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Introduction: Insertable cardiac monitors (ICMs) are commonly used to diagnose cardiac arrhythmias. False detections in the latest ICM systems remain an issue, primarily due to inaccurate R‐wave sensing. New discrimination algorithms were developed and tested to reduce false detections of atrial fibrillation (AF), pause, and tachycardia episodes in ICMs. Methods: Stored electrograms (EGMs) of AF, pause, and tachycardia episodes detected by Abbott Confirm Rx™ ICMs were extracted from the Merlin.net™ Patient Care Network, and manually adjudicated to establish independent training and testing datasets. New discrimination algorithms were developed to reject false episodes due to inaccurate R‐wave sensing, P‐wave identification, and R–R interval patterns. The performance of these new algorithms was quantified by false positive reduction (FPR) and true positive maintenance (TPM), relative to the existing algorithms. Results: The new AF detection algorithm was trained on 5911 EGMs from 744 devices, resulting in 66.9% FPR and 97.8% TPM. In the testing data set of 1354 EGMs from 119 devices, this algorithm achieved 45.8% FPR and 97.0% TPM. The new pause algorithm was trained on 7178 EGMs from 1490 devices, resulting in 70.9% FPR and 98.7% TPM. In the testing data set of 1442 EGMs from 340 devices, this algorithm achieved 74.4% FPR and 99.3% TPM. The new tachycardia algorithm was trained on 520 EGMs from 204 devices, resulting in 57.0% FPR and 96.6% TPM. In the testing data set of 459 EGMs from 237 devices, this algorithm achieved 57.9% FPR and 96.5% TPM. Conclusion: The new algorithms substantially reduced false AF, pause, and tachycardia episodes while maintaining the majority of true arrhythmia episodes detected by the Abbott ICM algorithms that exist today. Implementing these algorithms in the next‐generation ICM systems may lead to improved detection accuracy, in‐clinic efficiency, and device battery longevity. [ABSTRACT FROM AUTHOR]

Background Dofetilide is a class III antiarrhythmic drug that has been reported to be safe and efficacious in the treatment of atrial dysrhythmias with a known initial risk of QT prolongation and torsades de pointes (TdP). As a result, the Federal Drug Administration (FDA) mandated in-hospital dofetilide initiation and adherence to a common dosing protocol. However, there is a lack of clarity on how to manage dofetilide re-initiation. Methods An observational survey was performed including 347 cardiologists in the United States and worldwide to evaluate the deviations from approved manufacturer's protocol during dofetilide initiation and re-initiation among practicing cardiologists. Results Most practicing cardiologists were cautious about outpatient dofetilide use and adhered to the manufacturer's in-patient dofetilide protocol during de-novo initiation and reported low incidence of TdP in clinical practice. There were substantial differences among practicing cardiologists with deviation from the manufacturer's protocol during re-initiation of dofetilide. About 21% cardiologists always admitted patients to the hospital while 37% admitted patients < 10% of the time for dofetilide re-initiation. Only 4% reported major adverse events with outpatient dofetilide re-initiation. There was also wide variation regarding monitoring of electrolytes and QT interval as an outpatient with dofetilide. Conclusion There is significant practice pattern variation in the use of dofetilide for the management of AF. This degree of variation noted is concerning and is a reflection of the current lack of substantial clinical evidence in the re-initiation dofetilide protocol to help direct the provider. [ABSTRACT FROM AUTHOR]

Objective: We aimed to perform a meta-analysis from eligible studies to analyze the true impact of QL when compared with BL with regard to post-procedural outcomes including lead deactivation, revision or replacement. Background: Many observational and retrospective studies showed that quadripolar left ventricular leads (QL) are associated with better outcomes and fewer complications when compared with bipolar leads (BL). Methods: We performed a comprehensive literature search through June 30, 2015 using: quadripolar, bipolar, left ventricular lead and CRT in Pubmed, Ebsco and google scholar databases. Results: The analysis included 8 studies comparing QL and BL implantation. Post-procedural outcomes such as lead deactivation, revision or replacement were used as primary outcome and assessed with Mantel-Haenszel risk ratio (RR). Secondary outcomes included total fluoroscopy/procedure time, occurrence of phrenic nerve stimulation (PNS) and all-cause mortality on follow up. Follow-up duration for the studies ranged from 3 to 60 months. Compared with BL, the use of QL is associated with 52 % reduction (relative risk 0.48; 95% CI: 0.36- 0.64, p=0.00001) in the risk of deactivation, revision or replacement of the LV lead. QL had significantly lower fluoroscopy/procedure time, PNS and all-cause mortality when compared with BL. Conclusion: Our meta-analysis shows that QL implantation was associated with decreased risk of LV lead deactivation, revision or replacement when compared with BL. [ABSTRACT FROM AUTHOR]

