Comparison of high‐power short‐duration (HPSD) ablation of atrial fibrillation using a contact force‐sensing catheter and conventional technique: Initial results

Introduction: Atrial fibrillation (AFib) ablation is alternative treatment to drugs. Literature suggests that use of contact force (CF) catheter with higher power for short periods is effective and safe. Methods/Results: Retrospectively analyzed 76 patients undergoing the first ablation. Third five patients‐group A: 27 (77%) paroxysmal AFib (PAFib) and 8 (23%) persistent AFib (PersAFib) who underwent ablation at the power of 30 W‐17 mL/minute flow with a CF of 10‐30 g for 30 seconds. Fourty one patients‐group B: 28 (68.3%) PAFib and 13 (31.70%) PersAFib underwent ablation using 45 W on posterior wall with CF of 8/15 g, as well as 50‐W anterior wall with CF of 10/20 g‐35 mL/minute flow for 6 seconds. Pulmonary vein isolation in both groups and ablated. For patients not in the sinus, we performed cardioversion before ablation. No complications. Group A: Left atrial time 110 ± 29 minutes, total 148 ± 33.6 minutes, radiofrequency time (RF) 4558 ± 1998 seconds, X‐ray 8.5 ± 3.5 minutes, and elevation of esophageal temperature (ET) in 26 (74.3%). group B: Left atrial time 70.7 ± 18.5 minutes ( P < .00001), total 106 ± 23 minutes ( P < .00001), RF 1909 ± 675.8 seconds ( P < .00001), X‐ray 8.8 ± 6.6 minutes ( P = .221) and elevation of ET in 21 (51.20% ‐ P = .0578). In 6 and 12 months follow‐up, we had 9 (25.71%) and 11 (31.42%) recurrences in group A and 5 (12.19%) and 7 (17.07%) in group B ( P = .231 at 6 and P = .14 at 12 months), respectively. Conclusions: HPSD was safe, useful, and efficient compared with CT, and reduced procedural time and total RF time. HPSD may reduce esophageal injury because of lower heating rate and it may reduce the recurrence of atrial tachyarrythmias.     

Predictors of outcome after catheter ablation for atrial fibrillation: Group analysis categorized by age and type of atrial fibrillation

Background

The outcome of catheter ablation could probably differ among patients with atrial fibrillation (AF), depending on age and AF type. We aimed to investigate the difference in predictors of outcome after catheter ablation for AF among the patient categories divided by age and AF type.

Methods and Results

A total of 396 patients with AF (mean age 65.69 ± 11.05 years, 111 women [28.0%]) who underwent catheter ablation from January 2018 to December 2019 were retrospectively analyzed. We divided the patients into four categories: patients with paroxysmal AF (PAF) or persistent AF (PeAF) who were 75 years or younger (≤75 years) or older than 75 years (>75 years). Kaplan–Meier survival analysis demonstrated that patients with PAF aged ≤75 years had the lowest AF recurrence among the four groups (log-rank test, p = .0103). In the patients with PAF aged ≤75 years (N = 186, 46.7%), significant factors associated with recurrence were female sex (p = .008) and diabetes (p = .042). In the patients with PeAF aged ≤75 years (N = 142, 35.9%), the only significant factor associated with no recurrence was medication with a renin-angiotensin system inhibitor (p = .044). In the patients with PAF aged >75 years (N = 53, 14.4%), diabetes was significantly associated with AF recurrence (p = .021). No significant parameters were found in the patients with PeAF aged >75 years (N = 15, 4.1%).

Conclusions

Our findings indicate that the risk factors for AF recurrence after catheter ablation differed by age and AF type.     

Factors associated with early atrial fibrillation after ablation of common atrial flutter. A single centre prospective study.

