Consecutive Paroxysmal Atrial Fibrillation Patients Research Articles

Initial Result of Antrum Pulmonary Vein Isolation Using the RadiofrequencyHot-Balloon Catheter WithSingle-ShotTechnique.

This study sought to determine the feasibility of a novel simplified ablation protocol targeting only the pulmonary vein antrum using the radiofrequency hot-balloon catheter in patients with paroxysmal atrial fibrillation. Radiofrequency hot-balloon (RHB) catheter has been recently introduced into clinical practice for pulmonary vein isolation (PVI). The authors hypothesized that a novel simplified ablation protocol targeting only the PV antrum with energy application for a longer time (single-shot technique) could be an alternative approach to achieve PVI, while avoiding unnecessary energy application at the PV ostium. A total of 61 consecutive paroxysmal atrial fibrillation patients (age 64.1 ± 10.9 years, 48 male) who underwentantrum RHB-PVI were enrolled. Energy applications were performed following the pre-specified protocol only targeting the PV antrum. If the PVI was not achieved after 2 energy applications using the RHB, a touch-up ablation was performed. Of 241 PV, including 3 left common PV, 194 (80%) were isolated exclusively using the RHB. The target PVI average per group of 15 consecutive procedures improved from 75% (initial 15) to 89% (last 16) of patients. The injected volume was greatest in the right superior PV (13.1 ± 2.0 ml) and the smallest in the left inferior PV (10.8 ± 1.1 ml), and 23 PV (9.5%) required over 15 ml (estimated balloon diameter of 30 mm). Periprocedural complications were noted in 3 patients (4.9%), but phrenic nerve injury was not observed. Sinus rhythm maintenance at 12-month follow-up was achieved in 57 patients (93%). A novel simplified antrum RHB-PVI appears to be a feasible technique for the treatment of paroxysmal atrial fibrillation.

Evaluation of a new approach aiming to enclose the pulmonary veins with optimized and contiguous radiofrequency lesions: Results from a French median-volume ablation center

Recently, a new approach for paroxysmal atrial fibrillation (AF) treatment aiming to enclose the pulmonary veins (PV) by creation of optimized and contiguous radiofrequency (RF) lesions, has been shown to be highly efficient and safe in a high-volume centre (˃ 300 AF ablations/year). We aim to evaluate 1-year outcomes, safety and reproducibility of this new PV isolation (PVI) technique in a French medium-volume center (200 AF ablations/year). A total of 20 consecutive paroxysmal AF patients resistant or intolerant to antiarrhythmic drug therapy (ADT) were prospectively enrolled. Ablation Index guided (force-power-time integral) PVI with contiguous lesions was performed. RF was delivered targeting interlesion distance ≤ 6 mm and AI ≥ 550 arbitrary unit (au) at anterior wall, ≥ 400 au at posterior wall, ≥ 300 au at vicinity of esophagus. Cavo-tricuspid isthmus was performed only in case of atrial flutter (AFL). Recurrence was defined as any AF, atrial tachycardia (AT) or AFL (AF/AT/AFL ˃ 30s) on Holter electrocardiographs at 3, 6 and 12 months. ADT was encouraged to be stopped 3 months after ablation. PVI was obtained in all patients under general anesthesia, with a mean procedure time of 166 ± 22 min. Mean age was 64 ± 11 years. Mean BMI was 25.9 ± 3.6 kg/m 2 . Prevalence of HTA was 50%. Mean CHA2DS2-VASc and HATCH scores were respectively 2 ± 1.1 and 1 ± 0.9. At 12 months, 17/20 patients (85%) were free of AF/AT/AFL after a single procedure, with only 2/20 patients (10%) still on ADT for AF/AT/AFL recurrence. One complication occurred, unlinked to the ablation protocol (arterial pseudo-aneurysm requiring surgical repair). Our results confirm that the approach aiming to enclose the PVs by creation of optimized (Ablation Index guidance) and contiguous RF lesions, is highly efficient and safe in treating paroxysmal AF, with reproducible outcomes in a median-volume ablation center. Multicentre, larger-scale with longer follow-up studies are required.

Prospective Evaluation of Lesion Index-Guided Pulmonary Vein Isolation Technique in Patients with Paroxysmal Atrial Fibrillation: 1-year Follow-Up.

