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Objective: Posterior left atrial wall isolation (PWI) plus traditional pulmonary vein isolation (PVI) has been proposed as a promising intervention to decrease atrial fibrillation (AF) recurrence. We aim to investigate the efficacy and safety of adding PWI to the traditional PVI in patients with AF. Methods: A systematic review and meta‐analysis was conducted using synthesizing randomized controlled trials (RCTs) retrieved by systematically searching PubMed, Web of Science, SCOPUS, EMBASE, and Cochrane through June 14, 2023. We used Stata version 17 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD), with a 95% confidence interval (CI) (PROSPERO ID: CRD42023446227). Results: We included 11 RCTs with a total number of 1534 patients. Combined ablation with PWI + PVI was not associated with any significant difference over PVI only regarding the recurrence of clinical AF (RR: 0.86 with 95% CI [0.70–1.06]), all atrial arrhythmia (RR: 0.93 with 95% CI [0.82–1.07]), nonatrial fibrillation arrhythmia (RR: 1.22 with 95% CI [0.97–1.53]), early AF (RR: 0.89 with 95% CI [0.62–1.27]), and antiarrhythmic drugs at discharge (RR: 0.83 with 95% CI [0.67–1.04]). However, it was associated with increased total ablation duration (minutes) (MD: 12.58 with 95% CI [6.80–18.37]) and total procedure duration (minutes) (MD: 16.77 with 95% CI [9.63–23.91]), without any significant difference regarding adverse events (RR: 1.05 with 95% CI [0.63–1.74]). Conclusion: While the pooled data from PWI + PVI using point‐by‐point radiofrequency did not suggest a benefit in the recurrence of various atrial arrhythmias compared to PVI alone, PWI+PVI using direct posterior wall ablation, especially with cryoballoon, demonstrated a significant reduction in recurrence of AF/atrial arrhythmias. Also, PWI + PVI significantly increased the ablation and total procedure durations. [ABSTRACT FROM AUTHOR]

Introduction: Patients with Brugada syndrome (BrS) face an increased risk of ventricular arrhythmias and sudden cardiac death. Implantable cardiac monitors (ICMs) have emerged as effective tools for detecting arrhythmias in BrS. Technological advancements, including temperature sensors and improved subcutaneous electrocardiogram (subECG) signal quality, hold promise for further enhancing their utility in this population. Methods and results: We present a case of a 40‐year‐old man exhibiting a BrS type 2 pattern on 12‐lead ECG, who underwent ICM insertion (BIOMONITOR IIIm, BIOTRONIK) due to drug‐induced BrS type 1 pattern and a history of syncope, with a negative response to programmed ventricular stimulation. The device contains an integrated temperature sensor and can transmit daily vital data, such as mean heart rate and physical activity. Several months later, remote alerts indicated a temperature increase, along with transmitted subECGs suggesting a fever‐induced BrS type 1 pattern. The patient was promptly advised to commence antipyretic therapy. Over the following days, remotely monitored parameters showed decreases in mean temperature, physical activity, and mean heart rate, without further recurrence of abnormal subECGs. Conclusion: ICMs offer valuable insights beyond arrhythmia detection in BrS. Early detection of fever using embedded temperature sensors may improve patient management, while continuous subECG morphological analysis has the potential to enhance risk stratification in BrS patients. [ABSTRACT FROM AUTHOR]

Background Purpose Methods Results Conclusions The programing of subcutaneous implantable cardioverter‐defibrillators (S‐ICD) in clinical practice has been little studied, as the activation status of the SMART Pass filter, which was implemented to reduce inappropriate shocks.We assessed device programing during follow‐up and the rate of detected arrhythmias in consecutive S‐ICD recipients.We analyzed data from 670 S‐ICD patients followed on the remote network at 17 Italian centers for a median of 31 months (25th–75th percentile: 16–51). The enhanced SMART Pass version, introduced in October 2022, was expected to reduce the unintentional deactivation rate.At the latest remote data transmission, the median conditional zone cut‐off was set to 210 bpm (25th–75th percentile: 200–220), the shock zone cutoff was 250 bpm (25th–75th percentile: 240–250), and the SMART Pass was enabled in 586 (87%) patients. During follow‐up, 194 automatic deactivation events were reported in 118 (18%) patients. Shocks were delivered in 129 (19%) patients, and untreated arrhythmias were recorded in 136 (20%) patients. The rate of shocks was lower when SMART Pass was enabled ‐0.12/patient‐year (95% CI: 0.10–0.14) versus 0.20 (95% CI: 0.15–0.26) (p = .002), as it was the rate of untreated arrhythmias ‐0.12/patient‐year (95% CI: 0.11–0.14) versus 0.23 (95% CI: 0.18–0.30) (p = .001). The enhanced SMART Pass version was associated with a lower rate of deactivations ‐0.04/patient‐year (95% CI: 0.02–0.05) versus 0.14 (95% CI: 0.12–0.16) (p < .001), and with a reduction in treated and untreated arrhythmias (Incidence rate ratios: 0.40 (95% CI: 0.28–0.53) and 0.40 (95% CI: 0.30–0.55), respectively (p < .001)).Centers tend to program devices to detect high ventricular rates for arrhythmia detection, to minimize inappropriate shock occurrences. SMART Pass activation is associated with lower rates of detected and treated arrhythmias. The enhanced SMART Pass version seems associated with a lower deactivation rate and with a further decrease in treated arrhythmias. [ABSTRACT FROM AUTHOR]

Background Materials and Methods Results Conclusion Endless loop tachycardia (ELT) is the commonest pacemaker mediated tachycardia (PMT) encountered among patients with cardiac implantable electronic devices (CIEDs). Despite being enabled with various preventive algorithms, we encountered several cases having recurrent, long, and symptomatic ELT.We retrospectively analyzed consecutive device checkups at device clinic at a single center of eastern India between January 2019 to March 2023.There were 20 cases of confirmed and sustained ELT among 4520 device checks. Although mostly benign, in two cases ELT led to clinical worsening in patients having left ventricular (LV) systolic dysfunction. Even with good ventricular function, ELT resulted in improper atrioventricular (AV) synchrony leading to disabling symptom in one case. The differentiation of ELT from sinus tachycardia and atrial tachycardia (AT) was not always easy. Magnet application is certainly useful to differentiate. The situations that provoked ELT in this study were—long AV delays, VIP (ventricular intrinsic preferences)/MVP (managed ventricular pacing), atrial non‐capture, atrial under/over sensing, premature ventricular contractions (PVCs)/couplets, premature atrial contractions (PAC) and slower ventriculo‐atrial (VA) conduction. Rate responsive shortening of post‐ventricular atrial refractory period (PVARP) also promoted its occurrence and hindered troubleshooting. When ELT occurred despite post‐PVC extension of PVARP, lowering the atrial sensitivity, switching to bipolar sensing and manual setting of longer PVARP after measuring VA conduction time were useful. “Rate responsive PVARP” had to be turned off in a few cases to prevent ELT. On the contrary, an over aggressive prolongation of PVARP led to repetitive non‐reentrant ventriculo‐atrial synchrony (RNRVAS) in two cases. Checking VA conduction during implantation and noninvasive program stimulation (NIPS) during follow up were useful to check the tendency for ELT.Clinically significant ELT is rare but not uncommon among devices having in‐built preventive algorithms. Manual adjustments are often useful to troubleshoot the same. [ABSTRACT FROM AUTHOR]