Background Recent studies have suggested that prolonged outpatient rhythm monitoring results in increased detection of atrial fibrillation (AF) in patients with cryptogenic stroke (CS). However, the best monitoring strategy and its clinical utility is debatable. Objective To compare the effectiveness of implantable loop recorder (ILR) versus wearable devices in identifying AF in patients with CS. Methods and Results Three randomized controlled trials (RCTs) and 13 observational studies were identified by database searches. Seven studies (enrolling 774 patients) employed ILR for AF detection for a median duration of 365 days (range 50-569 days). Ten studies (enrolling 996 patients) employed continuous monitoring with wearable devices for a median duration of 21 days (range 4-30 days). One study performed 7 days of monitoring with wearable device followed by implantation of ILR, thus included in both groups. Pooled odds ratio (OR) of identifying AF in RCTs showed increased detection of AF with prolonged monitoring (OR 4.54, 95% confidence interval [CI] 2.92, 7.06; P < 0.00001) compared to routine outpatient follow-up. Overall detection of AF with outpatient monitoring was 17.6% (CI: 12.5-22.7). There was significantly higher AF detection with ILR (23.3%; CI: 13.83-32.29) compared to wearable devices (13.6%; CI: 7.91-19.32; P < 0.05). Patients with AF were older in age compared to patients without AF. Conclusion AF detection in patients with CS is improved with prolonged rhythm monitoring and is better with ILR compared to wearable devices. AF was more common in older patients. The clinical significance of these findings is unknown at this point. [ABSTRACT FROM AUTHOR]

The use of leadless pacemakers is rapidly expanding. There is limited experience of extraction of leadless pacemakers. This case describes the successful extraction of an underperforming leadless pacemaker several weeks after initial implantation. [ABSTRACT FROM AUTHOR]

The article discusses the promising strategy of Ethanol Infusion into the Vein of Marshall (EIVOM) as an adjunctive treatment during catheter ablation (CA) of persistent atrial fibrillation (AF). The study evaluates intraprocedural changes in the extent of EIVOM-induced low voltage area (LVA) using bipolar voltage mapping of atrial electrograms in patients undergoing AFCA.

Introduction: Among patients with non‐valvular atrial fibrillation (AF) and percutaneous left atrial appendage closure (LAAC) undergoing direct current cardioversion (DCCV), the need for and use of LAA imaging and oral anticoagulation (OAC) is unclear. Objective: The purpose of this study is to evaluate the real‐world use of transesophageal echocardiography (TEE) or cardiac computed tomography angiography (CCTA) before DCCV and use of OAC pre‐ and post‐DCCV in patients with AF status post percutaneous LAAC. Methods: This retrospective single center study included all patients who underwent DCCV after percutaneous LAAC from 2016 to 2022. Key measures were completion of TEE or CCTA pre‐DCCV, OAC use pre‐ and post‐DCCV, incidence of left atrial thrombus (LAT) or device‐related thrombus (DRT), incidence of peri‐device leak (PDL), and DCCV‐related complications (stroke, systemic embolism, device embolization, major bleeding, or death) within 30 days. Results: A total of 76 patients with AF and LAAC underwent 122 cases of DCCV. LAAC consisted of 47 (62%), 28 (37%), and 1 (1%) case of Watchman 2.5, Watchman FLX, and Lariat, respectively. Among the 122 DCCV cases, 31 (25%) cases were identified as "non‐guideline based" due to: (1) no OAC for 3 weeks and no LAA imaging within 48 h before DCCV in 12 (10%) cases, (2) no OAC for 4 weeks following DCCV in 16 (13%) cases, or (3) both in 3 (2%) cases. Among the 70 (57%) cases that underwent TEE or CCTA before DCCV, 16 (23%) cases had a PDL with a mean size of 3.0 ± 1.1 mm, and 4 (6%) cases had a LAT/DRT on TEE resulting in cancellation. There were no DCCV‐related complications within 30 days. Discussion: There is a widely varied practice pattern of TEE, CCTA, and OAC use with DCCV after LAAC, with a 6% rate of LAT/DRT. LAA imaging before DCCV appears prudent in all cases, especially within 1 year of LAAC, to assess for device position, PDL, and LAT/DRT. [ABSTRACT FROM AUTHOR]

