Background:Inflammation plays a prominent role in the etiology of the early recurrence of atrial fibrillation (ERAF). We prospectively compared the proportion of ERAF and time-course patterns of ...biomarkers between radiofrequency (RF) and cryoballoon (CB) ablation.Methods and Results:We enrolled 82 consecutive paroxysmal AF patients undergoing pulmonary vein (PV) isolation, performed with either a 28-mm 2nd-generation CB and 3-min freeze technique or point-by-point RF ablation. Each group had 41 patients. In the RF group, all PVs were successfully isolated with 28.9±6.5 min of RF delivery. In the CB group, a mean of 5.3±1.4 applications/patient was delivered. The proportion of ERAF was similar between the groups. The time-course patterns significantly differed between the groups for high-sensitivity C-reactive protein (hs-CRP) value (P=0.006) and myocardial injury markers (P<0.0001). Greater myocardial injury was observed in the CB than in the RF group (P<0.0001), whereas the peak hs-CRP value was comparable between the groups. The 2-day post-procedure hs-CRP value was the sole factor correlating with ERAF as identified by the multivariable analysis (hazard ratio 1.697; 95% confidence interval, 1.005–2.865; P=0.048) in the RF, but not the CB group.Conclusions:The proportion of ERAF was comparable after RF and 2nd-generation CB ablation. Despite CB ablation exhibiting greater myocardial injury than RF ablation, the inflammatory responses were comparable between the groups. The inflammatory response extent predicted ERAF post-RF ablation but not post-CB ablation. (Circ J 2016; 80: 346–353)
Background Phrenic nerve injury (PNI) is recognized as an important complication during atrial fibrillation ablation. This study aimed to investigate the incidence and outcome of PNI during superior ...vena cava isolation (SVCI) and circumferential pulmonary vein isolation (CPVI) using radiofrequency (RF) energy and the factors associated with its occurrence. Methods and results Five hundred sixty-seven consecutive patients who underwent SVCI after CPVI without substrate modification who completed a 12-month follow-up were retrospectively analyzed. Point-by-point RF applications were applied with maximum energy settings of 35 W and 30 seconds for the SVCI. In the former 210 patients, sites where pacing captured the PN were avoided whenever possible; however, the maximum power was 35 W. In the latter 357 patients, RF energy was delivered regardless of PN capture; however, the power at PN capture sites was limited to 10 W during continuous diaphragmatic movement monitoring on fluoroscopy. Circumferential pulmonary vein isolation and SVCI were successfully achieved in all. Twelve patients (2.1%) had PNI during SVCI but not during CPVI. Phrenic nerve injury completely recovered in all patients a median of 8.0 months after the procedure. The prevalence was higher in the former period (3.8% vs 1.1%; P = .03). A multivariate logistic regression analysis revealed that the study period (odds ratio 3.546; 95% CI 1.051-11.965; P = .041) was the sole independent predictor for identifying patients with PNI during SVCI. Conclusions Phrenic nerve injury occurred in 2.1% of the patients. All occurred during SVCI but not during contemporary CPVI. Energy titration and continuous diaphragmatic movement monitoring significantly decreased the incidence during SVCI.
Radiofrequency applications around pulmonary vein (PV) ostia often induce vagal reflexes.
This study aimed to evaluate the impact of the order of the targeted PV on the vagal response during ...second-generation cryoballoon ablation.
Eighty-one consecutive paroxysmal atrial fibrillation (AF) patients undergoing cryoballoon ablation were prospectively enrolled. PV isolation was performed with one 28-mm second-generation balloon using a 3-minute freeze technique. In the first 39 patients, the left superior PV (LSPV) was initially targeted. In the second 42, the LSPV was targeted following the right PVs.
