Early Repolarization Syndrome Research Articles

Out of Hospital Cardiac Arrest from Malignant Early Repolarization Syndrome

Out of Hospital Cardiac Arrest from Malignant Early Repolarization Syndrome

Primary Electrical Heart Disease-Principles of Pathophysiology and Genetics.

Primary electrical heart diseases, often considered channelopathies, are inherited genetic abnormalities of cardiomyocyte electrical behavior carrying the risk of malignant arrhythmias leading to sudden cardiac death (SCD). Approximately 54% of sudden, unexpected deaths in individuals under the age of 35 do not exhibit signs of structural heart disease during autopsy, suggesting the potential significance of channelopathies in this group of age. Channelopathies constitute a highly heterogenous group comprising various diseases such as long QT syndrome (LQTS), short QT syndrome (SQTS), idiopathic ventricular fibrillation (IVF), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and early repolarization syndromes (ERS). Although new advances in the diagnostic process of channelopathies have been made, the link between a disease and sudden cardiac death remains not fully explained. Evolving data in electrophysiology and genetic testing suggest previously described diseases as complex with multiple underlying genes and a high variety of factors associated with SCD in channelopathies. This review summarizes available, well-established information about channelopathy pathogenesis, genetic basics, and molecular aspects relative to principles of the pathophysiology of arrhythmia. In addition, general information about diagnostic approaches and management is presented. Analyzing principles of channelopathies and their underlying causes improves the understanding of genetic and molecular basics that may assist general research and improve SCD prevention.

Correction of Ito in human induced pluripotent stem Cell–derived cardiomyocyte carrying DPP6 mutation in early repolarization syndrome by CRISPR/Cas9 genome editing

Early repolarization syndrome (ERS) is defined as occurring in patients with early repolarization pattern who have survived idiopathic ventricular fibrillation with clinical evaluation unrevealing for other explanations. The pathophysiologic basis of the ERS is currently uncertain. The objective of the present study was to examine the electrophysiological mechanism of ERS utilizing induced pluripotent stem cells (iPSCs) and CRISPR/Cas9 genome editing. Whole genome sequencing was used to identify the DPP6 (c.2561T > C/p.L854P) variant in four families with sudden cardiac arrest induced by ERS. Cardiomyocytes were generated from iPSCs from a 14-year-old boy in the four families with ERS and an unrelated healthy control subject. Patch clamp recordings revealed more significant prolongation of the action potential duration (APD) and increased transient outward potassium current (Ito) (103.97 ± 18.73 pA/pF vs 44.36 ± 16.54 pA/pF at +70 mV, P < 0.05) in ERS cardiomyocytes compared with control cardiomyocytes. Of note, the selective correction of the causal variant in iPSC-derived cardiomyocytes using CRISPR/Cas9 gene editing normalized the Ito, whereas prolongation of the APD remained unchanged. ERS cardiomyocytes carrying DPP6 mutation increased Ito and lengthen APD, which maybe lay the electrophysiological foundation of ERS.

Clinical characteristics of electrical storm in patients with early repolarization syndrome

BackgroundEarly repolarization syndrome (ERS) is an idiopathic ventricular fibrillation (VF) associated with inferolateral J waves. While electrical storm (ES) in ERS is not rare, their characteristics and risk factors are not fully understood. ObjectiveThis study aimed to clarify the significance of ES in ERS. MethodsWe evaluated 44 patients with ERS who experienced VF/sudden cardiac death or arrhythmic syncope. We assessed clinical characteristics to identify the risk factors for ES. ResultsIn total, 13 patients (30%) experienced ES (ES group). Of these, 11 patients (85%) experienced ES during the acute phase of initial VF episodes and 2 patients (2%) experienced ES during follow-up. VF associated with ES occurred during therapeutic hypothermia in 6 of 13 patients (46%). The J-wave voltage during therapeutic hypothermia was higher in the ES group than that in the patients without ES. Isoproterenol was used in 5 patients (38%), which decreased J-wave voltage and relieved ES. Among the clinical markers, shorter QT and QTp intervals (the interval from QRS onset to the peak of T wave), pilsicainide-induced ST elevation, and high scores on the Shanghai Score System were associated with ES. Although pilsicainide induced ST elevation in 6 of 34 patients (18%), spontaneous Brugada electrocardiographic patterns did not appear to be associated with VF. Therapeutic hypothermia was also a risk factor for acute phase ES. ConclusionPatients with ERS in the ES group frequently had short QT and QTp intervals, pilsicainide-induced ST elevations, and high Shanghai Score System scores. Therapeutic hypothermia was also associated with acute phase ES.

