the occurrence, but it was lower during cryoballoon than radiofrequency ablation (P = 0.025). Pericardiocentesis was required in 44 (86.3%) patients, and the haemodynamic state stabilized after a total of 377 (260-530) mL of pericardial blood drainage except for in 2 (3.9%) patients requiring subsequent emergent surgical repairs. The pericardial drain was successfully removed after a median of 1.0 (1.0-2.0) days. In 44 patients, anticoagulation therapy was restarted a median of 3.0 (1.0-7.0) days after the procedure. Thirty (58.8%) patients experienced early recurrent AF with low-grade fevers (37.4 ± 0.5 °C) and an elevated C-reactive protein [2.4 (1.1-8.5) mg/dL]. After successful management of tamponade, 2 (3.9%) patients exhibited cerebral infarctions despite restarting anticoagulation therapy. One patient died, and the other completely recovered without any neurological deficit. Recurrent post-cardiac injury syndrome (PCIS) occurred on post-procedural Day 13 in another patient, requiring oral prednisone administration for 10 months. During a median follow-up of 23 (5.4-46.1) months, 34 (66.7%) patients were arrhythmia free. Conclusions: Despite an infrequent incidence, surgical backup is essential for performing AF ablation. Even after successful management of tamponade, care should be taken for subsequent complications.

Additional cryoapplications at the pulmonary vein antrum using a 28-mm second-generation cryoballoon: a pilot study of extra-pulmonary vein ablation.

Isolation areas post-28-mm cryoballoon pulmonary vein isolation (CB-PVI) are smaller than post-radiofrequency PV antrum isolation at the left superior PV (LSPV) antrum and recurrent atrial fibrillation (AF) can originate from this area. This pilot study evaluated the impact of additional extra-PV CB applications at the LSPV antrum following conventional CB-PVI. Eighteen paroxysmal AF patients underwent CB-PVI with single 3-min freeze techniques. Following the CB-PVI, 2-min CB applications were added once or twice at the LSPV antrum. Before and after extra-PV ablation, left atrial (LA) 3-D electroanatomical maps were created. Seventy-two total PVs were successfully isolated with 4.2 ± 0.4 applications/patient with 28-mm CBs. The mean LA posterior wall (LAPW) and non-isolated LAPW areas were 14.9 ± 3.6 and 6.9 ± 2.8 cm2, respectively. After 1.6 ± 0.5 mean extra-PV applications, the upper non-isolated LAPW area significantly decreased from 3.3 ± 1.8 to 2.5 ± 1.8 cm2 (p < 0.001). The lowest esophageal temperatures during the extra-PV ablation were 27 °C. The total procedure and fluoroscopic times were 72.8 ± 13.1 and 15.2 ± 5.9 min, respectively. Silent gastric hypomotility was detected in 2/9 patients 1 day later, and mild PV stenosis was observed in 4/72 PVs 3 months later, but did not progress. At 12-month after single procedures, 16 (88.9%) patients were free from recurrent AF off antiarrhythmic drugs. A median of 8.0 [6.0-10.0] months later, PV reconnections were detected in 3/12 (25.0%) PVs. The non-isolated LAPW area was significantly larger in the chronic than acute phase (14.3 ± 5.2 cm2, p = 0.016). This pilot study suggested the potential feasibility of additional LSPV antral cryoapplications following a conventional CB-PVI. The strategy warrants further study in more patients.

Persistence of an iatrogenic atrial septal defect after a second-generation cryoballoon ablation of atrial fibrillation.

Persistent iatrogenic atrial septal defects (iASDs) can be observed after intervention requiring a left atria (LA) access, including pulmonary vein isolation (PVI) of atrial fibrillation (AF). We investigated the incidence of iASDs post-second-generation cryoballoon ablation and the pre-procedural predictors. Eighty-three paroxysmal AF patients underwent PVI using second-generation cryoballoons. The LA was accessed with single 15-Fr steerable sheaths following a radiofrequency transseptal puncture, and the iASD was evaluated with transthoracic echocardiography (TTE), a median of 9.3 (7.1-13.3) months post-procedure. All patients underwent pre-procedural contrast-enhanced multi-detector computed tomography (CT) to evaluate the LA and PV anatomy. iASDs were detected by TTE in 7 (8.4%) patients, a median of 15.5 (6.8-17.3) months post-procedure. Patients with iASDs had significantly larger LA volumes and smaller atrial septal angles, defined as the angle between the atrial septum and sagittal line on the horizontal section at the height of the fossa ovalis, which could be the transseptal puncture site measured on CT, and more likely hypertension than those without. Multivariate analyses revealed that the atrial septal angle was the sole predictor of iASDs [odds ratio 0.764, 95% confidence interval (CI) 0.624-0.935, p = 0.009], and the optimal cut-off value was 57.5° (sensitivity 85.7%, specificity 88.2%, 95% CI 0.873-0.995, p < 0.0001). Patients with iASDs were asymptomatic and had no adverse clinical events during a 17.7 (14.4-25.8) month median follow-up. iASDs were still detectable in 8.4% of patients a median of 15.5 months after the second-generation CB ablation, and the atrial septal angle might aid in predicting persistent iASDs.

Early Recurrence after Longstanding Persistent Atrial Fibrillation Ablation.

Early recurrence (ER) of atrial fibrillation (AF) is common after ablation of longstanding persistent AF. However, optimal timing for repeat ablation has yet to be established.Two-hundred-four patients (mean age 62 ± 9 years) with longstanding persistent AF underwent catheter ablation including pulmonary vein (PV) isolation and substrate modification. ER defined as AF recurrence within 60 days, occurred in 115 patients (56.4%) 9 ± 1 days after the procedure. Analysis showed optimal blanking period to be 15 days. At 426 ± 224 days of follow-up, 30 of 50 (60.0%) patients with ER during the first 15 days (ER ≤ 15) and 13 of 65 (20.0%) patients with ER from the 16th to the 60th day (ER16-60) were free from protocol-defined treatment failure (PDTF) (P < 0.0001). In multivariate analysis, AF duration and LA diameter were independent predictors of ER16-60. Peak first ER was in the first 5 days, with a small maximum in the day 15~20 bin. The mean time to the first ER was longer in patients found to have PV reconnection during the repeat ablation than in those without (13 ± 14 versus 6 ± 7 days, P = 0.002).When adopting a blanking period of 15 days, fewer patients with an ER ≤ 15 had PDTF than those with an ER16-60. AF duration and LA diameter were predictive of an ER16-60.