Evaluation of a novel cardiac signal processing system for electrophysiology procedures: The PURE EP 2.0 study.

BACKGROUND: Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has known shortcomings and has not advanced in several decades. OBJECTIVE: The purpose of this study was to evaluate a new signal processing platform, the PURE EP™ system (PURE), in a multi-center, prospective study. METHODS: Intracardiac signal data of clinical interest were collected from 51 patients undergoing ablation procedures with PURE, the signal recording system, and the 3D mapping system at the same time stamps. The samples were randomized and subjected to blinded, controlled evaluation by three independent electrophysiologists to determine the overall quality and clinical utility of PURE signals when compared to conventional sources. Each reviewer assessed the same (92) signal sample sets and responded to (235) questions using a 10-point rating scale. If two or more reviewers rated the PURE signal higher than the control, it was deemed superior. RESULTS: A total of 93% of question responses showed consensus amongst the blinded reviewers. Based on the ratings for each pair of signals, a cumulative total of 164 PURE signals out of 218 (75.2%) were statistically rated as Superior for this data set (p < .001). Only 14 PURE signals out of 218 were rated as Inferior (6.4%). CONCLUSION: The PURE intracardiac signals were statistically rated as superior when compared to conventional systems.

Guidance for Rebooting Electrophysiology Through the COVID-19 Pandemic From the Heart Rhythm Society and the American Heart Association Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology: Endorsed by the American College of Cardiology.

Coronavirus disease 2019 (COVID-19) has presented substantial challenges to patient care and impacted health care delivery, including cardiac electrophysiology practice throughout the globe. Based upon the undetermined course and regional variability of the pandemic, there is uncertainty as to how and when to resume and deliver electrophysiology services for arrhythmia patients. This joint document from representatives of the Heart Rhythm Society, American Heart Association, and American College of Cardiology seeks to provide guidance for clinicians and institutions reestablishing safe electrophysiological care. To achieve this aim, we address regional and local COVID-19 disease status, the role of viral screening and serologic testing, return-to-work considerations for exposed or infected health care workers, risk stratification and management strategies based on COVID-19 disease burden, institutional preparedness for resumption of elective procedures, patient preparation and communication, prioritization of procedures, and development of outpatient and periprocedural care pathways.

Impact of a Multidisciplinary Treatment Pathway for Atrial Fibrillation in the Emergency Department on Hospital Admissions and Length of Stay: Results of a Multi-Center Study.

Background Variability in the management of atrial fibrillation (AF) in the emergency department (ED) leads to avoidable hospital admissions and prolonged length of stay (LOS). In a retrospective single-center study, a multidisciplinary AF treatment pathway was associated with a reduced hospital admission rate and reduced LOS. To assess the applicability of the AF pathway across institutions, we conducted a 2-center study. Methods and Results We performed a prospective, 2-stage study at 2 tertiary care hospitals. During the first stage, AF patients in the ED received routine care. During the second stage, AF patients received care according to the AF pathway. The primary study outcome was hospital admission rate. Secondary outcomes included ED LOS and inpatient LOS. We enrolled 104 consecutive patients in each stage. Patients treated using the AF pathway were admitted to the hospital less frequently than patients who received routine care (15% versus 55%; P<0.001). For admitted patients, average hospital LOS was shorter in the AF pathway cohort than in the routine care cohort (64 versus 105 hours, respectively; P=0.01). There was no significant difference in the average ED LOS between AF pathway and routine care cohorts (14 versus 12 hours, respectively; P=0.32). Conclusions In this prospective 2-stage, 2-center study, utilization of a multidisciplinary AF treatment pathway resulted in a 3.7-fold reduction in admission rate and a 1.6-fold reduction in average hospital LOS for admitted patients. Utilization of the AF pathway was not associated with a significant change in ED LOS.

Novel automated point collection software facilitates rapid, high-density electroanatomical mapping with multiple catheter types.

