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Navzer D Sachinvala,1 Angeline Stergiou,2 Duane E Haines3,4 1Retired, US Department of Agriculture-Agricultural Research Service, New Orleans, LA 70124, USA; 2Department of Medicine, Fairfield Medical Center, Lancaster, OH 43130, USA; 3Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; 4Department of Neurobiology and Anatomy, The University of Mississippi Medical Center, Jackson, MS 39216, USA Abstract: In this report, we discuss the case of an multiple sclerosis (MS) patient, age 62, who learned to attain and sustain euthymia despite his ailments. He has Ehlers Danlos Syndrome (EDS), asthma, MS, urticaria, and major depression (MD). Despite thriving limitations, the patient is an accomplished scientist, who struggled for > twelve years to emerge from being confined to bed and wheel chair with MS, to walking with crutches, scuba diving, writing manuscripts, and living a positive life. Through former educators, he reacquired problem-solving habits to study the literature on his illnesses; keep records; try new therapies; and use pharmaceutical, nutritional, physical, and psychological methods to attain euthymia. With this inculcation, years later, he discovered that dimethyl fumarate (DMF) suppressed inflammation, cramping, urticaria, and asthma; and the combination of bupropion, S-adenosylmethionine (SAMe), vitamin-D3 (vit-D3), yoga, and self-hypnosis relieved MD. Then, after a 14-month respite, the patient, discovered that he had adult onset craniopharyngioma: a benign, recurring, epithelial tumor that grows from vestigial embryonic tissue (Rathke’s pouch) which formed the anterior pituitary. The tumor grows aggressively and causes surrounding tissue and function losses. It caused headaches, disorientation, bitemporal vision loss, among other problems. To emerge from this conundrum, the patient employed his relearned habits; the above antidepressant cocktail (bupropion, SAMe, and vit-D3); and with 30 fractionated stereotactic radiation treatments shrank his tumor and gained relief. This is a single case, and methods we discovered serendipitously may not work for other chronically ill patients. Consequently, we want to encourage such patients and their physicians to discuss their experiences in peer-reviewed domains so readers may acquire new perspectives that help individualize their care, and have productive contented lives. Keywords: craniopharyngioma, euthymia, dimethyl fumarate, bupropion, S-adenosylmethionine, vitamin D3

Background: We sought to evaluate the anatomic and functional lesion development over time at different atrial sites immediately following delivery of pulsed field ablation (PFA)., Methods: Using a porcine model, PFA ablations were performed in the superior vena cava (SVC), right atrial lateral wall (RA), left atrial appendage (LAA), and right superior pulmonary vein (RSPV) using four different PFA profiles. Mapping was done sequentially in 5-20-min increments up to 280-min post lesion delivery for low voltage area (LVA) assessment and conduction velocity. Lesion characteristics were noted with voltage mapping immediately post ablation and at the serial time points., Results: In 9 animals, 33 sites were ablated. None of the four different profiles across all sites showed any statistical difference on acute lesion formation or persistence. Higher tissue contact was observed in the SVC and RSPV and lower tissue contact was observed in the LAA and RA locations. Higher contact areas were noted to have higher density electroanatomic low voltage area (LVA) (12/14 vs 5/18, p = 0.01) and larger lesions on gross pathology (2 /14 vs 6/16, p = 0.01) compared to lower contact areas. Lesion regression occurred in 16/33 sites. Sustained lesions were significantly more prevalent in higher versus lower contact sites (65% vs 38%, p = 0.037)., Conclusion: The development of significant and durable lesions for PFA in a porcine model appears to be dependent on tissue proximity and contact., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Transcatheter aortic valve replacement (TAVR) carries a risk of high-grade AV block requiring cardiac implantable electronic device (CIED) implantation, which has been associated with a higher mortality rate. However, the outcomes of TAVR in patients with preexisting CIEDs are not well understood. We conducted a retrospective analysis of consecutive patients who underwent TAVR from December 2014 to December 2019 at our institution. Patients were categorized into 3 groups: preexisting CIED pre-TAVR (group 1), CIED implanted within 30 days after TAVR (group 2), and no CIED implanted (group 3). Cox proportional hazard was conducted to determine the primary end point of all-cause mortality. A total of 366 patients were included, of whom 93 (25.4%), 51 (13.9%), and 222 (60.7%) comprised group 1, 2, and 3, respectively. The median follow-up time was 2.3 years. The all-cause mortality rate was higher in group 1 than group 2 (hazard ratio [HR] 2.60, 95% confidence interval [CI] 1.09 to 6.18, p = 0.03) and group 3 (HR 1.96, 95% CI 1.24 to 3.08, p = 0.004). On the multivariate analysis, there was no statistically significant difference in mortality among the groups (group 1 vs group 2: HR 1.95, 95% CI 0.70 to 5.44, p = 0.20 and group 1 vs group 3: HR 1.27, 95% CI 0.66 to 2.43, p = 0.47). Preoperative hemoglobin ≤12 g/100 ml was an independent predictor of all-cause mortality (HR 1.75, 95% CI 1.10 to 2.80, p = 0.02). Group 1 had a higher 1 year congestive heart failure readmission rate (29%) than group 2 (17.6%) and group 3 (8.1%; p <0.0001). In conclusion, there was no difference in the adjusted long-term survival based on the CIED grouping. However, patients with preexisting CIEDs had higher all-cause mortality and 1-year congestive heart failure readmission rates owing to their higher co-morbidity burden, irrespective of their Society of Thoracic Surgeons score. This can be taken into account for preoperative risk stratification., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2023. Published by Elsevier Inc.)