BACKGROUND: The occurrence of early atrial fibrillation (< or = 6 months) after ablation of common atrial flutter is of clinical significance. Variables predicting this evolution in ablated patients without a previous atrial fibrillation history have not been fully investigated. OBJECTIVES: The aim of the present study was: (1) to identify predictive factors of early atrial fibrillation (< or = 6 months) in the overall population following atrial flutter catheter ablation; (2) to identify predictive variables of early atrial fibrillation following (< or = 6 months) atrial flutter catheter ablation within a subgroup of patients without documented prior atrial fibrillation. METHODS: This study prospectively included 96 consecutive patients (age 65 +/- 13 years; 18 women) over a 12-month period. Their counterclockwise flutter was ablated by radiofrequency, by the same operator, with an 8-mm-tip catheter. Clinical, electrophysiological and echocardiographic data were collected and 27 variables were retained for analysis: age; gender; type of atrial flutter (permanent vs paroxysmal); symptom duration (months +/- SD); pre-ablation history of atrial fibrillation; structural heart disease; left ventricular ejection fraction (%); left atrial size (mm); cava--tricuspid isthmus dimension; septal isthmus dimension; systolic pulmonary pressure > or < or = 30 mmHg; right atrial area; left atrial area; isthmus block; number of radiofrequency applications (+/- SD); antiarrhythmic drugs at discharge; left ventricular diastolic diameter; left ventricular systolic diameter; left ventricular telediastolic volume; left ventricular telesystolic volume; A-wave velocity (cm . s(-1)); E-wave velocity (cm . s(-1)); E/A; isovolumetric relaxation time; E-wave deceleration time; significant mitral regurgitation and flutter cycle length (ms). RESULTS: Of the 96 consecutive ablated patients, early atrial fibrillation was documented in 16 patients (17%). Atrial fibrillation occurred 30 +/- 46 days (range 1 to 171 days) after ablation. Univariate analysis associated an early occurrence of atrial fibrillation with: atrial fibrillation history, left ventricular ejection fraction, left atrial size, left ventricular telesystolic volume, A-wave velocity, significant mitral regurgitation and flutter cycle length. Multivariate analysis using a Cox model found that the only independent predictors of early atrial fibrillation were left ventricular ejection fraction and pre-ablation history of atrial fibrillation. In the subgroup without prior atrial fibrillation history (n=63; 66%), the only independent predictor of early atrial fibrillation was the presence of a significant mitral regurgitation. CONCLUSIONS: In a subgroup of patients without atrial fibrillation history, 8% of patients revealed an early atrial fibrillation. Mitral regurgitation is a strong predictive factor of early atrial fibrillation occurrence with 80% sensitivity, 78% specificity and 98% negative predictive value. These data should be considered in post-ablation management.     

Approach and strategy for repeat catheter ablation of recurrent atrial fibrillation

Patients with atrial fibrillation often undergo repeat catheter ablation for the recurrence of tachyarrhythmia. If the pulmonary veins were isolated in prior procedure, the operator should focus on substrate homogenization with identification and ablation of only arrhythmogenic areas.     

Complications of catheter ablation for atrial fibrillation: incidence and predictors

Introduction: Pulmonary vein (PV) isolation by catheter ablation is an increasingly used strategy to treat atrial fibrillation (AF). Complication rates from AF ablation reported in different case series vary widely. We conducted a retrospective analysis of 641 consecutive ablation procedures to assess complication rates, temporal trends, and clinical predictors of adverse outcomes.
Methods: All patients (n = 517) undergoing catheter ablation for AF at Johns Hopkins Hospital between February, 2001 and June, 2007 were prospectively enrolled in a database. Data from 641 consecutive procedures were analyzed and complications considered if they occurred within 30 days of ablation. Major complications were defined as those that required intervention, resulted in long-term disability, or prolonged hospitalization.
Results: Thirty-two major complications occurred in 641 procedures (5%). Among the patients with major complications, seven had cerebrovascular accident (CVA), eight had tamponade, one had PV occlusion with hemoptysis, and 11 had vascular injury requiring surgical repair and/or transfusion. No periprocedural deaths occurred, and no instances of esophageal injury were seen. Complication rates were higher during the first 100 cases (9.0%) than during the subsequent 541 (4.3%). Major adverse clinical events were associated with age > 70 years (P = 0.007; odds ratio 3.7, 95% confidence interval 1.4–9.6) and female gender (P = 0.014; odds ratio 3.0, 95% confidence interval 1.3–7.2). No other clinical or procedural predictors of complication were identified.
Conclusions: Complication rates from AF ablation remain significant, despite improved techniques and increased awareness of procedural risks. Both advanced age and female gender predict major adverse events, suggesting careful consideration of the risk/benefit profile in these patients prior to ablation.     

The different mechanisms between late and very late recurrences of atrial fibrillation in patients undergoing a repeated catheter ablation

Introduction: The mechanisms of late (<1 year after the ablation) and very late (>1 year after the ablation) recurrences of paroxysmal atrial fibrillation (AF) after catheter ablation have not been reported.
Methods and Results: Fifty consecutive patients undergoing a repeated electrophysiologic study to investigate the recurrence of paroxysmal AF after the first ablation were included. Group 1 consisted of 12 patients with very late (26 ± 13 months) and group 2 consisted of 38 patients with late (3 ± 3 months) recurrence of paroxysmal AF. In the baseline study, group 1 had a lower incidence of AF foci from the pulmonary veins (PVs) (67% vs 92%, P = 0.048) and a higher incidence of AF foci from the right atrium (50% vs 13%, P = 0.014) than group 2. In the repeated study, group 1 had a higher incidence of AF foci from the right atrium (67% vs 3%, P < 0.001) and a lower incidence of AF foci from the left atrium (50% vs 97%, P < 0.001), including a lower incidence of AF foci from the PVs (50% vs 79%, P = 0.07) and from the left atrial free wall (0% vs 29%, P = 0.046) than group 2. Furthermore, most of these AF foci (64% of group 1, 65% of group 2) were from the previously targeted foci.
Conclusion: The right atrial foci played an important role in the very late recurrence of AF, whereas the left atrial foci (the majority were PVs) were the major origin of the late recurrence of AF after the catheter ablation of paroxysmal AF.     