A Junctional ectopic tachycardia diagnosis was performed using two electrophysiological maneuvers in an adult female with a narrow‐complex supraventricular tachycardia with a bystander AV‐node slow pathway conduction, who previously underwent catheter ablation attempts for an atrio‐ventricular nodal re‐entrant tachycardia misdiagnosis. The first maneuver was atrial entrainment with an atrial‐His‐His‐atrial response. The second was based on the response to a premature atrial complex delivered at different phases of the tachycardia cycle confirming that anterograde slow pathway conduction and retrograde fast pathway were not involved. Considering that verapamil, diltiazem, bisoprolol + flecainide, and nadolol were ineffective, we tried ivabradine with no sustained arrhythmias during 18‐months. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) may be associated with chest wall abnormalities such as pectus excavatum (PE). Pulmonary vein isolation (PVI) has proven to be a useful strategy for radiofrequency catheter ablation (RFCA) of AF. However, the presence of chest wall abnormalities, such as pectus excavatum, imposes certain challenges during ablation due to the anatomic distortion that it causes. We highlight these challenges during ablation in this three‐patient case series. [ABSTRACT FROM AUTHOR]

Background: Thromboembolic events related to invasive electrophysiology studies, while rare, can have devastating consequences. Use of systemic anticoagulation for a pediatric or adult‐congenital invasive electrophysiology study is recommended, however there is no established standard of practice in this population. Objective: To report on procedural practices for thromboembolism prophylaxis during invasive electrophysiology studies for pediatric patients and adults with congenital heart disease. Methods: An anonymous web‐based survey was sent to the members of the Pediatric and Congenital Electrophysiology Society. The survey focused on pre‐procedural, intra‐procedural, and post‐procedural thromboembolism prophylaxis practices during invasive electrophysiology studies. Significant practice variation was defined as <90% concordance among respondents. Results: Survey was completed by 73 members; 52 (71%) practicing in the United States, 65 (89%) practicing in an academic institution, and 14 (19%) in an institution that performs more than 200 invasive electrophysiology procedures annually. Responses showed significant variation in practice. Prior to an invasive electrophysiology procedure, 25% discontinue aspirin while 47% discontinue anticoagulants. Heparin is given for all procedures by 32%. When heparin is administered, the first dose is given by 32% after sheaths are placed, 42% after crossing into the systemic atrium, and 26% just prior to systemic‐side ablation. Most target an activated clotting time between 200–300 seconds. Post systemic‐side ablation, 58% do not initiate a heparin infusion. Post‐procedural oral agents were initiated on day of procedure by 34% of respondents and on post‐procedure day 1 by 53%. If treating with aspirin, 74% use low‐dose (3–5 mg/kg or 81 mg daily), and 68% treat for 4–6 weeks. Conclusion: There is significant variation in thromboembolism prophylaxis for invasive EP studies among pediatric and congenital electrophysiologists. Further studies are needed to optimize the management of thromboembolism prophylaxis in this population. [ABSTRACT FROM AUTHOR]

An 88‐year‐old Japanese woman underwent DDD pacemaker (MicroPort KORA 250 DR, V lead: VEGA R52) implantation for complete atrioventricular block. A 12‐lead electrocardiogram for a routine examination showed atrial pacing within the intrinsic P wave, followed by inhibition of ventricular pacing. Pacemaker interrogation revealed no abnormalities in the basic parameters; however, ventricular pacing was inhibited by far‐field sensing of intrinsic atrial waves before atrial events; type II far‐field P‐wave sensing. As a result, unusual atrial pacing occurred due to the pause suppression algorithm, which is the one of the functions that prevent atrial fibrillation development. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate the anatomical variations in femoral vasculature and evaluate the clinical value of ultrasound‐guided femoral vein puncture in catheter ablation procedures. Methods: In this retrospective analysis conducted from January 2023 to March 2023, we examined data from patients who underwent catheter ablation with ultrasound‐guided femoral venipuncture. We evaluated the anatomy of the femoral vasculature at both high and low inguinal levels. Based on the relationship between the femoral vein and artery, we classified the anatomy into four types: Type I (vein parallel to artery without overlap), Type II (vein medial to artery with lumen overlap ≤50%), Type III (vein posterior to artery with lumen overlap > 50%), and Type IV (vein lateral to artery). Additionally, we assessed procedure‐related vascular complications that required interventions or prolonged hospital stays. Results: A total of 254 patients were included in this study. At the upper inguinal level, most cases (92.5%) exhibited Type II, followed by Type I (6.5%), while Type III (0.6%) and IV (0.4%) were less common. At the lower inguinal level, Type II accounted for 70.7%, there was a significantly higher proportion of Type III (23.4%) and Type IV (5.9%). The overall complication rate was 0.4%, no pseudoaneurysm or hematoma was observed in our study. Conclusion: Our study revealed significant anatomical variations in the relationship between the femoral vein and femoral artery. Ultrasound‐guided femoral venipuncture significantly reduced vascular complication rate, making it a valuable tool for guiding puncture procedures. [ABSTRACT FROM AUTHOR]

Background: Paroxysmal supraventricular tachycardia (PSVT) is characterized by episodes of rapid tachycardia with sudden onset and sudden termination. PSVT treatment has evolved considerably over the past 30 years. Currently, radiofrequency catheter ablation is the first‐line treatment. Hypothesis: We conducted a randomized controlled trial to compare safety and effectiveness of PSVT ablation between the Jinjiang and Johnson (J&J) catheters in 57 patients in our hospital. Methods and results: Patients were randomly assigned to ablation procedures using either the Jinjiang system or the J&J Carto system. Follow‐up was performed 3 days, 1, and 6 months after the procedure. Success rate, ablation time, frequency of ablation, and rates of complications and recurrence did not significantly differ between the groups. One Jinjiang group patient (3.6%) experienced arrhythmia recurrence during the 6‐month follow‐up. Conclusions: The Jinjiang catheter for radiofrequency ablation of PSVT is as safe and effective as the J&J catheter. [ABSTRACT FROM AUTHOR]

Background: Precise mapping of the Purkinje fiber network is essential in catheter ablation of Purkinje‐related ventricular arrhythmias (PrVAs). We sought to evaluate the mapping ability of a multi‐spline duodecapolar catheter (PentaRay) for PrVAs. Methods: Mappings of Purkinje fibers by PentaRay catheters were compared with those by conventional mapping catheters in consecutive patients undergoing catheter ablation of PrVAs from 2015 to 2022. Results: Sixteen PrVAs (7 premature ventricular contractions or non‐reentrant fascicular tachycardias [PVCs/NRFTs] and 9 fascicular ventricular tachycardias [FVTs]) were retrospectively studied. In PVCs/NRFTs, earliest preceding Purkinje potentials (PPs) could be recorded by the PentaRay catheters but not by the mapping and ablation catheters in 5 cases. At the earliest PP sites, the precedence from the QRS onset was greater, and the amplitude of the preceding potentials was higher in the PentaRay catheter compared with those in the mapping and ablation catheter (−62.0 ± 42.8 vs. −29.4 ± 34.2 ms, P = 0.02; 0.45 ± 0.43 vs. 0.09 ± 0.08 mV, P = 0.02). In FVTs, late diastolic potentials (P1) were recorded by the PentaRay catheters but not by the mapping and ablation catheters or the linear duodecapolar catheter in 2 cases. The amplitude of P1 was higher in the PentaRay catheter compared with that in the linear duodecapolar catheter and the mapping and ablation catheters (0.72 ± 0.49 vs. 0.17 ± 0.18 vs. 0.27 ± 0.21 mV, P = 0.0006, P = 0.002). The localized critical PPs, defined as the earliest preceding potentials in PVCs/NRFTs and P1 in FVTs, could be recorded in all the patients by the PentaRay catheter. The mapping ability of critical PPs of PrVAs was better with the PentaRay catheter than with the conventional mapping catheters (16/16 vs. 9/16, P = 0.004 by McNemar exact test). Conclusions: The PentaRay catheter has clinical advantages in mapping of the Purkinje fiber network to reveal critical PPs as ablation targets of PrVAs. [ABSTRACT FROM AUTHOR]

The article discusses the case of an 11-year-old boy with nearly incessant supraventricular tachycardia (SVT) and explores the electrophysiological mechanism without employing pacing maneuvers. It focuses on the diagnosis of permanent junctional reciprocating tachycardia (PJRT) in the child, emphasizing the use of irrigated contact-force sensing catheters for radiofrequency ablation and the challenges in distinguishing PJRT from other long VA tachycardias in pediatric patients.