Baseline rhythms were sinus rhythm and AF in 34 and 5 patients in the first group, and 34 and 8 in the second group, respectively. In the first group, sinus bradycardia/arrest requiring back-up pacing occurred in 13 patients (38.2%) at a median of 41.0 (10.0-55.5) seconds after balloon deflation (90 60-100 seconds post freezing), and pauses requiring pacing in 1 (20.0%) with AF. In the second group, no sinus bradycardia/arrest occurred throughout the procedure; however, atrioventricular block requiring back-up pacing occurred 21 seconds after balloon deflation in 1 patient in whom right superior PV (RSPV) ablation was performed for only 60 seconds owing to right phrenic nerve injury. The cycle length was similar at baseline and post PV isolation between the 2 groups, and significantly shorter during RSPV ablation (P < .0001) in both. In total, marked vagal responses were significantly higher in the first than second group (14/39 vs 1/42, P < .0001).
LSPV cryoballoon ablation often provoked marked vagal responses; however, preceding RSPV ablation markedly suppressed this response.
Recent advancements in a 3-dimensional mapping system allow for the assessment of detailed conduction properties during sinus rhythm and thus the establishment of a strategy targeting functionally ...abnormal regions in scar-related ventricular tachycardia (VT). We hypothesized that a rotational activation pattern (RAP) observed in maps during baseline rhythm was associated with the critical location of VT.
We retrospectively examined the pattern of wavefront propagation during sinus rhythm in patients with scar-related VT. The prevalence and features of the RAP on critical VT circuits were analyzed. RAP was defined as >90° of inward curvature directly above or at the edge of the slow conductive areas.
Forty-five VTs in 37 patients (66±15 years old, 89% male, 27% ischemic heart disease) were evaluated. High-density substrate mapping during sinus rhythm (median, 2524 points) was performed using the CARTO3 system before VT induction. Critical sites for reentry were identified by direct termination by radiofrequency catheter ablation in 21 VTs or by pace mapping in 12 VTs. Among them, RAP was present in 70% of the 33 VTs. Four VTs had no RAP at the critical sites during sinus rhythm, but it became visible in the mappings with different wavefront directions. Six VTs, in which intramural or epicardial isthmus was suspected, were rendered noninducible by radiofrequency catheter ablation to the endocardial surface without RAP. RAP had a sensitivity and specificity of 70% and 89%, respectively, for predicting the elements in the critical zone for VT.
The critical zone of VT appears to correspond to an area characterized by the RAP with slow conduction during sinus rhythm, which facilitates targeting areas specific for reentry. However, this may not be applicable to intramural VT substrates and might be affected by the direction of wavefront propagation to the scar during mapping. Graphic Abstract: A graphic abstract is available for this article.
Background:Deep sedation or general anesthesia is generally used during atrial fibrillation (AF) ablation. The aim of this study was to report the safety and feasibility of minimal sedation during AF ...ablation.Methods and Results:One thousand and fifty-two AF ablation procedures in 819 patients (62±11 years, 621 men, 506 paroxysmal) were included. Boluses of intravenous hydroxyzine pamoate and pentazocine were administered, with a maximal dose of 100 mg of hydroxyzine and 60 mg of pentazocine in response to pain. If the pain was intolerable or patients requested deeper sedation, moderate sedation using dexmedetomidine or propofol was introduced. Among 819 consecutive first procedures, the procedure was completed under minimal sedation in 795 (97.1%) patients without inotropic drugs or respiratory support, whereas in 20 (2.4%) patients, anesthesia was switched to moderate sedation due to pain. Patients requiring a switch to moderate sedation were significantly younger than those without (53.6±2.3 vs. 62.6±10.4, P<0.01). No procedures were abandoned due to adverse effects of sedation. Significant intra-procedural blood pressure decreases requiring inotropic drugs were not observed in any patients. Among 233 patients who underwent repeat procedures, 6 (2.6%) requested moderate sedation before the procedure. The mean procedure time was 151±54 min. Cardiac tamponade, unrelated to sedation, was observed in 7 (0.66%) procedures.Conclusions:Minimal sedation might be acceptable anesthesia in the vast majority of AF ablation procedures performed in electrophysiological laboratories. (Circ J 2015; 79: 346–350)
