Adherent skin barrier drape use is associated with a reduced risk of cardiac implantable device infection: Results from a prospective study of 14,225 procedures.

Background: Cardiac implantable electronic device (CIED) infection is a costly and highly morbid complication. Perioperative interventions, including the use of antibiotic pouches and intensified perioperative antibiotic regimens, have demonstrated marginal efficacy at reducing CIED infection. Additional research is needed to identify additional interventions to reduce infection risk. Objective: We sought to evaluate whether adherent skin barrier drape use is associated with a reduction in CIED infection. Methods: A prospective registry of all CIED implantation procedures was established at our institution in January 2007. The registry was established in collaboration with our hospital infection prevention team with a specific focus on prospectively identifying all potential CIED infections. All potential CIED infections were independently adjudicated by 2 physicians blinded to the use of an adherent skin barrier drape. Results: Over a 13-year period, 14,225 procedures were completed (mean age 72 ± 14 years; female 4,918 (35%); new implants 10,005 (70%); pulse generator changes 2585 (18%); upgrades 1635 (11%). Of those, 2469 procedures (17.4%) were performed using an adherent skin barrier drape. There were 103 adjudicated device infections (0.73%). The infection rate in patients in the barrier use groups was 8 of 2469 (0.32%) as compared with 95 of 11,756 (0.8%) in the nonuse group (P = .0084). In multivariable analysis, the use of an adherent skin barrier drape was independently associated with a reduction in infection (odds ratio 0.32; 95% confidence interval 0.154-0.665; P = .002). Conclusion: The use of an adherent skin barrier drape at the time of cardiac device surgery is associated with a lower risk of subsequent infection.

Standard vs Augmented Ablation of Paroxysmal Atrial Fibrillation for Reduction of Atrial Fibrillation Recurrence: The AWARE Randomized Clinical Trial.

Importance: Recurrent atrial fibrillation (AF) commonly occurs after catheter ablation and is associated with patient morbidity and health care costs. Objective: To evaluate the superiority of an augmented double wide-area circumferential ablation (WACA) compared with a standard single WACA in preventing recurrent atrial arrhythmias (AA) (atrial tachycardia, atrial flutter, or atrial fibrillation [AF]) in patients with paroxysmal AF. Design, Setting, and Participants: This was a pragmatic, multicenter, prospective, randomized, open, blinded end point superiority clinical trial conducted at 10 university-affiliated centers in Canada. The trial enrolled patients 18 years and older with symptomatic paroxysmal AF from March 2015 to May 2017. Analysis took place between January and April 2022. Analyses were intention to treat. Interventions: Patients were randomized (1:1) to receive radiofrequency catheter ablation for pulmonary vein isolation with either a standard single WACA or an augmented double WACA. Main Outcomes and Measures: The primary outcome was AA recurrence between 91 and 365 days postablation. Patients underwent 42 days of ambulatory electrocardiography monitoring after ablation. Secondary outcomes included need for repeated catheter ablation and procedural and safety variables. Results: Of 398 patients, 195 were randomized to the single WACA (control) arm (mean [SD] age, 60.6 [9.3] years; 65 [33.3%] female) and 203 to the double WACA (experimental) arm (mean [SD] age, 61.5 [9.3] years; 66 [32.5%] female). Overall, 52 patients (26.7%) in the single WACA arm and 50 patients (24.6%) in the double WACA arm had recurrent AA at 1 year (relative risk, 0.92; 95% CI, 0.66-1.29; P = .64). Twenty patients (10.3%) in the single WACA arm and 15 patients (7.4%) in the double WACA arm underwent repeated catheter ablation (relative risk, 0.72; 95% CI, 0.38-1.36). Adjudicated serious adverse events occurred in 13 patients (6.7%) in the single WACA arm and 14 patients (6.9%) in the double WACA arm. Conclusions and Relevance: In this randomized clinical trial of patients with paroxysmal AF, additional ablation by performing a double ablation lesion set did not result in improved freedom from recurrent AA compared with a standard single ablation set. Trial Registration: ClinicalTrials.gov Identifier: NCT02150902.

