Direct Current Cardioversion Research Articles

The af virtual ward, right care, right time and right team

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial Fibrillation (AF) is the most common cardiac arrhythmia. AF related hospital admissions are rising, with significant cost and capacity implications. Virtual wards are novel pathways designed to support patients remotely, whilst maintaining safe high quality patient care, changing the landscape of care provision. Purpose The standard pathway for patients presenting acutely with AF or Atrial flutter (AFL), is to remain in hospital between 2-5 days, attached to a heart monitor until achieving rate or rhythm control. We developed an AF Virtual ward run by a specialist multi-disciplinary team; to provide remote out-of-hospital care for patients with AF or AFL and rapid ventricular response whilst focusing on improving patients’ care pathway and experience. Methods Patients presenting acutely with AF or AFL who met the criteria for our virtual ward, were on-boarded from an acute hospital admission area or outpatient department. Patients were given access to electronic platform (Dignio) via their smartphone or tablet. They were provided with instruction on how to use a blood pressure machine, single lead ECG device (Kardia) and a pulse oximeter. Once discharged they submitted readings, at least twice a day. Patients who didn’t have access to smart phones were provided with electronic tablets to ensure digital inclusion. Patients’readings, current medication and co-morbidities were assessed by Advanced Clinical Practitioners, Cardiology Registrars and Consultants on "virtual ward rounds". They were supported via messaging through the platform, telephone or video consultations. Health education, lifestyle advice, medication adjustments, and clinical decisions were undertaken remotely by the clinical team. Results A retrospective analysis of the first 50 virtual ward admissions from January - August 2022 was undertaken. Initial hospital admissions were completely avoided in 24 patients due to on-boarding from the outpatient department. Medical interventions by the specialist team prevented 25 readmissions, saving a total of 49 hospitalisations and between 98 - 245 bed days. A rhythm control strategy was pursued in 82% and sinus rhythm was achieved in 36% on discharge. A total of 28% patients were referred for direct current cardioversion (DCCV) and 30% for catheter ablation. The prompt development of a treatment plan avoided attendance in a specialist Cardiology outpatient clinic whose waiting time for an appointment is approximately 6 months. The NHS friends & family test was completed by 90% of the patients with 100% positive responses. Feedback themes revolved around empowerment, feeling safe, actively participating in their care, and avoiding hospital stay. Conclusion The innovative changes to create the AF Virtual ward has facilitated bed efficiencies allowing "hospital-at-home" remote care through prompt care by a specialist multidisciplinary team, with 100% patient satisfaction.

Direct current cardioversion practices following percutaneous left atrial appendage closure.

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. 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. 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. 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. 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.

Comparative Effectiveness of Direct Current Cardioversion in Patients With Atrial Fibrillation and Obesity With Body Mass Index ≥50 kg/m2

Atrial fibrillation is one of the most frequently encountered arrhythmia, with obesity being an independent risk factor. There are sparse data on the success rates of direct current cardioversion (DCCV) in patients with severe obesity. We compared the effectiveness of DCCV in patients with a body mass index (BMI) >50kg/m2 with those with a BMI <30kg/m2. A retrospective chart review of 111 patients was performed between January 1, 2011 and January 1, 2022. The study cohort was stratified into 2 groups: BMI ≥50kg/m2 and BMI <30kg/m2. The primary outcome was successful achievement of normal sinus rhythm after DCCV. The secondary outcomes included number of attempted shocks, number of successful shocks on first attempts, and energy of successful shock. The primary outcome occurred in 94.6% of patients with a BMI <30kg/m2 group compared with 81.8% in the patients with a BMI ≥50kg/m2 (p=0.042). Patients in the higher BMI cohort had a higher median energy during a successful shock than the lower BMI cohort (250J [200 to 360J] vs 200J [150 to 200J], p <0.001). There was no difference in the number of shocks used between the 2 groups or in the success of the first shock delivered between BMI ≥50kg/m2 and BMI <30 kg/m2 (75% vs 58.2%, p=0.093). In conclusion, patients with a BMI ≥50kg/m2 had lower rates of successful DCCV than patients with a BMI <30kg/m2; therefore, clinicians must be aware of the alternative strategies to improve DCCV success and the possibility of DCCV failure in patients with higher BMIs.