The article discusses the case of a 68-year-old woman with non-ischemic cardiomyopathy experiencing recurrent sustained wide QRS tachycardia. Through an electrophysiology study, the authors identify four types of tachycardia, including ventricular tachycardia (T1), ventricular tachycardia with alternating QRS complex morphologies (T2), a narrower QRS tachycardia with a 1:1 atrioventricular relationship (T3), and pure supraventricular tachycardia (T4).

Background: Remote monitoring is recommended for patients with implantable cardiac monitors (ICMs), but compared to other cardiac implantable devices, ICMs are less accurate and transmit a higher number of alerts. Objective: The aim of this study was to investigate the predictors of false‐positive (FP) arrhythmic alerts in patients with unexplained syncope who were implanted with ICM and followed by an automatic remote monitoring system. Methods: We retrospectively evaluated all consecutive patients who received a long‐sensing vector ICM for unexplained syncope between January 2019 to September 2021 at our Syncope Unit. The primary endpoint was the incidence of the first FP episode. The secondary endpoints included assessing the incidence of FP episodes for all types of algorhythms and indentifying the reasons for the misdetection of these episodes. Results: Among 105 patients (44.8% males, median age 51 years), 51 (48.6%) transmitted at least one FP alert during a median follow‐up of 301 days. The presence of pre‐ventricular complexes (PVCs) on the resting electrocardiogram was the only clinical characteristic associated with an increased risk of FP alerts (adjusted Hazard ratio [HR] 5.76 [2.66–12.4], p = 0.010). The other significant device‐related variables were a low‐frequency filter at 0.05 Hz versus the default 0.5 Hz (adjusted HR 3.82 [1.38–10.5], p = 0.010) and the R‐wave amplitude (adjusted HR 0.35 [0.13–0.99], p = 0.049). Conclusion: Patients who have PVCs are at higher risk of inappropriate ICM activations. To reduce the occurrence of FP alerts, it may be beneficial to target a large R‐wave amplitude during device insertion and avoid programming a low‐frequency filter at 0.05 Hz. [ABSTRACT FROM AUTHOR]

Background: Persistent left superior vena cava (PLSVC) is the most prevalent form of thoracic venous abnormality and can serve as a significant arrhythmogenic source in atrial fibrillation (AF). Methods and results: Among the 3950 patients who underwent radiofrequency ablation for AF between September 2014 to April 2020, 17 patients (mean age 59.4 ± 8.0 years, 64.7% male) with PLSVC were identified. Among them, nine patients (52.9%) had a prior history of pulmonary vein isolation (PVI) alone. Eight out of nine patients who experienced AF recurrence underwent PLSVC isolation with or without pulmonary vein (PV) reconnection. For the remaining eight patients (47.1%), PVI plus PLSVC isolation were performed during the index procedure. Ectopy originating from PLSVC was documented in 11 patients (64.7%) and successful PLSVC isolation was achieved in 16 patients (94.1%). After a median follow‐up of 28.3 months, freedom from AF/ atrial tachycardia (AT) was observed in 13 patients (76.5%). Conclusion: Empirical PLSVC isolation beyond PVI appears to be a feasible and safe strategy to prevent AF recurrence in patients with concomitant PLSVC. [ABSTRACT FROM AUTHOR]

The ventricular papillary muscles (VPMs) can be a source of premature ventricular contractions (PVCs). Catheter ablation of VPM PVCs is challenging because of the anatomical complexity, such as the apical structures in proximity to the ventricular walls. The QDOT MICRO catheter (Biosense Webster, Diamond Bar, CA, USA) has microelectrodes embedded along the circumference of its distal tip and can provide information on which side of its tip myocardial activation is earlier. This repaired truncus arteriosus case demonstrates the usefulness of the microelectrode recording in identifying a PVC origin in a right VPM apex close to the right ventricular anterior wall. [ABSTRACT FROM AUTHOR]

The association of psychosocial risk factors with cardiovascular disease is well‐established, and there is a growing recognition of their influence on atrial fibrillation (AF). A recent National Heart, Lung, and Blood Institute workshop called for transforming AF research to integrate social determinants of health. There is limited data examining the impact of psychosocial risk factors (PSRFs) on outcomes in patients with an established diagnosis of AF. Catheter ablation for AF has been shown to improve arrhythmia burden and quality of life compared with medical treatment alone. It is unknown how PSRFs affect clinical outcomes in patients undergoing AF ablation. It is important to understand this relationship, especially given the increasing adoption of catheter ablation in clinical practice. [ABSTRACT FROM AUTHOR]

Background: Prediction of the chamber of origin in patients with outflow tract ventricular arrhythmias (OTVA) remains challenging. A clinical risk score based on age, sex and presence of hypertension was associated with a left ventricular outflow tract (LVOT) origin. We aimed to validate this clinical score to predict an LVOT origin in patients with OTVA. Methods: In a two‐center observational cohort study, unselected patients undergoing catheter ablation (CA) for OTVA were enrolled. All procedures were performed using an electroanatomical mapping system. Successful ablation was defined as a ≥80% reduction of the initial overall PVC burden after 3 months of follow‐up. Patients with unsuccessful ablation were excluded from this analysis. Results: We included 187 consecutive patients with successful CA of idiopathic OTVA. Mean age was 52 ± 15 years, 102 patients (55%) were female, and 74 (40%) suffered from hypertension. A LVOT origin was found in 64 patients (34%). A score incorporating age, sex and presence of hypertension reached 73% sensitivity and 67% specificity for a low (0–1) and high (2–3) score, to predict an LVOT origin. The combination of one ECG algorithm (V2S/V3R‐index) with the clinical score resulted in a sensitivity and specificity of 81% and 70% for PVCs with R/S transition at V3. Conclusion: The published clinical score yielded a lower sensitivity and specificity in our cohort. However, for PVCs with R/S transition at V3, the combination with an existing ECG algorithm can improve the predictability of LVOT origin. [ABSTRACT FROM AUTHOR]

Introduction: The management of patients with conduction disease and supraventricular arrhythmias presents a multitude of clinical challenges.Intra‐Hisian block, a condition characterized by delayed or blocked electrical conduction within the His bundle, can result in debilitating symptoms, such as syncope or presyncope. This case report aims to elucidate the diagnostic and therapeutic considerations that were taken in a patient who presented with recurrent syncopal episodes that corresponded to atrial flutter (AFL) and subsequently underwent cavotricuspid isthmus ablation. Case presentation: A 65‐year‐old male with paroxysmal AFL and a pre‐existing right bundle branch block and left anterior fascicular block (RBBB+LAFB) experienced recurrent syncopal episodes that were found to be correlated with AFL episodes. Following CTI ablation, an electrophysiology study (EPS) revealed a prolonged HV interval of 101ms, which indicated potential conduction abnormalities. With coronary sinus pacing, an intra‐Hisian delay of 211ms was observed. During instances of atrioventricular block, intra‐Hisian delay was evident on conducted beats, followed by intra‐Hisian block on non‐conducted beats. Ultimately, the patient's syncopal episodes prompted the placement of a dual‐chamber pacemaker, which resulted in the resolution of symptoms. Conclusion: Intra‐Hisian block is a condition that is often associated with delayed or blocked electrical conduction within the His bundle. When symptomatic, patients often present with syncope or presyncope. Etiologies of this condition include degenerative changes, myocardial infarction, autoimmune disorders, infections, medications, and more. This case emphasizes the importance of electrophysiology studies (EPS) in the diagnosis and management of patients with intra‐Hisian block. Prompt intervention, such as the placement of a dual‐chamber pacemaker, can alleviate symptoms and improve patient outcomes. Thus, clinical awareness and utilization of EPS can aid in accurate diagnosis and appropriate treatment selection for patients with conduction abnormalities and supraventricular arrhythmias.cuspid isthmus (CTI) ablation. [ABSTRACT FROM AUTHOR]