Assessment of Sudden Cardiac Death Risk in Pediatric Primary Electrical Disorders: A Comprehensive Overview

Sudden cardiac death (SCD) in children is a devastating event, often linked to primary electrical diseases (PED) of the heart. PEDs, often referred to as channelopathies, are a group of genetic disorders that disrupt the normal ion channel function in cardiac cells, leading to arrhythmias and sudden cardiac death. This paper investigates the unique challenges of risk assessment and stratification for channelopathy-related SCD in pediatric patients—Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, idiopathic ventricular fibrillation, long QT syndrome, Anderson–Tawil syndrome, short QT syndrome, and early repolarization syndrome. We explore the intricate interplay of genetic, clinical, and electrophysiological factors that contribute to the complex nature of these conditions. Recognizing the significance of early identification and tailored management, this paper underscores the need for a comprehensive risk stratification approach specifically designed for pediatric populations. By integrating genetic testing, family history, and advanced electrophysiological evaluation, clinicians can enhance their ability to identify children at the highest risk for SCD, ultimately paving the way for more effective preventive strategies and improved outcomes in this vulnerable patient group.

Abstract 11956: Arumenamide-787 Suppresses Arrhythmogenesis Associated With the J Wave Syndrome as Well as Hypothermia

Background: The J-wave syndromes (JWS), comprised of Brugada (BrS) and early repolarization syndromes (ERS), increase the risk of life-threatening ventricular arrhythmias in patients resulting in sudden cardiac death. There are limited therapeutic strategies to treat these life-threatening conditions. Present management is via an implantable cardioverter defibrillator and/or medication, including quinidine. However, these treatments may have serious side-effects. Thus, novel therapies are needed to treat JWS. In this study, we investigate the effects of ARumenamide-787 (AR-787) in suppressing the electrocardiographic and arrhythmic manifestations of JWS and hypothermia. Methods: We studied the effects of AR-787 on sodium current (I Na ) and the delayed-rectifier potassium current (I Kr ) in HEK-293 cells stably expressing the α- and β1-subunits of the cardiac (Na V 1.5) sodium channel or the hERG channel. In addition, we studied its effect on the transient outward potassium current (I to ) and calcium current (I Ca ) from dissociated canine ventricular myocytes, along with action potentials and ECG from coronary-perfused right (RV) and left (LV) ventricular wedge preparations. The I to agonist, NS5806, I Ca blocker, verapamil, and sodium current (I Na ) blocker, ajmaline, to induce the electrocardiographic and arrhythmic manifestations of JWS (prominent J waves/ST segment elevation, phase 2 reentry, and polymorphic VT/VF) in right and left canine ventricular wedge preparations. Results: AR-787 exerted pleiotropic effects on the cardiac ion channels. The predominant effect was an inhibition of I to and enhancement of I Na , with subtle effects to inhibit the I Kr and augment I Ca . AR-787 diminished the electrocardiographic J wave and prevented and/or suppressed all arrhythmic activity in canine RV and LV experimental models of BrS, ERS and hypothermia. We observed no arrhythmogenic effects of AR-787 on I Kr . Conclusions: Our findings point to AR-787 as a promising candidate for the pharmacologic treatment of JWS and hypothermia. AR-787 suppresses the electrocardiographic and arrhythmic manifestations of JWS and hypothermia without significant prolongation of the QT interval, as with the classic BrS drug, quinidine.

Future direction of substrate-based catheter ablation in Brugada syndrome and other inherited primary arrhythmia syndromes: Systematic review and meta-analysis.