INTRODUCTION: Manual, point-by-point electroanatomical mapping requires the operator to directly evaluate each point during map construction. Consequently, point collection can be a slow process. An automated 3D mapping system was developed with the goal of improving key mapping metrics, including map completion time and point density. METHODS: Automated 3D mapping software that includes morphology and cycle length discrimination functions for surface and intracardiac electrograms was developed. In five swine, electroanatomical maps (EAMs) of all four cardiac chambers were generated in sinus rhythm. Four catheters were used: two different four-pole ablation catheters, a 20-pole circular catheter, and a 64-pole basket catheter. Automated and manual 3D mapping were compared for 12 different catheter-chamber combinations (paired sets of 10 maps for most combinations, for a total of 156 maps). RESULTS: Automated 3D mapping produced more than twofold increase in the number of points per map, as compared with manual 3D mapping (P ≤0.007 for all catheter-chamber combinations tested). Automated 3D mapping also reduced map completion time by an average of 29% (P < 0.05 for all comparisons). The amount of manual editing of the maps acquired with automated 3D mapping was minimal. CONCLUSION: Automated 3D mapping with the open-platform mapping software described in this study is significantly faster than manual, point-by-point 3D mapping. This resulted in shorter mapping time and higher point density. The morphology discrimination functions effectively excluded ectopic beats during mapping in sinus rhythm and allowed for rapid mapping of intermittent ventricular ectopic beats.

Pulmonary vein isolation for atrial fibrillation in the postpneumonectomy population: a feasibility, safety, and outcomes study.

BACKGROUND: Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized. METHODS: This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions. RESULTS: There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4, and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3, and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications. CONCLUSION: PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity.

Evaluation and management of the atrial fibrillation patient: a report from the Society of Cardiovascular Patient Care.

Atrial fibrillation (AF) is the most common cardiac dysrhythmia, and its prevalence is growing. The care of patients with AF is complex and involves multiple specialties and venues of care. Guideline recommendations are available for AF therapy; however, their implementation can be challenging. The Society of Cardiovascular Patient Care has developed an accreditation program, formulated by an expert committee on AF. Accreditation is based on specific criteria in 7 domains: (1) community outreach, (2) prehospital care, (3) early stabilization, (4) acute care, (5) transitions of care, (6) clinical quality measures, and (7) governance. This document presents the rationale, discussion, and supporting evidence for these criteria, in an effort to maximize effective and efficient AF care.

Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy.

Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation.

Accuracy of left atrial anatomical maps acquired with a multielectrode catheter during catheter ablation for atrial fibrillation.

INTRODUCTION: Left atrial geometry provided by preprocedural MRI/CT imaging studies is often used to guide pulmonary vein isolation. Rapid 3D reconstruction of the left atrium (LA) can be obtained using multielectrode catheters in conjunction with electro-anatomical mapping (EAM) and can also be used to guide ablation. The objective of this study is to assess the accuracy of electro-anatomical left atrial maps acquired with the multispine catheter by comparing them to CT and MRI images. METHODS: Forty patients undergoing ablation for atrial fibrillation were studied. All patients underwent preprocedural CT/MRI imaging. 3D reconstructions of the LA were obtained using a multispine catheter with the Ensite/NavX mapping system. The operator was blinded to the results of the preprocedural imaging studies while acquiring the LA maps. RESULTS: Mean map acquisition time was 10.3 ± 3.0 min. There was a strong correlation between maximum pulmonary vein (PV) ostial length and intervein distances measured on the electro-anatomical maps and on the CT/MRI images. Moreover, 11 patients had right middle PVs which were detected during map acquisition. Six out of nine (67%) early branches of the right inferior PV and three out of three (100%) early branches of right superior PV were also identified. In two patients, one branch of the left superior PV and one branch of the left inferior PV were not detected during mapping. CONCLUSION: Left atrial anatomical maps acquired using multielectrode catheters in conjunction with EAM are accurate and provide information regarding pulmonary vein dimensions and geometry which is similar to that obtained with CT/MR imaging.

Materials for multifunctional balloon catheters with capabilities in cardiac electrophysiological mapping and ablation therapy.

Developing advanced surgical tools for minimally invasive procedures represents an activity of central importance to improving human health. A key challenge is in establishing biocompatible interfaces between the classes of semiconductor device and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on materials that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide diverse, multimodal functionality suitable for clinical use. As examples, we present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radiofrequency electrodes for controlled, local ablation of tissue. Use of such 'instrumented' balloon catheters in live animal models illustrates their operation, as well as their specific utility in cardiac ablation therapy. The same concepts can be applied to other substrates of interest, such as surgical gloves.

Assessment of catheter tip contact force resulting in cardiac perforation in swine atria using force sensing technology.