Pulmonary vein isolation (PVI) using contact force (CF) sensing ablation catheters currently relies on CF and force-time integral (FTI) guidelines. Such measurement of lesion effectiveness still lacks information on current delivery to the tissue, influenced by system impedance and power. Lesion Index (LSI) is a multi-parametric index incorporating CF and radiofrequency current data across time. We aimed to prospectively assess the efficacy of an LSI-guided approach to PVI in patients with paroxysmal atrial fibrillation (PAF). The study prospectively enrolled 28 consecutive patients with PAF undergoing PVI with a CF sensing catheter (TactiCathTM, Abbott). LSI-guided ablation target was adapted according to the mean regional thickness of pulmonary vein antra (PVA): LSI range 5.5-6 was pursued in the anterior and septal portions of PVA, 5-5.5 elsewhere. Data from 32 consecutive PAF patients who underwent PVI ablation with a non-CF guided approach (NCF-group) were retrospectively collected for comparison of procedural and clinical outcome.AF-free survival rate at follow-up (17±6 months) was higher for LSI-guided group than NCF-group (89.3% vs 65.6%, p=0.037), with no increase in periprocedural complication rate (no tamponades or other major adverse events reported). Among 1126 lesions with LSI within target range (5-6), average CF was >10g and <30g for 976 lesions (86.7%). Moreover, 1015 lesions (90.1%) had FTI>400gs, but with wide distribution: 30.2% within 400-500gs, 30.0% within 501-600gs, 29.9% over 600gs. In this first prospective study, LSI-guided PVI improved clinical outcome without any increase in complication rate when compared with standard, non-LSI-guided approach.

Two-year clinical outcome after a single cryoballoon ablation procedure: A comparison of first- and second-generation cryoballoons

The ablation of paroxysmal atrial fibrillation (PAF) by cryoballoon has increased dramatically in recent years. However, there are few data comparing first- and second-generation cryoballoons. To compare safety and mid-term (2-year) efficacy of first- and second-generation cryoballoons in PAF ablation, using cryoballoon size tailored to pulmonary vein anatomy. In this single-centre study, we included the last 50 consecutive PAF patients who underwent cryoballoon-based pulmonary vein isolation using the first-generation cryoballoon (CB-1) and the first 50 patients using the second-generation cryoballoon (CB-2). The choice of 23 or 28mm cryoballoon was driven by patient anatomy. After discharge, follow-up was with systematic outpatient visits at 3, 6, 9, 12 and 24 months, including 12-lead electrocardiogram, Holter monitoring and telephone interviews, plus additional electrocardiograms, as required, in case of symptoms. Arrhythmia recurrence was defined as a documented atrial tachycardia or fibrillation episode>30seconds after a 3-month blanking period. At 24 months, freedom from arrhythmia after a single procedure was similar for both generations of cryoballoon (72.0% and 72.0% for CB-1 and CB-2, respectively; P=0.95). Mean procedure and fluoroscopy times were longer in the CB-1 group than in the CB-2 group: 139±37.8 vs 95.2±21.3minutes and 10.2±7.2 vs 5.1±2.4minutes, respectively (P<0.02 for both). Transient right phrenic nerve palsy occurred only in the CB-1 group (five patients, 9.8%). CB-1 and CB-2 showed similar efficacy for PAF ablation, with similar arrhythmia recurrence 24 months after a single ablation procedure. However, our findings suggest that CB-2 may have more effective cooling capabilities, enabling shorter procedure and fluoroscopy times.

Intra-Atrial Conduction Delay Revealed by Multisite Incremental Atrial Pacing is an Independent Marker of Remodeling in Human Atrial Fibrillation.