Background A significant proportion of patients treated with warfarin for atrial fibrillation (AF) become warfarin ineligible (WI) due to major bleeding events (MBE) or systemic thromboembolism (STE). We report a large multicenter real-world experience of the use of direct oral antagonists (DOACs) in these WI patients. Methods We report the outcomes of 263 WI patients treated with DOACs. The primary objective was to evaluate clinical outcomes of STE and MBE with DOACs. Secondary objective was to assess clinical predictors of repeat MBE and STE on DOACs. Results Note that 63% (166 of 263) patients had a repeat MBE on DOACs. Repeat MBE was significantly higher in patients with prior gastrointestinal bleeding (74.5% vs. 30%, P < 0.0001). Five percent (12 of 263) developed repeat STE. Higher mean CHA2DS2VASC (6.5 ± 1.7 vs. 3.3 ± 1.6 = 0.001) score was associated with repeat STE. About 34% (57 of 166) of patients had an intervention to manage repeat MBE. LAAO devices were successfully used in 67% (12 of 18) high-risk patients who underwent major interventions to manage MBE. Conclusion In WI patients rechallenged with DOACs, a significant proportion developed repeat MBE. LAAO devices seem reasonable in those patients who undergo major interventions to manage MBE with cautious and temporary continuation of DOAC. [ABSTRACT FROM AUTHOR]

AF Ablation After Watchman Background There have been an increasing number of atrial fibrillation (AF) patients with Watchman left atrial appendage occlusion (LAAO) device, requiring catheter ablation (CA) for maintenance of normal sinus rhythm. In this study, we describe our experience with the feasibility and safety of CA in patients with a preexisting Watchman LAAO device. Methods This was a retrospective multicenter AF registry of 60 patients with Watchman LAAO device who underwent CA for AF. Baseline clinical and procedural characteristics of the included subjects were retrieved from review of medical records and were analyzed. Results The mean age was 72.7 ± 4.9 years and the mean CHADS2 score was 2.3 ± 0.6. All patients had successful pulmonary vein isolation (PVI). The left atrial appendage (LAA) was electrically active in 34 (56%) while reentrant tachycardia and AF triggers were seen in 17 (28%) patients. Electrical isolation was attempted in these 17 patients with only 10 achieving complete LAA isolation. Repeat imaging showed new peri-device leaks in 30% (12/40) patients, while new significant peri-device leaks (≥5 mm) were noted in 10% (10/40) of patients after RFA, respectively, requiring continuation of oral anticoagulation. There were a higher proportion of patients with severe peri-device leaks (≥5 mm) after LAA isolation. However, >50% of those leaks sealed off on follow-up transesophageal echocardiogram. Conclusion AF ablation is a feasible and safe in patients with preexisting Watchman LAAO device. Electrical isolation of the LAA could be difficult and when attempted can result in increased risk of short-term peri-device leak and recurrence of AT/AF in almost all patients. [ABSTRACT FROM AUTHOR]

