Evaluation of Frontal QRS-T Angle in Children With ADHD and Healthy Controls.

INTRODUCTION: Conflicting findings exist regarding the link between attention deficit hyperactivity disorder (ADHD) and cardiovascular diseases. This study aimed to evaluate the frontal QRS-T (fQRS-T) angle and its correlation with symptom severity in children diagnosed with ADHD. METHODS: The study population consisted of 172 patients diagnosed with ADHD (120 drug naive and 52 drug positive) and 82 healthy controls. ADHD symptoms were assessed using the Atilla Turgay DSM-IV-Based Screening and Assessment Scale for Disruptive Conduct Disorders (T-DSM-IV-Scale). The fQRS-T angle and corrected QT (QTc) interval were obtained from the automated reports of 12-lead electrocardiography device for each patient. RESULTS: QTc interval and fQRS-T angle were significantly different among the groups. Post hoc analyses showed that QTc interval and fQRS-T angle of ADHD drug naive and ADHD drug positive patients were significantly higher than the healthy control groups. However, there was no significant difference between drug naive and drug positive patients regarding QTc interval and fQRS-T angle. Both QTc interval and fQRS-T angle showed positive correlations with the severity of ADHD symptoms (r = 0.263, p = .001 and r = 0.175, p = .023 respectively). CONCLUSION: We found that fQRS-T angle was significantly wider in children with ADHD. Therefore, we suggest that fQRS-T angle may help in cardiovascular risk assessment in children with ADHD.

Machine Learning-Based Clustering Using a 12-Lead Electrocardiogram in Patients With a Implantable Cardioverter Defibrillator to Identify Future Ventricular Arrhythmia.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) reduce mortality associated with ventricular arrhythmia in high-risk patients with cardiovascular disease. Machine learning (ML) approaches are promising tools in arrhythmia research; however, their application in predicting ventricular arrhythmias in patients with ICDs remains unexplored. We aimed to predict and stratify ventricular arrhythmias requiring ICD therapy using 12-lead electrocardiograms (ECGs) in patients with an ICD. METHODS AND RESULTS: This retrospective analysis included 200 adult patients who underwent ICD implantation at a single center. Patient demographics, clinical features, and 12-lead ECG data were collected. Unsupervised learning techniques, including K-means and hierarchical clustering, were used to stratify patients based on 12-lead ECG features. Dimensionality reduction methods were also used to optimize clustering accuracy. The silhouette coefficient was used to determine the optimal method and number of clusters. Of the 200 patients, 59 (29.5%) received appropriate therapy. The mean age of patients was 62.3 years, and 81.0% were male. The mean follow-up period was 2,953 days, with no significant intergroup differences. Hierarchical clustering into 3 clusters proved to be the most accurate (silhouette coefficient=0.585). Kaplan-Meier curves for these 3 clusters revealed significant differences (P=0.026). CONCLUSIONS: We highlight the potential of ML-based clustering using 12-lead ECGs to help in the risk stratification of ventricular arrhythmia. Future research in a larger multicenter setting may provide further insights and refine ICD indications.

REM sleep-related bradyarrhythmia syndrome.

Rapid eye movement sleep-related bradyarrhythmia syndrome is a rare condition marked by abnormal sinus arrest or atrioventricular conduction disturbance blocks during REM sleep unassociated with sleep disordered breathing. We present a case of a young man without a cardiovascular history exhibiting pauses of up to 9.7 seconds during polysomnography (PSG). Initially referred for suspected obstructive sleep apnea due to nocturnal awakenings with shortness of breath, confusion, and dizziness. PSG results were unremarkable apart from electrocardiogram findings revealing prolonged sinus pauses related to REM sleep. Evaluation via extended 14-day patch monitor revealed an overall normal sinus rhythm with the lowest heart rate recorded at 14 beats per minute and 412 pauses exceeding 2 seconds, with the longest pause lasting 12.5 seconds during nocturnal hours. A permanent pacemaker was considered, but after shared decision making with the patient, the decision was to continue monitoring without any intervention.

