Subcutaneous air entrapment after subcutaneous implantable cardioverter defibrillator implantation evaluated by computed tomography.

BACKGROUND: Inappropriate shock (IAS) caused by subcutaneous air entrapment (AE) in an early period after subcutaneous implantable cardioverter defibrillator (S-ICD) implantation has been reported, however, no detailed data on air volume are available. We evaluated the subcutaneous air volume after implantation and its absorption rate one week after implantation. METHODS: Patients who underwent S-ICD implantation in our hospital received chest CT scans immediately after implantation and followed up 1 week later. The total subcutaneous air volume, air around the generator, the distal electrode, and the proximal electrode within 3 cm were calculated using a three-dimensional workstation. Fat areas at the level of the lower edge of the generator were also analyzed. RESULT: Fifteen patients received CT immediately after implantation. The mean age was 45.6 ± 17.9 (66.7% of men), and the mean body mass index was 24.3 ± 3.3. The three-incision technique was applied in seven patients and two-incision technique was in the latter eight patients. The mean total subcutaneous air volume was 18.54 ± 7.50 mL. Air volume around the generator, the distal electrode, and the proximal electrode were 11.05 ± 5.12, 0.72 ± 0.72, and 0.88 ± 0.87 mL, respectively. Twelve patients received a follow-up CT 1 week later. The mean total subcutaneous air was 0.25 ± 0.45 mL, showing a 98.7% absorption rate. CONCLUSION: Although subcutaneous air was observed in all patients after S-ICD implantation, most of the air was absorbed within 1 week, suggesting a low occurrence of AE-related IAS after a week postoperation.

Prevalence, characteristics, and predictors of endocardial and nonendocardial conduction gaps during local impedance-guided extensive pulmonary vein isolation of atrial fibrillation with high-resolution mapping.

INTRODUCTION: Local impedance (LI) drops during radiofrequency ablation can predict lesion formation. Some conduction gaps during pulmonary vein isolation (PVI) can be associated with nonendocardial connections. This study aimed to investigate the incidence, characteristics, and predictors of endocardial and nonendocardial conduction gaps during an LI-guided PVI. METHODS AND RESULTS: We prospectively enrolled 157 consecutive patients undergoing an initial LI-guided extensive PVI of atrial fibrillation (AF). After the first-pass encirclement, the residual conduction gaps and reconnected gaps were mapped using Rhythmia (Boston Scientific) and a mini-basket catheter. Right and left PV (RPV/LPV) gaps were observed in 22.3% and 18.5% of the patients, respectively: 27 endocardial and 49 nonendocardial gaps. The carina regions were common sites for the gaps (51 carina-related vs. 25 noncarina-related). The carina-related gaps consisted of more nonendocardial gaps than endocardial gaps (RPVs: 90.0% vs. 10.0%, p = .001; LPVs: 76.2% vs. 23.8%, p < .001). A univariate analysis revealed that paroxysmal AF and the left atrial (LA) volume index for RPV endocardial gaps (odds ratio [OR]: 8.640 and 0.946; p = .043 and 0.009), minor right inferior PV diameter for RPV nonendocardial gaps (OR: 1.165; p = .028), and major left inferior PV diameter for LPV endocardial gaps (OR: 1.233; p = .028) were significant predictors. CONCLUSIONS: During the LI-guided PVI, approximately two-thirds of the conduction gaps were nonendocardial. The carina regions had more conduction gaps than noncarina regions, which was due to the presence of nonendocardial connections. Paroxysmal AF, a lower LA volume index, and larger inferior PV diameters may increase the risk of conduction gaps.

Impact of the size of non-ablated left atrial posterior wall area on outcomes after extensive encircling pulmonary vein isolation.

The aim of this study was to evaluate the impact of the size of the isolated surface area and non-ablated left atrial posterior area after extensive encircling pulmonary vein isolation (EEPVI) for non-paroxysmal atrial fibrillation (AF) on arrhythmia recurrence. This study included 132 consecutive persistent AF patients who underwent EEPVI guided by Ablation Index (AI). The isolated antral surface area (IASA) excluding the pulmonary veins, the non-ablated left atrial (LA) posterior wall surface area (PWSA), the ratio of IASA to LA surface area (IASA/LA ratio), and the ratio of PWSA to LA surface area (PWSA/LA ratio) were assessed using CARTO3 and the association with AF and atrial tachycardia (AT) recurrence was examined. At a mean follow-up of 13.2 ± 7.3 months, sinus rhythm was maintained in 115 (87%) patients. In the univariate Cox regression analysis, the factors that significantly predicted AT/AF recurrence were a history of heart failure, a higher CHA2DS2-VASc score, a larger LA diameter, and a larger PWSA/LA ratio. Multivariate Cox regression analysis revealed that the independent predictors of AT/AF recurrence were LA diameter [hazard ratio (HR) 1.120 per 1 mm increase; 95% confidence interval (CI) 1.006-1.247; P = 0.039] and PWSA/LA ratio (HR 1.218 per 1% increase; 95% CI 1.041-1.425; P = 0.014). Receiver operating characteristics curve analysis yielded an optimal cut-off value of 8% for the PWSA/LA ratio. The Kaplan-Meier survival curve showed that patients with a larger PWSA/LA ratio had poorer clinical outcomes (Log-rank P = 0.001). A larger PWSA/LA ratio was associated with a high AT/AF recurrence rate in patients with non-paroxysmal atrial fibrillation.