Flecainide for conversion and maintenance of sinus rhythm after mitral valve replacement in rheumatic atrial fibrillation

BackgroundDespite successful mitral valve replacement (MVR), many patients remain in AF. Flecainide can be useful in these patients but has not been used because of underlying structural heart disease. MethodsWe assessed oral flecainide for conversion and maintenance of SR in 25 patients of chronic rheumatic AF following MVR (age 34.4 yrs, mean AF duration: 3.6 yrs). Non-converters underwent DC cardioversion at 24 h and 4 weeks. Patients received flecainide and bb/diltiazem at discharge. ResultsSingle oral dose of Flecainide achieved SR in 6/25 (24%) while 19/25 achieved SR after DCC; at24 h 21/25 (84%) were in SR. With mean flecainide dose (93.10 ± 9.40 mg), successful maintenance of SR at 6 months was seen in 16/23 (69.5%). No significant changes in PR interval, QRS duration or QTc were noted; flecainide was well tolerated. Patients in SR had significantly better functional status, QOL scores and higher LA strain at 6 months (25.25 vs 17.43%, p < .0001). Baseline LA diameter ≤ 61 mm predicted SR at 6 months (sensitivity/specificity 93.7% and 85.71%) while the values for AF duration ≤ 4 years and LA strain > 21% for predicting SR were 87.5/71.43% and 100/85.71% respectively. ConclusionOral flecainide was safe and effective in post MVR rheumatic AF patients; maintenance of SR was achieved in 76% of initial converters and 64% of overall population, with better LA strain values. More studies are needed to validate these results.

Atrial fibrillation induced by gabapentin: a case report

BackgroundGabapentin is commonly prescribed for the treatment of neuropathic pain, restless leg syndrome, and partial-onset seizures. Although the most frequent side effects of gabapentin are associated with the central nervous system, gabapentin can also affect the cardiovascular system. Case reports and observational studies have showed that gabapentin can be associated with increased risk of atrial fibrillation. However, all the evidence is concentrated in patients older than 65 years old with comorbidities that predispose them to the development of arrhythmias.Case presentationWe describe a case of an African American male in his 20s that presented to our chronic pain clinic with lumbar radiculitis and developed atrial fibrillation 4 days after being started on gabapentin. Laboratory workup did not show significant abnormalities, including normal complete blood count, comprehensive metabolic panel, toxicology screen, and thyroid-stimulating hormone. Transthoracic and transesophageal echocardiography showed a patent foramen ovale with right-to-left shunt. The patient was initially treated with diltiazem for heart rate control and apixaban. Direct current cardioversion with successful conversion to sinus rhythm was performed 24 hours after admission. The patient was then discharged on apixaban and diltiazem. Apixaban was changed to low-dose aspirin 1 month after discharge.ConclusionWith rapidly increasing usage of gabapentin for approved and off-label indications, it is important to identify unintended adverse effects of this drug as they are considered safe alternatives to opioids. New-onset atrial fibrillation could be induced by gabapentin in young individuals.

Safety of Cardiac Computed Tomography to Exclude Left Atrial Appendage Thrombus Prior to Direct Current Cardioversion in Patients With Atrial Arrhythmias

Cardiac computed tomography (CCT) is a feasible imaging modality to exclude left atrial appendage (LAA) thrombus prior to pulmonary vein isolation procedures but has not been routinely used prior to direct current cardioversion (DCCV) for atrial arrhythmias until piloted during the COVID-19 pandemic. The safety of CCT to exclude LAA thrombus is evaluated in this study. All patients with atrial arrhythmias requiring DCCV as inpatients at Middlemore Hospital between 1 September 2020 to 31 December 2022, and who underwent CCT to exclude LAA thrombus were prospectively collected using the All New Zealand Acute Coronary Syndrome-Quality Improvement (ANZACS-QI) linked cardiac CT registry database. Patients’ clinical records were reviewed for the combined primary outcome of periprocedural and 60-day death, and thromboembolic events including cerebrovascular accidents. A total of 217 patients (64.5% male, mean age 57.8±14 years) underwent CCT during the study period. The majority (37%) were European, 19.8% were Māori, 30.4% were Pasifika, and 7% were other ethnicity. The mean body mass index was 34.8±8 kg/m2. Severe left ventricular systolic dysfunction was present in 70 (32.2%) patients. No LAA thrombus or slow flow was seen in 192 (88.4%) CCT scans. Transoesophageal echocardiography (TOE) was performed in 17 patients with LAA thrombus or slow flow on CCT, of which six had LAA thrombus. Direct current cardioversion was performed in 180 patients with no periprocedural or 60-day stroke. No deaths were recorded. Cardiac CT appears to be a safe alternative to TOE for excluding LAA thrombus prior to DCCV.

