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Superior vena cava isolation (SVCI) is widely performed adjunctively to atrial fibrillation (AF) ablation. Right phrenic nerve injury (PNI) is a complication of this procedure. The purpose of the study is to determine the optimal PNI prevention method in SVCI.A total of 1656 patients who underwent SVCI between 2009 and 2022 were retrospectively examined. PNI was diagnosed based on the diaphragm position and movement in the upright position on chest radiographs before and after SVCI.With the introduction of various PN monitoring systems over the years, the incidence of SVCI-associated PNI has decreased. However, complete PNI avoidance has not been achieved. PNI incidence according to fluoroscopy-guided PN monitoring, high-output pace-guided, compound motor action potential-guided, and 3-dimensional electro-anatomical mapping (EAM) systems was 8.1% (38/467), 2.7% (13/476), 2.4% (4/130), and 2.8% (11/389), respectively. However, a high-power, short-duration (50 W/7 s) radiofrequency (RF) energy application only on PNI risk points tagged by a 3-dimensional EAM system completely avoids PNI (0%; 0 /160 since April 2021). PNI showed no symptoms and recovered within an average of 188 days post-SVCI, except for a few patients who required 1 year.Although PNI incidence decreased annually with the introduction of various monitoring systems, these monitoring systems did not prevent PNI completely. Most notably, the delivery of a high-power, short-duration RF energy only on risk points tagged by EAM prevented PNI completely. PNI recovered in all patients. The application of higher-power, shorter-duration RF energy on risk points tagged by EAM appears to be an optimal PNI prevention maneuver.

Purpose Based on the high rate of coexisting atrial fibrillation (AF) and atrial flutter (AFL), prophylactic cavotricuspid isthmus ablation (CTIA) adjunctive to AF ablation has recently been attempted in patients with AF and without AFL. The present study aimed to determine the rates of AFL occurrence and CTI reconduction after performing CTI ablation adjunctive to AF ablation. Methods We analyzed the data of 3833 consecutive patients with AF, who underwent prophylactic CTIA with AF ablation between 2009 and 2020. Results In all patients, CTIA and AF ablations were successful. Clinical AFL occurred in seven patients (0.18%, 7/3,833), and the observed rate was lower than those reported for cases of AF ablation without CTIA and for those of CTIA for pure AFL. A second ablation was needed in 745 patients at a median of 253 days (25 and 75 percentiles, 116 and 775 days) after the first ablation. In 12.1% (90/745) of the patients, CTI reconduction was observed. The reconduction rate was lower than that previously reported for CTIA for pure AFL. Conclusions The present retrospective study found acceptably low rates of clinical AFL occurrence and CTI reconduction following prophylactic CTIA performed with AF ablation, which was supported by the findings obtained after performing a comparison of the rates with those of other ablations (AF ablation only and CTIA for pure AFL). Considering the high correlation between AF and AFL, the present study provided information regarding the efficacy of adjunctive CTIA.

Background: Electrical remodeling precedes structural remodeling. In adjunctive left atrial (LA) low-voltage area (LVA) ablation to pulmonary vein isolation of atrial fibrillation (AF), LA areas without LVA have not been targeted for ablation. We studied the effect of adjunctive LA posterior wall isolation (PWI) on persistent AF without LA-LVA according to electrophysiological testing (EP test). Methods: We examined consecutive patients with persistent AF with (n=33) and without (n=111) LA-LVA. Patients without LA-LVA were randomly assigned to EP test–guided (n=57) and control (n=54) groups. In the EP test–guided group, an adjunctive PWI was performed in those with positive results (PWI subgroup; n=24), but not in those with negative results (n=33). The criteria for positive EP tests were an effective refractory period ≤180 ms, effective refractory period>20 ms shorter than the other sites, and/or induction of AF/atrial tachycardia (AT) during measurements. LVA ablation was performed in the patients with LA-LVA. Results: During the follow-up period (62±33 weeks), the EP test–guided group had significantly lower recurrence rates (19%,11/57 versus 41%, 22/54, P =0.012) and higher Kaplan-Meier AF/AT–free survival curve rates than the control group ( P =0.01). No significant differences in the recurrence and AF/AT–free survival curve rates between the PWI (positive EP test) and non-PWI (negative EP test) subgroups were observed. Therefore, PWI for positive EP tests reduced the AF/AT recurrence in the EP test–guided group. A stepwise Cox proportional hazard analyses identified EP test–guided ablation as a factor reducing the recurrence rate. The recurrence rates in the LA-LVA ablation group and EP test–guided group were similar. Conclusions: This pilot study proposed that an EP test–guided adjunctive PWI of persistent AF without LA-LVA potentially reduced AF/AT recurrences. The results suggest that there is an AF substrate in the LA with altered electrophysiological function even when there is no LA-LVA. Graphic Abstract: A graphic abstract is available for this article.