Background: Embolic cerebrovascular events that remain of unknown etiology after a thorough diagnostic evaluation, are known as Embolic Strokes of Undetermined Source (ESUS). Subclinical atrial fibrillation (AF) represents a significant underlying cause of ESUS. Our aims were to examine the overall diagnostic yield of a prolonged cardiac monitoring wearable system (PCMw) after an ESUS to detect AF and factors associated with it, including the time frame from the ESUS event to PCMw initiation. Additionally, to evaluate the frequency of unexpected arrhythmic events (UAE) and their prognostic implications. Methods: We retrospectively analyzed 200 ECG recordings (3‐leads, 30 days duration) by means of a PCMw in patients with an ESUS to detect AF lasting longer than 30 s, between 2017 and 2021. UAE were defined as arrhythmia events that were not correlated to the main reason of prolonged cardiac monitoring. Results: AF was detected in 21 patients (10.5%). Patients with AF had more left atrial enlargement (OR = 4.22 [1.59–6.85]; p =.01) and atrial arrythmias in the initial 24‐h Holter during hospitalization (OR = 5.73 [2.03–16.49]; p =.001). The detection of AF was significatively higher if the PCMw was worn within the first 30 days after the ESUS compared to beyond 30 days (17% vs. 10.3%; p =.002). Fifty three patients (26.5%) had UAE during PCMw. In six of them these findings led to targeted treatment. Conclusion: PCMw represents a feasible non‐invasive device that could reliably detect subclinical AF episodes after an ESUS. Diagnostic yield was significatively higher when used within the first 30 days after the event, especially in selected patients. UAE were common, but did not impact prognosis. [ABSTRACT FROM AUTHOR]

Left ventricular (LV) summit premature ventricular contractions (PVCs) are often unresponsive to radiofrequency (RF) ablation. Retrograde venous ethanol infusion (RVEI) can be a valuable alternative in this scenario. A 43‐year‐old woman without structural heart disease presented with LV summit PVCs unresponsive to RF ablation because of their deep‐seated origin. Unipolar pace mapping performed through a wire inserted into a branch of the distal great cardiac vein (GCV) demonstrated 12/12 concordance with the clinical PVCs thus indicating close proximity to PVCs' origin. RVEI abolished the PVCs without complications. Subsequently, magnetic resonance imaging (MRI) evidenced an intramural myocardial scar produced by ethanol ablation. In conclusion, RVEI effectively and safely treated PVC arising from a deep site in the LVS. The scar provoked by chemical damage was well characterized by MRI imaging. [ABSTRACT FROM AUTHOR]

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X‐rays. X‐rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three‐dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X‐rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab. [ABSTRACT FROM AUTHOR]

Background: Automated threshold measurements (ATM) and output adaptation improved safety and follow‐up of cardiac implantable devices (CIED) in the last years. These algorithms were validated for conventional cardiac pacing; however, they were not suitable for permanent His Pacing. Left bundle branch area pacing (LBBAP) is an emerging technique to obtain physiologic cardiac stimulation; we tried to assess if ATM could be applied to this setting. Methods: Consecutive patients receiving ATM‐capable CIED and LBBAP in our hospital were enrolled in this prospective, observational trial; they were evaluated 3 months after implant, comparing pacing thresholds manually assessed and obtained via ATM. Subsequent remote follow‐up was carried on when available. Results: Forty‐five patients were enrolled. ATM for LBBAP lead provided consistent results in all the patients and was therefore activated; mean value of manually obtained LBBAP capture threshold was 0.66 ± 0.19 V versus ATM of 0.64 ± 0.19 V. TOST analysis showed equivalence of the two measures (p =.66). At subsequent follow‐up (mean follow up 7.7 ± 3.2 months), ATM was effective in assessing pacing thresholds and no clinical adverse event was observed. Conclusions: ATM algorithms proved equivalent to manual testing in determining capture threshold and were reliably employed in patients receiving LBBAP CIED. [ABSTRACT FROM AUTHOR]

Background: J‐waves may be observed during coronary angiography (CAG) or intracoronary acetylcholine (ACh) administration, but their significance is unknown. Methods: Forty‐nine patients, 59.1 ± 11.5 years old and 59% male, were studied on suspicion of vasospastic angina, and J wave dynamicity was compared between CAG and Ach administration. Results: Diagnostic (≥0.1 mV) or nondiagnostic (<0.1 mV) J waves in 9 and 3 patients, respectively, were augmented, and J waves were newly observed in 2 patients during CAG and Ach administration. Similar changes in the J‐wave amplitude were observed: from 0.10 ± 0.09 mV to 0.20 ± 0.15 mV (p <.002) and from 0.10 ± 0.10 mV to 0.20 ± 0.16 mV (p <.001) during CAG and Ach administration, respectively. J waves were located in the inferior leads and changed only during the right coronary interventions. In the remaining 35 patients, J waves were absent before and during the coronary interventions. Augmentation of J waves was found when the RR interval was shortened in some patients. Injection of anoxic media into the coronary artery might induce a conduction delay from myocardial ischemia that manifests as augmentation or new occurrence of J waves. Conclusions: Both CAG and intracoronary Ach administration affected J waves similarly in the same individuals. A myocardial ischemia‐induced conduction delay may be responsible for the changes in J waves, but further studies are needed. [ABSTRACT FROM AUTHOR]

Background: The Ventricular fibrillation and flutter (VF/VFL)‐related mortality trends in the United States (US) population have not yet been investigated. We aimed to assess the trends of VT/VFL‐related mortality from 1999 to 2019 among subjects aged more than 15 years old in the US. Methods: Data derived from the Centers for Disease Control and Prevention's (CDC) WONDER were analyzed between 1999 and 2019 for VF/VFL‐related mortality in subjects aged more than 15 years of age. Adjusted mortality rates (AAMRs) per 100,000 people by year, sex, race and urban‐rural status with relative confidence intervals (CIs) were determined. Both the average annual percent change (AAPC) and the annual percent change (APC) with 95% Cis were calculated. Results: Between 1999 and 2019, 242,125 VT/VFL‐related deaths occurred in the US. The overall AAMR steadily declined [AAPC −4.4% (95% CI: −4.7 to −4.0, p <.0001)]. Women showed a more pronounced AAMRs decline [AAPC: −4.8% (95% CI: −5.3 to −4.3, p <.0001). AAMR steadily declined in white subjects and in those of other races [AAPC: −4.5 (95% CI: −4.7 to −4.2, p <.0001) and AAPC: −4.3 (95% CI: −5.1 to −3.5, p <.001), respectively]. Conversely, African Americans showed a steadily AMMR decline between 1999 and 2007 [APC: −8.3 (95% CI: −9.2 to −7.3, p <.0001)], followed by a period of stability from 2007 to 2019 (p =.73). A similar decline was observed for the AAMR among subjects living in urban and rural areas. Conclusions: VT/VFL‐related mortality steadily decreased between 1999 and 2019 in US. Despite the encouraging results, further efforts are needed to prevent VF/VFL‐related mortality in US subjects. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is a rapidly increasing global public health concern entailing a high risk for ischemic stroke that can largely be avoided with anticoagulation therapy. AF is often underdiagnosed and there is a need for a reliable method of detection in individuals with additional risk factors for stroke such as coronary artery disease. We aimed to validate an automatic rhythm interpretation algorithm in thumb ECG in subjects with recent coronary revascularization. Methods: Thumb ECG, a patient‐operated handheld single‐lead ECG recording device with an automatic interpretation algorithm, was performed three times daily for a month after coronary revascularization and 2‐week periods 3, 12, and 24 months post‐procedure. The detection of AF by the automatic algorithm on subject and single‐strip ECG level was compared to manual interpretation. Results: 48,308 of 30 s thumb ECG recordings from 255 subjects (mean 212 ± 3.5 recordings per subject) were retrieved from a database (AF 47 subjects/655 recordings; non‐AF 208 subjects/47,653 recordings). The algorithm sensitivity at subject level was 100%, specificity 11.2%, positive predictive value (PPV) 20.2%, and negative predictive value (NPV) 100%. At the single‐strip ECG level, sensitivity was 87.6%, specificity 94.0%, PPV 16.8%, and NPV 99.8%. The most common reasons for false positive results were technical disturbance and frequent ectopic beats. Conclusions: The automatic interpretation algorithm in a handheld thumb ECG device can rule out AF in patients recently undergoing coronary revascularization with high accuracy, but manual confirmation is needed to confirm the diagnose of AF because of high false positive rates. [ABSTRACT FROM AUTHOR]