Use of corticosteroids before and after atrial fibrillation (AF) ablation can decrease acute inflammation and reduce AF recurrence. To assess the efficacy of oral prednisone in improving the outcomes of pulmonary vein isolation with radiofrequency ablation and its effect on inflammatory cytokines, a total of 60 patients with paroxysmal AF undergoing radiofrequency ablation were randomized (1:1) to receive either 3 doses of 60 mg daily of oral prednisone or a placebo. Inflammatory cytokine levels (TNF-α, IL-1, IL6, IL-8) were measured at baseline, prior to ablation, immediately after ablation, and 24 hours post ablation. Patients underwent 30 day event monitoring at 3 months, 6 months and 12 months post procedure. Immediate post ablation levels of inflammatory cytokines were lower in the steroid group when compared to the placebo group; IL-6: 9.0 ±7 vs 15.8 ±13 p=0.031; IL-8: 10.5 ±9 vs 15.3 ±8; p=0.047 respectively. Acute PV reconnection rates during the procedure (7/23% vs 10/36%; p = 0.39), and RF ablation time (51±13 vs 56±11 min, p = 0.11) trended to be lower in the placebo group than the steroid group. There was no difference in the incidence of early recurrence of AF during the blanking period and freedom from AF off AAD at 12 months between both groups (5/17% vs 8/27%; p = 0.347 and 21/70% vs 18/60%; p=0.417 in placebo and steroid groups respectively). CONCLUSION: Although oral corticosteroids have significant effect in lowering certain cytokines, it did not impact the clinical outcomes of AF ablation. [ABSTRACT FROM AUTHOR]

Background: Insertable cardiac monitors (ICMs) are essential for ambulatory arrhythmia diagnosis. However, definitive diagnoses still require time‐consuming, manual adjudication of electrograms (EGMs). Objective: To evaluate the clinical impact of selecting only key EGMs for review. Methods: Retrospective analyses of randomly selected Abbott Confirm Rx™ devices with ≥90 days of remote transmission history were performed, with each EGM adjudicated as true or false positive (TP, FP). For each device, up to 3 "key EGMs" per arrhythmia type per day were prioritized for review based on ventricular rate and episode duration. The reduction in EGMs and TP days (patient‐days with at least one TP EGM), and any diagnostic delay (from the first TP), were calculated versus reviewing all EGMs. Results: In 1000 ICMs over a median duration of 8.1 months, at least one atrial fibrillation (AF), tachycardia, bradycardia, or pause EGM was transmitted by 424, 343, 190, and 325 devices, respectively, with a total of 95 716 EGMs. Approximately 90% of episodes were contributed by 25% of patients. Key EGM selection reduced EGM review burden by 43%, 66%, 77%, and 50% (55% overall), while reducing TP days by 0.8%, 2.1%, 0.2%, and 0.0%, respectively. Despite reviewing fewer EGMs, 99% of devices with a TP EGM were ultimately diagnosed on the same day versus reviewing all EGMs. Conclusion: Key EGM selection reduced the EGM review substantially with no delay‐to‐diagnosis in 99% of patients exhibiting true arrhythmias. Implementing these rules in the Abbott patient care network may accelerate clinical workflow without compromising diagnostic timelines. [ABSTRACT FROM AUTHOR]

Introduction: Defibrillation testing (DT) is recommended during the subcutaneous defibrillator (S‐ICD) placement. We sought to compare 10 J shock impedance in sinus rhythm (SR) with 65 J defibrillation impedance and evaluate device position on a postimplant chest X‐ray (CXR) using an intermuscular (IM) technique. Methods: Consecutive S‐ICD implantations between 12/2019 and 12/2020 at The Ohio State University were reviewed. All implantations were performed using a two‐incision IM technique. Standard DT with 65 J shock and 10 J shock in SR were performed unless contraindicated. The PRAETORIAN score was calculated based on CXR. Results: A total of 37 patients (age: 47.2 ± 15.8 years old, male: n = 26 [70.3%], body mass index: 30.1 ± 6.7 kg/m2) underwent IM S‐ICD implantation, and of those, 27 (73%) underwent both 65 J shock and 10 J shock in SR. The coefficient of determination (R2) between 10 J shock impedance and 65 J shock impedance was 0.84. The mean of an impedance difference was 1.6 ± 4.8 Ω (minimum – 11 and maximum 8). Postimplant CXR was available for 33 out of 37 patients (89.2%). The PRAETORIAN score was less than 90 in all patients and the mean score was 32.7 ± 8.8. Conclusion: We demonstrated that 10 J shock impedance in SR correlated well with 65 J defibrillation impedance during IM S‐ICD implantation. An IM implantation technique provides excellent generator location on postimplant CXR. The IM technique combined with 10 J shock in SR may be sufficient to predict and ensure the defibrillation efficacy of the S‐ICD. [ABSTRACT FROM AUTHOR]