Effect of preventing air intrusion on silent strokes during atrial fibrillation ablation using a mini-basket catheter.

BACKGROUND: Air bubble intrusion through transseptal sheaths during left atrial (LA) catheter ablation can cause cerebral embolisms, especially when using complex-shape catheters. This study aimed to compare the incidence of silent cerebral events (SCEs) after atrial fibrillation (AF) catheter ablation using a mini-basket catheter (IntellaMap Orion; Boston Scientific) between the following groups: group SP, strict prevention of LA air intrusion and group CP, conventional air intrusion prevention. METHODS: We enrolled 123 consecutive AF patients (group SP, n = 61 and group CP, n = 62) who underwent brain magnetic resonance imaging after a local-impedance-guided ablation using one mini-basket catheter and one circular mapping catheter. The preventive strategy in group SP included (a) the insertion of the mini-basket catheter into the transseptal sheaths in a container filled with heparinized saline and (b) no exchange of all catheters over the sheaths. RESULTS: SCEs were detected in 67 patients (54.5%), and the incidence of SCEs did not significantly differ between groups SP and CP (55.7% vs 53.2%; P = .780). A multivariate analysis demonstrated that an older age, non-paroxysmal AF, and radiofrequency (RF) power output were independent positive predictors of SCEs (odds ratios: 1.079, 5.613, and 1.405; P = .005, <.001, and .012). On the follow-up MR imaging, 83.5% of the SCEs in group SP and 87.7% in group CP disappeared (P = .398). CONCLUSIONS: Strict prevention of LA air intrusion may have no additional effect for reducing the incidence of SCEs after local impedance-guided AF ablation using a mini-basket catheter. An older age, non-paroxysmal AF, and high-power RF applications may increase the risk of SCEs.

Incidence and characteristics of silent cerebral embolisms after radiofrequency-based atrial fibrillation ablation: A propensity score-matched analysis between different mapping catheters and indices for guiding ablation.

INTRODUCTION: The difference in the incidence and characteristics of silent cerebral events (SCEs) after radiofrequency-based atrial fibrillation (AF) ablation between the different mapping catheters and indices used for guiding radiofrequency ablation remains unclear. This study aimed to compare the incidence and characteristics of postablation SCEs between the following two groups: Group C, Ablation Index-guided ablation using two circular mapping catheters with CARTO (Biosense Webster); Group R, local impedance-guided ablation using one mini-basket catheter and one circular mapping with Rhythmia (Boston Scientific). METHODS AND RESULTS: Of 211 consecutive patients who underwent an AF ablation and brain magnetic resonance (MR) imaging after the ablation, 120 patients (each group, n = 60) were selected by propensity score matching. SCEs were detected in 37 patients (30.8%). Group R had a higher incidence of SCEs (51.7% vs. 10.0%; p < .001) and more SCEs per patient (median, 3 vs. 1, p = .028) than Group C. A multivariate analysis demonstrated that nonparoxysmal AF and being Group R were independent positive predictors of SCEs (odds ratios, 6.930 and 15.464; both p < .001). On the follow-up MR imaging, all SCEs in Group C and 87.9% of the SCEs in Group R disappeared (p = .537). CONCLUSIONS: Group R had a significantly higher incidence of SCEs than Group C. Most probably the use of a complexly designed basket mapping catheter is the reason for the difference in the incidence of SCEs but further validation is needed. A nonparoxysmal form of AF may also increase the risk of SCEs during these ablation procedures.

The effect of bilateral cardiac sympathetic denervation for refractory ventricular tachycardia in ischemic cardiomyopathy.

Recent studies have shown that cardiac sympathetic denervation (CSD) is effective in the treatment of refractory ventricular tachyarrhythmia in patients with structural heart disease. This case report aimed to highlight the effect of bilateral CSD in suppressing treatment-resistant ventricular tachycardia in patients with ischemic cardiomyopathy.

Impact of the type of electroanatomic mapping system on the incidence of cerebral embolism after radiofrequency catheter ablation of left atrial tachycardias.