Background: Toxic dilated cardiomyopathy (T‐DCM) due to substance abuse is now recognized as a potential cause of severe left ventricular dysfunction. The burden of ventricular arrhythmias (VA) and the role of a prophylactic implantable cardioverter‐defibrillator (ICD) are not well documented in this population. We aim to assess the usefulness of ICD implantation in a T‐DCM cohort. Methods: Patients younger than 65 years with a left ventricular ejection fraction (LVEF) < 35% followed at a tertiary center heart failure (HF) clinic between January 2003 and August 2019 were screened for inclusion. The diagnosis of T‐DCM was confirmed after excluding other etiologies, and substance abuse was established according to the DSM‐5 criteria. The composite primary endpoints were arrhythmic syncope, sudden cardiac death (SCD), or death of unknown cause. The secondary endpoints were the occurrence of sustained VA and/or appropriate therapies in ICD carriers. Results: Thirty‐eight patients were identified, and an ICD was implanted in 19 (50%) of these patients, only one for secondary prevention. The primary outcome was similar between the two groups (ICD vs. non‐ICD; p = 1.00). After a mean follow‐up of 33 ± 36 months, only two VA episodes were reported in the ICD group. Three patients received inappropriate ICD therapies. One ICD implantation was complicated with cardiac tamponade. Twenty‐three patients (61%) had an LVEF ≥35% at 12 months. Conclusion: VA are infrequent in the T‐DCM population. The prophylactic ICD benefit was not observed in our cohort. The ideal timing for potential prophylactic ICD implantation in this population needs further studies. [ABSTRACT FROM AUTHOR]

Background: Reduced systolic myocardial function in the inferior region of the left ventricle has been suggested to be associated with malignant arrhythmias. We tested this hypothesis in patients with non‐ischemic heart failure. Methods: Patients with non‐ischemic heart failure (left ventricular ejection fraction [LVEF] < 35%) were evaluated by 2D‐speckle‐tracking echocardiography. The regional longitudinal strain was calculated for each of the six left ventricular walls. The reduced regional function was defined as strain below the median. The outcome was a composite of sudden cardiac death, admission with sustained ventricular arrhythmia, resuscitated cardiac arrest, and appropriate therapy from a primary prophylactic implantable cardioverter defibrillator. Time‐to‐first‐event analysis was performed using a Cox model. Results: From two centers, 401 patients were included (median age: 63 years, 72% male) with a median LVEF of 25% (interquartile range [IQR] 20;30), and a median inferior wall strain of –9.0% (–12.5; –5.4). During a median follow‐up of 4.0 years, 52 outcomes occurred. After multivariate adjustment for clinical and electrocardiographic parameters, inferior wall strain was independently associated with the outcome (HR 2.50 [1.35; 4.62], p =.003). No independent association was found between the composite outcome and reduced strain in any of the other left ventricular walls, Global Longitudinal Strain (HR 1.66 [0.93; 2.98], p =.09), or LVEF (HR 1.33 [0.75; 2.33], p =.33). Conclusions: Below median strain in the left ventricular inferior region was independently associated with a 2.5‐fold increase in the risk of malignant arrhythmias and sudden cardiac death in patients with non‐ischemic heart failure. [ABSTRACT FROM AUTHOR]

Background: The ablation of arrhythmias arising near the His‐bundle region in the non‐coronary aortic cusp (NCAC) is challenging. Among the aortic sinuses of Valsalva, the NCAC is located between the right atrium and the left atrium. For this reason, pacing from the NCAC should result in atrial capture while pacing from the right and left coronary cusps (LCC) may result in ventricular capture. The objective of this study is to prove that atrial capture during pacing from the sinuses of Valsalva may be used to confirm a correct position in the non‐coronary cusp. Methods: A total of 30 patients with structurally normal heart undergoing left sided ablation procedures, underwent electrophysiological study of the aortic cusps. Each of the aortic valve cusps was paced with increasing outputs and analyzed offline to determine their unique electrocardiographic characteristics. Results: In the NCAC, we obtained an atrial capture in 29 out of 30 patients (96.6%). The atrial capture was highly specific for a position in the NCAC (p <.001). The median output required to capture from the cusp was 10 mA (range 5–25 mA) at a pulse width of 2 ms. In the right coronary cusp (RCC) and LCC, we obtained ventricular capture in all patients (100%). The median output required to capture from the cusp was 10 mA (range 10–25 mA) in RCC and 25 mA (range 10–25 mA) in LCC at a pulse width of 2 ms. Conclusions: Atrial capture during a pacemapping from the aortic cusps can be considered proof of a correct position in NCAC. [ABSTRACT FROM AUTHOR]

Background: It remains unclear whether carotid atherosclerosis (CAS) increases the atrial fibrillation (AF) recurrence rate after ablation. The aim was to assess the association between CAS, defined as carotid intima‐media thickness (CIMT) ≥1 mm and or presence of carotid plaques, and AF recurrence rate after ablation. Methods: We retrospectively collected patients who underwent carotid ultrasonography and AF ablation at the First Affiliated Hospital of Zhengzhou University. The AF recurrence was defined as documented atrial arrhythmias over 30 s on ECG or 24‐h Holter monitoring after the first three months blanking period. Cox regression models were used to analyze the risk of AF recurrence. Results: Overall, 385 patients were analyzed (mean age, 60.58±10.98 years old; female, 41.30%; persistent AF, 47.27%). After a follow‐up of 1 year, 138 (35.84%) patients experienced recurrence, Kaplan–Meier analysis showed that patients with the presence of carotid plaques, CIMT ≥1 mm, and CAS had a higher risk of recurrence compared with the absence (all log‐rank p <.05). In multivariate Cox regression analysis, CAS (HR 2.159, ±95% CI 1.320‐3.532, p =.002), carotid plaque (HR 1.815, ±95%CI 1.160‐2.841, p =.009), and CIMT ≥1 mm (HR 1.696, ±95%CI 1.192‐2.413, p =.003) were independently associated with a higher risk of recurrence. In subgroup analysis, the association of CAS, carotid plaque, and AF recurrence rate was weaker in men than women. Conclusion: Carotid atherosclerosis, CIMT ≥1 mm, and carotid plaque were significantly associated with a higher AF recurrence rate after radiofrequency catheter ablation. They were all risk factors for the recurrence of AF. [ABSTRACT FROM AUTHOR]

Brugada syndrome (BrS) is a controversial disease whose pathophysiology is still far from being fully understood. Unlike other cardiological disorders, a definite etiology has not yet been established so that it could be summarized under two main chapters: "functional" or "organic", "repolarization" or "depolarization" disorder. Despite initial descriptions leaned towards the organic substrate and delayed depolarization features, functional and repolarization theories have attracted most of the Cardiological attention for many years. Data from electrocardiography, endocavitary tracings, electroanatomic mapping and histopathology, however, demonstrated that BrS is mainly characterized by structural myocardial changes mostly at the right ventricular outflow tract (RVOT), but also at the right ventricle (RV) and by delayed conduction at the same sites. Conduction disorders at different levels may also be present and identify patients at high risk for major arrhythmic events. The aim of the present review is to provide the current state of art of the pathophysiology of BrS, focusing on electro‐vectorcardiography and electrophysiological features, histopathology, echocardiography, and cardiac magnetic resonance imaging (CMRI). [ABSTRACT FROM AUTHOR]