A Randomized Trial of Lenient Versus Strict Arm Instruction Post Cardiac Device Surgery (LENIENT).

BACKGROUND: Arm restriction after cardiac implantable electronic device (CIED) placement is common practice despite minimal supporting evidence. Patients receive a range of restriction recommendations of variable durations with the goal of reducing complications such as wound dehiscence, infection, lead dislodgement, or hematoma formation. These movement limitations can lead to emotional stress and anxiety, complications such as frozen shoulder, and upper extremity venous thrombosis due to immobilization. There are no published clinical trials assessing the benefits and risks of arm restrictions post-CIED implant. OBJECTIVES: The randomized trial of lenient vs strict arm and activity instruction post-CIED surgery (LENIENT trial; NCT04915261) is a single center nonblinded randomized prospective study designed to evaluate lenient compared to restrictive post-CIED care instructions. We hypothesize that there will be no significant difference in complications between the arms. METHODS/DESIGN: All patients receiving a de novo CIED or those with upgrades and revisions requiring a new lead implant will be enrolled. Subjects are enrolled in a nonblinded randomized prospective trial with 6 randomly assigned 8-month periods, during which either a lenient or restrictive postoperative activity instructions will be given to all patients. Postoperative instructions are given at the time of discharge and further reinforced by recurrent interactive voice recognition (IVR) phone calls, text messages and emails. The requirement for individual consent has been waived. The primary end point is a composite of (1) lead dislodgement, (2) frozen shoulder, (3) upper extremity venous thrombosis, (4) clinically significant hematoma, and (5) infection occurring within 52 weeks of index surgery. The study is a noninferiority trial with a sample size of 1,250 per group. DISCUSSION: This is the first large randomized clinical trial designed to establish an evidence-based postoperative standard of care for patients undergoing CIED implantation. This will improve the quality of care provided to patients and help guide implanting physicians providing postoperative care instructions. TRIAL REGISTRATION: ClinicalTrials.gov NCT04915261.

Is Maintenance of Sinus Rhythm of Value in Patients with Atrial Fibrillation and Heart Failure?

PURPOSE OF REVIEW: Heart failure (HF) and atrial fibrillation (AF) frequently co-exist, with the prevalence of AF increasing in patients with more advanced HF symptoms. When present, AF increases morbidity and mortality in patients with HF. The purpose of this review is to examine emerging evidence addressing the value of restoration and maintenance of sinus rhythm in patients with HF. RECENT FINDINGS: Earlier trials comparing a rhythm control strategy with antiarrhythmic drugs have failed to demonstrate benefit in patients with HF and reduced ejection fraction. More recent trials, including the recently published RAFT-AF, utilizing catheter ablation for rhythm control, have shown greater promise, possibly due to reduced medication-related side effects and higher efficacy in maintaining sinus rhythm. A strategy of sinus rhythm maintenance with catheter ablation appears to improve mortality, reduce HF events and improve quality of life in patients with AF and HF.

Rhythm-Monitoring Strategy and Arrhythmia Recurrence in Atrial Fibrillation Ablation Trials: A Systematic Review.