Background: Freedom from atrial arrhythmia (AA) recurrence ≥30 seconds after pulsed field ablation (PFA) in patients with atrial fibrillation (AF) was reported in PULSED AF (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF; ClinialTrials.gov Identifier: NCT04198701). AA burden may be a more clinically meaningful endpoint., Objective: The purpose of this study was to determine the influence of monitoring strategies on AA detection and AA burden association with quality of life (QoL) and health care utilization (HCU) after PFA., Methods: Patients underwent 24-hour Holter monitoring at 6 and 12 months and weekly, and symptomatic transtelephonic monitoring (TTM). AA burden post-blanking was calculated as the greater of (1) percentage of AA on total Holter time; or (2) percentage of weeks with ≥1 TTM with AA out of all weeks with ≥1 TTM., Results: Freedom from all AAs varied by >20% when differing monitoring strategies were used. PFA resulted in zero burden in 69.4% of paroxysmal atrial fibrillation (PAF) and 62.2% of persistent atrial fibrillation (PsAF) patients. Median burden was low (<9%). Most PAF and PsAF patients had ≤1 week of AA detection on TTM (82.6% and 75.4%) and <30 minutes of AA per day of Holter monitoring (96.5% and 89.6%), respectively. Only PAF patients with <10% AA burden averaged a clinically meaningful (>19 point) QoL improvement. PsAF patients experienced clinically meaningful QoL improvements irrespective of burden. Repeat ablations and cardioversions significantly increased with higher AA burden (P <.01)., Conclusion: The ≥30-second AA endpoint is dependent on the monitoring protocol used. PFA resulted in low AA burden for most patients, which was associated with clinically relevant improvement in QoL and reduced AA-related HCU., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Ablation strategies remain poorly defined for persistent atrial fibrillation (AF) patients with recurrence despite intact pulmonary vein isolation (PVI). As the ability to perform durable PVI improves, the need for advanced mapping to identify extra-PV sources of AF becomes increasingly evident. Multiple mapping technologies attempt to localize these self-sustained triggers and/or drivers responsible for initiating and/or maintaining AF; however, current approaches suffer from technical limitations. Electrographic flow (EGF) mapping is a novel mapping method based on well-established principles of optical flow and fluid dynamics. It enables the full spatiotemporal reconstruction of organized wavefront propagation within the otherwise chaotic and disorganized electrical conduction of AF. Given the novelty of EGF mapping and relative unfamiliarity of most clinical electrophysiologists with the mathematical principles powering the EGF algorithm, this paper provides an in-depth explanation of the technical/mathematical foundations of EGF mapping and demonstrates clinical applications of EGF mapping data and analyses. Starting with a 64-electrode basket catheter, unipolar EGMs are recorded and processed using an algorithm to visualize the electrographic flow and highlight the location of high prevalence AF "source" activity. The AF sources are agnostic to the specific mechanisms of source signal generation., (© 2022. The Author(s).)