Background: Although premature atrial contractions (PACs) just after catheter ablation (CA) for atrial fibrillation (AF) are common, their clinical significance is uncertain. This study aimed to evaluate whether the PAC burden after an initial CA for AF was associated with late recurrence. Methods: We enrolled 346 patients with AF (median age, 65 years; 30% female; 57% with paroxysmal AF) who underwent an initial radiofrequency CA and a 24‐h Holter monitoring the day after the procedure. PAC was defined as supraventricular complexes occurring ≥30% earlier than expected compared with a previous RR interval, and the number of PAC/24 h during post‐procedural Holter monitoring was analyzed. Results: AF recurred in 106 patients (31%) during a median follow‐up of 19 months. These patients had significantly more PAC/24 h than those without (median [interquartile range], 891 [316–4351] beats vs. 409 [162–1,303] beats; p < 0.01). The number of PACs was independently associated with AF recurrence after adjustment for clinical parameters and left atrial (LA) enlargement. Receiver operating characteristic (ROC) curve analysis revealed that 1431 PAC/24 h was the optimal cut‐off value for predicting AF recurrence. Adding the PAC/24 h to the prediction model with LA diameter appeared to correctly reclassify patients who were thought to be at high risk for AF recurrence into the low‐risk group and vice versa. Conclusions: The number of PACs was an independent risk factor for AF recurrence. A 24‐h Holter recording the day after an initial CA is a simple and beneficial tool for the risk stratification of AF recurrence. [ABSTRACT FROM AUTHOR]

Background: Many algorithms have been developed to ensure the safety and accuracy of cardiac implantable electric devices (CIED). A specific algorithm designed to prevent pacemaker induced tachycardia (PMT) after a premature ventricular complex (PVC response) is available in all Abbott (former St. Jude Medical) CIED. However, a few case reports suggest that this algorithm may be proarrhythmic when programmed to Atrial Pace (A‐Pace on PVC). Methods: We analyzed the data of all (n = 333) Abbot implantable cardioverter defibrillator (ICD) and cardiac resynchronization defibrillator (CRT‐D) devices followed remote using the Merlin.net Patient Care Network in our institute in 2020. Status of the PVC response algorithm A‐Pace on PVC or Off was collected, and all atrial mode switch (AMS) episodes longer than 30 s were thoroughly evaluated. Data on clinical characteristics of the patients was collect from the electronic patient records. Results: A total of 173 patients had A‐Pace on PVC and twenty‐five of them (14%) had at least one atrial high rate episode (AHRE) >30 s (AHRE) triggered by the action of this algorithm. The median PVC count was higher in patients who had algorithm triggered AHRE than in those with no algorithm‐triggered AHRE (1.7% [IQR 0–3.2] vs. 0% [IQR 0–1.1], p <.0001). The major clinical characteristics were comparable in the two groups. Conclusion: The A‐Pace on PVC setting was frequently used in our patients. Our study shows that a considerable number of patients had at least one AHRE triggered by the algorithm. The use of this algorithm should be carefully reconsidered. [ABSTRACT FROM AUTHOR]

Left ventricular assist devices (LVAD) have been increasingly utilized end‐stage heart failure despite guidelinedirected medical therapy (due to limited organ availability) as a bridge to transplant or destination therapy, with improved overall survival.Majority of patients undergoing LVAD implantation have pre‐existing implantable cardioverter‐defibrillator (ICD) in‐situ.We present a case of device‐device interaction resulting in EMI inducing recurrent inappropriate device therapies inducing ventricular arrhythmia followed by the inappropriate triggering of noise reversion mode, thereby inhibiting device therapies.With the increase in number of end‐stage heart failure patients with ICDs in situ (and limited organ availability) undergoing LVAD implantation, it is imperative to recognize potential device‐device interactions to avoid unwarranted invasive interventions. [ABSTRACT FROM AUTHOR]

Phenytoin is a versatile drug with utility in neurological, dermatological, and even cardiac disease processes. Though phenytoin is widely available due to its excellent anti‐epileptic properties, it is now rarely used as an antiarrhythmic. Phenytoin has well‐studied sodium‐channel blocking abilities which can be taken advantage of to treat ventricular arrhythmias. Thus, it should remain in the arsenal of antiarrhythmics for any electrophysiologist. We present two cases of intractable ventricular arrhythmia in children that were controlled with phenytoin at supra‐therapeutic serum levels, preventing the need for heart transplantation. [ABSTRACT FROM AUTHOR]

Aims: Our objective was to explore whether the accuracy of the transitional zone index (TZI) for outflow tract ventricular arrhythmias (OT‐VAs) origin is affected by cardiac rotation and the additive value of interventricular septum angle (IVSa) obtained from coronary computed tomography angiography (CCTA). Methods: Standard 12‐lead ECGs of OT‐VAs with inferior axis in consecutive patients undergoing both CCTA examination and successful ablation were retrospectively analyzed. The IVSa was defined as an angle between the long axis of IVS and sagittal axis of the body from CCTA. Results: 64 patients (31 men; mean age 54.2 ± 11.6 years) were enrolled. The OT‐VAs exhibited right ventricular outflow tract origin in 46 (71.9%) patients and 36 (78.3%) were diagnosed correctly by TZI. The left ventricular outflow tract origin OT‐VAs was observed in 18 (28.1%) patients and 16 (88.9%) were diagnosed correctly by TZI. The patients were then divided into TZI correct group (n = 52) and TZI incorrect group (n = 12). In the TZI incorrect group, 11/12 (91.7%) cases were R/S transition in lead V3 with the TZ score during premature ventricular contractions [2.8(2.5−3.4)], and the TZI between −1.5 and 0. The IVSa was significantly larger in the TZI incorrect group than correct group (52.0 ± 6.9° vs. 39.0 ± 6.1°; p <.0001). The IVSa ≥46° predicted TZI incorrect with 92% sensitivity, 94% specificity, and 94% accuracy. Conclusion: The IVSa is a novel cardiac rotation index that reliably improves TZI to differentiate the OT‐VAs origin, especially for the OT‐VAs with lead V3 R/S transition. [ABSTRACT FROM AUTHOR]

The article presents the case of a 19-year-old male patient with rheumatic heart disease, post mitral valve replacement three years earlier, presented with recurrent episodes of palpitations and whose ECG showed regular wide complex tachycardia (WCT) at a rate of 140 beats per minute (bpm) with QRS identical to sinus rhythm. Topics discussed include findings of his ventricular pacing, and clinical findings on the patient's tachycardia.

Background: There are few large studies on which factors are associated with the occurrence of arrhythmias. Implantable loop recorders (ILR) are useful in detecting arrhythmia due to prolonged and continuous ECG monitoring. Therefore, the aim of this study is to identify and evaluate clinical characteristics and ECG parameters for predicting arrhythmias requiring pacemaker/ICD implantation by analyzing a study cohort with ILR. Methods: This bicentric study comprised a study cohort of 451 patients (mean age 64 ± 16 years, 209 women) receiving ILR implantation between 2011 and 2021. Patients were followed up on a 3 monthly outpatient interval. All arrhythmias with a pacemaker or ICD indication were considered clinically relevant. The primary study endpoint was the detection of clinically relevant arrhythmia. Results: During a follow up of 678 ± 392 days, a clinically relevant arrhythmia was detected in 81 of 451 patients (18%). Multivariate analysis revealed five independent risk factors: coronary artery disease (HR 1.954, CI 1.077–3.546, p =.028), atrial fibrillation (HR 2.253, CI 1.201–4.228, p =.011), previous syncope (HR 6.404, CI 3.202–12.808, p <.001), right bundle branch block (HR 4.370, CI 2.215–8.621, p <.001) and left bundle branch block (HR 2.685, CI 1.116–6.461, p =.028). Our risk model, based on these independent predictors, divided the study cohort into patients with low (2%), intermediate (18%), medium (34%), and high (45%) risk for clinically relevant arrhythmia. Conclusion: By the use of ILR, a clinically relevant arrhythmia has been detected in almost one fifth of the study cohort. In addition, clinical and electrocardiographic parameters were shown to be suitable predictors of clinically relevant arrhythmia. [ABSTRACT FROM AUTHOR]