Background: : The rhythm-monitoring strategy after catheter ablation (CA) for atrial fibrillation (AF) impacts the detection of atrial arrhythmia recurrence and is not well characterized. We performed a systematic review and meta-regression analysis to determine whether the duration and mode of rhythm monitoring after CA affects detection of atrial arrhythmia recurrence. Methods: Databases were systematically searched for randomized controlled trials of adult patients undergoing first CA for AF from 2007 to 2021. Duration and strategy of rhythm monitoring were extracted. Meta-regression was used to identify any association between duration of monitoring and detection of atrial arrhythmia recurrence. The primary measure of outcome was single-procedure recurrence of atrial arrhythmia. Results: The search strategy yielded 57 trial arms from 56 randomized controlled trials comprising 5322 patients: 36 arms of patients with paroxysmal AF (PAF), and 21 arms of patients with persistent AF (PeAF) or both PAF/PeAF. Intermittent monitoring was associated with detection of significantly less atrial arrhythmia recurrence than continuous monitoring in PAF arms (31.2% vs 46.9%, P = 0.001), but not in PeAF/PAF-PeAF combined arms (43.3% vs 63.6%, P = 0.12). No significant relationship was seen between the duration of intermittent rhythm monitoring and atrial arrhythmia recurrence detection in either the PAF (P = 0.93) or PeAF/PAF-PeAF combined arms (P = 0.20). Conclusions: Continuous rhythm monitoring detected higher atrial arrhythmia recurrence rates, compared to intermittent rhythm monitoring, in patients with PAF. The duration of intermittent monitoring did not show a statistically significant relationship to the yield of arrhythmia detection, in near identical cohorts of trial subjects undergoing similar interventions, with clinical and research implications.

Contexte: La stratégie qui consiste à surveiller le rythme cardiaque après une ablation par cathéter dans le traitement de la fibrillation auriculaire (FA) a un effet sur la détection de récidive de l'arythmie auriculaire, mais elle n'est pas bien définie. Nous avons mené une revue systématique et une méta-régression pour déterminer si le mode employé pour surveiller le rythme après une ablation par cathéter et la durée de cette surveillance ont un effet sur la détection de récidive de l'arythmie auriculaire. Méthodologie: Des bases de données ont été systématiquement épluchées à la recherche d'essais contrôlés randomisés menés auprès d'adultes subissant leur première ablation par cathéter pour une FA entre 2007 et 2021. La durée et la stratégie utilisées dans la surveillance du rythme ont été recensées. La méta-régression a été utilisée pour déceler tout lien entre la durée de la surveillance et la détection d'une récidive de l'arythmie auriculaire. Le paramètre d'évaluation principal était la récidive de l'arythmie auriculaire avec une seule intervention. Résultats: La stratégie de recherche a fait ressortir 57 groupes de 56 essais contrôlés randomisés comprenant 5 322 patients : 36 groupes de patients présentant une FA paroxystique et 21 groupes de patients présentant une FA persistante ou ces deux types de FA (paroxystique et persistante). La surveillance intermittente a été associée à une moins grande détection de cas d'arythmie auriculaire récidivante, comparativement à la surveillance constante (31,2 % vs 46,9 %, p = 0,001), ce qui n'a pas été le cas dans les groupes où les types de FA (persistante ou paroxystique et persistante) étaient combinés (43,3 % vs 63,6 %, p = 0,12). Aucun lien notable n'a été observé entre la durée de la surveillance intermittente du rythme et la détection de l'arythmie auriculaire récidivante dans le groupe FA paroxystique (p = 0,93) ou dans le groupe des types de FA combinés (p = 0,20). Conclusions: Le taux de détection de l'arythmie auriculaire récidivante était plus élevé avec la surveillance constante qu'avec la surveillance intermittente chez les patients atteints de FA paroxystique. La durée de la surveillance intermittente n'a pas eu de lien statistiquement significatif avec le rendement de détection de l'arythmie, dans des cohortes presque identiques de participants aux essais subissant des interventions similaires, comportant des implications cliniques ou expérimentales.

Should they stay, or should they go: Do we need to remove the old cardiac implantable electronic device if a new system is required on the contralateral side?