Self-administered intranasal medication to terminate supraventricular tachycardia

Paroxysmal supraventricular tachycardia, a common arrhythmia with a prevalence of 2·25 cases per 1000 individuals, 1 Brugada J Katritsis DG Arbelo E et al. 2019 ESC guidelines for the management of patients with supraventricular tachycardia. Eur Heart J. 2020; 41: 655-720 Crossref PubMed Scopus (439) Google Scholar results in considerable morbidity and use of health-care facilities, including recurrent visits to the emergency department for termination of an event and clinic appointments for long-term management. In the USA alone, paroxysmal supraventricular tachycardia accounts for an estimated 50 000 hospital admissions each year. 1 Brugada J Katritsis DG Arbelo E et al. 2019 ESC guidelines for the management of patients with supraventricular tachycardia. Eur Heart J. 2020; 41: 655-720 Crossref PubMed Scopus (439) Google Scholar , 2 Kotadia ID Williams SE O'Neill M Supraventricular tachycardia: an overview of diagnosis and management. Clin Med (Lond). 2020; 20: 43-47 Crossref PubMed Scopus (10) Google Scholar Acute management involves vagal manoeuvres, intravenously delivered calcium-channel blockers (eg, verapamil or diltiazem), β blockers (eg, metoprolol), or adenosine. In patients for whom initial intravenous medical therapy does not terminate an event, or for those who are haemodynamically compromised, direct current cardioversion is used. 1 Brugada J Katritsis DG Arbelo E et al. 2019 ESC guidelines for the management of patients with supraventricular tachycardia. Eur Heart J. 2020; 41: 655-720 Crossref PubMed Scopus (439) Google Scholar Self-administered intranasal etripamil using a symptom-prompted, repeat-dose regimen for atrioventricular-nodal-dependent supraventricular tachycardia (RAPID): a multicentre, randomised trialUsing a symptom-prompted, self-administered, initial and optional-repeat-dosing regimen, intranasal etripamil was well tolerated, safe, and superior to placebo for the rapid conversion of atrioventricular-nodal-dependent paroxysmal supraventricular tachycardia to sinus rhythm. This approach could empower patients to treat paroxysmal supraventricular tachycardia themselves outside of a health-care setting, and has the potential to reduce the need for additional medical interventions, such as intravenous medications given in an acute-care setting. Full-Text PDF Open Access

Electromechanical Cycle Length Mapping for atrial arrhythmia detection and cardioversion success assessment

Background:Direct current cardioversion (DCCV) is an established treatment to acutely convert atrial fibrillation (AF) to normal sinus rhythm. Yet, more than 70% of patients revert to AF shortly thereafter. Electromechanical Cycle Length Mapping (ECLM) is a high framerate, spectral analysis technique shown to non-invasively characterize electromechanical activation in paced canines and re-entrant flutter patients. This study assesses ECLM feasibility to map and quantify atrial arrhythmic electromechanical activation rates and inform on 1-day and 1-month DCCV response. Methods:Forty-five subjects (30 AF; 15 healthy sinus rhythm (SR) controls) underwent transthoracic ECLM in four standard apical 2D echocardiographic views. AF patients were imaged within 1 h pre- and post-DCCV. 3D-rendered atrial ECLM cycle length (CL) maps and spatial CL histograms were generated. CL dispersion and percentage of arrhythmic CLs≤333ms across the entire atrial myocardium were computed transmurally. ECLM results were subsequently used as indicators of DCCV success. Results:ECLM successfully confirmed the electrical atrial activation rates in 100% of healthy subjects (R2=0.96). In AF, ECLM maps localized the irregular activation rates pre-DCCV and confirmed successful post-DCCV with immediate reduction or elimination. ECLM metrics successfully distinguished DCCV 1-day and 1-month responders from non-responders, while pre-DCCV ECLM values independently predicted AF recurrence within 1-month post-DCCV. Conclusions:ECLM can characterize electromechanical activation rates in AF, quantify their extent, and identify and predict short- and long-term AF recurrence. ELCM constitutes thus a noninvasive arrhythmia imaging modality that can aid clinicians in simultaneous AF severity quantification, prediction of AF DCCV response, and personalized treatment planning.