Abstract Background Cardiac computed tomography (CT) provides accurate imaging of the pulmonary vein (PV) and left atrial (LA) anatomy. This study aimed to evaluate the prevalence and morphological ...characteristics of anatomical variants that could influence atrial fibrillation (AF) ablation procedures. Methods and results One thousand forty consecutive patients (62 ± 10 years, 243 female, 644 paroxysmal AF) undergoing pre-procedural imaging with a 320-row CT and their first AF ablation procedure were analyzed. A total of 194 (18.7%) patients had anatomical variants. Left, right, and inferior common PVs were observed in 118, 5, and 6 patients, respectively. Three right and left PVs were observed in 44 and 4 patients, respectively. Three patients had remnants of PVs after lobectomies, and significant PV stenosis was observed in one. Supernumerary PVs that drained into the LA and diverticula were observed in eight patients. One patient had a string-like structure connecting the LA septum and posterior LA, and the others had membranous structures incompletely compartmentalizing the LA. Three patients had persistent left superior vena cavae, two strong deviations of the LA and PVs, and one dexiocardia. All patients underwent successful PV isolation during the index procedure. Conclusions Patients referred for AF ablation often have anatomical variants, which could influence the procedure. This information might aid in planning procedural strategies, and reducing unexpected procedural complications in AF ablation.
Bilateral Diaphragmatic CMAPs During Cryoablation
Background
Left phrenic nerve injury (PNI) can occur during cryoballoon ablation of the left pulmonary veins (PVs). This study aimed to evaluate the ...feasibility of monitoring the bilateral phrenic nerve function during cryoballoon ablation of atrial fibrillation (AF).
Methods
Fifty consecutive paroxysmal AF patients undergoing cryoballoon ablation using one 28‐mm second‐generation balloon were prospectively enrolled. Bilateral diaphragmatic compound motor action potentials (CMAPs) were obtained from modified surface electrodes by pacing from the bilateral subclavian veins, and monitored during 3‐minute cryoballoon applications at the ipsilateral PVs.
Results
One hundred ninety of 202 PVs were successfully isolated exclusively using 28‐mm cryoballoons. CMAPs could be obtained in all except 3 cases with catheter inaccessibility in the left subclavian vein. The left and right CMAP amplitudes were similar at baseline (1.04 ± 0.41 mV vs. 1.01 ± 0.43 mV, P = 0.49). Among 105 left and 132 right PV applications while monitoring CMAPs, 2 (1.9%) and 13 (9.8%) applications were interrupted for a decreased CMAP amplitude (P = 0.01). Among them, CMAPs decreased due to right PNI in 4 applications/patients and to catheter dislodgement in the remaining applications. PNI remained in 1 and recovered in the remaining 3 patients one day after the procedure. Applications without requiring interruptions exhibited no significant CMAP amplitude changes throughout the applications, and the time‐course pattern was similar between the bilateral CMAPs (P = 0.292).
Conclusions
A stable bilateral diaphragmatic CMAP could be similarly obtained during cryoballoon applications in the vast majority of patients. Monitoring CMAPs might be useful to anticipate not only right but also left PNI during cryoballoon ablation.
Background:Clinical outcomes after atrial fibrillation (AF) ablation are evaluated using standard 24-h Holter monitoring, and the large spontaneous variability of AF episodes and incidence of silent ...AF are major limitations. Further, symptoms generally decrease after AF ablation.Methods and Results:Newly developed extended external auto-trigger loop recorders (ELR) were used for 14-day consecutive monitoring to detect atrial tachyarrhythmia (ATa). Continuous tracings were stored for the initial 24h. Among 500 examinations after AF ablation in 342 patients, 40 ATa episodes were manually detected in 25 patients during the initial 24h. All episodes including 27 asymptomatic episodes (67.5%) were successfully identified using ELR. Recurrent ATa after AF ablation were detected in 83 patients, and a median monitoring duration of 4.0 days (IQR, 1.0–7.75 days) was required to detect the first episode of recurrence. The sensitivity of 24-h monitoring in detecting arrhythmia recurrence was 27.7% relative to the 14-day monitoring. The diagnostic yield gradually improved with longer monitoring duration regardless of the period after the ablation procedure. Longer follow-up, however, was required to obtain similar diagnostic yield >1 year after as compared to <1 year after the procedure.Conclusions:Twenty-four-hour monitoring detected a part of the ATa recurrences after ablation procedures. Extended ELR enabled arrhythmia monitoring for longer, with higher diagnostic yield of recurrence, regardless of patient symptoms. (Circ J 2014; 78: 2637–2642)
The superior vena cava (SVC) is an infrequent but important source of atrial fibrillation (AF), but is not always easy to identify.