Background Some patients with atrial fibrillation (AF) received underdoses of non-vitamin K antagonist oral anticoagulants (NOACs) in the real world. Underdosing is defined as administration of a dose lower than the manufacturer recommended dose. Objectives To identify the efficacy and safety of underdosing NOACs as perioperative anticoagulation for atrial fibrillation ablation. Methods We retrospectively analyzed patients who received rivaroxaban or dabigatran etexilate according to dosage: adjusted low dosage (reduced by disturbed renal function; n = 30), underdosage (n = 307), or standard dosage (n = 683). Non-vitamin K antagonist oral anticoagulants and dosing decisions were at the discretion of treating cardiologists. Results Patients who received underdosed NOACs were older, more often female, and had lower body weight and lower renal function than those who received standard dosages. Activated clotting time at baseline in patients who received adjusted low dosage or underdosages was slightly longer than that in patients receiving standard dosages (156 ± 23, 151 ± 224, and 147 ± 24 seconds, respectively). Meaningful differences were not observed in other coagulation parameters. Adjusted low-, under-, and standard-dosing regimens did not differ in perioperative thromboembolic complications (0/30, 0.0%; 1/307, 0.3%; and 0/683, 0%, respectively) or major (0/30, 0.0%; 2/307, 0.6%; 3/683, 0.4%) and minor (1/30, 3.3%; 13/307, 4.2%; 25/683, 3.6%) bleeding episodes. When comparisons were performed for each NOAC, similar results were observed. Conclusions With consideration of patient condition, age, sex, body weight, body mass index, and renal function, underdosing NOACs was effective and safe as a perioperative anticoagulation therapy for atrial fibrillation ablation. The therapeutic range of NOACs is potentially wider than manufacturer recommendations.

This study aimed to investigate the effects of anticoagulants on ultra-aged patients with nonvalvular atrial fibrillation (AF). We retrospectively studied 320 consecutive patients with AF (median age, 91 years; range 90-100.1 years). Patients were categorized as follows: patients taking direct oral anticoagulant (DOAC group, n = 93), those taking warfarin (warfarin group, n = 147), and those not taking oral anticoagulants (non-OAC group, n = 80). During the follow-up periods (median 3.00 years; first and fourth quantiles, 1.13 and 4.56 years, respectively), in thromboembolic events, the DOAC, warfarin, and non-OAC groups showed the lowest (0%, 0/93; 0%/year), intermediate (4.7%, 7/149; 1.43%/year), and highest (5%, 4/80; 2.65%/year) incidence rates, respectively. In major bleeding events, the DOAC, warfarin, and non-OAC groups showed the highest (9.67%, 9/96; 5.00%/year), intermediate (8.1%, 12/149; 2.46%/year), and lowest (0%, 0/80; 0%/year) incidence rates, respectively. These differences in the relationships of the 3 groups were statistically significant. Confounding factors did not affect these results. Bruises associated with impairment of motor function with aging caused major bleeding in approximately 60% of major bleeding cases. The Cox proportional hazards model revealed that warfarin decreased mortality, whereas antiplatelet drugs increased mortality. In conclusion, DOACs had considerably high incidence of major bleeding events, whereas absence of OAC treatment was associated with substantially high thromboembolic events. Warfarin showed acceptable incidence ratios of both events. At present, warfarin is thus believed to be adequate for ultra-aged (≥90 years) patients with nonvalvular AF. Avoidance of bruises was important to prevent major bleeding events. Antiplatelet drugs were suggested not to be adequate for these patients.