Background: Ipsilateral approach in patients requiring cardiac implantable electronic device (CIED) revision or upgrade may not be feasible, primarily due to vascular occlusion. If a new CIED is implanted on the contralateral side, a common practice is to explant the old CIED to avoid device interaction. Objective: The purpose of this study was to assess a conservative approach of abandoning the old CIED after implanting a new contralateral device. Methods: We used an artificial intelligence algorithm to analyze postimplant chest radiographs to identify those with multiple CIEDs. Outcomes of interest included device interaction, abandoned CIED elective replacement indicator (ERI) behavior, subsequent programming changes, and explant of abandoned CIED. Theoretical risk of infection with removal of abandoned CIED was estimated using a validated scoring system. Results: Among 12,045 patients, we identified 40 patients with multiple CIEDs. Occluded veins were the most common indication for contralateral implantation (n = 27 [67.5%]). Fifteen abandoned CIEDs reached ERI, with 4 reverting to VVI 65. One patient underwent explant due to device interaction, and 2 required device reprogramming. Of 32 patients with an implantable cardioverter-defibrillator, 8 (25%) had treated ventricular arrhythmia. There were no failed or inappropriate therapies due to interaction. Eighteen patients (45%) had hypothetical >1% annual risk of hospitalization for device infection if the abandoned CIED had been explanted. Conclusion: In patients requiring new CIED implant on the contralateral side, abandoning the old device is feasible. This approach may reduce the risk of infection and concerns regarding abandoned leads and magnetic resonance imaging scans. Knowledge of ERI behavior is essential to avoid device interactions.

Outcomes of a comprehensive strategy during repeat atrial fibrillation ablation.

BACKGROUND/PURPOSE: Atrial fibrillation (AF) recurs post-ablation in 30-40% of patients. The approach to a repeat ablation, beyond isolation of reconnected pulmonary veins (PVs), is not well established. We sought to prospectively assess outcomes and predictors of recurrence among consecutive patients who underwent repeat AF ablation with a standardized approach. METHODS: This was a single-center prospective study of consecutive patients who underwent repeat AF ablation. Our protocol consisted of six steps: PV re-isolation, ablation of left atrial low-voltage areas (LVAs), ablation of isoproterenol-induced non-PV triggers, electrophysiology study (EPS) and ablation of induced AVNRT/AVRT, ablation of induced clinical atrial flutters, and lastly empiric ablation as per operator discretion if no other ablation was performed. RESULTS: Among 725 AF ablations performed during the study period, 74 were repeat ablations. Of those undergoing repeat ablation, 53 (72%) had PV reconnection, 30 (41%) had LVAs, seven (10%) had non-PV triggers, five (7%) had AVNRT, and 15 (20%) had typical atrial flutter. Following repeat ablation, arrhythmia-free survival was 65% at 1 year. The absence of PV reconnection was the only factor independently associated with recurrence after repeat ablation (recurrence rate 71%, adjusted OR 7.91, 95% CI 2.31-27.16, p = 0.001). CONCLUSIONS: A comprehensive approach to repeat AF ablation including PV re-isolation, LVA ablation, non-PV trigger ablation, EPS, and flutter ablation was associated with a 65% 1-year arrhythmia-free survival. The absence of PV reconnection was the only independent predictor of arrhythmia recurrence. Further research is needed to identify therapies beyond PV isolation for patients undergoing repeat ablation.

Predictors of perforation during lead extraction: Results of the Canadian Lead ExtrAction Risk (CLEAR) study.

BACKGROUND: Transvenous lead extraction can have serious adverse events, such as cardiac or vascular perforation. Risk factors have not been well characterized. OBJECTIVE: The purpose of this study was to identify factors associated with perforation and death, and to characterize lead extraction in a large contemporary population. METHODS: We performed a retrospective multicenter study examining patients undergoing lead extraction at 8 Canadian institutions from 1996 through 2016. Demographic and clinical data were used to identify variables associated with perforation and mortality using logistic regression modeling. RESULTS: A total of 2325 consecutive patients (age 61.9 ±16.5 years) underwent extraction of 4527 leads. Perforation rate was 2.7% (63/2325) and 30-day mortality was 1.6% (38/2325), with mortality of 0.4% due to perforation (10/2325). Variables associated with perforation included no previous cardiac surgery (odds ratio [OR] 3.33; 95% confidence interval [CI] 1.54-7.19; P = .002), female sex (OR 3.27; 95% CI 1.91-5.60; P <.001); left ventricular ejection fraction ≥40% (OR 2.81; 95% CI 1.28-6.14; P = .010); lead age >8 years (OR 2.64; 95% CI 1.52-4.60; P <.001); ≥2 leads extracted (OR 2.49; 95% CI 1.23-5.04; P = .011); and diabetes (OR 2.12; 95% CI 1.16-3.86; P = .014). Variables associated with death included infection as indication for extraction (OR 3.85; 95% CI 1.38-10.73; P = .010); anemia (OR 3.14; 95% CI 1.38-6.61; P = .003), and patient age (OR 1.04; 95% CI 1.01-1.07; P = .012). CONCLUSION: Risk factors associated with perforation in lead extraction include no history of cardiac surgery, female sex, preserved left ventricular ejection fraction, lead age >8 years, ≥2 leads extracted, and diabetes.