Background: Pulsed field ablation uses electrical pulses to cause nonthermal irreversible electroporation and induce cardiac cell death. Pulsed field ablation may have effectiveness comparable to traditional catheter ablation while preventing thermally mediated complications., Methods: The PULSED AF pivotal study (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF) was a prospective, global, multicenter, nonrandomized, paired single-arm study in which patients with paroxysmal (n=150) or persistent (n=150) symptomatic atrial fibrillation (AF) refractory to class I or III antiarrhythmic drugs were treated with pulsed field ablation. All patients were monitored for 1 year using weekly and symptomatic transtelephonic monitoring; 3-, 6-, and 12-month ECGs; and 6- and 12-month 24-hour Holter monitoring. The primary effectiveness end point was freedom from a composite of acute procedural failure, arrhythmia recurrence, or antiarrhythmic escalation through 12 months, excluding a 3-month blanking period to allow recovery from the procedure. The primary safety end point was freedom from a composite of serious procedure- and device-related adverse events. Kaplan-Meier methods were used to evaluate the primary end points., Results: Pulsed field ablation was shown to be effective at 1 year in 66.2% (95% CI, 57.9 to 73.2) of patients with paroxysmal AF and 55.1% (95% CI, 46.7 to 62.7) of patients with persistent AF. The primary safety end point occurred in 1 patient (0.7%; 95% CI, 0.1 to 4.6) in both the paroxysmal and persistent AF cohorts., Conclusions: PULSED AF demonstrated a low rate of primary safety adverse events (0.7%) and provided effectiveness consistent with established ablation technologies using a novel irreversible electroporation energy to treat patients with AF., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT04198701., Competing Interests: Disclosures Drs Verma, Boersma, Calkins, Haines, Hindricks, Kuck, Marchlinski, Natale, Packer, De Lurgio, and Sanders receive consultation funds from Medtronic, Inc. Dr Onal and J. Cerkvenik are employees of Medtronic, Inc. Dr Verma receives grants or consultation funds from Biosense Webster, Bayer, Medlumics, Adagio Medical, and Boston Scientific. Dr De Lurgio receives consultation or honoraria funds from Atricure and Boston Scientific. Dr Marchlinski receives grants, consultation, or honoraria funds from Biosense Webster, Abbott Medical, and Biotronik. Dr Sood receives consultation or honoraria funds from Johnson & Johnson, Boston Scientific, Atricure, Bristol Myers, and Pfizer. Dr Boersma receives consultation funds from Boston Scientific, Abbott Medical, Adagio Medical, Acutus Medical, and Philips Medical. Dr Kuck receives consultation funds from Cardiovalve. Dr Natale receives consultation funds from Abbott Medical, Baylis, Biosense Webster, Biotronik, and Boston Scientific. Dr Sanders receives grants or honoraria funds from Boston Scientific, Abbott Medical, Becton Dickenson, Pacemate, and CathRx. Dr Tada receives funds from Abbott Medical Japan LLC, Nippon Boehringer Ingelheim Co Ltd, Daiichi Sankyo Company Ltd, Alvaus Inc, Biotronik Japan Inc, Bristol Myers Squibb, and Novartis Pharma KK. Dr Calkins receives consultation or honoraria funds from Boston Scientific, Abbott Medical, Atricure, and Biosense Webster.

Pulsed field ablation (PFA) has the potential to evolve into an efficient alternative to traditional RF ablation for atrial fibrillation treatment. However, achieving irreversible tissue electroporation is critical to suppressing arrhythmic pathways, raising the need for accurate lesion characterization. To understand the physics behind the tissue response PFA, we propose a quasi-dynamic model that quantifies tissue conductance at end-electroporation and identifies regions that have undergone fully irreversible electroporation (IRE). The model uses several parameters and numerically solves the electrical field diffusion into the tissue by iteratively updating the tissue conductance until equilibrium at end-electroporation. The model yields a steady-state tissue conductance map used to identify the irreversible lesion. We conducted numerical experiments mimicking a lasso catheter featuring nine 3-mm electrodes spaced circumferentially at 3.75 mm and fired sequentially using a 1500 V and 3000 V pulse amplitude. The IRE lesion region has a surface area and volume of 780 mm 2 and 1411 mm 3 , respectively, at 1500 V, and 1178 mm 2 and 2760 mm 3 , respectively, at 3000 V. Lesion discontinuity was observed at 5.0 mm depth with 1500 V, and 7.2 mm depth with 3000 V. This quasi-dynamic model yields tissue conductance maps, predicts irreversible lesion and lesion penumbra at end-electroporation, and confirms larger lesions with higher pulse amplitudes.

Background: Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may reduce the risk of phrenic nerve injury but has not been well characterized., Methods: Accelerometers and continuous pacing were used during PFA deliveries in a porcine model. Acute dose response was established in a first experimental phase with ascending PFA intensity delivered to the phrenic nerve (n=12). In a second phase, nerves were targeted with a single ablation level to observe the effect of repetitive ablations on nerve function (n=4). A third chronic phase characterized assessed histopathology of nerves adjacent to ablated cardiac tissue (n=6)., Results: Acutely, we observed a dose-dependent response in phrenic nerve function including reversible stunning (R 2 =0.965, P <0.001). Furthermore, acute results demonstrated that phrenic nerve function responded to varying levels of PFA and catheter proximity placements, resulting in either: no effect, effect, or stunning. In the chronic study phase, successful isolation of superior vena cava at a dose not predicted to cause phrenic nerve dysfunction was associated with normal phrenic nerve function and normal phrenic nerve histopathology at 4 weeks., Conclusions: Proximity of the catheter to the phrenic nerve and the PFA dose level were critical for phrenic nerve response. Gross and histopathologic evaluation of phrenic nerves and diaphragms at a chronic time point yielded no injury. These results provide a basis for understanding the susceptibility and recovery of phrenic nerves in response to PFA and a need for appropriate caution in moving beyond animal models.