Smart watch applications in atrial fibrillation detection: Current state and future directions.

INTRODUCTION: Atrial fibrillation (Afib) is a prevalent chronic arrhythmia associated with severe complications, including stroke, heart failure, and increased mortality. This review explores the use of smartwatches for Afib detection, addressing the limitations of current monitoring methods and emphasizing the potential of wearable technology in revolutionizing healthcare. RESULTS/OBSERVATION: Current Afib detection methods, such as electrocardiography, have limitations in sensitivity and specificity. Smartwatches with advanced sensors offer continuous monitoring, improving the chances of detecting asymptomatic and paroxysmal Afib. The review meticulously examines major clinical trials studying Afib detection using smartwatches, including the landmark Apple Heart Study and ongoing trials such as the Heart Watch, Heartline, and Fitbit Heart Study. Detailed summaries of participant numbers, smartwatch devices used, and key findings are presented. It also comments on the cost-effectiveness and scalability of smartwatch-based screening, highlighting the potential to reduce healthcare costs and improve patient outcomes. CONCLUSION/RELEVANCE: The integration of wearable technology into healthcare can lead to earlier diagnosis, improved patient engagement, and enhanced cardiac health monitoring. Despite ethical considerations and disparities, the potential benefits outweigh the challenges. This review calls for increased awareness, collaboration with insurance companies, and ongoing research efforts to optimize smartwatch accuracy and encourage widespread adoption of Afib detection. With insights from major trials, this review serves as a comprehensive reference for healthcare professionals and policymakers, guiding future strategies in the early diagnosis and management of atrial fibrillation.

Dofetilide for the treatment of premature ventricular complexes and ventricular tachycardia in patients with structural heart disease.

BACKGROUND: Dofetilide is a class III antiarrhythmic agent approved for the treatment of atrial fibrillation and atrial flutter. Given the efficacy of other class III agents, it has been used off-label for the treatment of premature ventricular complexes (PVCs) and ventricular tachycardias (VTs). OBJECTIVE: The purpose of this study was to determine the efficacy and safety of dofetilide for ventricular arrythmias (VAs). METHODS: In this retrospective cohort study, 81 patients (59 men; age = 60 ± 14 years; LVEF = 0.34 ± 0.16) were admitted for dofetilide initiation to treat PVCs (29), VTs (42) or both (10). A ≥ 80% decrease in PVC burden was defined as a satisfactory response. An ICD was present in 72 patients (89%). Another antiarrhythmic was previously used in 50 patients (62%). Prior catheter ablation had been performed in 33 patients (41%). RESULTS: During intitiation, dofetilide was discontinued in 12 patients (15%) due to QT prolongation (8) and inefficacy to suppress VAs (4). Among the 32 patients with PVCs who successfully started dofetilide, the mean PVC burden decreased from 20 ± 10% to 8 ± 8% at a median follow-up of 2.6 months (p < .001). PVC burden was reduced by ≥80% in only 11/32 patients (34%). During 7 ± 1 years of follow-up, 41/69 patients (59%) continued to have VAs and received appropriate ICD therapies for monomorphic VTs (35) and polymorphic VT/VF (6) at a median of 8.0 (IQR 2.6-33.2) months. Dofetilide had to be discontinued in 50/69 patients (72%) due to inefficacy or intolerance. The composite outcome of VT/VF recurrence, heart transplantation, or death occurred in 6/12 patients (50%) without dofetilide and 49/69 patients (71%) with dofetilide. The event free survival was similar between patients treated with and without dofetilide (log-rank p = .55). CONCLUSIONS: Treatment with dofetilide was associated with a decrease in PVCs, however clinically significant suppression occurred in a minority of patients. Dofetilide failed to suppress the occurrence of VTs in a majority of patients.

Acute Alcohol Consumption and Arrhythmias in Young Adults: The MunichBREW II Study.