Corticosteroid and Immunosuppressant Therapy for Cardiac Sarcoidosis: A Systematic Review.

Background Corticosteroid therapy for the treatment of clinically manifest cardiac sarcoidosis is generally recommended. Our group previously systematically reviewed the data in 2013; since then, there has been increasing quality and quantity of data and also interest in nonsteroid agents. Methods and Results Studies were identified from MEDLINE, EMBASE, Cochrane Controlled Trials Register, Cochrane Database of Systematic Reviews, and the National Institutes of Health ClinicalTrials.gov database. The quality of included articles was rated using Scottish Intercollegiate Guidelines Network 50. Outcomes examined were atrioventricular conduction, left ventricular function, ventricular arrhythmias, and mortality. A total of 3527 references were retrieved, and 34 publications met the inclusion criteria. There were no randomized trials, and only 2 studies were rated good quality. In the 34 reports (total of 1297 patients), 1125 patients received corticosteroids, 235 received additional or other immunosuppressant therapy, and 97 patients received no therapy. There were 178 patients treated for atrioventricular conduction disease, with 76/178 (42.7%) improving. In contrast, 21 patients were not treated with corticosteroids and/or immunosuppressant therapy, and none of them improved. Therapy was associated with the prevention of deterioration in left ventricular function. A total of 8 publications reported on ventricular arrhythmia burden, and 19 reported on mortality; the data quality was too limited to draw conclusions for the latter 2 outcomes. Conclusions The best quality data relate to atrioventricular nodal conduction and left ventricular function recovery. In both situations, therapy with corticosteroids and/or immunosuppressant therapy were sometimes associated with positive outcomes. The data quality is too limited to draw conclusions for ventricular arrhythmias and mortality.

Prevalence of Left Atrial Appendage Thrombus in Patients Anticoagulated With Direct Oral Anticoagulants: Systematic Review and Meta-analysis.

BACKGROUND: Multiple studies have examined the prevalence of left atrial appendage thrombus (LAAT) in patients anticoagulated with direct oral anticoagulants (DOACs) and have reported conflicting results. METHODS: Studies reporting the prevalence of LAAT on transesophageal echocardiography (TEE) after 3 or more weeks of DOAC therapy were identified. The proportions of anticoagulated patients diagnosed with LAAT were pooled using random-effects models. Prespecified subgroup analyses by the indication of TEE (pre-atrial fibrillation [AF] ablation vs cardioversion) and TEE strategy (routine use vs selective) were conducted via stratification. RESULTS: Forty studies were identified: 22 full manuscripts and 18 abstracts. Only 11 studies performed TEE routinely. Most studies included patients with paroxysmal AF and low thromboembolic risk. The pooled prevalence of LAAT was 2.5% (95% confidence interval [1.6%-3.4%]). The prevalence of LAAT is lower in the pre-AF ablation group compared with pre-cardioversion (1.1% vs 4.0%, P = 0.033). Routine TEE strategy yielded a lower LAAT prevalence in both groups (0.1% vs 2.3%, P = 0.002 and 3.2% vs 5.8%, P = 0.432, respectively). CONCLUSION: The reported prevalence of LAAT on TEE in patients treated with DOACs is highly variable. Factors associated with a high LAAT prevalence were pre-cardioversion indication and selective TEE strategy. Routine use of TEE before AF ablation may not be warranted.