Inherited Primary Arrhythmias Syndromes (IPAS), especially Brugada syndrome (BrS), have been associated with arrhythmogenic substrates that can be targeted through ablation. This meta-analysis evaluated the outcomes of catheter ablation (CA) in different types of IPAS based on procedural guidance and location. A systematic search was conducted across multiple databases to identify studies reporting on ventricular arrhythmia (VA) events before and after CA in IPAS, including BrS, Long-QT syndrome (LQTS), Early repolarization syndrome (ERS), and Idiopathic ventricular fibrillation (IVF). The primary outcomes were VA recurrence and VA burden, evaluated through conditional subgroup analysis. Procedural data were collected as secondary outcomes. A total of 21 studies involving 584 IPAS patients who underwent CA were included. Following a mean follow-up duration of 33.5 months, substrate-based ablation demonstrated efficacy in reducing VA recurrence across all types of IPAS [RR 0.23; 95% CI (0.13-0.39); p < .001; I 2 = 74%]. However, activation guidance ablation was found to be effective only in IVF cases. Although recurrences still occurred, CA was successful in reducing VA burden [MD -4.70; 95% CI (-6.11-(-3.29); p < .001; I 2 = 74%]. The mean size of arrhythmogenic substrate was 15.70 cm2 [95% CI (12.34-19.99 cm2)], predominantly distributed in the epicardial right ventricular outflow tract (RVOT) in BrS cases and LQTS [Proportion 0.99; 95% CI (0.96-1.00) and Proportion 0.82; 95% CI ( 0.59-1.00), respectively]. Substrate-based CA has demonstrated effective prevention of VA and reduction in VA burden in IPAS cases.

Significance of left posterior extension of early repolarization in patients with J-wave syndrome

J waves in the inferior or lateral leads are characteristic electrocardiographic (ECG) changes in patients with early repolarizationsyndrome (ERS). However, the presence of J waves in the left posterior region has not yet been evaluated. The purpose of this study was to clarify the significance of J waves in the posterior left ventricle using leads V7-V9 and a body surface mapping (BSM) system. Forty patients diagnosed with ERS were included. All patients exhibited J waves in either the contiguous inferior, lateral, or posterior leads. We evaluated the incidence of J waves in the inferolateral and posterior leads using a 15-lead ECG with synthesized V7-V9 and an 87-lead BSM. Additionally, we assessed the arrhythmogenicity of the posterior regions based on the morphology ofthe premature ventricular complexes (PVCs) associated with ventricularfibrillation (VF). J waves were observed in the lateral, inferior, and posterior leads of 26 (65%), 31 (78%), and 39 (97%) patients, respectively. J waves were found only in the posterior leads of 5 patients. BSM was evaluated in 9 patients, all of whom exhibited a positive area on the posterior region. PVCs associated with VF were recorded in 5 patients. Among patients with inferolateral and posterior J waves, all except 1 patient who displayed left bundle branch block morphology showed PVCs originating from the posterior left ventricular region. Posterior J waves are common in ERS patients. This abnormality can be detected using leads V7-V9 and the BSM system and may be associated with arrhythmogenesis.

Early Repolarization Syndrome Leading to Recurrent Cardiac Arrest ina Young Active Duty Patient.

A previously healthy, active duty 37-year-old male experienced recurrent cardiac arrests because of ventricular fibrillation and polymorphic ventricular tachycardia. Initial evaluation did not reveal a clear ischemic, structural, toxic, or metabolic cause. Close monitoring of telemetry before his third cardiac arrest revealed the cause to be early repolarization syndrome (ERS). In this case, we review the diagnosis, epidemiology, and prognostic significance of early repolarization pattern as it relates to ERS. We also discuss acute and long-term treatment strategies for patients with ERS.

Subepicardial Cardiomyopathy: A Disease Underlying J-Wave Syndromes and Idiopathic Ventricular Fibrillation.

Brugada syndrome (BrS), early repolarization syndrome (ERS), and idiopathic ventricular fibrillation (iVF) have long been considered primary electrical disorders associated with malignant ventricular arrhythmia and sudden cardiac death. However, recent studies have revealed the presence of subtle microstructural abnormalities of the extracellular matrix in some cases of BrS, ERS, and iVF, particularly within right ventricular subepicardial myocardium. Substrate-based ablation within this region has been shown to ameliorate the electrocardiographic phenotype and to reduce arrhythmia frequency in BrS. Patients with ERS and iVF may also exhibit low-voltage and fractionated electrograms in the ventricular subepicardial myocardium, which can be treated with ablation. A significant proportion of patients with BrS and ERS, as well as some iVF survivors, harbor pathogenic variants in the voltage-gated sodium channel gene, SCN5A, but the majority of genetic susceptibility of these disorders is likely to be polygenic. Here, we postulate that BrS, ERS, and iVF may form part of a spectrum of subtle subepicardial cardiomyopathy. We propose that impaired sodium current, along with genetic and environmental susceptibility, precipitates a reduction in epicardial conduction reserve, facilitating current-to-load mismatch at sites of structural discontinuity, giving rise to electrocardiographic changes and the arrhythmogenic substrate.

Trigger and Substrate Mapping and Ablation for Ventricular Fibrillation in the Structurally Normal Heart.