Background: An important complication of cardiac implantable electronic devices (CIED) implantation is the development of hematoma and device infection., Objective: We aimed to evaluate a novel mechanical compression device for hematoma prevention and cosmetic outcomes following CIED implantation., Methods: An open, prospective, randomized, single-center clinical trial was performed in patients undergoing CIED implantation. Patients were randomized to receive a novel mechanical compression device (PressRite, PR) or to receive the standard of care post device implantation. Skin pliability was measured with a calibrated durometer; the surgical site was evaluated using the Manchester Scar Scale (MSS) by a blinded plastic surgeon and the Patient and Observer Scar Scale (POSAS). Performance of PR was assessed through pressure measurements, standardized scar scales and tolerability., Results: From the total of 114 patients evaluated for enrollment, 105 patients were eligible for analysis. Fifty-one patients were randomized to management group (PR) and 54 to the control group. No patients required early removal or experienced adverse effects from PR application. There were 11 hematomas (14.8% vs. 5.9% in the control and PR group respectively, p = NS). The control group had higher post procedure durometer readings in the surgical site when compared with the PR group (7.50 ± 3.45 vs. 5.37 ± 2.78; p = < .01). There were lower MSS scores in the PR group after 2 weeks (p = .03)., Conclusion: We have demonstrated the safety of PR application and removal. In addition, PR appears to improve postoperative skin pliability, which could facilitate wound healing., (© 2022 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

The incidence of new-onset secondary atrial fibrillation (NOSAF) is as high as 44% in noncardiac critical illness. A systematic review and meta-analysis were performed to evaluate the impact of NOSAF, compared with history of prior atrial fibrillation (AF) and no history of AF in noncardiac critically ill patients. Patients undergoing cardiothoracic surgery were excluded. NOSAF incidence, intensive care unit (ICU)/hospital length of stay (LOS), and mortality outcomes were analyzed. Of 2,360 studies reviewed, 19 studies met inclusion criteria (n = 306,805 patients). NOSAF compared with no history of AF was associated with increased in-hospital mortality (risk ratio [RR] 2.06, 95% confidence interval [CI] 1.76 to 2.41, p <0.001), longer ICU LOS (standardized difference in means [SMD] 0.66, 95% CI 0.41 to 0.91, p <0.001), longer hospital LOS (SMD 0.31, 95% CI 0.07 to 0.56, p = 0.001) and increased risk of long-term (>1 year) mortality (RR 1.76, 95% CI 1.29 to 2.40, p <0.001). NOSAF compared with previous AF was also associated with higher in-hospital mortality (RR 1.29, 95% CI 1.12 to 1.49, p <0.001), longer ICU LOS (SMD 0.37, 95% CI 0.03 to 0.70, p = 0.03) but no difference in-hospital LOS (SMD -0.18, 95% CI -0.66 to 0.31, p = 0.47). In conclusion, NOSAF, in the setting of noncardiac critical illness is associated with increased in-hospital mortality compared with no history of AF and previous AF. NOSAF (vs no history of AF) is also associated with increased long-term mortality., Competing Interests: Disclosures The authors have no conflicts of interest to declare., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Pulsed field ablation (PFA) is a novel form of ablation using electrical fields to ablate cardiac tissue. There are only limited data assessing the feasibility and safety of this type of ablation in humans., Methods: PULSED AF (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF; https://www.clinicaltrials.gov; unique identifier: NCT04198701) is a nonrandomized, prospective, multicenter, global, premarket clinical study. The first-in-human pilot phase evaluated the feasibility and efficacy of pulmonary vein isolation using a novel PFA system delivering bipolar, biphasic electrical fields through a circular multielectrode array catheter (PulseSelect; Medtronic, Inc). Thirty-eight patients with paroxysmal or persistent atrial fibrillation were treated in 6 centers in Australia, Canada, the United States, and the Netherlands. The primary outcomes were ability to achieve acute pulmonary vein isolation intraprocedurally and safety at 30 days., Results: Acute electrical isolation was achieved in 100% of pulmonary veins (n=152) in the 38 patients. Skin-to-skin procedure time was 160±91 minutes, left atrial dwell time was 82±35 minutes, and fluoroscopy time was 28±9 minutes. No serious adverse events related to the PFA system occurred in the 30-day follow-up including phrenic nerve injury, esophageal injury, stroke, or death., Conclusions: In this first-in-human clinical study, 100% pulmonary vein isolation was achieved using only PFA with no PFA system-related serious adverse events. Graphic Abstract: A graphic abstract is available for this article.