Deep sedation for catheter ablation of atrial fibrillation: a prospective study in 650 consecutive patients

Deep Sedation for Catheter Ablation of AF. Introduction: Catheter ablation of atrial fibrillation (AF) is a highly invasive and relatively long‐lasting procedure with specific requirements for patient sedation. The feasibility and safety of deep sedation is described in a prospective study of 650 consecutive patients. Methods: Sedation was initiated with an intravenous (iv) bolus of midazolam, and analgesia with an iv fentanyl bolus. After an iv propofol bolus, maintenance of sedation was achieved with continuous iv administration of propofol with a guide dose of 5 mg per kg per hour. Heart rate, invasive arterial blood pressure, and oxygenation were continuously monitored. The administration of sedation and analgesia medication were performed by a nurse under the supervision and instructions of the electrophysiologist. Results: The mean dose of the initial midazolam bolus was 2.4 ± 0.7 mg and of the initial propofol bolus 32 ± 11 mg. The beginning dose of continuous propofol infusion was 352 ± 66 mg/h; titration to the desired effect of deep sedation required adjustment on an average of 3.8 ± 2.6 times leading to a maintenance dose of continuous propofol infusion of 399 ± 99 mg/h. No major sedation‐related complications were observed. Endotracheal intubation was necessary in none of the patients. Heart rate, invasive arterial blood pressure, and oxygenation remained stable during sedation. Conclusion: Deep sedation for catheter ablation of AF is feasible and safe. Especially, the goal of keeping the patient in deep sedation while maintaining spontaneous ventilation and cardiovascular hemodynamic stability was accomplished. Endotracheal intubation or consultation of an anesthesiologist was not necessary in any patient. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1339‐1343, December 2011)     

Left atrial strain,intervendor variability,and atrial fibrillation recurrence after catheter ablation: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis is to investigate the capacity of preinterventional left atrial strain (LAS) to predict AF recurrence (AFR) after catheter ablation by using all relative published data. Intervendor variability regarding different ultrasound stations and strain analysis software suites was taken into consideration. The research was performed according to PRISMA guidelines. The Cochrane database, MEDLINE, and EMBASE were searched for studies assessing echocardiography LAS prior to catheter ablation of AF cases. The systematic research yielded 10 studies (2 retrospective and 8 prospective, 880 patients in total). LAS differed significantly between the patients with AFR and those with no AF recurrence (nAFR) during the follow-up period (LAS_AFR: 17.5 ± 8.7% vs. LAS_nAFR: 24.1 ± 9.5%, p < 0.00001). A pooled cutoff value of 21.9% for LAS was extracted for the prediction of ablation success. Regarding intervendor variability, subgroup analyses were able to be performed for studies using GE and TomTec software. The difference in LAS_AFR and LAS_nAFR remained significant (p < 0.00001 and p < 0.0001 for TomTec and GE, respectively), while significant intervendor difference in absolute strain values was also detected (p < 0.0001 for both AFR and nAFR groups). LAS prior to catheter ablation is consistently lower in patients who experience AF recurrence. Its incorporation in clinical practice would assist physicians detect patients who require closer follow-up. Intervendor variability appears to be considerable and steps must be taken to document it thoroughly and mitigate it if possible.     

Predicting the arrhythmogenic foci of atrial fibrillation before atrial transseptal procedure: implication for catheter ablation