ObjectivesThis study sought to characterize direction-dependent and coupling interval–dependent changes in left atrial conduction and electrogram morphology in uniformly classified patients with paroxysmal atrial fibrillation (AF) and normal bipolar voltage mapping.BackgroundAlthough AF classifications are based on arrhythmia duration, the clinical course, and treatment response vary between patients within these groups. Electrophysiological mechanisms responsible for this variability are incompletely described.MethodsIntracardiac contact mapping during incremental atrial pacing was used to characterize atrial conduction, activation dispersion, and electrogram morphology in 15 consecutive paroxysmal AF patients undergoing first-time pulmonary vein isolation. Outcome measures were vulnerability to AF induction at electrophysiology study and 2-year follow-up for arrhythmia recurrence.ResultsConduction delay showed a bimodal distribution, occurring at either long (high right atrium pacing: 326 ± 13 ms; coronary sinus pacing: 319 ± 16 ms) or short (high right atrium pacing: 275 ± 11 ms; coronary sinus pacing: 271 ± 11 ms) extrastimulus coupling intervals. Arrhythmia recurrence was found only in patients with conduction delay at long extrastimulus coupling intervals, and patients with inducible AF were characterized by increased activation dispersion (activation dispersion time: 168 ± 29 ms vs. 136 ± 11 ms). Electrogram voltage and duration varied throughout the left atrium, between patients, and with pacing site but were not correlated with AF vulnerability or arrhythmia recurrence.ConclusionsWithin the single clinical entity of paroxysmal AF, incremental atrial pacing identified a spectrum of activation patterns correlating with AF vulnerability and arrhythmia recurrence. In contrast, electrogram morphology (characterized by electrogram voltage and duration) was highly variable and not associated with AF vulnerability or recurrence. An improved understanding of the electrical phenotype in AF could lead to improved mechanistic classifications.

Prevalence of right atrial non-pulmonary vein triggers in atrial fibrillation patients treated with thyroid hormone replacement therapy.

Thyroid hormone (TH) is known to enhance arrhythmogenicity, and high-normal thyroid function is related with an increased recurrence of atrial fibrillation (AF) after catheter ablation. However, the impact of thyroid hormone replacement (THR) on AF ablation is not well known. This study evaluated 1163 consecutive paroxysmal AF patients [160 (14%) on THR and 1003 (86%) without THR] undergoing their first catheter ablation. A total of 146 patients on THR and 146 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model (age, sex, body mass index, and left atrium size). The presence of non-pulmonary vein (PV) triggers was disclosed by a high-dose isoproterenol challenge (up to 30μg/min) after PV isolation. Clinical characteristics were not different between the groups. When compared to the control, non-PV triggers were significantly greater in the THR patients [112 (77%) vs. 47 (32%), P < 0.001], and most frequently originated from the right atrium (95 vs. 56%, P < 0.001). Other sources of non-PV triggers were the interatrial septum (25 vs. 11%, P = 0.002), coronary sinus (70 vs. 52%, P = 0.01), left atrial appendage (47 vs. 34%, P = 0.03), crista terminalis/superior vena cava (11 vs. 8%, P = 0.43), and mitral valve annulus (7 vs. 5%, P = 0.45) (THR vs. control), respectively. After mean follow-up of 14.7 ± 5.2months, success rate was lower in patients on THR therapy [94 (64.4%)] compared to patients not receiving THR therapy [110 (75.3%), log-rank test value = 0.04]. Right atrial non-PV triggers were more prevalent in AF patients treated with THR. Elimination of non-PV triggers provided better arrhythmia-free survival in the non-THR group.

Long-term outcome after catheter ablation of paroxysmal atrial fibrillation: Impact of different atrial fibrillation foci

BackgroundWe aimed to determine whether differing foci in paroxysmal atrial fibrillation (PAF) affected the long-term outcome of catheter ablation (CA). MethodsA total of 865 consecutive PAF patients (age, 61±10years; 670 male) undergoing initial AF ablation were included. After pulmonary vein (PV) isolation, superior vena cava (SVC) isolation was performed for SVC foci; other non-PV foci were focally ablated. Long-term outcomes were compared among patients with SVC foci (Group SVC), other non-PV foci (Group Non-PV), and those without these foci (Group PV). ResultsGroups PV, SVC, and Non-PV contained 740 (85.8%), 57 (6.6%), and 68 (7.6%) patients, respectively. Structural heart disease (P=0.01) and duration of AF history (P=0.04) were significantly associated with Group Non-PV, and female sex (P=0.0002) was significantly associated with Group SVC. AF recurrence-free rates at 5years in Group PV, SVC, and Non-PV were 62.0%, 66.3%, and 49.3%, respectively (P=0.03), after the initial CA, and 84.7%, 83.9%, and 77.0%, respectively (P=0.02), after the final CA. The duration of AF history (HR, 1.04, P<0.0001) and left atrial dimension (HR, 1.37 per 10mm increase, P=0.0003) were significant predictors of AF recurrence after the initial CA. Although Group Non-PV was weakly associated (HR 1.38, P=0.08) with AF recurrence, Group SVC was not associated with AF recurrence. ConclusionsLong-term outcome of CA of PAF was significantly worse in patients with non-PV foci other than SVC foci. These foci may affect the outcome not independently but as an aspect of atrial remodeling.