This study aimed to identify predictors of an arrhythmogenic SVC ...(a-SVC) in patients undergoing AF ablation.
Eight hundred thirty-six consecutive patients undergoing AF ablation were analyzed. All patients underwent pulmonary vein antrum isolation during the index procedure. An a-SVC, defined as SVC-triggered AF and an SVC associated with the maintenance of AF, was evaluated by mapping catheters throughout the procedure.
An a-SVC was identified in 44 patients (5.3%) during a total of 1063 procedures. Patients with an a-SVC were younger, less obese, and had a smaller left atrial (LA) size and more paroxysmal AF than those without an a-SVC. The presence of structural heart disease and hypertension was lower, and the coexistence of spontaneous common atrial flutter (AFL) before or during the index procedure was higher in those with an a-SVC than in those without. A multiple logistic regression analysis revealed that the LA size (odds ratio 0.93; 95% confidence interval 0.88-0.99; P = .038) and coexistence of spontaneous common AFL (odds ratio 2.01; 95% confidence interval 1.00-4.02; P = .048) were independent predictors identifying an a-SVC. Although 19 patients (43.2%) required repeat procedures, 39 (88.6%) were free from any atrial tachyarrhythmias without antiarrhythmic drugs at a median of 16.5 months (25th-75th percentiles 9.0-27.0 months) after a mean of 1.5 ± 0.7 procedures.
A smaller LA size and coexistence of spontaneous common AFL were independent predictors of an a-SVC in the context of AF ablation.
Dormant Conduction After Cryothermal PVI
Background
Adenosine triphosphate (ATP) testing reveals dormant pulmonary vein (PV) conduction after electrical PV isolation (PVI). This study aimed to ...evaluate the incidence of latent PV conduction after cryothermal PVI.
Methods
Fifty‐four consecutive paroxysmal atrial fibrillation patients undergoing cryothermal PVI were prospectively enrolled. PVI was performed with one 28‐mm second‐generation balloon using a 3‐minute freeze technique, and touch‐up lesions were created by focal cryothermal applications. ATP testing was performed following PVI with a 20‐mm circular mapping catheter placed in each PV.
Results
Of 217 PVs, 205 (94.5%) were isolated using a cryoballoon, and 12 required additional focal ablation. ATP testing was performed in 46 patients for 173 and 8 PVs, which were isolated by cryoballoons and focal ablation, respectively. No dormant PV conduction was provoked in any PVs, which were isolated by cryoballoons, whereas 4 (50.0%) out of 8 PVs requiring focal ablation had transient ATP‐provoked reconnections (0 vs. 50.0%, P < 0.0001) with a median duration of 11.3 (10.7–17.1) seconds. The latent PV conduction site was identical to the residual conduction gap site after cryoballoon ablation in all. All latent conduction was successfully eliminated by 2 (2.0–9.5) additional focal applications. At a mean follow‐up of 7.7 ± 1.6 months, 81.5% of the patients were arrhythmia free after a single procedure.
Conclusions
No dormant PV conduction was provoked in PVs, which were isolated by 28‐mm second‐generation cryoballoons, but was provoked in 50% of PVs, which were isolated by focal cryoablation. These findings suggest that creating contiguous lesions is essential for eliminating dormant conduction in cryothermal ablation.
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