INTRODUCTION: Use of endocardial atrial activation sequences from recording catheters in the right atrium, His bundle, and coronary sinus to predict the location of initiating foci of atrial fibrillation (AF) before an atrial transseptal procedure has not been reported. The purpose of the present study was to develop an algorithm using endocardial atrial activation sequences to predict the location of initiating foci of AF before transseptal procedure. METHODS AND RESULTS: Seventy-five patients (60 men and 15 women, age 68 +/- 12 years) with frequent episodes of paroxysmal AF were referred for radiofrequency ablation. By retrospective analysis, characteristics of the endocardial atrial activation sequences of right atrial, His-bundle, and coronary sinus catheters from the initial 37 patients were correlated with the location of initiating foci of AF, which were confirmed by successful ablation. The endocardial atrial activation sequences of the other 38 patients were evaluated prospectively to predict the location of initiating foci of AF before transseptal procedure using the algorithm derived from the retrospective analysis. Accuracy of the value <0 msec (obtained by subtracting the time interval between high right atrium and His-bundle atrial activation during atrial premature beats from that obtained during sinus rhythm) for discriminating the superior vena cava or upper portion of the crista terminalis from the pulmonary vein (PV) foci was 100%. When the interval between atrial activation of ostial and distal pairs of the coronary sinus catheter of the atrial premature beats was <0 msec, the accuracy for discriminating left PV foci from right PV foci was 92% in the 24 foci from the left PVs and 100% in the 19 foci from the right PVs. CONCLUSION: Endocardial atrial activation sequences from right atrial, His-bundle, and coronary sinus catheters can accurately predict the location of initiating foci of AF before transseptal procedure. This may facilitate mapping and radiofrequency ablation of paroxysmal AF.     

心房颤动射频消融术后复发危险因素的研究进展

心房颤动（房颤）是临床最常见的心律失常类型之一,给患者和社会带来沉重的生活和经济负担。尽管目前射频消融术已经成为房颤的重要治疗手段,但术后复发一直是医生面临的难题,也成为研究者关注的热点。本文总结了国内外有关房颤射频消融术后复发危险因素的最新研究进展。     

Comparison of cool tip versus 8-mm tip catheter in achieving electrical isolation of pulmonary veins for long-term control of atrial fibrillation: a prospective randomized pilot study

Objective: To compare safety and efficacy of 8-mm versus cooled tip catheter in achieving electrical isolation (EI) of pulmonary veins (PV) for long-term control of atrial fibrillation (AF).
Background: There is paucity of studies comparing safety/efficacy of 8-mm and cooled tip catheters in patients undergoing AF ablation.
Methods and Results: This was a randomized and patient-blinded study. Subjects were followed by clinic visits (at 6 weeks and 6 months) and transtelephonic monitoring (3-week duration) done around each visit. Primary endpoints were: (1) long-term AF control (complete freedom and/or >90% reduction in AF burden on or off antiarrhythmic drugs at 6 months after a single ablation), and (2) occurrence of serious adverse events (cardiac tamponade, stroke, LA-esophageal fistula, and/or death). Eighty-two patients (age 56 ± 9 years, 60 males, paroxysmal AF = 59) were randomized (42 patients to 8-mm tip and 40 patients to cooled tip). EI of PVs was achieved in shorter time by the 8-mm tip as compared with cooled tip catheter (40 ± 23 minutes vs 50 ± 30 minutes; P < 0.05) but long-term AF control was not different between the two (32 patients [78%] vs 28 patients [70%], respectively; P = NS). One serious adverse event occurred in each group (LA-esophageal fistula and stroke, respectively) and no significant PV stenosis was observed in either.
Conclusion: EI of PVs using either 8-mm or cooled tip catheter results in long-term AF control in the majority after a single ablation procedure, with comparable efficacy and safety.     

P wave signal-averaged electrocardiography predicts recurrence of paroxysmal atrial fibrillation in patients with Wolff-Parkinson-White syndrome who underwent successful catheter ablation: a prospective study

INTRODUCTION: Paroxysmal atrial fibrillation (PAF) frequently occurs in patients with Wolff-Parkinson-White (WPW) syndrome. Catheter ablation of the accessory pathway eliminates PAF in some patients, but PAF frequently recurs in other patients. The present study was designed to determine prospectively whether P wave signal-averaged electrocardiography (P-SAECG) predicts the recurrence of PAF after successful ablation in patients with WPW syndrome. METHODS AND RESULTS: Forty-six patients with WPW syndrome who had episodes of PAF were prospectively followed. SAECG recording was performed on day 7 after successful ablation of the accessory pathway at study entry. Abnormal P-SAECG for the prediction of recurrence of PAF was defined as a filtered P wave duration > 130 msec. Eleven patients had an abnormal P-SAECG (group 1), whereas 35 patients (group 2) did not. The two groups did not differ in terms of gender, age, left atrial dimension, and atrial vulnerability as determined by electrophysiologic study. During follow-up (40 +/- 19 months), the recurrence of PAF was noted in 10 (91%) of 11 patients in group 1, whereas it was observed in only 2 (6%) of 35 patients in group 2. Kaplan-Meier analysis revealed that the recurrence of PAF was significantly more frequent in group 1 than in group 2 (log rank test, P < 0.0001). By multivariate analysis, filtered P wave duration >130 msec was an independent predictor of recurrence of PAF after ablation (Chi-square = 21.5, P < 0.0001). CONCLUSION: The results of this study indicate that P-SAECG may be useful for identifying patients at risk for recurrence of PAF after successful ablation of WPW syndrome.