Background: Limited data exists for outcomes in patients undergoing cardiovascular implantable electronic device (CIED) transvenous lead extraction (TLE) without clear indications for device reimplantation. The implantable loop recorder (ILR) may be an effective strategy for continuous monitoring in select individuals. Objective: This retrospective analysis aims to investigate patients who have undergone ILR implant following TLE without CIED reimplantation. Methods: Clinical data from consecutive patients who have undergone TLE with ILR implant and without CIED reimplantation from October 2016 to May 2020 at a single center were collected. Results: Among 380 patients undergoing TLE, 28 (7.7%) underwent ILR placement without CIED reimplantation. TLE indications were systemic infection (n = 13, 46.4%), pain at the site (n = 8, 28.6%), device/lead malfunction (n = 4, 14.2%), and other. Devices extracted included: dual‐chamber and single‐chamber pacemaker (n = 14, 50%; n = 4, 14.2%), dual‐chamber implantable cardiac defibrillator (n = 10; 35.7%), and cardiac‐resynchronization therapy with defibrillator (n = 1, 3.5%). Reasons for no reimplantation included no longer meeting CIED criteria (n = 14, 50%), patient preference (n = 9, 32.1%), and no clear or inappropriate indication for initial CIED implantation (n = 5, 18%). During an average of 12.3 ± 13.1 months of follow‐up, there were no lethal arrhythmias, and four (13.3%) patients underwent permanent pacemaker reimplantation due to symptomatic sinus bradycardia and atrioventricular block with syncope as discovered on ILR. Three patients died due to unknown causes (n = 1), noncardiac (n = 1), and acute coronary syndrome (n = 1). Conclusions: In patients undergoing TLE without reimplantation, an ILR may be an effective monitoring strategy in patients at low risk for cardiac arrhythmia. [ABSTRACT FROM AUTHOR]

We present the case of a 75‐year‐old woman with severe aortic stenosis and moderate left ventricular dysfunction, who underwent elective transcatheter aortic valve replacement. After the procedure, the patient developed a left bundle branch block and a long PR interval. For this reason, a dual chamber pacemaker with pacing in the left bundle branch area was implanted. On device interrogation, we confirmed the presence of functional atrial undersensing causing loss of ventricular electric resynchronization. This case highlights the importance of recognizing this problem and, by means of device reprogramming and pharmacological intervention, suggests a stepwise approach to solve it. [ABSTRACT FROM AUTHOR]

Background: Little is known regarding the characterization of electrical substrate in both atria in patients with atrial fibrillation (AF). Methods: Eight consecutive patients undergoing AF ablation (five paroxysmal, three persistent) underwent electrical substrate characterization during sinus rhythm. Mapping of the left (LA) and right atrium (RA) was performed with the use of the HD Grid catheter (Abbott). Bipolar voltage maps were analyzed to search for low voltage areas (LVA), the following electrophysiological phenomena were assessed: (1) slow conduction corridors, and (2) lines of block. EGMs were characterized to search for fractionation. Electrical characteristics were compared between atria and between paroxysmal versus persistent AF patients. Results: In the RA, LVAs were present in 60% of patients with paroxysmal AF and 100% of patients with persistent AF. In the LA, LVAs were present in 40% of patients with paroxysmal AF and 66% of patients with persistent AF. The areas of LVA in the RA and LA were 4.8±7.3 cm2 and 7.8±13.6 cm2 in patients with paroxysmal AF versus 11.7±3.0 cm2 and 2.1±1.8 cm2 in patients with persistent AF. In the RA, slow conduction corridors were present in 40.0% (paroxysmal AF) versus 66.7% (persistent AF) whereas in the LA, slow conduction corridors occurred in 20.0% versus 33.3% respectively (p = ns). EGM analysis showed more fractionation in persistent AF patients than paroxysmal (RA: persistent AF 10.8 vs. paroxysmal AF 4.7%, p =.036, LA: 10.3 vs. 4.1%, p =.108). Conclusion: Bi‐atrial involvement is present in patients with paroxysmal and persistent AF. This is expressed by low voltage areas and slow conduction corridors whose extension progresses as the arrhythmia becomes persistent. This electrophysiological substrate demonstrates the important interplay with the pulmonary vein triggers to constitute the substrate for persistent arrhythmia. [ABSTRACT FROM AUTHOR]

The premature ventricular contractions (PVCs) have usually good prognosis in patients without structural heart disease. In case of left ventricular ejection fraction depression or symptoms, antiarrhythmic drugs or cardiac ablations could be an option for management. We present a case of a patient with high burden of PVC admitted for cardiac ablation. Preoperative assessment revealed hyperkalemia and metabolic acidosis which ended up with type‐4 renal tubular acidosis (RTA). Its rare cause and management may draw attention to the possibility of type ‐4 RTA as the cause of the PVC, and hyperkalemia. [ABSTRACT FROM AUTHOR]

J wave syndrome is a spectrum of proarrhythmic disorders including Brugada syndrome and early repolarization syndrome (ERS), that are prone to ventricular fibrillation and sudden cardiac death (SCD). In this case report we present a patient with ERS and aborted SCD complicated with cognitive impairment. We also investigated whether performing transcranial direct current stimulation to target his cognitive impairment, interfered with the function of his implantable cardioverter defibrillator. [ABSTRACT FROM AUTHOR]

Background: Restricted outdoor activity during COVID‐19 related lockdown may accelerate heart failure (HF) progression and thereby increase cardiac arrhythmias. We analyzed the impact of March/April 2020 lockdown on physical activity and arrhythmia burden in HF patients treated with cardiac resynchronization therapy (CRT) devices with daily, automatic remote monitoring (RM) function. Methods: The study cohort included 405 HF patients enrolled in Observation of Clinical Routine Care for Heart Failure Patients Implanted with BIOTRONIK CRT Devices (BIO|STREAM.HF) registry in 16 countries, who had left ventricular ejection fraction (LVEF) ≤40% (mean 28.2 ± 6.6%) and NYHA class II/III/IV (47.9%/49.6%/2.5%) before CRT pacemaker/defibrillator implantation. The analyzed RM data comprised physical activity detected by accelerometer, mean heart rate and nocturnal rate, PP variability, percentage of biventricular pacing, atrial high rate episode (AHRE) burden, ventricular extrasystoles and tachyarrhythmias, defibrillator shocks, and number of implant interrogations (i.e., follow‐ups). Intraindividual differences in RM parameters before (4‐week period) versus during (4‐week period) lockdown were tested for statistical significance and independent predictors were identified. Results: There was a significant relative change in activity (mean −6.5%, p <.001), AHRE burden (+17%, p =.013), and follow‐up rate (−75%, p <.001) during lockdown, with no significant changes in other RM parameters. Activity decreased by ≥8 min/day in 46.5% of patients; predictors were higher LVEF, lower NYHA class, no defibrillator indication, and more activity before lockdown. AHRE burden increased by ≥17 min/day in 4.7% of patients; predictors were history of atrial fibrillation, higher LVEF, higher body mass index, and activity decrease during lockdown. Conclusion: Unfavorable changes in physical activity, AHRE burden, and follow‐up rate were observed during lockdown, but not in ventricular arrhythmia. [ABSTRACT FROM AUTHOR]