BACKGROUND: and aims: Acute excessive alcohol intake may cause the holiday heart syndrome, characterized by cardiac arrhythmias including atrial fibrillation. Since underlying data are scarce, the study aimed to prospectively investigate the temporal course of occurring cardiac arrhythmias following binge drinking in young adults. METHODS: A total of 202 volunteers planning acute alcohol consumption with expected peak breath alcohol concentrations (BAC) of ≥1.2 g/kg were enrolled. The study comprised 48-hour electrocardiogram (ECG) monitoring covering baseline (hour 0), 'drinking period' (hours 1-5), 'recovery period' (hours 6-19), and two control periods corresponding to 24 hours after the 'drinking' and 'recovery periods', respectively. Acute alcohol intake was monitored by BAC measurements during the 'drinking period'. ECGs were analyzed for mean heart rate, atrial tachycardia, premature atrial complexes (PAC), premature ventricular complexes (PVC), and heart rate variability (HRV) measures. RESULTS: Data revealed an increase in heart rate and an excess of atrial tachycardias with increasing alcohol intake. HRV analysis indicated an autonomic modulation with sympathetic activation during alcohol consumption and the subsequent 'recovery period', followed by parasympathetic predominance thereafter. PACs occurred significantly more frequently in the 'control periods', whereas PVCs were more frequent in the 'drinking period'. Ten participants experienced notable arrhythmic episodes, including atrial fibrillation and ventricular tachycardias, primarily during the 'recovery period'. CONCLUSIONS: The study demonstrates the impact of binge drinking on heart rate alterations and increased atrial tachycardias during 'drinking period', and the occurrence of clinically relevant arrythmias during the 'recovery period', emphasizing the holiday heart syndrome as a health concern.

Pulsed-Field Ablation in Management of Ventricular Tachycardia: A Systematic Review of Case Reports and Clinical Outcomes.

BACKGROUND: Pulsed-field ablation (PFA) is a cutting-edge technique that employs non-thermal energy to cause cell death by inducing irreversible electroporation of cell membranes. This systematic review evaluates the PFA effectiveness as a potential alternative to radiofrequency and cryo-ablation for treating ventricular tachycardia. METHODS: PubMed, Embase, Scopus, and Web of Science were systematically searched using keywords related to ventricular tachycardia and pulsed-field ablation. Eligible Studies evaluating this therapeutic approach for ventricular tachycardia were included in the final analysis. RESULTS: We included six studies (five case reports and one case series) in our systematic review. Eight (88.8%) of procedures were successful with 100% long-term efficacy. No procedural complications or ventricular tachycardia (VT) recurrence were observed in the cases. CONCLUSION: The absence of complications, high effectiveness, and long-term success rate make PFAs a good VT treatment option. However, PFA safety and efficacy studies for VT treatment are scarce. Thus, larger investigations on this topic are urgently needed.

Anterior pituitary hormone dysfunction among individuals with complete heart block requiring pacemaker.

Background & objectives Neuronal hypoxia associated with conditions like traumatic brain injury and cardiac tachyarrhythmia has been implicated in causing hypopituitarism. Individuals with complete heart block (CHB) may be predisposed to develop anterior pituitary hormone dysfunction in the long term. The objective of this study was to investigate anterior pituitary hormone functions in individuals after CHB. Methods This prospective cohort study included 30 individuals (21 men and 9 women) with CHB requiring pacemaker implantation, who were evaluated at admission and then at a mean follow up of 12.4 ± 2.2 months to look for development of any degree of hypopituitarism. In addition to the measurement of hormones like follicle-stimulating hormone (FSH), luteinising hormone (LH), thyroid stimulating hormone (TSH), total tetra iodothyronines (TT4), free tetraiodothyronines (FT4), cortisol, insulin-like growth factor-1 (IGF-1), testosterone and estradiol, a fixed-dose glucagon stimulation test (GST) was performed to assess growth hormone (GH) and adrenocorticotrophic hormone (ACTH) axis. Results The mean age of the participants was 64.9 ± 11.3 yr. At follow up evaluation, 17 (56.7%) had low serum IGF-1, and among them, seven (23%) had growth hormone deficiency (GHD) (peak GH <1.0 ng/ml after GST). Six participants (20%) had ACTH deficiency (peak cortisol <9 ug/dl after GST) and one had TSH deficiency. None had prolactin (PRL) or gonadotropin deficiency. Overall, hormone deficiencies were observed in nine patients (30%). Interpretation & conclusions This pilot study detected loss of anterior pituitary hormones in a significant number of individuals of CHB at 12 months follow up. Unrecognised hypopituitarism may have resulted in significant morbidity and mortality in these individuals.

