Impact of unipolar voltage criteria for left atrial posterior wall on atrial fibrillation recurrence after pulmonary vein isolation.

INTRODUCTION: Beyond pulmonary vein isolation (PVI), additional therapeutic strategies for atrial fibrillation (AF) have not been established. Remodeling of the left atrium (LA) could impact AF recurrence post-PVI. We investigated the impact of unipolar voltage (UV) criteria for the LA posterior wall (LA-PW) on AF recurrence post-PVI. METHODS: We reviewed the cases of 106 AF patients (mean age 63.8 years, nonparoxysmal AF: 59%) who underwent extensive encircling PVI by radiofrequency ablation guided by a 3-dimension mapping system, investigating the impact on AF recurrence of the UV criteria of the LA. RESULTS: Out of all patients, 26 patients had AF recurrence during post-PVI follow-up [median 603 days]. They showed a higher percentage of nonparoxysmal AF (80.8 vs. 52.5%, p = .011), longer AF duration (2.9 ± 2.7 vs. 1.0 ± 1.7 years, p = .002), and larger area size of UV < 2.0 mV in LA-PW (2.8 ± 1.8 vs. 1.0 ± 1.5 cm2 , p < .001) than those without recurrence. Cox Hazard analysis for AF recurrence adjusted by age, gender, AF duration, body mass index and left atrial volume index revealed that an area size over 2.0 cm2 of UV < 2.0 mV in LA-PW (HR 6.9 [95% CI:1.3-35.5], p = .021) posed independent risks for AF recurrence post-PVI. The atrial arrhythmia-free survival rate was higher in those with no area of UV < 3.0 mV in LA-PW compared to those with a sizable area (>2.0 cm2 ) of UV < 3.0 mV and <2.0 mV (95.0% vs. 74.2% vs. 57.1%, Log-Rank: p < .001). In the AF etiology of patients with AF recurrence, 9 of 14 patients who underwent the 2nd procedure had no PV reconnection, and 8 patients required the LA-PW isolation for their non-PV AF. CONCLUSION: UV criteria of LA-PW is a useful parameter for AF-recurrence post-PVI. Lower UV in LA-PW as an indication of electrical remodeling could indicate a higher risk of AF recurrence and the need for further therapeutic strategies.

Unipolar-voltage-based evaluation of left atrial tissue properties and ablation outcome in patients with atrial fibrillation.

AIMS: The relationship between local unipolar voltage (UV) in the pulmonary vein (PV)-ostia and left atrial wall thickness (LAWT) and the utility of these parameters as indices of outcome after atrial fibrillation (AF) ablation remain unclear. METHODS AND RESULTS: Two-hundred seventy-two AF patients who underwent AF ablation were enrolled. Unipolar voltage of PV-ostia was measured using a CARTO system, and LAWT was measured using computed tomography. The primary endpoint was atrial tachyarrhythmia (ATA) recurrence including AF. The ATA recurrence was documented in 74 patients (ATA-Rec group). The UV and LAWT of the bilateral superior PV roof to posterior and around the right-inferior PV in the ATA-Rec group were significantly greater than in patients without ATA recurrence (ATA-Free group) (P < 0.001). The UV had a strong positive correlation with LAWT (R2 = 0.446, P < 0.001). The UV 2.7 mV and the corresponding LAWT 1.6 mm were determined as the cut-off values for ATA recurrence (P < 0.001, respectively). Multisite LA high UV (HUV, ≥4 areas of >2.7 mV) or multisite LA wall thickening (≥5 areas of >1.6 mm), defined as LA hypertrophy (LAH), was related to higher ATA recurrence. Among 92 LAH patients, 66 had HUV (LAH-HUV) and the remaining 26 had low UV (LAH-LUV), characterized by history of non-paroxysmal AF and heart failure, reduced LV ejection fraction, or enlarged LA. In addition, LAH-LUV showed the worst ablation outcome, followed by LAH-HUV and No LAH (log-rank P < 0.001). CONCLUSION: Combining UV and LAWT enables us to stratify recurrence risk and suggest a tailored ablation strategy according to LA tissue properties.

Electrogram characteristics at successful cryoablation sites in slow-fast atrioventricular nodal reentrant tachycardia.