Purpose: Guidelines have differing recommendations for aspirin use in patients with an indication for anticoagulation. The purpose of this study was to evaluate the incidence of major bleeding and thromboembolic events (TEs) in patients with atrial fibrillation (AF) receiving warfarin alone (monotherapy group) versus warfarin plus aspirin (combination therapy group). Methods: This was a retrospective, cohort study including patients from a pharmacist-run anticoagulation clinic. Inclusion criteria were patients with AF receiving anticoagulation between January 2013 and January 2014 observed over 5 years. Results: One hundred forty-two patients were included in the combination group versus 89 in monotherapy group. In the combination group, 60 (42.3%) patients were on aspirin for no apparent indication, 19 (13.4%) had stable coronary artery disease and diabetes, and 26 (18.3%) had diabetes alone. Major bleeding occurred in 21 (14.9%) patients in the combination group versus 7 (7.9%) patients in the monotherapy group (odds ratio [OR] = 2.02, 95% confidence interval [CI]: 0.78-5.91; P =.17). TE occurred in 10 (7%) patients in the combination group versus 4 (4.5%) in the monotherapy group (OR = 1.61, 95% CI: 0.44-7.24; P =.57). There was no significant difference in bleeding (P =.85) or TE (P =.37) rates between aspirin indications in the combination group. Conclusion: Combination therapy versus monotherapy may increase bleeding risk with little benefit in decreasing AF-related stroke or cardiovascular events. [ABSTRACT FROM AUTHOR]

Introduction: The LARIAT epicardial suture snaring device has been fraught with technical challenges and procedural complications. Over time, technique modification and improved operator experience have helped overcome many of these challenges. Methods and Results: Studies reporting left atrial appendage epicardial closure over a 12‐year period from 2009 to 2020 were evaluated. The primary efficacy outcome evaluated was left atrial appendage closure with residual flow ≤1 mm. Safety outcomes evaluated were periprocedural and long term complications after device placement. Nine studies consisting of 1430 patients were included in this analysis, of which 1386 (97%) underwent successful device placement. The mean age was 69.3 years, with a mean CHADS2‐VASC score of 3.78. Primary efficacy end point was achieved in 95.8% patients immediately after device placement, and in 92.8% patients on long term follow‐up. Early procedural complications consisted of pericardial effusion 5.6%, cardiac perforation 2.7%, pericarditis 2.6%, and need for open heart surgery 1.5%. Long term complications consisted of all‐cause mortality 2.3%, stroke 1.5%, and left atrial appendage thrombus 2.3%. Reduced complications were noted using micropuncture needles (2.20% vs. 10.14%; p <.0001), a longer duration pericardial drainage, and use of anti‐inflammatory medications (1.58% vs. 8.4%). Oral anticoagulation use decreased from 44.7% to 22.9% post device implantation, and to 8.5% on last clinical follow up. Conclusions: The LARIAT device is effective in epicardial closure of the left atrial appendage. Improvement in device techniques such as use of micropuncture needle, prophylactic colchicine, and maintenance of a pericardial drain have helped improve safety over time. [ABSTRACT FROM AUTHOR]