Antiarrhythmic potentials of irisin in ischemia/reperfusion injury of diabetic rats through modulating mitochondria-endoplasmic reticulum interaction and inhibiting pyroptosis.

Objectives: Myocardial arrhythmia is a major complication of ischemia-reperfusion (I/R) injury in patients with diabetes. Irisin has significant cardioprotective effects, while its role in the pathophysiology of I/R injury-induced myocardial arrhythmia in the presence of diabetes is not well identified. Here, we aimed to investigate the potential antiarrhythmic impacts and mechanisms (mitochondrial biogenesis, endoplasmic reticulum (ER) stress, and pyroptosis) by which irisin reduces I/R injury-induced myocardial arrhythmia in diabetic rats. Materials and Methods: Thirty high-fat diet-induced diabetic rats were subjected to I/R injury and myocardial arrhythmia. Irisin (0.5 µg/kg/day) was injected intraperitoneally before induction of I/R injury. Electrocardiography was used to measure the incidence and severity of ventricular arrhythmias. ELISA and western blotting analyses were employed to quantify the expression of mitochondrial biogenesis, ER stress, and pyroptosis-related proteins in ischemic myocardium. Results: Irisin treatment in diabetic rats significantly decreased the lactate dehydrogenase level and the number and severity of arrhythmia induced by I/R injury. Irisin up-regulated the expression of mitochondrial biogenesis-related proteins while down-regulating the expression of ER stress and pyroptosis-related proteins. Furthermore, the inhibition of mitochondrial quality control by mdivi-1 significantly abolished the cardioprotective effect of irisin. Conclusion: Our findings suggest that irisin reduced myocardial arrhythmia induced by I/R injury in diabetic rats by modulating the interaction of mitochondrial biogenesis and ER stress proteins and inhibiting the pyroptosis pathway. These findings provide a promising strategy for managing myocardial arrhythmia in diabetic patients, but supplementary studies are needed to confirm the clinical efficacy of irisin in these patients.

Premature ventricular contraction patterns associated with nonsustained ventricular tachycardia.

BACKGROUND: Occurrence of nonsustained ventricular tachycardia (NSVT) is associated with negative outcomes. It is not clear whether specific electrocardiographic characteristics of premature ventricular contractions (PVCs) are associated with the occurrence of NSVT. The aim of this study was to identify electrocardiographic patterns associated with the presence of NSVT during 24-h electrocardiographic monitoring in patients with >10 PVCs per hour. METHODS: This was a retrospective, observational, cross-sectional study. We reviewed consecutive patients who received 24-h ECG monitoring performed at a single outpatient cardiology center. Patients who received 24-h electrocardiographic monitoring, with a PVC burden ≥10 PVCs/h were included. Occurrence of NSVT during 24-h electrocardiographic monitoring was the main outcome. RESULTS: A total of 343 patients were analyzed (mean [SD] age, 69.7 [12.5] years; 177 men [51.6 %]). NSVT occurred in 72 patients who were compared with 271 patients without NSVT. The novel term "premature beat ratio", which aims to correlate the coupling interval and compensatory pause, was introduced; a value >0.5 was independently associated with NSVT according to the multivariate model (OR = 3.73, 95 % CI = 1.57-8.82; P = 0.002). PVC burden (OR = 1.09, 95 % CI = 1.02-1.17; P = 0.006), and triplets (OR = 18.19, 95 % CI = 7.32-45.18 P = 0.0) were also associated with NSVT in the multivariate model. CONCLUSION: These findings suggest that patients with a high PVC burden, triplets, and a premature beat ratio greater than 0.5 have an increased probability of presenting with NSVT and may benefit from more rigorous follow-up.