PURPOSE: Cryoablation is a safe alternative to radiofrequency (RF) ablation for slow-fast atrioventricular reentrant tachycardia (AVNRT); however, optimal electrogram parameters for site selection remain unknown. We retrospectively investigated local electrograms for slow pathway (SP) modification in cryoablation. METHODS: Forty-five consecutive patients with slow-fast AVNRT who underwent cryoablation using a 6-mm-tip catheter were enrolled. Electrogram parameters for sites of successful SP modification (success-sites) were investigated; these included the interval between atrial activation at His and the last deflection of SP potential, defined as the His(A)-SPP interval. In 8 patients, 3-dimensional mapping by multi-electrode catheter was performed pre-ablation for more detailed SP assessment. RESULTS: Twenty-seven of 45 patients had successful SP modification by 1 cycle of freeze-thaw-freeze cryoablation at a single site with a low amplitude and fragmented SP potential. Among a total of 76 cryoablation sites in all patients, the His(A)-SPP interval at success-sites (45 sites) was significantly longer than that at unsuccess-sites (31 sites) (86 ± 9 vs.78 ± 10 msec, p < 0.0001). The AV amplitude ratio was not significantly different between success-and unsuccess-sites (0.21 ± 0.22 vs.0.25 ± 0.23, p = 0.429). The cutoff value of the His(A)-SPP interval for successful cryoablation was 82 msec with a sensitivity of 0.67 and specificity of 0.71 (AUC: 0.739; 95%CI: 0.626-0.852; p < 0.0001). Three-dimensional mapping in all 8 patients showed that sites with the most delayed atrial activation and the last deflection of the fragmented SP potential within the Koch's triangle coincided with success-sites. CONCLUSION: A longer His(A)-SPP interval and fractionated SP potential were characteristics of successful cryoablation for SP modification in slow-fast AVNRT.

Usefulness of Optimization of Interventricular Delay Using an Electrical Cardiometry Method in Patients with Cardiac Resynchronization Therapy Implantation.

There are no studies examining interventricular (VV) delay optimization by an electrical cardiometry method in relation to subsequent cardiac function in cardiac resynchronization therapy (CRT) -implanted patients. This study aimed to compare the VV delay in CRT-implanted patients by the dp/dt and electrical cardiometry and to examine the optimization of VV delay and improvement of cardiac function. We examined 19 consecutive CRT-implanted patients. The protocol included biventricular stimulation with either simultaneous or sequential pacing, and we evaluated systolic volume (SV) using an electrical cardiometry and the dp/dt of the left ventricle. The optimal VV delay was determined by the maximum SV using the electrical cardiometry. Two groups were defined, those whose increase in SV was at or above the median and those whose SV increase was below the median; changes in left ventricular ejection fraction (LVEF). The correlation between the VV delay optimized by the electrical cardiometry and dp/dt methods was high (R = 0.61, P = 0.006). Compared to the baseline SV (43.4 mL), the SV increased to 47.8 mL with simultaneous biventricular pacing (versus baseline P = 0.008) and further increased to 49.8 mL with optimized VV delay (versus simultaneous biventricular pacing P = 0.020). LVEF after 6 months significantly improved in the above-median SV increase group (37.6 versus 28.2%, P = 0.041), but not in the below-median SV increase group (26.5 versus 26.5%, P = 0.985). In conclusion, the optimal VV delay by electrical cardiometry method was almost concordant with that by the dp/dt method. Cardiac function significantly improved in the group with the above-median SV increase.

Sleep Rate Mode of Pacemaker-Dependent Patients with Sick Sinus Syndrome Increases Dipper Blood Pressure and Dipper Heart Rate Patterns.

Cardiovascular event rates of patients with a dipper blood pressure (BP) and dipper heart rate (HR) pattern are lower than those of patients with nondipper BP and HR patterns. However, how the pacemaker mode affects the diurnal BP and HR patterns remains unclear.We enrolled nine patients (average age 74.4 ± 6.6 years, 4 males and 5 females) with sick sinus syndrome who required atrial pacing. We investigated sequential 6-month pacing regimens (DDD mode at 60 bpm and sleep rate mode). We set the lower rate of sleep rate mode as follows: 60 bpm during the daytime and 50 bpm during the nighttime. The order of pacing mode was randomized, with crossover design. Ambulatory BP monitoring was performed at baseline, 6 months, and 12 months, BP category was classified into four groups (extreme dipper, dipper, nondipper, and riser pattern), and HR was classified into dipper and nondipper patterns.Nighttime HR during the sleep rate mode was significantly lower than that at DDD (57.1 ± 6.2 versus 63.5 ± 3.8 bpm, P = 0.001). The dipper HR pattern was increased in the sleep rate mode compared with those at baseline or DDD mode (versus baseline: 89% versus 44%, P = 0.035; versus DDD: 89% versus 22%, P = 0.004). The dipper BP pattern significantly increased in the sleep rate mode compared with the baseline (56% versus 11%, P = 0.035), but the difference between the sleep rate mode and DDD mode was statistically marginal (56% versus 22%, P = 0.081).The pacemaker settings in the sleep rate mode increased the dipper HR and BP patterns in pacemaker-dependent patients with sick sinus syndrome.

