Clinical and functional characteristics of children with ventricular arrhythmias depending on the ectopic focus localization

Aim. To determine the prevalence of ventricular arrhythmias (VA) among children with cardiac arrhythmias and to assess the clinical, functional, and electrophysiological characteristics of VA, depending on the localization of the ectopic focus.Methods. The study included 260 children, 153 (58,8%) boys, the mean age of patients was 13.4±3.1years. Based on clinical and anamnestic data, ECG, Holter monitoring, echocardiography, dosed exercise test, invasive electrophysiological study (EPS), radiofrequency ablation (RFA) a comparative assessment of the clinical and functional features of the most frequently diagnosed localizations of the ectopic focus in children with VA was carried out according to the data of invasive EPS, RFA.Results. According to invasive EPI, the most frequent localization of VA in children is the right ventricle outflow tract (RVOT) - 144 (55%), less often - the Valsalva sinuses - 52 (20%) and the RV free wall - 47 (18%). In most cases (255 children, 98%) there was a focal arrhythmia (trigger activity). The localization of ectopia in the RV free wall is characterized by the predominance of single ventricular premature beats (VPB) or in combination with a paired VPB (78,7%) and polymorphism of ventricular complexes (30%). The peculiarity of ventricular tachycardia in this localization is its stable character (17,0%) and low heart rate in volleys (idioventricular rhythm) (12,8%). When the focus was localized in the RVOT, as well as when it was localized in the RV free wall, single VPB or in combination with paired VPB prevailed (84,7%), but polymorphism of ventricular complexes was less often observed (10,4%). Differences in myocardial contractility at the sinus rhythm in right ventricular arrhythmias were revealed. Thus, the ejection fraction at the localization of the lesion in the RV free wall was significantly lower than in the RVOT (63.4±5.5% and 65.8±5.9%, respectively; p<0.01). Hemodynamic significance is characteristic for RV arrhythmias (21.3% and 16.0% of patients) and was practically not observed at the left-sided localization of the arrhythmogenic focus (3.8%; p<0.01). VA in patients without structural heart disease, regardless of the localization of the arrhythmic focus in children, is asymptomatic and is detected, in most cases, within the framework of clinical examination 206 patients, 79.2%. The prevalence of syncope in children with idiopathic VA is 15.8% (41 patients), and in most cases, they are of vaso-vagal origin. In most children (178, 70%), idiopathic VA is dependent on the level of parasympathetic influences on the heart, disappearing or significantly decreasing during exercise, which is revealed during the stress test confirming the high role of autonomic influences on the regulation of heterotopic rhythm in children with VA.Conclusion. VA is a common arrhythmia in children. Depending on the localization of the arrhythmogenic focus, characteristic features of the structure and density of the heart, as well as differences in the contractile function of the myocardium on the sinus rhythm and on the ectopic complex were revealed.

Pediatric arrhythmology is an important direction of pediatric cardiology

Проблема сердечно-сосудистых заболеваний на протяжении последних трех десятилетий в мире остается одной из наиболее актуальных для здравоохранения.

Predictive value of electrophysiological study for risk stratification of ventricular tachyarrhythmias in patients with non-ischemic cardiomyopathy and chronic systolic heart failure

A systematic review and meta-analysis of studies providing information on the use of intracardiac electrophysiological study (EPS) to stratify the risk of ventricular tachyarrhythmia (VT) in patients with non-ischemic chronic heart failure with low left ventricle ejection fraction (HFrEF). Relevant publications were searched until 20.01.2021 by two independent researchers in major search engines, electronic archives of clinical research, and open access preservatives repository. The end point considered was an episode of sudden cardiac death or sustained paroxysm of VT, or an appropriate electrotherapy of an implanted cardiac defibrillator. Ten clinical trials with 608 relevant patients (mean age: 51.5 ± 12 years; mean left ventricle EF: 26.8±8.5%, NYHA class: I - 17.7%; II - 33.7%; III - 35.9%, IV - 12.7%) were selected. The end point was registered in 92 patients (15.1%): in 47 patients (43.9%) with previously induced VT during EPS and in 45 patients (8.9%) without VT. The diagnostic odds ratio was 5.57 (2.27-13.63). The combined sensitivity and specificity of the EPS were 42% (26-61%) and 88% (83-92%) respectively. The results indicate the potential of EPS to stratify the arrhythmic risk in patients with non-ischemic HFrEF.

Intraprocedural electrocardiographic imaging of a hemodynamically unstable ischemic ventricular tachycardia originating from the interventricular septum

The article presents a clinical case of catheter treatment of hemodynamically unstable ischemic ventricular tachycardia originating from interventricular septum using electrocardiographic imaging and high-density endocardial substrate mapping.

Clinical features and antiarrhythmic therapy in patients with catecholaminergic polymorphic ventricular tachycardia

Aims. To evaluate the long-term efficacy of antiarrhythmic therapy in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT).Methods. CPVT was diagnosed in 11 patients between the ages of 3-12 years with a minimum follow-up of 10 years. The data analyzed was obtained from existing medical records that included symptoms, family screenings, treadmill tests, electrocardiography, echocardiography, implanted cardioverter-defibrillator data (ICD), and medical treatments.Results. Cardiac events were registered in 75% of patients on beta-blocker therapy. Supraventricular arrhythmias such as atrial and atrioventicular nodal tachycardia, atrial fibrillation and atrial flutter were detected using various ECG diagnostic methods in all patients, which is significantly higher than reported in similar studies. A combination of anti-arrhythmic therapy and beta-blocker treatment reduced the number of cardiac events by 50% as compared to only beta-blocker treatment.Conclusion. Multiple supraventricular arrhythmias have a high prevalence in patients with CPVT and can trigger ventricular arrhythmia. Combined antiarrhythmic therapy is effective because it prevents cardiac events in patients with CPVT. Combined antiarrhythmic therapy improves the prognosis of patients with CPVT and may help to avoid or postpone ICD implantation.