Sudden cardiac death (SCD) represents approximately 50% of all cardiovascular mortality in the United States. The majority of SCD occurs in individuals with structural heart disease; however, around 5% of individuals have no identifiable cause on autopsy. This proportion is even higher in those <40 years old, where SCD is particularly devastating. Ventricular fibrillation (VF) is often the terminal rhythm leading to SCD. Catheter ablation for VF has emerged as an effective tool to alter the natural history of this disease among high-risk individuals. Important advances have been made in the identification of several mechanisms involved in the initiation and maintenance of VF. Targeting the triggers of VF as well as the underlying substrate that perpetuates these lethal arrhythmias has the potential to eliminate further episodes. Although important gaps remain in our understanding of VF, catheter ablation has become an important option for individuals with refractory arrhythmias. This review outlines a contemporary approach to the mapping and ablation of VF in the structurally normal heart, specifically focusing on the following major conditions: idiopathic ventricular fibrillation, short-coupled ventricular fibrillation, and the J-wave syndromes-Brugada syndrome and early-repolarization syndrome.

PO-04-053 OUT-OF-HOSPITAL CARDIAC ARREST ASSOCIATED WITH EARLY REPOLARIZATION

Early repolarization syndrome (ERS) is characterized by J-point elevation presenting as slurring or notching of the terminal part of the QRS complex. Of the several congenital and acquired disorders that encompass J-wave syndromes, ERS has been linked to increased risk of developing polymorphic VT and idiopathic VF that can lead to sudden cardiac death. To describe a patient who presented after a cardiac arrest with initial ECG criteria consistent with Type III ERS who recieved a dual-chamber ICD. n/a We present a case of a 42-year-old man without any prior history that presented to the emergency room after successful resuscitation from out-of-hospital cardiac arrest due to VF. After noticing agonal respiration during early morning hours, his wife called emergency medical services (EMS) and promptly performed cardiopulmonary resuscitation. Upon arrival, EMS found the patient to be in VF. He was shocked once by an automatic external defibrillation leading to ROSC with restoration of sinus rhythm. In the ED, his initial vitals were 122/93 mmHg, 104 bpm, 95% oxygen saturation on room air, and temperature of 36.4 °C. He denied any family history of sudden cardiac death. Wife reported prior history of nocturnal agonal respirations. Initial diagnostic work-up was significant for a leukocytosis of 19,000 and serial high-sensitivity cardiac troponins of 130, 305, and 364 with a 0/3-hour delta change of 234. A12-lead ECG upon presentation is shown in Figure 1 without previous ECGs available for comparison. An emergent coronary angiography was performed which revealed no significant coronary obstruction or anomaly. With both his ECG findings and a Shanghai Score of 7, a diagnosis of Type III ERS was highly suspected. Further diagnostic testing included a TTE showing left ventricular dysfunction with an ejection fraction of 40-45%. CMR showed no delayed gadolinium enhancement. Ultimately, a dual-chamber ICD was implanted during the admission. Follow-up ECGs revealed resolution of slurred terminal QRS complexes. He was discharged on beta blocker and low-dose losartan with close outpatient follow-up with electrophysiology. ECG changes of ERS can be dynamic and may sometimes be concealed, particularly in the setting of an out-of-hospital cardiac arrest. It is important to identify early repolarization patterns due to the adverse prognostic significance especially of Type III ERS which is associated with the highest level of risk for development of malignant arrhythmia.

Functional identification of hot-spot mutations in cardiac calcium channel genes associated with the J wave syndromes.

J wave syndrome (JWS) is an inherited cardiac channelopathy associated with malignant ventricular arrhythmias and sudden cardiac death (SCD), which comprises early repolarization syndrome and Brugada syndrome. Here, we explore the association between variants in the L-type calcium channel gene subunits, α1C (CACNA1C) and β2b (CACNB2b), and the JWS phenotype. Using next-generation genetic sequencing of 402 JWS probands and their family members, we identified a CACNA1C-G37R (p.Gly37Arg) mutation in five individuals in four families, two of which had a family history of SCD as well as a CACNB2b-S143F (p.Ser143Phe) mutation in seven individuals in three families, two of which had a family history of SCD. The variants were located in exon 2 in CACNA1C and exon 5 in CACNB2b; both were in highly conserved amino acid residues. Whole-cell patch-clamp results showed that compared with the wild-type group, calcium current density of CACNB2b-S143F and CACNA1C-G37R were significantly lower displaying a dominant-negative effect. Our findings provide further support for the hypothesis that variants in CACNA1C and CACNB2b are associated with JWS. The results suggest that mutations in these two genes lead to loss-of-function of the cardiac calcium channel current warranting their inclusion in genetic screening protocols. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

The value of the 12-lead electrocardiogram in the prediction of sudden cardiac death.