Transesophageal Echocardiogram Before Cardioversion in Atrial Fibrillation Patients.

Transesophageal echocardiography (TEE) offers an invaluable, non-invasive avenue for diagnosing and managing various cardiac conditions, including atrial fibrillation (AF). As the most common cardiac arrhythmia, AF affects millions and can lead to severe complications. Cardioversion, a procedure to restore the heart's normal rhythm, is frequently conducted on AF patients resistant to medication. Due to inconclusive data, TEE's utility prior to cardioversion in AF patients remains ambiguous. Understanding TEE's potential benefits and limitations in this population could significantly influence clinical practice. This review aims to scrutinize the current literature on the use of TEE before cardioversion in AF patients. The principal objective is to understand TEE's potential benefits and limitations comprehensively. The study seeks to offer a clear understanding and practical recommendations for clinical practice, thereby improving the management of AF patients before cardioversion using TEE. A literature search of databases was conducted using the keywords "Atrial Fibrillation," "Cardioversion" and "Transesophageal echocardiography," resulting in 640 articles. These were narrowed to 103 following title and abstract reviews. After applying exclusion and inclusion criteria with a quality assessment, 20 papers were included: seven retrospective studies, 12 prospective observational studies, and one randomized controlled trial (RCT). Stroke risk associated with direct-current cardioversion (DCC) potentially results from post-cardioversion atrial stunning. Thromboembolic events occur post cardioversion, with or without prior atrial thrombus or cardioversion complications. Generally, cardiac thrombus localizes in the left atrial appendage (LAA), a clear contraindication to cardioversion. Atrial sludge without LAA thrombus in TEE is a relative contraindication. TEE before electrical cardioversion (ECV) in anticoagulated AF individuals is uncommon. In AF patients planned for cardioversion, contrast enhancement facilitates thrombus exclusion in TEE images, reducing embolic events. Left atrial thrombus (LAT) frequently occurs in AF patients, necessitating TEE examination. Despite the increased use of pre-cardioversion TEE, thromboembolic events persist. Notably, patients with post-DCC thromboembolic events had no LA thrombus or LAA sludge. The use of TEE-guided DCC has grown due to its ability to detect atrial thrombi pre-cardioversion, aiding risk stratification. Thrombus in the left atrium also signals an elevated risk of future thromboembolic events in AF patients. While atrial stunning post cardioversion detected by TEE is a significant risk factor for future thromboembolic events, further evidence is required. Therapeutic anticoagulation is essential during and post cardioversion, even if no atrial thrombus is detected. Current data recommends cardioversion guided by TEE, particularly in outpatient settings.

A very wide complex tachycardia

A 74-year-old woman with a history of persistent atrial fibrillation, hypertension, and hyperlipidemia presented to the emergency department (ED) after 3 days of intermittent palpitations and presyncope. She had been treated for atrial fibrillation with flecainide (150 mg twice daily) and metoprolol succinate (25 mg daily) for more than 20 years. In the ED, her heart rate was 150 bpm, and her blood pressure was 102/87. The electrocardiogram (ECG) is shown in Figure 1. The ECG obtained after a 150-mg bolus of intravenous amiodarone followed by a 200-J biphasic direct current shock is shown in Figure 2A . The ECG recorded soon after administration of 100 mEq of hypertonic sodium bicarbonate is shown in Figure 2B. What is the most likely cause of the wide complex tachycardia (WCT)? Figure 2A: Electrocardiogram with normal sinus rhythm and prolonged PR, QRS, and corrected QT intervals following direct current cardioversion. B: Electrocardiogram after treatment. View Large Image Figure Viewer Download Hi-res image

Determinants of left atrial local impedance: relationships with contact force, atrial fibrosis and rhythm