Durability of cryothermal pulmonary vein isolation — Creating contiguous lesions is necessary for persistent isolation

BackgroundElectrical reconnections after pulmonary vein isolation (PVI) are common in catheter ablation. This study aimed to evaluate the impact of the ablation method on the durability of cryothermal PVI. MethodsOne hundred thirty-two consecutive paroxysmal atrial fibrillation patients undergoing cryothermal PVI were enrolled. PVI was performed with one 28-mm second-generation balloon using 3-minute freeze techniques, and touch-up lesions were created by focal cryothermal applications. ResultsOut of 520 PVs, 503 (96.7%) were isolated using exclusively cryoballoons, and 17 required additional focal ablation. Adenosine testing was performed in 111 patients for 439 PVs including 427 isolated with cryoballoons and 12 isolated by focal ablation. The incidence of dormant conduction was significantly higher in PVs isolated by focal ablation than by cryoballoons (4/12 vs. 3/427 PVs, p<0.0001). All latent conduction was successfully eliminated by additional cryoapplications. In 36 patients, 142 PVs were re-evaluated during repeat procedures a median of 6 [4.3–9.0] months after the initial procedure. Late reconnections were detected in 32 (22.5%) PVs. The incidence of late reconnections was significantly higher in PVs isolated by focal ablation than by cryoballoons (5/6 vs. 27/136 PVs, p=0.0003). Among the PVs requiring touch-up ablation, both the acute dormant conduction and late reconnection sites were identical to sites requiring touch-up ablation. ConclusionsThe incidence of both acute latent and late PV reconnections was significantly higher when PVI was achieved by focal cryoablation than by cryoballoon ablation despite using the same energy source. These data suggest that creating contiguous lesions is essential for achieving a durable PVI.

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

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. 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. 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. 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.

The mechanism of mitral regurgitation assessed by preprocedural echocardiography is associated with the outcome of catheter ablation in patients with paroxysmal atrial fibrillation.

Mitral regurgitation (MR) is generally classified as either primary (organic) or secondary (functional). Although patients with atrial fibrillation (AF) often exhibit MR, the relation between the etiology of MR and the outcome of catheter ablation (CA) remains unknown. We conducted this study in order to elucidate this association. Among 1330 consecutive paroxysmal AF patients who underwent initial catheter ablation in our institution, 92 patients (62 men, mean age 65 ± 7years) who had moderate or severe MR were included in this study; 46 were classified to have primary and the remaining 46 to have secondary MR by preoperative echocardiography. These patients were prospectively monitored after the CA. During a mean follow-up period of 27.9 ± 28.8months, AF recurred in 26/46 (56.6%) of primary MR patients and in 15/46 (32.6%) of those with secondary MR (P < 0.02). Although univariate analysis found that diabetes, left atrial volume indexed by body surface area (LAVI), and primary MR were significantly associated with AF recurrence, primary MR (hazard ratio (HR), 2.47; 95% confidence interval (CI), 1.30-4.88; P = 0.006) and LAVI (HR, 1.03/1mL/m(2) increase; 95% CI, 1.00-1.06; P = 0.03) remained significant predictors on multivariate analysis. The AF recurrence-free rate was lower in patients with primary MR after both the initial and final CA. In patients with paroxysmal AF and moderate or severe MR, primary MR may increase the risk of AF recurrence after the initial and final CA.

Impact of Pulmonary Vein Isolation on Superior Vena Cava Potentials With a Second-Generation Cryoballoon.