Sudden cardiac death (SCD) can be caused by several clinical conditions, overt or misconceived, which recognize different pathophysiologies determining the development of fatal arrhythmic events. In the various forms of structural heart disease such as ischaemic heart disease, cardiomyopathies (e.g. hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy), channelopathies (e.g. long-QT syndrome, congenital short QT, Brugada syndrome, early repolarization (ER) syndrome, and idiopathic ventricular fibrillation) but also in the apparently healthy subject, the 12-lead electrocardiogram (ECG) has proved, over the years, to be a reliable and readily available method for stratifying the risk of adverse arrhythmic events and consequently SCD. Several electrocardiographic markers have been shown to be associated with adverse outcomes in different types of patients. Although with different sensitivity and specificity in each clinical condition, depolarization abnormalities, such as QRS fragmentation, Q waves, QRS duration, left posterior fascicular block, low QRS voltage, and left ventricular hypertrophy and similarly repolarization abnormalities as ER pattern, T wave alternans, QT interval, and QT dispersion, have shown significant efficacy in predicting SCD. Despite the advancement of techniques especially in the field of imaging, the correct interpretation of the 12-lead ECG remains, therefore, an effective tool for assessing the possible prognostic outcome in terms of arrhythmic risk and SCD in different types of patients.

Ablation of ventricular arrhythmias in cardiogenetic diseases.

Sudden cardiac death is a leading cause of mortality, claiming millions of lives every year. Recent advances in cardiac arrhythmia mapping have demonstrated that the ventricular epicardial region has a critical arrhythmogenic role in some inherited cardiogenetic diseases. Historically, electroanatomic abnormalities have been identified in the ventricular epicardium of patients with arrhythmogenic right ventricular cardiomyopathy. More recently, epicardial pathological substrates have been identified also in electrical disease (Brugada syndrome, early repolarization syndrome) and currently in long QT syndrome. In light of these findings, the epicardial area has emerged as an important determinant in sudden cardiac death-related cardiomyopathies.

Vagal response is involved in the occurrence of ventricular fibrillation in patients with early repolarization syndrome

Patients with early repolarization syndrome (ERS) and Brugada syndrome (BruS) have comparable clinical symptoms. In both conditions, ventricular fibrillation (VF) is experienced often near midnight or in the early morning hours when the parasympathetic tone is augmented. However, differences between ERS and BruS regarding the risk of VF occurrence have recently been reported. The role of vagal activity remains especially unclear. The study's goal was to determine the relationship between VF occurrence and autonomic nervous activity in patients with ERS and BruS. We enrolled 50 patients with ERS (n = 16) and BruS (n = 34) who received implantable cardioverter-defibrillators. Of these, 20 patients (5 ERS and 15 BruS) experienced VF recurrence (recurrent-VF group). We investigated baroreflex sensitivity (BaReS) with the phenylephrine method and heart rate variability (HRV) using a Holter ECG in all patients to estimate autonomic nervous function. In both patients with ERS and BruS, there was no significant difference in HRV between the recurrent-VF and the non-recurrent-VF groups. However, in patients with ERS, BaReS was significantly higher in the recurrent-VF group than in the non-recurrent-VF group (p = 0.03); this difference was not evident in BruS patients. High BaReS was independently associated with VF recurrence in patients with ERS, according to Cox proportional hazards regression analyses (HR: 1.52; 95% CI: 1.031-3.061; p = 0.032). Our findings suggest that in patients with ERS, an exaggerated vagal response, as represented by increased BaReS indices, may be involved in the risk of VF occurrence.

Sudden Cardiac Death Risk Stratification of the Early Repolarization Syndrome: An Updated Review of the Literature.