Background: Transfemoral venous access (TFV) is the cornerstone of minimally invasive cardiac procedures. Although the presence of inferior vena cava filters (IVCFs) was considered a relative contraindication to TFV procedures, small experiences have suggested safety. We conducted a systematic review of the available literature on cardiac procedural success of TFV with IVCF in-situ., Methods: Two independent reviewers searched PubMed, EMBASE, SCOPUS, and Google Scholar from inception to October 2020 for studies that reported outcomes in patients with IVCFs undergoing TFV for invasive cardiac procedures. We investigated a primary outcome of acute procedural success and reviewed the pooled data for patient demographics, procedural complications, types of IVCF, IVCF dwell time, and procedural specifics., Results: Out of the 120 studies initially screened, 8 studies were used in the final analysis with a total of 100 patients who underwent 110 procedures. The most common IVCF was the Greenfield Filter (36%), 60% of patients were males and the mean age was 67.8 years. The overall pooled incidence of acute procedural success was 95.45% (95% confidence interval = 89.54-98.1) with no heterogeneity (I 2  = 0%, p = 1) and there were no reported filter-related complications., Conclusion: This systematic review is the largest study of its kind to demonstrate the safety and feasibility of TFV access in a variety of cardiac procedures in the presence of IVCF., (© 2021 Wiley Periodicals LLC.)

Importance: It has been suggested that atrial fibrillation (AF) is the new cardiovascular disease epidemic of the 21st century. Clinical cardiology has largely focused on AF treatment and associated stroke prevention rather than preventing AF itself. To reduce the global consequences and associated costs of AF, it is critical to now embrace prevention as a priority. Proactively addressing the risk factors for AF and the underlying unhealthy lifestyle habits that contribute to them, using research-based counseling approaches, represents a complementary and adjunctive alternative in combatting this disease burden., Observations: Encouraging and sustaining patient involvement to reduce AF incidence and improve outcomes begins with screening to identify risk factors, unhealthy lifestyle habits, and characteristics associated with failed attempts at favorably modifying these causalities. Modulators of and common barriers to achieving risk reduction and lifestyle change include self-efficacy, social support, age, sex, marital and socioeconomic status, education, employment, and psychosocial factors such as depression, isolation, anxiety and chronic life stress. Focused behavioral counseling approaches, including assessing the patient's readiness to change, motivational interviewing and using the 5 A's (assess, advise, agree, assist, arrange), along with employing initial downscaled goals to overcome inertia, are proven methodologies to overcome these common barriers to favorably modifying risk factors and unhealthy lifestyle habits., Conclusions and Relevance: To complement and enhance the current armamentarium for the medical management of cardiac arrhythmias, there is an urgent need to proactively address the causative factors triggering new-onset, recurrent and persistent AF. Beyond the counseling skills of highly trained professionals (eg, psychiatrists, psychologists), this narrative review highlights the need for and potential impact on lifestyle modification that non-behavioral scientists, including internal medicine, cardiology, and allied health professionals, can have on the patients they serve., Competing Interests: Declaration of competing interest None., (Copyright © 2021 Elsevier Inc. All rights reserved.)

There are an increasing number of cardiac electronic device implants and generator changes with a longer patient life expectancy along with concomitant increase in antiplatelet and anticoagulant regimens, which can increase the incidence of pocket hematomas. We have conducted an in-depth analysis on the relevant literature, which is rife with varying definition of hematomas, on ways to reduce pocket hematomas. We have analyzed studies on periprocedural medication management, intraprocedural use of prohemostatic agents, and postprocedure role of compression devices., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Pulsed field ablation (PFA) has been identified as an alternative to thermal-based ablation systems for treatment of atrial fibrillation patients. The objective of this Good Laboratory Practice (GLP) study was to characterize the chronic effects and safety of overlapping lesions created by a PFA system at intracardiac locations in a porcine model., Methods: A circular catheter with nine gold electrodes was used for overlapping low- or high-dose PFA deliveries in the superior vena cava (SVC), right atrial appendage (RAA), and right superior pulmonary vein (RSPV) in six pigs. Electrical isolation was evaluated acutely and chronic lesions were assessed via necropsy and histopathology after 4-week survival. Acute and chronic safety data were recorded peri- and post-procedurally., Results: No animal experienced ventricular arrhythmia during PFA delivery, and there was no evidence of periprocedural PFA-related adverse events. Lesions created in all anatomies resulted in electrical isolation postprocedure. Lesions were circumferential, contiguous, and transmural, with all converting into consistent lines of chronic replacement fibrosis, regardless of trabeculated or smooth endocardial surface structure. Ablations were non-thermally generated with only minimal post-delivery temperature rises recorded at the electrodes. There was no evidence of extracardiac damage, stenosis, aneurysms, endocardial disruption, or thrombus., Conclusion: PFA deliveries to the SVC, RAA, and RSPV resulted in complete circumferential replacement fibrosis at 4-week postablation with an excellent chronic myocardial and collateral tissue safety profile. This GLP study evaluated the safety and efficacy of a dosage range in preparation for a clinical trial and characterized the non-thermal nature of PFA., (© 2021 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Introduction: A weight-based heparin dosing policy adjusted for preprocedural oral anticoagulation was implemented to reduce the likelihood of subtherapeutic dosing during left atrial catheter ablation procedures. We hypothesized that initiation of the protocol would result in a greater prevalence of therapeutic activated clotting time (ACT) values and decreased time to therapeutic ACT during left atrial ablation procedures., Methods: A departmental protocol was initiated for which subjects received intravenous unfractionated heparin (UFH) to achieve and maintain a goal of ACT >300 s. Initial bolus dose was adjusted for pre-procedure oral anticoagulation and weight as follows: 50 units/kg for those receiving warfarin, 75 units/kg for those not anticoagulated, and 120 units/kg for those on direct oral anticoagulants (DOACs). A UFH infusion was initiated at 10% of the bolus per hour. One hundred consecutive left atrial ablation procedures treated with Protocol Guided heparin dosing were compared with a retrospective consecutive cohort of Usual Care heparin dosing., Results: When the Usual Care and Protocol Guided cohorts were compared, significant findings were limited to those on pre-procedure DOAC. The initial UFH bolus increased from 99.3 ± 24.8 to 118.2 ± 22.8 units/kg (p < .001), the proportion of therapeutic ACT on the first draw after heparin administration increased from 57.7% to 76.6% (p = .010), and the time to therapeutic ACT after UFH administration decreased from 37.8 ± 19.8 to 30.2 ± 16.4 min (p = .032)., Conclusion: A weight-based protocol for periprocedural UFH administration resulted in a higher proportion of therapeutic ACT values and decreased the time to therapeutic ACT for those on pre-procedure DOAC., (© 2021 Wiley Periodicals LLC.)