Mechanisms underlying spontaneous termination of Torsade de Pointes in an experimental model of long QT syndrome.

BACKGROUND: Torsade de pointes (TdP) represents a complex polymorphic ventricular tachycardia. While the triggering mechanisms of early afterdepolarization and increased dispersion of repolarization are well investigated, the sudden self-limiting termination remains poorly understood. OBJECTIVE: Analysis of TdP to investigate factors causing spontaneous termination. METHODS: We used a large data set of Langendorff experiments in isolated rabbit hearts in which drug-induced QT prolongation, bradycardia and hypokalemia provoke TdP. We included 427 episodes with typical TdP characteristics of polymorphic, self-terminating beats and twisting QRS complexes occurring in the presence of abnormal QT prolongation due to various different QT prolonging agents. The use of eight monophasic action potential catheters allowed the characterization of action potential duration, configuration, and dispersion of repolarization beyond the capabilities of the surface ECG. To identify possible mechanisms of arrhythmia termination, the initial, midpoint, and terminal three ventricular complexes were analyzed for each episode. RESULTS: An abrupt decrease in spatial dispersion over the course of a TdP episode was identified as a precursor for termination of TdP. Within the last three beats, a sudden significant decrease in dispersion of repolarization was observed as a predictor of termination. In parallel, there was a decrease in action potential duration (APD90) before termination. Also, a change in action potential configuration (APD90/50 ratio) in terms of loss of action potential dome with restitution of action potential triangulation was observed. CONCLUSION: In more than 400 TdP episodes homogenization of myocardial repolarization with the recovery of action potential configuration determines the termination of TdP episodes.

Heart transplantation for pediatric patients with malignant arrhythmias: Indications and Outcomes.

BACKGROUND: Arrhythmias can lead to cardiac arrest (CA) and heart failure. When intractable, heart transplant (HTX) can become the only viable treatment. This rare, high-risk cohort has not been reported as a distinct group. OBJECTIVE: Characterize the outcomes of pediatric patients listed for HTX with the primary indication being malignant arrhythmia (MA). METHODS: Using the Pediatric Heart Transplant Society prospective registry, we identified all patients <18 years-old listed between 2014-2022. MA as the listing indication was categorized into primary tachy-arrhythmia (PT), inherited arrhythmia (IA), congenital heart disease (CHD) and cardiomyopathy (CM) with secondary arrhythmia. Demographic, listing and transplant data were analyzed. RESULTS: Among 4630 patients listed and 3317 transplanted, MA was the indication in 63 (1.4%) and 49 (1.5%), respectively. MA patients were categorized as PT in 11, IA in 4, CHD in 6 and CM in 42. When compared to the non-MA cohort, patients listed for MA were older (mean (SD) age 10.6 (6.2) vs. 6.1 (6.2) years, p<0.01), more likely to present with a CA (43% vs. 11%, p<0.01), and less likely to be in the intensive care unit (40% vs. 58%, p<0.01) or on inotropes (30% vs. 60%, p<0.01) at listing. Outcomes including waitlist mortality, transplantation, post-transplant survival and freedom from rejection were comparable to the non-MA cohort. CONCLUSION: Patients with MA constitute a small proportion of those listed for HTX in childhood. CM was the most common category, while IA and PT were rare. Their waitlist mortality and post-transplant outcomes were comparable to the non-MA cohort.

Elevated B-Type Natriuretic Peptide Level as a Residual Risk Factor for Ventricular Arrhythmias Among Patients Undergoing Cardiac Resynchronization Therapy With Improved Left Ventricular Ejection Fraction.