Magnetic resonance imaging diagnostic potential in “idiopathic” ventricular arrhythmias in children

The study aims to assess the role of magnetic resonance tomography (MRI) in identifying the substrate of “idiopathic” ventricular arrhythmias in pediatric patients.Methods. One hundred and seven children with “idiopathic” ventricular arrhythmias were enrolled. All patients underwent MRI on a high-field Magnetom Trio A Tim (Siemens) tomograph with a magnetic field induction of 3.0 T.Results. According to MRI data, dilated ventricles and/or a decreased ejection fraction were found in 55 (51%) patients. Based on structural abnormalities of the myocardium patients were divided into 2 groups: group 1 “normal”, without abnormalities, (69 (64.5%) children); group 2 - “fibrosis”, fibrotic changes were detected on late gadolinium enhancement (38 (35.5%) patients). Significant differences of indexed MR-indicators in these two groups were not found. However, in the “fibrosis” group, biventricular dysfunction occurred significantly more often than in the “normal” group, respectively (14 (37%) and 9 (13%) (p = 0.006)).Conclusion. MRI is important in assessing structural changes in pediatric patients with ventricular arrhythmias, and the combination of MRI results with clinical and electrophysiological data can significantly affect the change in management and treatment strategy in pediatric patients.

Historical aspects of the development of the theory of ventricular preexcitation

The paper conducts a review of the literature on the problem of cognition of the nature of the syndrome of preexcitation of the ventricles. Despite the data of early publications, supporting the theory of bypass as a substrate of preexcitation, disputes and searches for the nature of this clinical syndrome continued until 1970, until surgical procedures and the first electrophysiological studies confirmed the “bypass” of the normal conducting system. Article describes the chronology of events related to the understanding of the syndrome, which bears the name Wolff-Parkinson-White.

Experience in the management of infants with multifocal atrial tachycardia

Purpose. To study the clinical course of multifocal atrial tachycardia (MAT) and to evaluate the effectiveness of antiarrhythmic therapy (AAT) in patients with onset of arrhythmia before the age of 1 year.Methods. The study included 15 children with primary registration of MAT at the age of 2.04±2.27 months, 4 of them - in utero. The follow-up period was 35.9±26.9 months (Me 29 months). All patients underwent laboratory monitoring, 12-lead ECG recording, 24-hour ECG monitoring, echocardiography at baseline and during time of observation.Results. Tachycardia was persistent in 80% of patients. Tachycardia-induced cardiomyopathy (TIC) was present in 7 (46%) patients. Structural heart disease was detected in 6 patients. The average heart rate at the onset of the disease was 157.9±23.78 bpm, the maximum - 256.7±35.84 bpm. Fourteen (93.3%) children received AAT. Seven patients were prescribed propranolol first, 6 - amiodarone, 1 - digoxin. Monotherapy was effective in 2 patients. Combined AAT was used in 12 patients, including three children with three drugs combination. No benefits were found for any of the drugs combinations. Stable sinus rhythm at the time of discharge was observed in 4 (28,6%) patients, sinus rhythm with atrial ectopic activity was registered in 2 of them; criteria for normosystole were achieved in 7 patients; in one child with TIC daytime tachysystole persisted despite three-component AAT, but echocardiography parameters improved. Arrhythmia was disappeared in 13 (86.6%) patients; the duration of arrhythmia in them from 1 to 15 months, duration of AAT - 1 ±7.5 months (Me 9.5 months). MAT persists in two patients with structural heart disease. One patient underwent radiofrequency ablation at the age of 5, with no effect. One patient had side effects from therapy that required correction. There were no lethal outcomes.Conclusion. MAT with a debut at the age of 1 year with timely prescribed treatment has a favorable course and a good prognosis, but the probability of AAT resistance is high. These cases require a long-term selection of therapy using various combinations of antiarrhythmic drugs. Heart rate control strategy can be sufficient to prevent the development of TIC.

Remote magnetic navigation ablation of incisional atrial flutters in adolescent with a giant right atrium after surgical correction of tetralogy of Fallot and Ebstein's anomaly

We describe a clinical case of a 17-years-old adolescent with congenital heart disease after three open-heart surgery procedures for correction of tetralogy of Fallot and Ebstein's anomaly who presented with drug-resistant, persistent atrial flutter and giant right atrium (8.2 cm by transthoracic echocardiography). The successful ablation procedure of the two types of incisional atrial flutter was performed using remote magnetic navigation without any complications with 2.2 minutes of fluoroscopy. The patient remained free of any arrhythmias without antiarrhythmic drugs during 12 months of follow-up with a reduction of right atrium size (5.8 cm by transthoracic echocardiography).

Sergei P. Golitsyn - 70 years

Всероссийское общество специалистов по клинической аритмологии, электрофизиологии и электрокардиостимуляции, редакционная коллегия журнала «Вестник аритмологии» и трудовой коллектив ФГБУ «НМИЦ кардиологии» МЗ РФ поздравляют с юбилеем профессора Сергея Павловича Голицына; 2 декабря 2021 года ему исполнилось 70 лет.