Objectives: This study aimed to characterize corrected QT (QTc) prolongation in a cohort of hospitalized patients with coronavirus disease-2019 (COVID-19) who were treated with hydroxychloroquine and azithromycin (HCQ/AZM)., Background: HCQ/AZM is being widely used to treat COVID-19 despite the known risk of QT interval prolongation and the unknown risk of arrhythmogenesis in this population., Methods: A retrospective cohort of COVID-19 hospitalized patients treated with HCQ/AZM was reviewed. The QTc interval was calculated before drug administration and for the first 5 days following initiation. The primary endpoint was the magnitude of QTc prolongation, and factors associated with QTc prolongation. Secondary endpoints were incidences of sustained ventricular tachycardia or ventricular fibrillation and all-cause mortality., Results: Among 415 patients who received concomitant HCQ/AZM, the mean QTc increased from 443 ± 25 ms to a maximum of 473 ± 40 ms (87 [21%] patients had a QTc ≥500 ms). Factors associated with QTc prolongation ≥500 ms were age (p < 0.001), body mass index <30 kg/m 2 (p = 0.005), heart failure (p < 0.001), elevated creatinine (p = 0.005), and peak troponin (p < 0.001). The change in QTc was not associated with death over the short period of the study in a population in which mortality was already high (hazard ratio: 0.998; p = 0.607). No primary high-grade ventricular arrhythmias were observed., Conclusions: An increase in QTc was seen in hospitalized patients with COVID-19 treated with HCQ/AZM. Several clinical factors were associated with greater QTc prolongation. Changes in QTc were not associated with increased risk of death., Competing Interests: Author Disclosures Dr. Haines has received honoraria from Biosense Webster, Farapulse and Sagentia; and has been a consultant for Affera, Boston Scientific, Integer, Medtronic, Philips Healthcare, and Zoll. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Pulmonary vein (PV) stenosis is a highly morbid condition that can result after catheter ablation for PV isolation. We hypothesized that pulsed field ablation (PFA) would reduce PV stenosis risk and collateral injury compared with irrigated radiofrequency ablation (IRF)., Methods: IRF and PFA deliveries were randomized in 8 dogs with 2 superior PVs ablated using one technology and 2 inferior PVs ablated using the other technology. IRF energy (25-30 W) or PFA was delivered (16 pulse trains) at each PV in a proximal and in a distal site. Contrast computed tomography scans were collected at 0, 2, 4, 8, and 12-week (termination) time points to monitor PV cross-sectional area at each PV ablation site., Results: Maximum average change in normalized cross-sectional area at 4-weeks was -46.1±45.1% post-IRF compared with -5.5±20.5% for PFA ( P ≤0.001). PFA-treated targets showed significantly fewer vessel restrictions compared with IRF ( P ≤0.023). Necropsy showed expansive PFA lesions without stenosis in the proximal PV sites, compared with more confined and often incomplete lesions after IRF. At the distal PV sites, only IRF ablations were grossly identified based on focal fibrosis. Mild chronic parenchymal hemorrhage was noted in 3 left superior PV lobes after IRF. Damage to vagus nerves as well as evidence of esophagus dilation occurred at sites associated with IRF. In contrast, no lung, vagal nerve, or esophageal injury was observed at PFA sites., Conclusions: PFA significantly reduced risk of PV stenosis compared with IRF postprocedure in a canine model. IRF also caused vagus nerve, esophageal, and lung injury while PFA did not.