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.

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.

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.

A case of successful radiofrequency catheter ablation of ventricular tachycardia from the noncoronary cusp.

Idiopathic ventricular tachycardias (VTs) originating from the non-coronary cusp (NCC) are very rare. The previous reports suggested NCC-VTs were characterized by a narrower QRS duration and smaller III/II ratio than VTs originating from other coronary-cusps. We present a rare case of an NCC-VT with a local fragmented potential recorded at the NCC inconsistent with the known ECG characteristics of NCC-VTs.

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.

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.

A larger vectorcardiographic QRS area is associated with left bundle branch block and good prognosis in patients with cardiac resynchronization therapy.

BACKGROUND: The association between the vectorcardiographic QRS area, bundle branch pattern and clinical long-term prognosis in patients who have undergone cardiac resynchronization therapy (CRT) has been unclear. METHODS: We enrolled 50 consecutive patients who underwent CRT. Vectorcardiograms were constructed from preprocedural digital 12-lead electrocardiograms using the inverse Dower method. The vectorcardiographic QRS area was defined as the root of the sum of the square in the integral between the ventricular deflection curve and the baseline from QRS beginning to end in leads X, Y, and Z. The primary endpoints were total mortality and admission due to heart failure. RESULTS: The vectorcardiographic QRS area in left bundle branch block (N = 13), right bundle branch block (N = 13), interventricular conduction delay (N = 11) and pacemaker rhythm (N = 13) were 218 ±â€¯99, 97 ±â€¯44, 90 ±â€¯40, and 131 ±â€¯58 µVs, respectively (ANOVA p < 0.001). During the mean follow-up period of 28 (2-86) months, 13 primary endpoints occurred. We divided patients into two groups: a large QRS area group (QRS area ≥114 µVs, N = 25) and a small QRS area group (QRS area <114 µVs, N = 25) by the median. The large QRS area group had a significantly lower rate of the primary endpoint compared with that of the small QRS area group (log rank 4.35, p = 0.037). The Cox regression analysis revealed that a QRS area <114 µVs was a significant predictor of the primary endpoint (HR 3.98, 95% CI 1.01-15.63, p = 0.048). CONCLUSIONS: A larger preprocedural vectorcardiographic QRS area was associated with left bundle branch block and good prognosis in patients who underwent CRT.

Validation of electrical ostial pulmonary vein isolation verified with a spiral inner lumen mapping catheter during second-generation cryoballoon ablation.

BACKGROUND: Achieve catheters are cryoballoon guidewires that enable pulmonary vein (PV) potential mapping. The single catheter approach in conjunction with the Achieve catheter is currently standard practice in second-generation cryoballoon ablation, yet circumferential mapping catheters are the gold standard for evaluating PV isolation (PVI). The study sought to validate the ostial PVI verified by an Achieve catheter alone. METHODS: One hundred fifty-one paroxysmal atrial fibrillation patients undergoing PVI using exclusively 28-mm second-generation cryoballoons were enrolled. PV recordings were analyzed during (real-time recordings) and after cryoballoon applications with 20-mm Achieve mapping catheters, and subsequently validated by 20-mm conventional circumferential mapping catheters. RESULTS: Out of 596 PVs, 576 (96.6%) were isolated using cryoballoons, and 20 required touch-up ablation. PVI was verified during cryoballoon applications with real-time monitoring in 299, and after applications in 280 PVs by Achieve catheters alone. The time-to-isolation was 27.2 ± 22.0 seconds. Validation with standard circumferential mapping catheters confirmed ostial PVIs in 296 of 299 (99.0%) PVs that real-time PVI was obtained during applications, and in 242 of 280 (86.5%) PVs that PV activities were not visible during applications and PVI was verified after the applications. The accuracy of ostial PVIs with Achieve catheters in PVs without obtaining real-time PV recordings was 40/47 (85.1%), 58/65 (89.2%), 77/79 (97.5%), 61/81 (75.3%), and 6/8 (75.0%) in left superior, left inferior, right superior, right inferior, and left common PVs, respectively. CONCLUSIONS: In second-generation 28-mm cryoballoon ablation, verification of ostial PVIs using Achieve mapping catheters alone might not be sufficient to accurately confirm an ostial PVI when real-time PVI was not obtained.