Background: Patients who achieve improved left ventricular ejection fraction (LVEF >35%) with cardiac resynchronization therapy (CRT) are at a lower risk of ventricular arrhythmia (VA). Little is known about the significance of the B-type natriuretic peptide (BNP) level for the risk of VA. This study investigated the risk factors for VA in CRT and the risk stratification of VA with BNP in CRT with improved LVEF. Methods and Results: This study evaluated 352 CRT patients from 2012 to 2020. Patients were categorized into 2 groups: improved LVEF (impEF; LVEF >35%), and low LVEF (lowEF; LVEF ≤35%). The serum BNP levels 6 months after CRT device implantation were measured. The primary endpoint was defined as VA requiring treatment with anti-tachycardia pacing or shock or persisting for ≥30 s. Overall, 102 patients had improved LVEF. The impEF group had a significantly lower VA risk than the lowEF group. Patients with low BNP had a lower VA risk than those with high BNP; however, no significant difference was observed between patients with high BNP and those in the lowEF group. Univariate analysis revealed that high BNP was a predictor of VA in the impEF group. Conclusions: The VA risk is reduced with improved LVEF after CRT but not with high BNP levels. The post-BNP level after CRT implantation is a useful marker for predicting VA in patients with improved LVEF.

Electrocardiographic ventricular arrhythmia parameters during diagnosis and after the treatment of acromegaly: A case-control study.

Background: The risk of death is increased in acromegaly patients compared to the general population, and cardiovascular system-related complications are among the risk factors decreasing life expectancy. The Tp-e interval, which is the distance between the point where the T-wave peaks and ends on electrocardiography (ECG), shows ventricular rapolarization and, together with the Tp-e/QT and Tp-e/QTc ratios, these are relatively new tools that predict ventricular arrhythmia. We aimed to evaluate the ECG of acromegaly patients at the time of diagnosis and compare the results with current ECG findings. Material and methods: The study included 103 acromegaly patients and 81 control subjects. Of the 103 patients, 41 patients had only baseline ECG, 23 patients had only current ECG and 39 patients had both baseline and current ECGs. Heart rate, QT interval and corrected QT (QTc) interval, Tp-e, Tp-e/QT, Tp-e/QTc values on the ECGs were measured by a cardiologist. Results: In the acromegaly patients with both baseline and current ECGs, heart rate, QRS duration, Tp-e, and Tp-e/QTc ratio were decreased. The decrease in these arrhythmia parameters was similar in active and remission patients. Compared to the control group, in acromegaly patients with only baseline ECG, heart rate, QTc interval, Tp-e, Tp-e/QT, and Tp-e/QTc were decreased. Conclusion: Ventricular arrhythmia parameters improve with treatment in patients with acromegaly. The decrease in ventricular arrhythmia parameters was similar in active and remission patients, which can be explained by the significant decrease in IGF-1 levels compared to the time of diagnosis, even in patients with active disease.

Mesenteric Ischemia.

Mesenteric ischemia occurs when perfusion of the visceral organs fails to meet normal metabolic requirements and subsequently results in abdominal symptoms such as diffuse postprandial pain, peritonitis, food fear, and weight loss. While generally divided into acute and chronic manifestations, mesenteric ischemia is commonly misdiagnosed at initial presentation due to the significant overlap with symptoms of other abdominal pathologies. Prompt recognition and diagnosis, mesenteric revascularization, and critical care management remain the mainstay of treatment in these patients for optimal outcomes. This review will highlight acute versus chronic mesenteric ischemia, their etiology, diagnostic criteria, treatment options, and will emphasize the joint role of the gastrointestinal and vascular surgeon in the timely management of this condition to prevent devastating outcomes.

Best practices in robotic magnetic navigation-guided catheter ablation of cardiac arrhythmias, a position paper of the Society for Cardiac Robotic Navigation.