Early repolarization syndrome (ERS), once thought to be innocuous, has now been shownto be responsible for ventricular arrythmias and sudden cardiac death occurrence. This review will help the clinicianto identify the patients who are most at risk for arrhythmias,so that they can adopt a preventive or secondary treatment approach, either of which is still poorly defined. Patients at high risk are found to be particularly young men, with a personal or family history of syncope or sudden death, who have an inferolateral ER on the electrocardiogram, more elevated J-point, longer J-wave duration and wider J angle, a horizontal or descending ST segment, lower T/R ratio, and small and/or inverted waves. The association with a structural heart disease or another channelopathy potentiates this arrhythmic risk. Taken together, these parameters allow prediction of the malignancy of ER pattern with a certain reliability. Further research is however needed to develop concrete risk stratification algorithms and the therapeutic strategies taken in function of it.

Association of Cardiac Electrical Disorders With KCND3 Gene Mutation.

Globally, cardiac channelopathies leading to electrical disorders are responsible for a significant number of sudden cardiac deaths without structural heart disease. Many genes encoding different ion channels in the heart were identified and their impairment was found to be associated with life-threatening cardiac abnormalities. KCND3, one of the genes expressed both in the heart and brain, is reported to have an association with Brugada syndrome, early-onset atrial fibrillation, early repolarization syndrome, and sudden unexplained death syndrome. KCND3 genetic screening could be a promising tool for functional studies for an understanding of the pathogenesis and genetic determinants of the above-mentioned electrical disorders.

The year in cardiovascular medicine 2022: the top 10 papers in arrhythmias.

(A) Comprehensive clinical, electrocardiographic, and genetic overview of the various diseases associated with VA or SCD as reported in the 2022 ESC Guidelines for VA and SCD.1 The VA/SCD Guidelines provide many updated recommendations for the management of patients with congenital heart disease, idiopathic VF, acquired Long QT, Brugada and early repolarization syndrome, as well as catecholaminergic polymorphic VT, and short QT syndrome. (B) From the same Guidelines, an algorithm for the management of sustained monomorphic ventricular tachycardia in patients with chronic coronary artery disease.1 The algorithm also holdsin partfor non-ischaemic pathologies. Note, the new VA/SCD Guidelines promote VT ablation significantly. It may e.g. be performed to ameliorate or avoid ICD therapy, or to enhance resynchronization therapy by ablation of frequent monomorphic PVCs (extrasystolopathy). The trials PARTITA, PAUSE-SCD, and SURVIVE-VT, discussed in the present paper, all strengthen the recommendations for application of catheter ablation.57 (C) Exercise causes downregulation of genes coding intercalated disk proteins, as well as scaffolding and ion channel proteins, both in normal mice and PKP2 conditional knockouts. Consistent with PKP2-dependent muscle mass deficit, cardiac dimensions in human athletes carrying PKP2 mutations were reduced (data not shown), compared with matched controls. Exercise challenges a cardiomyocyte desmosomal reserve which, if impaired genetically (e.g. Plakophilin2 loss), can cause accelerated progression of the cardiomyopathy.3 Reprinted with permission.

НАРУШЕНИЯ РИТМА И ПРОВОДИМОСТИ У ПАЦИЕНТОВ С ЭЛЕКТРОКАРДИОГРАФИЧЕСКИМ ФЕНОМЕНОМ РАННЕЙ РЕПОЛЯРИЗАЦИИ ЖЕЛУДОЧКОВ

The frequency and nature of cardiac arrhythmias and conduction disturbances in children and adolescents with electrocardiographic syndrome of early ventricular repolarization were studied. It has been determined that cardiac rhythm and conduction disturbances in patients with early ventricular repolarization syndrome are quite common, with a predominance of arrhythmias caused by a change in the automatism function of the sinus node and the presence of intraventricular blockades. It was revealed that in children with this electrocardiographic phenomenon, in the vast majority of cases, there are manifestations of the syndrome of connective tissue dysplasia - minor anomalies in the development of the heart – 84.1%, (p &lt; 0.001), and additional chords are most often recorded in the cavity of the left ventricle – 85.6% (p &lt; 0.001), both isolated and in combination with other anomalies and congenital heart defects. It was found that cardiac rhythm and conduction disturbances in patients with electrocardiographic syndrome of early ventricular repolarization are quite common (78.6±1.84%), with a predominance of cases of arrhythmias caused by changes in the automatism function of the sinus node (p &lt; 0.001) and the presence of intraventricular blocks. In children and adolescents with early ventricular repolarization, additional chords are most often recorded (85.6%, (p &lt; 0.001)), both isolated and in combination with other heart anomalies. The data obtained indicate the presence of a relationship between the early ventricular repolarization syndrome and connective tissue dysplasia, which makes it possible to attribute this electrocardiographic syndrome to the conditions associated with this syndrome.