Radiofrequency ablation of the right superior pulmonary vein (RSPV) can lead to inadvertent superior vena cava (SVC) isolation due to the close anatomical proximity. This study aimed to evaluate the impact of PV isolation on SVC potentials with a second-generation cryoballoon. Thirty-one consecutive paroxysmal atrial fibrillation patients who underwent PV isolation exclusively with a 28 mm second-generation cryoballoon and single 3-minute freeze technique were prospectively enrolled. The produced SVC potential conduction delay during the RSPV isolation was prospectively evaluated using circular mapping catheters placed in the SVC throughout the cryoballoon procedure. Stable SVC potentials were recorded in 28 (90.3%) patients. The produced SVC potential conduction delay during the RSPV isolation was a median of 6.0 (0.5-7.6) milliseconds, and >5.0 milliseconds in 16 (57.1%) patients. Among them, the delay had shortened by >5.0 milliseconds in 7 (43.8%) patients within 5 minutes after the RSPV application. The distance between the RSPV ostium and SVC was the sole parameter correlated with the produced delay (R = 0.77, P < 0.0001). For the association between the distance and a produced delay of >5 milliseconds, the area under the curve was 0.896 (95% confidential interval = 0.775-1.000). The optimal cutoff point for the distance predicting the occurrence of the conduction delay (>5 milliseconds) was 2.5 mm (sensitivity 83.3%, specificity 81.2%). RSPV isolation with a second-generation cryoballoon could produce an SVC potential conduction delay. The anatomical distance between the RSPV and SVC significantly correlated with the impact.

Reduced residual conduction gaps and favourable outcome in contact force-guided circumferential pulmonary vein isolation

AimsAlthough contact force (CF)-guided circumferential pulmonary vein isolation (CPVI) for paroxysmal atrial fibrillation (PAF) is useful, AF recurrence at long-term follow-up still remains to be resolved. The purpose of this study was to assess safety and efficacy of CF-guided CPVI and to compare residual conduction gaps during CPVI and long-term outcome between the conventional (non-CF-guided) and the CF-guided CPVI.Methods and resultsWe studied the 50 consecutive PAF patients undergoing CPVI by a ThermoCool EZ Steer catheter (conventional group, mean age 61 ± 10 years) and the other 50 consecutive PAF patients by a ThermoCool SmartTouch catheter (CF group, 65 ± 11 years). The procedure parameters and residual conduction gaps during CPVI, and long-term outcome for 12 months were compared between the two groups. Circumferential pulmonary vein isolation was successfully accomplished without any major complications in both groups. Total procedure and total fluoroscopy times were both significantly shorter in the CF group than in the conventional group (160 ± 30 vs. 245 ± 61 min, P < 0.001, and 17 ± 8 vs. 54 ± 27 min, P < 0.001, respectively). Total number of residual conduction gaps was significantly less in the CF group than in the conventional group (2.7 ± 1.7 vs. 6.3 ± 2.7, P < 0.05). The AF recurrence-free rates after CPVI during 12-month follow-up were 96% (48/50) in the CF group and 82% (41/50) in the conventional group (P = 0.02 by log rank test). Multivariate Cox regression analysis further supported this finding.ConclusionContact force-guided CPVI is safe and more effective in reducing not only the procedure time but also the AF recurrence than the conventional CPVI, possibly due to reduced residual conduction gaps during CPVI procedure.

Adenosine Triphosphate Test After Cryothermal Pulmonary Vein Isolation: Creating Contiguous Lesions Is Essential for Eliminating Dormant Conduction

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. 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. 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. 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.

Prospective Evaluation of Bilateral Diaphragmatic Electromyograms During Cryoballoon Ablation of Atrial Fibrillation.

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). 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. 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). 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.

The impact of haemodialysis on the outcomes of catheter ablation in patients with paroxysmal atrial fibrillation

The outcomes of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF) who are undergoing haemodialysis (HD) have not been fully elucidated. This study aimed to determine the impact of HD on CA outcome in these patients. We examined 1364 consecutive PAF patients (mean age, 61 ± 10 years) who underwent CA, including 32 (2.3%) patients undergoing HD. The patients undergoing HD had a significantly lower body mass index (P < 0.0001), higher CHADS2 score (P = 0.006), and higher prevalence of structural heart disease (P < 0.0001), hypertension (P = 0.002), and congestive heart failure (P = 0.02). Echocardiography indicated a larger left atrial diameter (P < 0.0001) and left ventricular diameter (P = 0.0002) in the HD patients. Haemodialysis was a significant predictor of AF recurrence (hazard ratio 2.56; 95% confidence interval 1.56-4.03; P = 0.0004) in the overall population. Sinus rhythm maintenance rates in the HD patients at 1, 3, and 5 years were 42.3, 37.6, and 19.7%, respectively, after the first procedure, and 64.7, 54.9, and 47.1%, respectively, after the final procedure (median, 2; range, 1-2 procedures); these rates were significantly lower than those in the non-HD patients (P < 0.0001). The 5-year survival rate was 78.1% in the HD patients. Haemodialysis was significantly associated with AF recurrence after CA for PAF. However, an ∼50% success rate for sinus rhythm maintenance without antiarrhythmic drug therapy in HD patients suggested that CA could be an option for the treatment of AF.