Preamble: Robotic magnetic navigation (RMN)-guided catheter ablation (CA) technology has been used for the treatment of cardiac arrhythmias for almost 20 years. Various studies reported that RMN allows for high catheter stability, improved lesion formation and a superior safety profile. So far, no guidelines or recommendations on RMN-guided CA have been published. Purpose: The aim of this consensus paper was to summarize knowledge and provide recommendations on management of arrhythmias using RMN-guided CA as treatment of atrial fibrillation (AF) and ventricular arrhythmias (VA). Methodology: An expert writing group, performed a detailed review of available literature, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Recommendations on RMN-guided CA are presented in a guideline format with three levels of recommendations to serve as a reference for best practices in RMN procedures. Each recommendation is accompanied by supportive text and references. The various sections cover the practical spectrum from system and patient set-up, EP laboratory staffing, combination of RMN with fluoroscopy and mapping systems, use of automation features and ablation settings and targets, for different cardiac arrhythmias. Conclusion: This manuscript, presenting the combined experience of expert robotic users and knowledge from the available literature, offers a unique resource for providers interested in the use of RMN in the treatment of cardiac arrhythmias.

Stereotactic arrhythmia radioablation (STAR) opens a new era in the treatment of arrhythmias?

Tachyarrhythmias are common cardiovascular emergencies encountered in clinical practice. Among these, atrial fibrillation (AF) and ventricular tachycardia (VT) pose significant hazards due to their prevalence and severity. Initially, non-invasive pharmacological antiarrhythmic interventions were the primary treatment modality; however, due to their limited control rates and side effects, invasive therapies have been introduced in recent years. These include catheter ablation, alcohol ablation, cardiac implantable electronic devices, and heart transplantation. Nonetheless, for some patients, invasive treatments do not offer a definitive cure for arrhythmias and carry the risk of recurrence, especially with AF and VT, where the relapse rates are high and the treatment for VT is correlated with the type of tachycardia present. Currently, novel non-invasive treatment methods are emerging, with stereotactic radioablation therapy becoming an effective alternative for the management of refractory tachyarrhythmias. This review provides an overview of the application background of Stereotactic Arrhythmia Radioablation (STAR) therapy and promising results from its use in animal models and clinical applications.

Caught in the Act: A Detailed Analysis of Cardiac Event Monitoring in a Cohort of Pediatric and ACHD Patients.

BACKGROUND: Event monitors are being increasingly used in pediatric and adult congenital heart disease (ACHD) patients for arrhythmia evaluation. Data on their diagnostic yield are limited. OBJECTIVES: To evaluate the diagnostic yield of event monitors, patient characteristics associated with critical events, and clinical response to events. METHODS: We retrospectively assessed event monitors prescribed to patients at our institution's Heart Center from 2017 to 2020. Thirty-day event monitor tracings were reviewed by an electrophysiologist (EP) to identify critical events defined as supraventricular tachycardia (SVT, re-entrant, atrial tachycardia, atrial flutter, and atrial fibrillation), ventricular tachycardia (VT), atrioventricular block, and pauses greater than 3 s. Patient characteristics and treatment data were collected. Characteristics associated with events were assessed using multivariable logistic regression. Trends in monitor prescription over time, diagnostic yield, and clinical response to events were analyzed. RESULTS: 204/2330 (8.8%) event monitors had EP-confirmed critical events. Critical events included SVT (51.5%), VT (38.5%), atrioventricular block (4%), and pauses (6%). 129/198 (65%) patients with critical events underwent treatment. Event monitoring usage increased by 52% between 2017 and 2020 (p < 0.0001). Complex CHD (OR 2.1, 95% CI 1.3-3.4, p = 0.004), cardiomyopathy (OR 2.9, 95% CI 1.5-4.8, p < 0.001), and EP-ordered monitors (OR 1.6, 95% CI 1.2-2.1, p = 0.001) were more highly associated with critical events. CONCLUSION: Event monitor use is common, and critical events were captured in 8.8% of patients. The majority of patients with critical events underwent treatment. Factors associated with critical events include EPs as ordering providers, complex CHD, and cardiomyopathy.