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Boston Scientific Background The relationships between baseline tissue local impedance (LI), contact force (CF), atrial fibrosis and atrial rhythm are uninvestigated in a clinical setting. Objectives To compare the relationship of LI and CF between atrial fibrillation (AF) and sinus rhythm (SR). Establish the effects of atrial fibrosis as assessed by bipolar voltage and LI. Methods Patients undergoing persistent AF ablation were recruited. The ablation catheter was placed against the left atrial wall and CF levels varied from 1-40g. LI was recorded concurrent to changes in CF at these locations, with data collected at the same locations in AF and SR following DC cardioversion. LI values were referenced to patient blood pool, (LIr). Results 20 patients were recruited. 109 locations were sampled obtaining 1903 datapoints (SR: 966, AF: 937). CF correlated strongly with LI (repeated measures correlation = 0.64). The relationship between CF and LIr was logarithmic. Rhythm and CF had a significant main (both p &amp;lt; 0.0005) and interaction effect (p = 0.022) on tissue LI: AF demonstrated higher LIr values than SR for similar CF (Figure 1). Furthermore, AF modelled a more predictable relationship between CF and LI than SR (R2 = 0.21 vs 0.13). Bipolar voltage had no effect on the relationship of CF to LIr in either rhythm when using conventional cut-offs to determine scar (0.05mV and 0.5mV). Cut-offs for assessing scar using LIr used values of 0.5Ω and 10.5Ω based on concurrent work. Through assessing fibrosis using these values, LIr showed an interaction effect with CF for LIr in SR and AF, (SR: p &amp;lt;0.0005, AF: p = 0.01), with more fibrosis demonstrating shallower CF-LIr curves than healthier tissue, (Figure 2). Conclusions CF and rhythm significantly affect the measured LIr of LA myocardium. Optimal catheter-tissue coupling may be better achieved with higher levels of CF and in AF rather than SR. Atrial fibrosis as assessed by bipolar voltage did not affect the CF-LI relationship, but was when assessed by LIr.

Assessment of scar between atria, rhythms and atrial fibrillation types: does ultra high density mapping offer new insights?

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Boston Scientific Background 3D electroanatomical mapping systems demonstrate atrial scar by recording local tissue voltages as a surrogate. Increased scar has been shown with both progression of atrial fibrillation, (AF, paroxysmal (PAF) to persistent (PeAF)), and between sinus rhythm (SR) and AF on low density mapping systems. The introduction of ultra high density mapping allows a more detailed comparison. Objectives Assessment of atrial scar determined by voltages and surface area between atria, rhythm, and AF type. Methods Ultra high density 3D electroanatomical maps of left and right atria (LA, RA) were created. PeAF patients had maps created in AF and SR following DC cardioversion. PAF patients had maps created in SR only. Electrograms (EGMs) on corresponding AF and SR maps were paired using exported co-ordinates. Percentage surface area of scar was and assigned as low voltage myocardium (LVM, ≤ 0.05mV), intermediate, (IVM, 0.05 - 0.5mV), or normal, (NVM, &amp;gt; 0.5mV). Results 95 maps were produced using 913480 EGMs. Paired SR-AF EGM voltages had a moderate correlation in the LA (Bipolar: Pearson’s R = 0.32, unipolar: R = 0.36, both p &amp;lt;0.0005), and weak correlation in the RA, (Bipolar: R = 0.19, unipolar: R = 0.25, both p &amp;lt; 0.0005). Paired voltages were significantly higher in SR in both atria, LA/RA, bipolar/unipolar all p &amp;lt; 0.0005). There was significantly more LVM/IVM percentage surface area in AF over SR in the LA, (SR to AF - LVM: 6.4 ± 6.9 to 12.2 ± 9.5; IVM 41.0 ± 12.1 to 50.5 ± 10.0; NVM: 51.7 ±17.2 to 37.3 ± 16.1, p &amp;lt; 0.0005), but not in the RA (SR to AF – LVM: 6.5 ± 5.3 to 8.4 ± 8.3; IVM 42.0 ± 10.1 to 44.6 ± 6.9;NVM: 51.5 ± 13.6 to 47.0 ± 13.8, p = 0.62) Figure 1A. Global tissue voltages in SR were significantly higher in PAF over PeAF in both atria, (LA –bipolar: 1.13 vs 0.52mV, unipolar 1.96 vs 1.44mV, RA – bipolar 0.93 vs 0.57mV, unipolar: 1.68 vs 1.33mV all p &amp;lt; 0.0005). There was significantly more LVM/IVM surface area demonstrated in PeAF over PAF in the LA, (PAF to PeAF - LVM: 0.6 ± 0.7 to 6.6 ± 6.8; IVM 29.5 ± 12.3 to 43.1 ±11.4; NVM: 69.8 ± 12.8 to 50.3 ± 16.4, p = 0.01), but not in the RA, (PAF to PeAF - LVM: 4.6 ± 3.6 to 6.5 ± 5.3; IVM 32.7 ± 9.5 to 42.0 ±10.1; NVM: 62.7 ± 12.1 to 51.5 ± 13.6, p = 0.20). Figure 1B Comparing atria, the LA had a significantly lower voltage in SR, but this difference was small (LA/RA = 0.89, p &amp;lt; 0.0005). The percentage surface area of scar was comparable, (LA to RA - LVM: 4.0 ± 5.6 to 5.6 ± 4.5; IVM: 38.4 ± 37.6 to 37.6 ± 10.6; NVM: 57.5 ±18.4 to 56.8 ± 13.8). Figure 1C Conclusions Ultra high density mapping confirms atrial voltages are higher in SR over AF, and PAF over PeAF. The RA is comparable to the LA for tissue voltages but does not demonstrate a change in surface area of scar between AF and SR or PAF and PeAF. This may reflect the complexity of AF wavefronts in the LA compared to the RA leading to more bipole orientation related overestimation of scar in the fibrillating LA.