BACKGROUND: Left atrial tachycardias (ATs) often occur after left atrial ablation. The incidence of symptomatic and silent cerebral embolism after radiofrequency catheter ablation of left ATs and the impact of the type of 3-dimensional electroanatomic mapping (3D-EAM) system on the incidence of cerebral embolism remain unclear. OBJECTIVES: This study aimed to investigate the incidence of cerebral embolism after a 3D-EAM system-guided left AT ablation procedure and compare that between the different 3D-EAM systems. METHODS: We prospectively enrolled 59 patients who underwent left AT ablation and brain magnetic resonance imaging after the procedure: 30 were guided by the Rhythmia system (Boston Scientific, Marlborough, MA) and 29 by the CARTO system (Biosense Webster, Diamond Bar, CA) (groups R and C, respectively). RESULTS: One transient ischemic attack occurred in group R, and no symptomatic embolism occurred in group C. Silent cerebral ischemic lesions (SCILs) were observed in 35 patients (59.3%), and group R had a significantly higher incidence of SCILs than did group C (86.2% vs 33.3%; P < .001). In multivariate analysis, group R and left atrial linear ablation were independent positive predictors of SCILs (odds ratio 12.822 and 8.668; P = .001 and P = .005). The incidence of bleeding complications was comparable between groups R and C (0% vs 3.3%; P = .508). CONCLUSION: Group R exhibited a higher incidence of postablation cerebral embolism than did group C. The use of the high-resolution 3D-EAM system with a mini-basket catheter to guide radiofrequency ablation of left atrial macroreentrant tachycardias may markedly increase the risk of silent cerebral embolism. The present results require further validation in a randomized study.

Postablation cerebral embolisms in balloon-based atrial fibrillation ablation with periprocedural direct oral anticoagulants: A comparison between cryoballoon and HotBalloon ablation.

INTRODUCTION: This prospective observational study aimed to investigate the incidence of symptomatic and silent cerebral embolisms after balloon-based ablation of atrial fibrillation (AF) in patients receiving periprocedural anticoagulation with direct oral anticoagulants (DOACs), and compare that between cryoballoon and HotBalloon ablation (CBA and HBA). METHODS AND RESULTS: We enrolled 123 consecutive AF patients who underwent a balloon-based pulmonary vein isolation (PVI) and brain magnetic resonance (MR) imaging after the ablation procedure (CBA, n = 65; HBA, n = 58). The DOACs were continued in 62 patients throughout the periprocedural period and discontinued in 61 on the procedural day. Intravenous heparin was infused to maintain an activated clotting time of 300 to 400 seconds during the procedure. No symptomatic embolisms occurred in this series. Silent cerebral ischemic lesions (SCILs) were observed on MR imaging in 22 patients (17.9%), and the incidence of SCILs did not significantly differ between the CBA and HBA groups (21.5 vs 13.8%; P = 0.263). According to a multivariate logistic regression analysis, an older age was an independent positive predictor of SCILs (odds ratio, 1.062; 95% CI, 1.001-1.126; P = 0.046), but neither the balloon catheter type nor periprocedural continuation or discontinuation of the DOACs were significant predictors. The incidence of major and minor bleeding complications was comparable between the CBA and HBA groups (1.5 vs 0%, P = 0.528; 7.7 vs 5.2%, P = 0.424). CONCLUSIONS: Both CBA and HBA of AF revealed a similar incidence of postablation cerebral embolisms. Elderly patients may be at a risk of SCILs after a balloon-based PVI with periprocedural DOAC treatment.

Clinical Characteristics and Social Frailty of Super-Elderly Patients With Heart Failure　- The Kitakawachi Clinical Background and Outcome of Heart Failure Registry.

BACKGROUND: Social background is important in preventing admission/readmission of heart failure (HF) patients. However, few clinical studies have been conducted to assess the social background of these patients, especially elderly patients.Methods and Results:The Kitakawachi Clinical Background and Outcome of Heart Failure (KICKOFF) Registry is a prospective multicenter community-based cohort of HF patients, established in April 2015. We compared the clinical characteristics and social background of the super-elderly group (≥85 years old) and the non-super-elderly group (<85 years old). This study included 647 patients; 11.8% of the super-elderly patients were living alone, 15.6% were living with only a partner, and of these, only 66.7% had the support of other family members. The super-elderly group had less control over their diet and drug therapies than the non-super-elderly group. Most patients in the super-elderly group were registered for long-term care insurance (77.4%); 73.5% of the super-elderly patients could walk independently before admission, but only 55.5% could walk independently at discharge, whereas 94% of the non-super-elderly patients could walk independently before admission and 89.4% could walk independently at discharge. CONCLUSIONS: The KICKOFF Registry provides unique detailed social background information of Japanese patients with HF. Super-elderly patients are at serious risk of social frailty; they need the support of other people and their ability to perform activities of daily living decline when hospitalized.