Adaptive-servo ventilation combined with deep sedation is an effective strategy during pulmonary vein isolation

Pulmonary vein isolation (PVI) by catheter ablation for atrial fibrillation (AF) requires suppression of patient restlessness by sufficient sedation in addition to maintaining stable respiration. We applied adaptive-servo ventilation (ASV) and examined the effects of ASV combined with deep propofol sedation on PVI using a NavX. We analysed 75 paroxysmal AF (PAF) patients (62 ± 11 years; 53 men and 22 women) who underwent PVI for treatment of PAF using an ASV system combined with deep sedation (ASV group). Control patients included 75 consecutive PAF patients (62 ± 11 years; 51 men and 24 women) who underwent PVI just before introduction of the ASV system. Deep sedation was defined as a Ramsay sedation score of 6. The ASV group had a lower frequency of restless body movements compared with the control group during PVI (1.5 ± 0.7 vs. 7.8 ± 1.4 times, P < 0.01). The frequency of respiratory compensation and EnGuide alignment of catheter position by the NavX was lower in the ASV (4.2 ± 3.3 and 8.8 ± 7.1 times) than control group (7.1 ± 5.1 and 15.2 ± 10.0 times, P < 0.05 and <0.01, respectively). Consequently, significantly lower total electrical energy supply (48.7 ± 6.0 KJ) was required in the ASV than control group (64.5 ± 24.9 KJ, P < 0.01). Further, significantly shorter fluoroscopy and procedural times were observed in the ASV (28 ± 5 and 109 ± 25 min) than the control group (33 ± 6 and 141 ± 38 min, respectively, P < 0.01) and the AF recurrence rate was significantly lower in the ASV than the control group (12 vs. 25%, P < 0.01). ASV combined with deep sedation is an effective strategy during PVI using the NavX in patients with PAF.

Bepridil is effective and improves QOL in multidrug-resistant paroxysmal atrial fibrillation

Efficacy and safety of long-term administration of bepridil as a rhythm and rate controller were comprehensively evaluated in patients with multidrug-resistant paroxysmal atrial fibrillation (PAF). A retrospective survey from 1992 to 2006 was conducted on 62 multidrug-resistant PAF patients treated with bepridil from 480 consecutive PAF patients. In addition, a 5-year follow-up study was conducted on 28 of the 62 patients, being continued from 2006 to 2011. The efficacy of bepridil, improvement in symptoms including patients' quality of life (QOL), ECGs, hemodynamics, and its adverse effects were examined. In the retrospective survey, 127 ± 44 mg of bepridil was given for 21 ± 18 months and 40.3% maintained sinus rhythm. Reductions in the frequency and the duration of each episode of PAF and improvement in symptoms were seen in 48.4, 50.0 and 93.5% of the 62 patients, respectively. Reversible torsades de pointes (TdP) occurred in two aged women. Bradycardia and hepatic dysfunction developed in one patient each. In the follow-up study, 100 ± 20 mg of bepridil was given. Sinus rhythm was maintained in 13 patients. Although the occurrences of PAF continued in 14 patients, their symptoms and QOL were improved. No adverse effects were noted in all 28 patients of the follow-up study. Bepridil was effective in rhythm control in 40% of PAF patients resistant to other antiarrhythmics. Even in those who had failed to maintain sinus rhythm, continued administration of low-dose bepridil improved their symptoms and QOL with few adverse effects. Bepridil is worth returning to use.