Autonomic nervous system modulation and clinical outcome after pulmonary vein isolation using the second-generation cryoballoon.

BACKGROUND: The intrinsic cardiac autonomic nervous system (ANS) plays a significant role in atrial fibrillation (AF) mechanisms. This study evaluated the incidence and impact of intraprocedural vagal reactions and ANS modulation by pulmonary vein isolation (PVI) using second-generation cryoballoons on outcomes. METHODS: One hundred three paroxysmal AF patients underwent PVI with one 28-mm second-generation balloon. The median follow-up was 15.0 (12.0-18.0) months. ANS modulation was defined as a >20% cycle length decrease on 3-minute resting electrocardiograms at 1, 3, 6, and 12 months postindex procedure relative to baseline if sinus rhythm was maintained. RESULTS: Marked sinus arrests/bradycardia and atrioventricular block (intraprocedural vagal reaction) occurred in 14 and 2 patients, and all sinus arrest/bradycardia occurred in 44 patients with left superior pulmonary veins (PVs) targeted before right PVs. ANS modulation was identified in 66 of 95 (69.5%) patients, and it persisted 12-month postprocedure in 36 (37.9%) patients. Additional ß-blocker administration was required in 9 patients for sinus tachycardia. ANS modulation was similarly observed in patients with and without intraprocedural vagal reactions (P = 0.443). Forty-eight (46.6%) patients experienced early recurrences, and the single procedure success at 12 months was 72.7%. Neither intraprocedural vagal reactions nor ANS modulation predicted AF freedom within or after the blanking period. Thirty-three patients underwent second procedures, and reconnections were detected in 39 of 130 (30.0%) PVs among 23 (69.7%) patients. The incidence of reconnections was similar in patients with and without ANS modulation. CONCLUSIONS: Increased heart rate persisted in 37.9% of patients even at 12-month post-second-generation cryoballoon PVI. Neither intraprocedural vagal reactions nor increased heart rate predicted a single procedure clinical outcome.

Esophagus-Related Complications During Second-Generation Cryoballoon Ablation-Insight from Simultaneous Esophageal Temperature Monitoring from 2 Esophageal Probes.

BACKGROUND: Monitoring luminal esophageal temperatures (LETs) helps predict esophageal thermal lesions (ETLs) after catheter ablation. This study aimed to evaluate esophagus-related complications after second-generation cryoballoon ablation under simultaneous LETs monitoring from 2 esophageal probes. METHODS: Forty consecutive paroxysmal atrial fibrillation patients undergoing second-generation cryoballoon ablation under conscious sedation followed by esophagogastroscopy were prospectively included. Two temperature probes inserted bi-nasally (both non-deflectable in 13, non-deflectable and deflectable in 27 patients) were used for LET monitoring. Pulmonary vein isolation was performed with one 28-mm balloon using single 3-minute freeze techniques. RESULTS: The lowest LETs significantly correlated between different probes; however, deflectable probe showed significantly lower nadir LETs than non-deflectable probes (14.6 ± 9.2 vs. 20.0 ± 10.6 ℃, P<0.0001). Esophagogastroscopy post-ablation demonstrated ETLs and gastroparesis in 8 (20%) and 7 (17.5%) patients (total 13 [32.5%]), respectively. The optimal cutoff for the lowest LET measured on any probe for predicting no ETLs was 12.8 ℃ (sensitivity 78.1%, specificity 100%). When using deflectable and non-deflectable catheters, the optimal cutoff point for the lowest LET for predicting no ETLs was 11.4 ℃ (sensitivity 70.0%, specificity 100%) and 19.4 ℃ (sensitivity 63.6%, specificity 100%), respectively. No ETLs were detected in 12 (30%) patients with the esophagus located between the left atrium and spine. All esophagus-related complications were asymptomatic and had healed on repeat esophagogastroscopy by a mean of 53 ± 25 days after the procedure. CONCLUSIONS: The lowest LET highly depended on the temperature probe location. However, if a different cutoff value was applied, LET monitoring, regardless of the probe type, and anatomical information might help predict ETLs during second-generation cryoballoon ablation.