INTRODUCTION: De nombreuses études ont porté sur la prévalence des thrombi se formant dans l'appendice auriculaire gauche (TAAG) chez les patients qui reçoivent des anticoagulants oraux directs (AOD) et ont révélé des résultats contradictoires. MÉTHODES: Nous avons recensé les études qui ont fait état de la prévalence des TAAG à l'échocardiographie transœsophagienne (ETO) trois semaines ou plus après le traitement par AOD. Les modèles à effets aléatoires ont permis de regrouper les patients qui prenaient des anticoagulants et avaient reçu un diagnostic de TAAG. Nous avons réalisé les analyses de sous-groupes prédéterminés par l'indication d'ETO (fibrillation auriculaire [FA] avant l'ablation vs FA avant la cardioversion) et la stratégie d'utilisation de l'ETO (systématique vs sélective) grâce à la stratification. RÉSULTATS: Nous avons recensé 40 études : 22 manuscrits complets et 18 résumés. Seules 11 études portaient sur l'utilisation systématique de l'ETO. La plupart des études portaient sur des patients qui étaient atteints de FA paroxystique et exposés à un faible risque thromboembolique. La prévalence groupée de TAAG était de 2,5 % (intervalle de confiance à 95 % [1,6 %-3,4 %]). La prévalence de TAAG était plus faible dans le groupe de FA avant l'ablation que dans le groupe de FA avant la cardioversion (1,1 % vs 4,0 %, P = 0,033). La stratégie d'utilisation systématique de l'ETO a permis d'obtenir une prévalence plus faible de TAAG dans les deux groupes (0,1 % vs 2,3 %, P = 0,002 et 3,2 % vs 5,8 %, P = 0,432, respectivement). CONCLUSION: La prévalence de TAAG à l'ETO chez les patients traités par AOD varie beaucoup. Les facteurs associés à une prévalence élevée de TAAG étaient l'indication avant la cardioversion et la stratégie d'utilisation sélective de l'ETO. L'utilisation systématique de l'ETO avant l'ablation peut ne pas être justifiée.

Intracardiac Echocardiography During Transvenous Lead Extraction.

Transvenous lead extraction is an invaluable procedure within the contemporary management of cardiac implantable electronic devices. Transvenous lead extraction has traditionally been guided by fluoroscopy. Complementary imaging with intracardiac echocardiography can provide valuable additional information, such as identification of complications, lead-adherent echodensities, and sites of lead-tissue adherence. As such, it can be used to aid in risk stratification before lead removal, help to choose tools or techniques, and provide visual monitoring throughout the procedure. Intracardiac echocardiography can be incorporated into the lead extraction workflow of the contemporary electrophysiologist and provide valuable information supporting safety and efficacy.

High-power, short-duration atrial fibrillation ablation compared with a conventional approach: Outcomes and reconnection patterns.