Impact of pulmonary vein isolation on atrial late potentials: association with the recurrence of atrial fibrillation

In patients with paroxysmal atrial fibrillation (AF), the P-wave signal-averaged electrocardiogram often demonstrates a low-amplitude potential at the terminal part of filtered P-wave (atrial late potential: ALP), which would originate from delayed pulmonary vein (PV) potentials. The aim of this study was to investigate the impact of PV isolation on P-wave morphology, and explore the association between ALP and AF recurrence after ablation. We enrolled 88 consecutive paroxysmal AF patients scheduled for ablation. The signal-averaged electrocardiogram was obtained at baseline and 1 day after ablation. An ALP was defined as a P-wave duration of ≥ 130 ms and a root-mean-squared voltage of the terminal 20 ms of ≤ 2.0 μV. A pre-procedural ALP was found in 37 (42%) patients and a post-procedural ALP was found in 26 (30%) patients. We completed PV isolation in all patients and followed them for 16 ± 4 months. The AF recurrence rate was 30% (26 patients) and was similar between patients with and without pre-procedural ALP (27 vs. 31%, respectively, P = 0.66); however, AF recurrence was significantly higher in patients with than without post-procedural ALP (54 vs. 19%, respectively, P = 0.001). In multivariate logistic regression analysis, post-procedural ALP was independently associated with AF recurrence (odds ratio = 4.22, 95% confidence interval = 1.52-11.7). Pulmonary vein isolation can modify ALP in a substantial number of patients with paroxysmal AF. Post-procedural ALP is associated with increased risk of future AF recurrence.

The incidence and clinical significance of non-isolation of the pulmonary vein carina after encircling ipsilateral pulmonary veins isolation for paroxysmal atrial fibrillation: a pitfall of the double-Lasso technique

Encircling ipsilateral pulmonary veins (PVs) isolation (EIPVsI) with the double-Lasso technique has proven to be effective to cure atrial fibrillation (AF). However, in this technique, PV mapping with circular catheters may miss a non-isolation of the PV carina. The purpose of this study was to reveal the incidence and clinical significance of a non-isolation of the PV carina after EIPVsI. We studied 81 consecutive paroxysmal AF patients (age 61 ± 12 years, 56 men), in whom EIPVsI was successfully performed in one encircling line with the endpoint of the demonstration of bidirectional conduction block between the PVs and left atrium (LA) with the double-Lasso technique. After a successful EIPVsI, pacing from the PV carina was performed and it captured the LA in 17 (21.0%) patients. During a mean follow-up period of 19 ± 13 months, AF recurred in 13 (16.0%) patients. A multivariate Cox proportional analysis revealed that a non-isolation of the PV carina after the EIPVsI was a significant predictor (hazard ratio = 3.91, 95% confidence interval = 1.13-14.16, P = 0.03) of AF recurrence. Pulmonary vein mapping with the double-Lasso technique did miss the non-isolation of the PV carina after a successful EIPVsI, which was an independent predictor of AF recurrence after the EIPVsI. Pacing from the PV carina may be required to confirm the electrical isolation of the PV carina after EIPVsI with the double-Lasso technique.

Mechanism of Atrial Tachycardia Induced by Atrial Pacing after Extensive Encircling Pulmonary Vein Isolation

Objective: Our objective was to evaluate the mechanism of atrial tachycardia (AT) induced by atrial pacing using EnSite NavX multi-electrode mapping system after extensive encircling pulmonary vein isolation (EEPVI) for the paroxysmal atrial fibrillation (AF). Methods: We evaluated 100 consecutive paroxysmal AF patients undergoing EEPVI (all were first procedures, age 60±11 years, 66 males, LA diameter 34±5 mm). Rapid atrial pacing up to 170 ms was performed to induce AF or AT after EEPVI. Activation mapping of induced AT was performed using EnSite NavX. Results: EEPVI was completed in all patients. After EEPVI, AF was induced in 13 patients and AT was induced in 31 patients (34 AT). Atrial activation sequences of 27 AT were evaluated. In the 27 AT, 22 (81%) were macro-reentrant AT and 5 (19%) were focal AT. In the 22 macro-reentrant AT, 11 were peri-mitral AT with a cycle length (CL) of 200±25 ms, 5 were roof-dependent AT (CL 202±56 ms, 3 around left PV and 2 around right PV) and 6 were atrial flutter around tricuspid annulus (CL 212±22 ms). Conclusions: Majority of AT induced by atrial pacing after the completion of EEPVI are macro-reentrant AT. Three reentrant circuits, i.e., around mitral valve, tricuspid valve and pulmonary vein, relate with maintenance of the macro-reentrant AT.