Atrial fibrillation detection using the ECG signal in the left in ear region: validation study on patients electively admitted for DC cardioversion

Abstract Funding Acknowledgements Type of funding sources: None. Early detection of atrial fibrillation is a major opportunity for mobile health, as portable devices nowadays available can detect multiple-lead electrocardiogram (ECG). The study aims to validate the in-ear region as a new anatomical site for ECG signal detection in patients (pts) affected by atrial fibrillation (AF). Methods We performed the ECG using KardiaMobile 6L device on 40 patients affected by AF and admitted to our hospital for elective electrical cardioversion. All the digital ECGs were detected in a modified modality or using the left in-ear region instead of the right hand. All the recorded ECGs were analyzed by the device and the results checked by two cardiologists. Results We successfully collected all 40 modified digital ECGs performed on the group of 40 pts: age 69.4 ± 9.4 years; male 28 (70)%; medium HR 95±25.4bpm; 26 (65%) affected by hypertension; 2 (5%) affected by diabetes mellitus; 37 (92,5%) in NOACs. In all cases, the KardiaMobile 6L automatic diagnosis of the ECG detected by this modified modality was correct in 100% of cases. Conclusion The in-ear region could be a reliable novel anatomical site for ECG signal detection in patients affected by atrial fibrillation. These data could support the development of new portable mobile ECG devices using the left in ear region and so leaving at least one hand free.

Biomarkers of Atrial Fibrillation Recurrence in Patients with Paroxysmal or Persistent Atrial Fibrillation Following External Direct Current Electrical Cardioversion.

Atrial fibrillation (AF) is associated with atrial remodeling, cardiac dysfunction, and poor clinical outcomes. External direct current electrical cardioversion is a well-developed urgent treatment strategy for patients presenting with recent-onset AF. However, there is a lack of accurate predictive serum biomarkers to identify the risks of AF relapse after electrical cardioversion. We reviewed the currently available data and interpreted the findings of several studies revealing biomarkers for crucial elements in the pathogenesis of AF and affecting cardiac remodeling, fibrosis, inflammation, endothelial dysfunction, oxidative stress, adipose tissue dysfunction, myopathy, and mitochondrial dysfunction. Although there is ample strong evidence that elevated levels of numerous biomarkers (such as natriuretic peptides, C-reactive protein, galectin-3, soluble suppressor tumorigenicity-2, fibroblast growth factor-23, turn-over collagen biomarkers, growth differential factor-15) are associated with AF occurrence, the data obtained in clinical studies seem to be controversial in terms of their predictive ability for post-cardioversion outcomes. Novel circulating biomarkers are needed to elucidate the modality of this approach compared with conventional predictive tools. Conclusions: Biomarker-based strategies for predicting events after AF treatment require extensive investigation in the future, especially in the presence of different gender and variable comorbidity profiles. Perhaps, a multiple biomarker approach exerts more utilization for patients with different forms of AF than single biomarker use.