BACKGROUND: The effectiveness, safety, and pulmonary vein (PV) reconnection patterns of point-by-point high-power, short-duration (HPSD) ablation relative to conventional force-time integral (FTI)-guided strategies for atrial fibrillation (AF) ablation are unknown. OBJECTIVES: To compare 1-year freedom from atrial arrhythmia (AA), complication rates, procedural times, and PV reconnection patterns with HPSD AF AF ablation versus an FTI-guided low-power, long-duration (LPLD) strategy. METHODS: We compared consecutive patients undergoing a first ablation procedure for paroxysmal or persistent AF. The HPSD protocol utilized a power of 50 W and durations of 6-8 s posteriorly and 8-10 s anteriorly. The LPLD protocol was FTI-guided with a power of ≤25 W posteriorly (FTI ≥ 300g·s) and ≤35 W anteriorly (FTI ≥ 400g·s). RESULTS: In total, 214 patients were prospectively included (107 HPSD, 107 LPLD). Freedom from AA at 1 year was achieved in 79% in the HPSD group versus 73% in the LPLD group (p = .339; adjusted hazard ratio with HPSD, 0.67; 95% confidence interval, 0.36-1.23; p < .004 for non-inferiority). Procedure duration was shorter in the HPSD group (229 ± 60 vs. 309 ± 77 min; p < .005). Patients undergoing repeat ablation had a higher propensity for reconnection at the right PV carina in the HPSD group compared with the LPLD group (14/30 = 46.7% vs. 7/34 = 20.6%; p = .035). There were no differences in complication rates. CONCLUSION: HPSD AF ablation resulted in similar freedom from AAs at 1 year, shorter procedure times, and a similar safety profile when compared with an LPLD ablation strategy. Patients undergoing HPSD ablation required more applications at the right carina to achieve isolation, and had a significantly higher rate of right carinal reconnections at redo procedures.

Para-Hisian Pacing During Sinus Rhythm: Establishing Threshold Values to Distinguish Nodal From Septal Pathway Conduction.

OBJECTIVES: This study sought to identify minimum threshold values below which conduction over the atrioventricular (AV) node would be unexpected. BACKGROUND: Para-Hisian pacing is used to evaluate for the presence of a septal accessory pathway (AP); however, threshold values to differentiate nodal from AP conduction are unknown. METHODS: The authors performed high- and low-output para-Hisian pacing during sinus rhythm to capture the His and para-Hisian ventricular myocardium (H+V) and para-Hisian ventricular myocardium (V) alone, respectively. The change in stimulation (stim)-to-atrial electrogram interval after loss of His bundle capture in patients with (AP+) and without (AP-) a septal AP was evaluated. Stim-to-proximal coronary sinus (PCS) and stim-to-high right atrium (HRA) intervals were measured and within-patient differences (△) for V and H+V capture were calculated. RESULTS: A total of 23 AP+ and 45 AP- patients were evaluated. The difference in stimulus to earliest atrial signal in the high right atrial catheter seen with the loss of His bundle capture (△-stim-HRA) (21 ms; interquartile range [IQR]: 3 to 43 ms vs. 64 ms; IQR: 56 to 73 ms; p < 0.001) and difference in stimulus to earliest atrial signal in the proximal coronary sinus catheter seen with the loss of His Bundle capture (△-stim-PCS) (11 ms; IQR: 0 to 30 ms vs. 61 ms; IQR: 52 to 72 ms; p < 0.001) were shorter in AP+ patients. The shortest △-stim-PCS and △-stim-HRA in AP- patients were 37 ms and 32 ms, respectively, whereas the longest corresponding intervals in AP+ patients were 51 ms and 75 ms, respectively. CONCLUSIONS: A △-stim-PCS <37 ms or △-stim-HRA <32 ms confirmed the presence of a septal AP, whereas a value >51 ms for △-stim-PCS or >75 ms for △-stim-HRA excluded it. Alternatively, the minimum △-stim-PCS with loss of His capture compatible with AV nodal conduction in isolation was 37 ms, and a △-stim-PCS >51 ms effectively ruled out the presence of a septal AP.

Epicardial Ablation in Nonischemic Ventricular Tachyardia.

In patients with nonischemic cardiomyopathy, epicardial ablation is critical in targeting epicardial paravalvular substrate. Epicardial access and ablation can be performed safely with attention to epicardial structures, such as the coronary arteries, phrenic nerve, and epicardial fat. This review explores the indications, techniques, complications, and outcomes of epicardial ablation in patients with nonischemic cardiomyopathy. Although epicardial ablation adds to the complexity and risk of the ablation procedure, it is a vital tool that, combined with endocardial mapping and ablation, improves outcomes in patients with nonischemic cardiomyopathy suffering from ventricular arrhythmias.