Pulsed-field ablation (PFA) is a promising new ablation modality for the treatment of atrial fibrillation. This energy form employs a train of microsecond duration high amplitude electrical pulses that ablate myocardium by electroporation of the sarcolemmal membrane without measurable tissue heating. The ablation pulse waveform has multiple variable components that can affect ablation efficacy, thus each proprietary system has unique properties that cannot be generalized to other systems. Success with PFA depends upon the proximity of the electrode to the target tissue, but not necessarily upon contact. A unique feature of PFA is tissue specificity. Myocardium is very susceptible to irreversible injury whereas the esophagus, phrenic nerves, pulmonary veins, and coronary arteries are relatively resistant to injury. The tissue specificity of PFA may result in a wide therapeutic range and improved safety profile during atrial fibrillation ablation. Vein isolation can be achieved very rapidly (seconds) promising that PFA may reduce procedure time to 1 hour or less. This attractive new technology promises to be a major advance in the field of atrial fibrillation ablation., (© 2020 Wiley Periodicals, Inc.)

Introduction: Catheter ablation of atrial fibrillation (AF) may lead to collateral damage to the esophagus. We tested the hypothesis that luminal esophageal temperature (LET)-guided esophageal cooling might reduce the incidence of esophageal thermal lesions (ETL)., Methods: Seventy-six patients from August 2015 to March 2017 with paroxysmal or persistent AF underwent a first-time catheter ablation procedure with or without LET-guided active esophageal cooling through an orogastric tube placed in the esophagus. Esophageal cooling occurred if and only if LET exceeded 0.5 °C from baseline while ablating the LA posterior wall. All patients underwent esophagogastric endoscopy the next day., Results: Of the 76 patients studied, 38 (50%) patients underwent esophageal cooling. Baseline characteristics of the non-cooled and cooled groups were comparable. Of these, 59% of patients had ETL. There was a non-significant trend for more severe lesions (grades 3, 4) in the non-cooled group (29% vs. 13.5%, p = 0.10). Average power delivered on the left atrial posterior wall (27 ± 1.8 W vs. 27 ± 3.8 W, p = 0.34) and average force of contact (10.1 g vs. 9.8 g, p = 0.38) were similar in both groups while more time was spent ablating on the posterior wall in the non-cooled group (24.6 ± 7.3 min vs. 20.4 ± 5.9 min, p = 0.014). In a multivariate analysis, esophageal cooling had no significant effect on the esophageal lesion grade post-ablation., Conclusion: The incidence of ETL in patients undergoing left atrial posterior wall isolation is substantial. Our method of esophageal cooling did not decrease the incidence of ETL. There was a non-significant trend toward fewer severe lesions with cooling, but one cannot conclude the value of cooling from this pilot study.

Background: Centers for Medicare and Medicaid Services has mandated the use of shared decision-making (SDM) for implantable cardioverter-defibrillator (ICD) implantation. SDM tools help facilitate quality SDM by presenting patients with balanced evidence-based facts related to risk and benefits. Perceptions of ICD implantation may differ based on patients' sex and race., Objective: To determine if and how physicians are incorporating SDM in counseling patients about ICD and if they are aware of sex- and race-based differences in patients' perception of ICDs., Methods: This was a pilot study involving an online survey targeting attending physicians who implant ICDs. Physicians were randomly selected by a computer-based program; 350 surveys were sent., Results: Of the 124 (35%) respondents to the survey, 102 (84%) met the inclusion criteria, and of those, 99 (97%) were adult electrophysiologists. Most physicians (90, 88%) stated they engaged in SDM during the general consent process. Sixty-three (62%) physicians discuss end of life issues while obtaining general consent. Forty-four (43%) physicians said they use an existing SDM tool with the Colorado SDM tool being the most common (39, 89%). The majority of physicians were unaware of sex- and race-based differences in perceptions related to ICD implantation (sex 64, 63% and race 63, 62%)., Conclusion: A vast majority of physicians are engaging in SDM; however less than half are using a formal SDM tool, and a minority of physicians were aware of sex- and race-based differences in patients' perception of ICD implantation. Sex- and race-based tools might help address this gap., (© 2019 Wiley Periodicals, Inc.)