To evaluate diagnostic accuracy of different protocols of contrast enhanced computed tomography venogram (CTV) for LAA thrombus detection in patients undergoing AF ablation and study the correlation of the novel LAA enhancement index (LAA-EI) to LAA flow velocity obtained using transesophageal echocardiography (TEE). Study comprised of patients undergoing CTV and TEE on the same day from October 2016 to December 2017. Three CTV scanning protocols (described in results), were evaluated wherein ECG gating was used only for those with sinus rhythm on day of CTV. LAA-EI was calculated as Hounsfield Unit (HU) in the LAA divided by the HU unit in the center of the LA. The diagnostic accuracy for CTV was calculated in comparison to TEE. The LAA-EI was compared to LAA emptying velocities as obtained from TEE. 590 patients with 45.6% non-ECG-gated without delayed imaging, 26.9% non-ECG-gated with delayed imaging and 27.5% ECG-gated with delayed imaging, were included in the study. All three protocols had 100% negative predictive value with improvement in specificity from 61.8% to 98.1% upon adding delayed imaging. The LAA-EI correlated significantly with reduced LAA flow velocities (r = 0.45, p <.0001). The mean LAA emptying velocity in patients with LAA-EI of ≤ 0.6 was significantly lower than in those with LAA-EI of >0.6 (36.2 cm/s [95% CI: 32.6–39.7] vs, (58 cm/s [95% CI 55.3–60.8]), respectively (p <.0001). CTV with delayed imaging (with or without ECG gating) is highly specific in ruling out LAA thrombus. The novel LAA-EI can detect low LAA flow velocities. • Largest study to show that CT venogram has 100% negative predictive value for ruling out left atrial appendage (LAA) thrombus. • Delayed imaging is superior to non-delayed imaging resulting in fewer non-diagnostic results and higher specificity. • Novel LAA enhancement index correlated well with LAA velocity from transesophageal echocardiogram. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation (CA) is an established treatment for patients with symptomatic atrial fibrillation (AF). The purpose of this study was to evaluate the safety and efficacy of single CA in AF patients with extreme obesity (body mass index [BMI] ≥ 40 kg/m2) and its long-term impact on body weight. Methods: Patients with BMI ≥40 kg/m2 who underwent CA at the Ohio State University between 2012 and 2016 were included. The primary efficacy endpoint was no atrial arrhythmia lasting > 30 seconds without anti-arrhythmic drugs during 1-year follow-up after a single procedure. Results: Out of 230 AF patients with BMI ≥ 40 kg/m2 undergoing CA, pulmonary vein isolation was achieved in 226 (98%) patients. Seventeen patients (7.4%) experienced acute major complications, including pericardial effusion, vascular complications and respiratory failure. Patient characteristics for 135 patients with complete 1-year follow-up were as follows: mean age 58.6 ± 9.6 years, mean BMI 44.5± 4.7 kg/m², female 63 (47%), non-paroxysmal AF 100 (74%), median CHA2DS2-VASc score 2 (IQR:1-3). In this cohort, the primary efficacy endpoint was achieved in 44 (33%) patients. Paroxysmal AF was associated with higher CA success compared to non-paroxysmal (51 vs. 26% [p < 0.01]).There was no significant weight change even in patients with successful AF CA. Conclusions: Extreme obesity is associated with low AF CA success, particularly in those with non-paroxysmal AF. Successful AF CA was not associated with long-term weight reduction. A better treatment strategy is needed in this population of AF and extreme obesity [ABSTRACT FROM AUTHOR]

Pleural Effusions After the Lariat Procedure Background The Lariat procedure is increasingly used for the exclusion of the left atrial appendage (LAA) in atrial fibrillation (AF) patients. There are anecdotal reports of pleural effusions after the Lariat procedure. However, the incidence, demographics, and pathophysiology of these effusions are largely unknown. Objective Characterization of pleural effusions in patients who underwent LAA exclusion using the Lariat procedure. Methods We report the incidence, demographics, and clinical and laboratory characteristics of patients from a multicenter prospective registry who underwent the Lariat procedure and subsequently developed pleural effusions. Results A total of 10 out of 310 (3.2%) patients developed significant pleural effusions after the Lariat procedure. The mean age of these patients was 67 ± 9, ranging from 52 to 78 years and included 5 (50%) males. Nine patients had persistent AF with median CHADS2 score of 2.7 ± 1.2. The LAA was successfully ligated in all these patients. Post-Lariat procedure, 6 patients developed bilateral and 4 patients developed left-sided pleural effusions. Pleural tap revealed transudative in 2 and exudative in 6 patients. The remaining 2 patients responded to active diuresis and behaved clinically like transudative effusions. There is a statistically significant difference between the onset of pleural effusion after the Lariat procedure between tPLE versus ePLE groups (14 ± 1.2 vs. 6 ± 6, P = 0.05). Conclusion Incidence of clinically significant pleural effusion is uncommon after the Lariat procedure and can be either exudative or transudative in nature depending on the underlying mechanisms. More prospective studies are needed to study the pathophysiologic basis of development of pleural effusions after the Lariat procedure. [ABSTRACT FROM AUTHOR]