BACKGROUND: Force sensing is a recently developed technology that allows the determination of the contact force (CF) at the tip of the catheter during electrophysiology procedures. Previous studies suggested that the optimal CF for adequate catheter contact ranges between 10 and 40 g. The aim of this study was to determine the CF needed to cause perforation in the swine atria. METHODS AND RESULTS: Pericardial access was obtained at the beginning of the study in a swine model to drain pericardial effusions. Electroanatomic maps of the right atrium (RA) and left atrium (LA) were constructed. Ablation was performed using an irrigated-tip radiofrequency catheter equipped with force-sensing technology (30 W, 30 mL/min, for 30 seconds). Perforations of the LA and RA wall were intentionally performed in different locations with and without radiofrequency ablation. CF values preceding each perforation were recorded. A total of 111 cardiac perforations were achieved in 7 pigs. The overall average CF resulting in perforation was 175.8±60.4 g (range, 77 to 376 g). This was significantly lower after 30 seconds of radiofrequency delivery: 151.8±49.9 g versus 197±61.3 g (P=0.00005). The average value of CF resulting in perforation was not statistically different between the RA and the LA (169.6±61.6 g versus 181.7±59.3 g) (P=0.29). CONCLUSIONS: Perforation of the atrial wall in a swine model can occur over a wide range of CF values. Perforation can occur with a CF as low as 77 g. Ablation reduces the perforating force by 23%.

Incidence and electrophysiologic properties of dissociated pulmonary vein activity following pulmonary vein isolation during catheter ablation of atrial fibrillation.

INTRODUCTION: pulmonary veins (PV) play an important role in the arrhythmogenesis of atrial fibrillation (AF). Catheter-based PV isolation is one of the primary treatments for symptomatic drug refractory AF. Following electrical isolation, isolated rhythms in the PV are encountered. The aim of this study was to assess the frequency of postisolation PV activity and classify the different rhythms observed. METHODS AND RESULTS: this single center prospective study sought to assess the dissociated activity in the PVs following their isolation during AF ablation. In 100 consecutive patients (60 paroxysmal, 40 persistent) undergoing AF ablation, dissociated PV activity was recorded using a multielectrode mapping catheter following antral PV isolation. The dissociated PV activity was classified as (1) silent, (2) isolated ectopic beats, (3) ectopic rhythm, and (4) PV fibrillation. All the PVs were successfully isolated in all the patients. In 91 of 100 patients, there was dissociated activity in at least 1 isolated ipsilateral PV group. There was no significant difference in spontaneous PV activity between patients with paroxysmal and persistent AF (91.7% vs 90%, P = 1.0). Among the 200 isolated ipsilateral PV groups, 64 of 200 (32%) were silent, 86 of 200 (43%) demonstrated isolated ectopic beats, 41 of 200 (20.5%) had ectopic rhythms and 9 of 200 (4.5%) had PV fibrillation. The average cycle length of the PV ectopic rhythm was 2594 ± 966 ms (range 1193-4750 ms). CONCLUSIONS: following PV isolation, a majority of patients demonstrate dissociated activity in at least 1 PV. This finding was evident in patients with both paroxysmal and persistent AF.

Successful release of entrapped circumferential mapping catheters in patients undergoing pulmonary vein isolation for atrial fibrillation.

OBJECTIVES: The purpose of this study was to demonstrate a method for successful and safe release of an entrapped circular catheter. BACKGROUND: Segmental pulmonary vein (PV) isolation is widely practiced for patients with symptomatic drug-refractory atrial fibrillation. A circular mapping catheter is sometimes used with this technique to map the electrical connection between the left atrium (LA) and the PVs. This catheter reportedly can become entrapped in the mitral valve apparatus. Attempts to free the entrapped catheter can result in serious complications, including damage to the mitral valve chordae tendineae or fracture of the catheter itself. METHODS: Three patients were referred for PV isolation for atrial fibrillation. A circular mapping catheter was used to map the sites of LA-PV electrical connections. RESULTS: During the procedure, the circular mapping catheter became entrapped in the mitral valve apparatus in two patients and in the PV in one patient. A series of maneuvers, which included use of another catheter and guiding sheaths as well as pushing forward rather than pulling back on the entrapped catheter, allowed safe and successful release of the entrapped catheter in all patients. CONCLUSIONS: Entrapment of the circular mapping in the mitral valve apparatus or the PVs during PV isolation is a rare complication associated with use this catheter. We describe a series of maneuvers that may allow safe and successful release of the entrapped catheter.