Background: Empagliflozin is a selective SGLT2 inhibitor and provides a significant reduction in hospitalizations in heart failure patients and a reduction in combined cardiovascular deaths regardless of diabetes. The mechanisms of favorable effects remain unclear. Improvement in left ventricular diastolic function and a decrease in filling pressure are any mechanisms of positive effects. These effects may show themselves with some changes on the electrocardiography (ECG). So, we aimed to evaluate the effect of empagliflozin on P wave parameters in type 2 diabetes mellitus patients without HF. Method: Fifty‐three patients were included in the study. The electrocardiographic and echocardiographic evaluations were examined at the baseline and end of the third month for all patients. Results: The median age of all patients was 55 (45–64 IQR). After treatment, LA volume (p <.001) and diameter (p =.001) in both the parasternal long‐axis (p =.001) and the apical four‐chamber view decreased. E/e′ and systolic pulmonary arterial pressure were significantly decreased after treatment. P wave duration max,min, PWDmin, and PWdis were significantly shorter after treatment. The P wave peak time (PWPT) in lead Dıı and V1 were significantly shorter after treatment. Conclusion: We found shortening of PWPT, PWdis, and PWD as reflections of improvements in left atrial volume and LV diastolic function on ECG after empagliflozin treatment. [ABSTRACT FROM AUTHOR]

Introduction: Pre‐implant ECG screening is performed to ensure that S‐ICD recipients have at least one suitable sensing vector, yet cardiac over‐sensing remains the commonest cause of inappropriate shock therapy in the S‐ICD population. One explanation would be the presence of dynamic variations in ECG morphology that result in variations in vector eligibility. Methods: Adult ICD patients had a 24‐h ambulatory ECG performed using a digital Holter positioned to record all three S‐ICD vectors. Using an S‐ICD simulator, automated screening was then performed at one‐minute intervals. In vectors with a mean vector score > 100 (the accepted value for a passing vector when screened on a single occasion), the percentage of all screening assessments that passed, eligible vector time (EVT), was calculated. EVT was compared statistically to QRS duration, corrected time to peak T (pTc) and mean vector score. Results: Ambulatory monitoring was performed in 14 patients (mean age 63.7 ± 5.2 years, 71.4% male) with 42 vectors analysed. In 19 vectors the mean vector score was > 100. Within this "passing" cohort EVT varied between 42.7% and 100%. In 7/19 (37%) the EVT was <75%. A negative correlation was found between QRS duration and EVT (Pearson correlation ‐.60, p =.007). No correlation was found between EVT and mean vector score or pTc. Conclusion: Vector eligibility is dynamic. When "passing" vectors are subjected to repeated screening, 37% are found to be ineligible, more than a quarter of the time. Further investigation is required to determine the clinical significance of these findings. [ABSTRACT FROM AUTHOR]

Background: Physical activity (PA) is an important determinant of cardiovascular health that may be affected the COVID‐19 pandemic. Therefore, we examined the immediate and long‐term effects of the pandemic and lockdown on PA in patients with established cardiovascular risk. Methods: Objectively‐measured daily PA data was obtained from cardiovascular implantable electronic devices (CIEDs) from 3453 U.S patients (mean and standard deviations [SD] age, 72.65 [13.24] years; 42% women). Adjusted mixed‐effects models stratified by device type were used to compare daily PA from periods in 2020: pre‐lockdown (March 1–14), lockdown (March 15 to May 8), and the reopening phase of the pandemic (May 9 to December 31) versus 2019. Patient characteristics and events associated with inactivity during lockdown and the proportion of patients who returned to their 2019 PA‐level by the end of reopening phase (December 31, 2020) were examined. Results: Daily PA was significantly lower during the lockdown compared to the same period in 2019 (−15%; p <.0001), especially for pacemaker patients, adults aged <65, and patients more active prior to lockdown. Non‐COVID hospitalization and ICD shock were similarly associated with low PA during lockdown (p =.0001). In the reopening phase of the pandemic, PA remained 14.4% lower in the overall sample and only 23% of patients returned to their 2019 PA level by the end of follow‐up. Conclusions: In this large cohort of patients with CIEDs, PA was markedly lower during the lockdown and remained lower for months after restrictions were lifted. Strategies to maintain PA during a national emergency are urgently needed. [ABSTRACT FROM AUTHOR]

Background: The subcutaneous cardioverter‐defibrillator (S‐ICD) continues to be preferentially used in relatively young patients, with less advanced heart disease. Objective: We, therefore, studied the short and long‐term efficacy and safety of the S‐ICD in subgroups of patients, which are underreported at present. Methods: A total of 218 patients between November 2010 and February 2019 undergoing S‐ICD with a follow up of at least 6 months implantation were included in a prospective registry. Mean follow up was 38 months. Results: The most common indication for S‐ICD implantation was ischemic cardiomyopathy (n = 106, 49%). Complication rate needing invasive intervention was 9% (n = 21). Appropriate shock rate in patients with an S‐ICD was 3.5%/year. A total of 30 inappropriate shocks (IAS) occurred in 19 patients (8.7%; 2.7%/year). The proportion of appropriate and inappropriate shock rates in patients with different cardiomyopathies shows remarkable variances. There were significant more IAS (3.6%/year vs. 1.7%/year, p =.048) in patients with non‐ischemic cardiomyopathy versus patients with ischemic cardiomyopathy. Multivariate analysis identified, besides type of cardiomyopathy, atrial fibrillation (AF) as predictor for IAS. Conclusion: In this real‐world prospective registry we analyzed S‐ICD performance in the more traditional ICD patient. Patients with ischemic cardiomyopathy had significantly less inappropriate therapy compared to patients with non‐ischemic cardiomyopathy and appear to be appropriate patients for this type of device. [ABSTRACT FROM AUTHOR]

Background: It remains uncertain whether low‐level electrical stimulation (LL‐ES) of the ventricular ganglionated plexi (GP) improves heart function. This study investigated the anti‐arrhythmic and anti‐heart failure effects of LL‐ES of the aortic root ventricular GP (ARVGP). Methods: Thirty dogs were divided randomly into control, drug, and LL‐ES groups after performing rapid right ventricular pacing to establish a heart failure (HF) model. The inducing rate of arrhythmia; levels of bioactive factors influencing HF, including angiotensin II type I receptor (AT‐1R), transforming growth factor‐beta (TGF‐β), matrix metalloproteinase (MMP), and phosphorylated extracellular signal‐regulated kinase (p‐ERK1/2); left ventricular stroke volume (LVSV), and left ventricular ejection fraction (LVEF)were measured after treatment with placebo, drugs, and LL‐ES. Results: The inducing rate of atrial arrhythmia decreased from 60% in the control group to 50% in the drug group and 10% in the LL‐ES group (p =.033 vs. drug group) after 1 week of treatment. The ventricular effective refractory period was prolonged from 139 ± 8 ms in the drug group to 166 ± 13 ms in the LL‐ES group (p =.001). Compared to the drug group, the expressions of AT‐1R, TGF‐β, and MMP proteins were down‐regulated in the LL‐ES group, whereas that of p‐ERK1/2 was significantly increased (all p =.001). Moreover, in the LL‐ES group, LVSV increased markedly from 13.16 ± 0.22 to 16.86 ± 0.27 mL, relative to that in the drug group (p =.001), and LVEF increased significantly from 38.48% ± 0.53% to 48.94% ± 0.57% during the same time frame (p =.001). Conclusion: Short‐term LL‐ES of ARVGP had both anti‐arrhythmic and anti‐inflammatory effects and contributed to the treatment of tachycardia‐induced HF and its associated arrhythmia. [ABSTRACT FROM AUTHOR]

Patients infected with novel coronavirus (SARS‐CoV‐2) can present with a variety of arrhythmias. We report an unusual case of reversible complete heart block (CHB) in the setting of acute coronavirus disease 2019 (COVID‐19). A 23‐year‐old male with a history of Hodgkin's Lymphoma presented with dizziness and syncope. He was found to be in CHB associated with hypotension requiring a transvenous pacemaker. Methylprednisolone and remdesivir were started with rapid resolution of the CHB. Further study is needed to determine the mechanism of CHB in COVID‐19. This case underscores the importance of including COVID‐19 in one's differential diagnosis for acute CHB. [ABSTRACT FROM AUTHOR]