PO-01-108 ELUCIDATING THE MECHANISM OF ATRIAL FIBRILLATION IN LAMIN A/C HEART DISEASE USING HUMAN IPSC-DERIVED ATRIAL CARDIOMYOCYTES

Mutations in the LMNA gene, encoding the nuclear envelope proteins lamin A/C, cause cardiac arrhythmias, conduction disease, and dilated cardiomyopathy. Malignant arrhythmias such as atrial fibrillation (AF) and ventricular tachycardia are common and pose an increased risk of stroke and sudden cardiac death. To investigate the etiological mechanisms by which a heterozygous pathogenic LMNA-S143P mutation causes early-onset AF using mature human iPSC-derived atrial cardiomyocytes (hiPSC-aCM) generated from a large kindred with a strong cardiac phenotype. Detailed phenotyping of a 4-generation family pedigree and generation of hiPSCs from the proband using a comprehensive approach for the differentiation of mature hiPSC-aCMs. Action potential duration was measured by optical voltage mapping. Calcium transients were measured by confocal microscopy. The proband (III-3) is a 42-year-old female of European and Asian descent who developed symptomatic early-onset AF at age 35. She underwent direct current cardioversion (DCCV), pulmonary vein isolation, and implantation of a biventricular pacemaker. Cardiac MRI showed an enlarged left atrium with preserved left ventricular systolic function (EF 56%). A detailed family history revealed early-onset AF and AV block, congestive heart failure (CHF), and sudden death (Fig. 1). Genetic testing of the proband revealed a pathogenic missense mutation in LMNA (c427T>Cp. Ser143Pro). Mature LMNA-S143P-hiPSC-aCMs displayed prolongation of the atrial action potential duration (APD90) with delayed afterdepolarizations, abnormal calcium transients, and AF as compared to wild-type hiPSC-aCMs. Detailed phenotyping of a large LMNA kindred revealed a phenotype of AF, cardiac conduction disease, dilated cardiomyopathy, and sudden death. Our hiPSC-aCM studies uncovered a triggered mechanism for the AF with ion channel remodeling and pave the way for targeting calcium handling proteins as a potential therapeutic strategy in LMNA associated arrhythmias.

PO-04-079 FIRING EXTRA CHAMBERS: COR TRIATRIATUM SINISTER WITH ATRIAL FIBRILLATION

Cor triatriatum sinister (CTS) is a rare congenital defect in which the left atrium is divided into two chambers by a fenestrated fibromuscular septum. It is found in less than 0.1% of clinically diagnosed cardiomyopathy and 0.4% of autopsies of congenital heart disease patients. Dyspnea was reported as the most common symptom and atrial fibrillation (AF) was described in 30% of the published cases of CTS. We report a young patient with CTS who had recurrent paroxysmal atrial fibrillation (PAF) that underwent standard radiofrequency (RF) pulmonary vein isolation (PVI). 1. To recognize the relation of a rare congenital anomaly to AF 2. Effectiveness of standard PVI in CTS with AF NA A 39-year-old male was referred for symptomatic PAF with CHAD2VASc score of 3. Medical history was significant for CTS, tachybrady syndrome status post leadless pacemaker, diabetes, hypertension, HFpEF, and sleep apnea on CPAP. Pertinent medications were rivaroxaban, diltiazem and metoprolol. AF burden could not be determined. Echocardiogram revealed LA volume of 119 ml, CTS with volume index 52ml/m2 with an opening of 0.8 cm2 and moderate mitral regurgitation with valve area 2.9cm2, PHT 77 ms. Right heart cath showed PAP 50/30 mmHg, PCWP 30 mmHg and PVR 0.8 Woods unit. Cardiac index was 3.5L/min/m2. Despite optimization of rate control therapy and DC cardioversion, the patient had recurrent debilitating AF and decided to undergo RF AF ablation. Intracardiac echo showed the membrane to be attached to the posterolateral ridge laterally and to the interatrial septum medially. Voltage mapping revealed a healthy posterior wall. PVI was achieved successfully with first pass ablation. Patient maintained sinus rhythm at the 3 months follow up. CTS was first described in 1868 by Church. Development of AF from CTS in adults can be related to calcification of the membrane fenestrations leading to mitral stenosis and eventual development of mitral regurgitation with aging.