We evaluated the effects of adjunctive left anterior line (LAL) ablation on LA dyssynchrony and function using real-time three-dimensional echocardiography (3DE) in connection with thromboembolic complications and tachyarrhythmia recurrence in patients with persistent atrial fibrillation (AF). We randomly and prospectively assigned consecutive persistent AF patients to the LAL (n = 52, 65 ± 7 years) and control groups (n = 50, 64 ± 10 years). In the LAL group, extensive encircling pulmonary vein isolation (EEPVI), roof line ablation, and LAL ablation regardless of the extent of the low-voltage area (LVA) were performed. The control group underwent EEPVI and roof line ablation. After ablation, 3DE demonstrated LA dyssynchrony in 23 (46%) and 4 patients (8%, P

BACKGROUND Different target activated clotting times (ACTs) during atrial fibrillation (AF) ablation have been proposed. Moreover, relationships between initial bolus dose of heparin at the start of AF ablation in patients receiving edoxaban anticoagulation therapy and ACT are unclear. METHODS Patients who received anticoagulation with uninterrupted warfarin (control; n = 120) or interrupted edoxaban (n = 120) on the morning of day of ablation were studied. An initial dose of 100 U/kg heparin was administered as a reliable control for warfarin. Initial heparin doses of 120, 130, 140, or 150 U/kg were randomly administered to the edoxaban group. RESULTS Edoxaban group showed shorter baseline ACT before the procedure (130 ± 16 seconds) than the warfarin group (152 ± 26 seconds, P

Objective Data on the efficacy of adjunctive interpulmonary isthmus ablation following completion of extensive encircling pulmonary vein isolation (EEPVI) on atrial fibrillation (AF) recurrence have still been insufficient. We aimed to compare the AF recurrence between EEPVI with and without adjunctive interpulmonary isthmus ablation. Methods We enrolled 200 consecutive patients with paroxysmal AF (first session) who underwent EEPVI with double-Lasso technique. Patients were prospectively randomised into two groups: EEPVI with (group 1) and without (group 2) adjunctive interpulmonary isthmus ablation. Results No differences were found in patients’ clinical and echocardiographic backgrounds, including arrhythmia status, between the two groups. No differences were also observed in complications (two groin haematoma in both groups). All patients in both groups reached the EEPVI endpoint. The AF recurrence rate between groups 1 (32/100, 32%) and 2 (33/100, 33%; p=1.0) was quite similar during the follow-up period (45±5 months; 36–54 months). The two groups showed identical Kaplan-Meier AF-free curves (p=0.460; NS). Similar pulmonary vein (PV) reconnection incidence was observed in both groups during the second session. Durable isolation between the superior and inferior PVs was confirmed in 88% (21/27) of patients in group 1, indicating that interpulmonary isthmus ablation maintained a non-conducting state in a considerable number of patients. Nevertheless, AF recurrence was identical between the two groups. Conclusion The results of our study showed similar AF recurrence rates between the two groups, indicating that adjunctive interpulmonary isthmus ablation with EEPVI has no obvious effects on AF recurrence.

The usefulness of dabigatran etexilate for the prevention of stroke in patients with atrial fibrillation (AF) has been reported. In this study the efficacy and safety of dabigatran etexilate for anticoagulation for AF ablation were examined. Patients were divided into three groups: Group 1, interrupted warfarin bridged by heparin between pre- and post-ablation; Group 2, continuous warfarin therapy; and Group 3, dabigatran etexilate therapy. Anticoagulation therapy with warfarin or dabigatran etexilate was performed from 30 days before to at least 90 days after AF ablation. Dabigatran etexilate was administered at 110 or 150 mg twice daily, depending on renal function and age. Patients’ clinical characteristics, associated disorders, echocardiographic parameters and arrhythmia status were not different among the three groups. Procedural parameters such as procedural time and radiofrequency energy supply were also not different among the three groups. The dabigatran etexilate group and the warfarin groups had no embolic complications (stroke, cerebral transient ischaemic attack, deep venous thrombosis or pulmonary embolism). No pericardial tamponade was observed in the dabigatran etexilate group, while two patients in each of Group 1 (2/194, 1.0 %) and Group 2 (2/203, 0.98 %) developed cardiac tamponade, though the differences were not significant. Pericardial effusion and groin haematoma were observed in one patient each (1/105, 0.9 %) in the dabigatran etexilate group, and the incidences were not different from the warfarin group (Group 1: 4/194, 2.1 % and 2/194, 1.0 %; Group 2: 3/203, 1.5 % and 2/203, 1.0 %, respectively). As a whole, the safety outcomes did not differ among the three groups. Dabigatran etexilate is an effective and safe anticoagulation therapy for AF ablation. Thus, dabigatran etexilate appears to be useful as an alternative anticoagulant therapy to warfarin for AF ablation.

Aims 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. Methods and results 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