Background: A common approach to ablating along the posterior wall of the left atrium in atrial fibrillation ablation is to use low power with longer duration for durable lesions and reducing thermal injury. We hypothesize that similar lesions can be safely obtained at high power with low open-irrigation flow and low duration., Methods: Twenty-two porcine ventricles were placed in a tissue bath with circulating 0.45% NaCl at a maintained temperature of 37 °C. Bipolar radiofrequency ablation (RFA) with a 4-mm-tip irrigated, force-sensing catheter was performed with various combinations of irrigation, power, and duration at 20g of contact force. Fiber optic temperature probes were placed at depths of 3 mm and 5 mm. Temperature was measured during and 30 s after each ablation., Results: Two hundred sixty-eight lesions were made. At a fixed power and flow rate, lesion surface diameter, maximum lesion width, and lesion depth all increased with longer ablation duration. At fixed duration and irrigation flow rate, increased power led to increased lesion dimensions. At a lower flow rate (2 ml/min), surface lesion diameter and maximum width were significantly larger compared to a higher flow rate (17 ml/min), but lesion depth was not significantly different. The maximum temperature and the rate of temperature rise at a depth of 5 mm with different power settings and ablation durations were lower as compared to a depth of 3 mm at both flow rates (2 ml/min and 17 ml/min)., Conclusions: Effective lesions can be performed with high-power and short-ablation durations, thereby reducing RFA procedure time. Higher power, shorter duration lesions result in adequate temperature for myocardial lesion formation at 3 mm, but do not result in excessive temperature at 5 mm depth, potentially reducing the risk of collateral injury. Compared to higher irrigation flow rate, larger surface lesions and comparable maximum lesion width are achieved with lower irrigation flow rate, thus resulting in better lesion contiguity.

Background: Radiofrequency (RF) has become an accepted energy source for myocardial ablation but may result in discontinuous lesions and nontargeted tissue injury. We examined the feasibility and safety of lesion formation using high-amplitude, bipolar pulsed electric fields delivered from a multielectrode array catheter., Objective: The purpose of this study was to compare duty-cycled radiofrequency ablation (RFA) to pulsed field ablation (PFA) in terms of acute electrical effects, 2-week lesion formation, and injury to nontargeted tissues., Methods: Intracardiac ablations were performed in 6 pigs using a circular pulmonary vein ablation catheter. The energy source for ablation delivery was randomized to deliver either PFA or RFA to 3 atrial endocardial sites. Bipolar pace capture and electrogram amplitude measurements were recorded at each site. Histopathology and necropsies were performed after 2 weeks., Results: The circular pulmonary vein ablation catheter was used to deliver pulsed electric fields to produce cardiac lesions without skeletal muscle stimulation. Evaluating all ablations in each site, electrogram amplitudes were reduced to <0.5 mV in 67.5% of PFA vs 27.0% of RFA deliveries (P <.001). Bipolar cardiac capture was lost after 100% vs 92.0% of PFA vs RFA (P = .005). At 2 weeks, PFA resulted in consistent transmural and homogeneous replacement fibrosis devoid of lingering myocyte "sequesters." RFA lesions showed a stronger inflammatory response extending to the epicardial fat, arterial injury, and thrombosis. Neither PFA nor RFA lesions showed endocardial thrombus., Conclusion: Intracardiac PFA can be feasibly delivered from a circular catheter to create fibrotic lesions that have acute electrical effects, without injury to nontargeted tissue., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Visualizing myocardium with near field ultrasound (NFUS) transducers in the tip of the catheter might provide an image of the evolving pathological lesion during energy delivery., Background: Radiofrequency (RF) catheter ablation has been effective in arrhythmia treatment, but no technology has allowed lesion formation to be visualized in real time in vivo., Methods: RF catheter ablations were performed in vivo with the goal to create transmural atrial lesions and large ventricular lesions. RF lesion formation was imaged in real time using M-mode, tissue Doppler, and strain rate information from the NFUS open irrigated RF ablation catheter incorporating 4 ultrasound transducers (1 axial and 3 radial), and growth kinetics were analyzed. Nineteen dogs underwent ablation in the right and left atria (n = 185), right ventricle (n = 67), and left ventricle (n = 66). Lesions were echolucent with tissue strain rate by NFUS., Results: Lesion growth frequently progressed from epicardium to endocardium in thin-walled tissue. The half time of lesion growth was 5.5 ± 2.8 s in thin-walled and 9.7 ± 4.3 s in thick-walled tissue. Latency of lesion onset was seen in 57% of lesions ranging from 1 to 63.8 s. Tissue edema (median 25% increased wall thickness) formed immediately upon lesion formation in 83%, and intramyocardial steam was seen in 71% of cases., Conclusions: NFUS was effective in imaging RF catheter ablation lesion formation in real time. It was useful in assessing the dynamics of lesion growth and could visualize impending steam pops. It may be a useful technology to improve both safety and efficacy of RF catheter ablation., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)