E-3 | Do Patients With Dilated Left Atrium Appendage Orifice Require More Joules for Direct Current Cardioversion to Restore Sinus Rhythm?

E-3 | Do Patients With Dilated Left Atrium Appendage Orifice Require More Joules for Direct Current Cardioversion to Restore Sinus Rhythm?

E-4 | Do Obese Patients With Atrial Fibrillation Require More Joules for Direct Current Cardioversion to Restore Sinus Rhythm?

E-4 | Do Obese Patients With Atrial Fibrillation Require More Joules for Direct Current Cardioversion to Restore Sinus Rhythm?

Safety and efficacy of a nurse-led elective cardioversion with etomidate for atrial arrhythmia in a tertiary hospital

Management of cardiac arrhythmias often requires direct current cardioversion (DCC) to restore sinus rhythm. This intervention varies greatly between countries and hospitals, mostly regarding the organization of an elective DCC, and the choice of the sedation. The aim of this study is to assess the safety and efficacy of an elective DCC performed in a cardiology day hospital, led by trained nurses, and using intravenous Etomidate as sedation. We performed a retrospective cohort study at a single tertiary hospital in Belgium. Data were collected from January 2017 to October 2020. A total of 788 electrical cardioversions were performed on 574 patients from 2017 to 2020. Age was 70.9 ± 10 years. Restoration of sinus rhythm was obtained in 89.5% of the patients. One (0.1%) patient experienced ischemic stroke within 24 h, despite adequate anticoagulation. There were 4 (0.5%) cases of transient sinus arrest requiring atropine. Three patients (0.4%) experienced respiratory depression, requiring bag-mask ventilation but not oro-tracheal intubation. There were no cases of hypotension. No periprocedural death was reported. In conclusion, an elective electrical cardioversion performed and led by trained nurses, using Etomidate as sedation, appears to be both safe and effective.

Amplified sinus-P-wave analysis predicts outcomes of cryoballoon ablation in patients with persistent and long-standing persistent atrial fibrillation: A multicentre study.

Outcomes of catheter ablation for non-paroxysmal atrial fibrillation (AF) remain suboptimal. Non-invasive stratification of patients based on the presence of atrial cardiomyopathy (ACM) could allow to identify the best responders to pulmonary vein isolation (PVI). Observational multicentre retrospective study in patients undergoing cryoballoon-PVI for non-paroxysmal AF. The duration of amplified P-wave (APW) was measured from a digitally recorded 12-lead electrocardiogram during the procedure. If patients were in AF, direct-current cardioversion was performed to allow APW measurement in sinus rhythm. An APW cut-off of 150 ms was used to identify patients with significant ACM. We assessed freedom from arrhythmia recurrence at long-term follow-up in patients with APW ≥ 150 ms vs. APW < 150 ms. We included 295 patients (mean age 62.3 ± 10.6), of whom 193 (65.4%) suffered from persistent AF and the remaining 102 (34.6%) from long-standing persistent AF. One-hundred-forty-two patients (50.2%) experienced arrhythmia recurrence during a mean follow-up of 793 ± 604 days. Patients with APW ≥ 150 ms had a significantly higher recurrence rate post ablation compared to those with APW < 150 ms (57.0% vs. 41.6%; log-rank p < 0.001). On a multivariable Cox-regression analysis, APW≥150 ms was the only independent predictor of arrhythmia recurrence post ablation (HR 2.03 CI95% 1.28-3.21; p = 0.002). APW duration predicts arrhythmia recurrence post cryoballoon-PVI in persistent and long-standing persistent AF. An APW cut-off of 150 ms allows to identify patients with significant ACM who have worse outcomes post PVI. Analysis of APW represents an easy, non-invasive and highly reproducible diagnostic tool which allows to identify patients who are the most likely to benefit from PVI-only approach.