Biventricular / Left Ventricular Pacing in Hypertrophic Obstructive Cardiomyopathy: An Overview

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant inherited genetic disease characterized by compensatory pathological left ventricle (LV) hypertrophy due to sarcomere dysfunction. In an important proportion of patients with HCM, the site and extent of cardiac hypertrophy results in severe obstruction to LV outflow tract (LVOT), contributing to disabling symptoms and increasing the risk of sudden cardiac death (SCD). In patients with progressive and/or refractory symptoms despite optimal pharmacological treatment, invasive therapies that diminish or abolish LVOT obstruction relieve heart failure-related symptoms, improve quality of life and could be associated with long-term survival similar to that observed in the general population. The gold standard in this respect is surgical septal myectomy, which might be supplementary associated with a reduction in SCD. Percutaneous techniques, particularly alcohol septal ablation (ASA) and more recently radiofrequency (RF) septal ablation, can achieve LVOT gradient reduction and symptomatic benefit in a large proportion of HOCM patients at the cost of a supposedly limited septal myocardial necrosis and a 10-20% risk of chronic atrioventricular block. After an initial period of enthusiasm, standard DDD pacing failed to show in randomized trials significant LVOT gradient reductions and objective improvement in exercise capacity. However, case reports and recent small pilot studies suggested that atrial synchronous LV or biventricular (biV) pacing significantly reduce LVOT obstruction and improve symptoms (acutely as well as long-term) in a large proportion of severely symptomatic HOCM patients not suitable to other gradient reduction therapies. Moreover, biV/LV pacing in HOCM seems to be associated with significant LV reverse remodelling

Mid-term echocardiographic follow up of left ventricular function with permanent right ventricular pacing in pediatric patients with and without structural heart disease

BACKGROUND: Chronic right ventricular apical pacing may have detrimental effect on left ventricular function and may promote to heart failure in adult patients with left ventricular dysfunction. METHODS: A group of 99 pediatric patients with previously implanted pacemaker was studied retrospectively. Forty-three patients (21 males) had isolated congenital complete or advanced atrioventricular block. The remaining 56 patients (34 males) had pacing indication in the presence of structural heart disease. Thirty-two of them (21 males) had isolated structural heart disease and the remaining 24 (13 males) had complex congenital heart disease. Patients were followed up for an average of 53 ± 41.4 months with 12-lead electrocardiogram and transthoracic echocardiography. Left ventricular shortening fraction was used as a marker of ventricular function. QRS duration was assessed using leads V(5 )or II on standard 12-lead electrocardiogram. RESULTS: Left ventricular shortening fraction did not change significantly after pacemaker implantation compared to preimplant values overall and in subgroups. In patients with complex congenital heart malformations shortening fraction decreased significantly during the follow up period. (0.45 ± 0.07 vs 0.35 ± 0.06, p = 0.015). The correlation between the change in left ventricular shortening fraction and the mean increase of paced QRS duration was not significant. Six patients developed dilated cardiomyopathy, which was diagnosed 2 months to 9 years after pacemaker implantation. CONCLUSION: Chronic right ventricular pacing in pediatric patients with or without structural heart disease does not necessarily result in decline of left ventricular function. In patients with complex congenital heart malformations left ventricular shortening fraction shows significant decrease

2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death the Task Force for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death of the European Society of Cardiology (ESC) Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC)

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Ventricular Tachycardia Catheter Ablation: Retrospective Analysis and Prospective Outlooks—A Comprehensive Review

Ventricular tachycardia is a potentially life-threatening arrhythmia associated with an overall high morbi-mortality, particularly in patients with structural heart disease. Despite their pivotal role in preventing sudden cardiac death, implantable cardioverter-defibrillators, although a guideline-based class I recommendation, are unable to prevent arrhythmic episodes and significantly alter the quality of life by delivering recurrent therapies. From open-heart surgical ablation to the currently widely used percutaneous approach, catheter ablation is a safe and effective procedure able to target the responsible re-entry myocardial circuit from both the endocardium and the epicardium. There are four main mapping strategies, activation, entrainment, pace, and substrate mapping, each of them with their own advantages and limitations. The contemporary guideline-based recommendations for VT ablation primarily apply to patients experiencing antiarrhythmic drug ineffectiveness or those intolerant to the pharmacological treatment. Although highly effective in most cases of scar-related VTs, the traditional approach may sometimes be insufficient, especially in patients with nonischemic cardiomyopathies, where circuits may be unmappable using the classic techniques. Alternative methods have been proposed, such as stereotactic arrhythmia radioablation or radiotherapy ablation, surgical ablation, needle ablation, transarterial coronary ethanol ablation, and retrograde coronary venous ethanol ablation, with promising results. Further studies are needed in order to prove the overall efficacy of these methods in comparison to standard radiofrequency delivery. Nevertheless, as the field of cardiac electrophysiology continues to evolve, it is important to acknowledge the role of artificial intelligence in both the pre-procedural planning and the intervention itself

Not Just a One-Way: Mahaim Accessory Pathway Concomitantly Supporting Orthodromic Atrioventricular Re-Entrant Tachycardia

Introduction: We report the case of a 41-year-old female with documented narrow QRS tachycardia. During electrophysiological study, both orthodromic and antidromic atrioventricular reentry tachycardia (AVRT) were demonstrated as well as short episodes of pre-excited atrial fibrillation. Programmed atrial stimulation resulted in decremental anterograde conduction on the AP, thus confirming an unexpected Mahaim accessory pathway (AP) diagnosis. Discussion: Limited 3D activation maps of the right atrium during orthoAVRT, respectively, and the right ventricle (RV) during antiAVRT were constructed and helped accurately describe the atrial and ventricular insertion points, which were superposed on the tricuspid ring, confirming the existence of a single short atrio-ventricular right free wall AP. Short atrioventricular APs with anterograde Mahaim-type conduction concomitantly sustaining orthodromic AVRT are extremely rare. Conclusions: Electroanatomical 3D mapping may help both to clarify the diagnosis and increase the success rate by accurately describing the insertion points of complex accessory pathways

Optimal Cardiac Resynchronization Therapy with Conduction System Pacing Guided by Electro-Anatomical Mapping: A Case Report

Introduction: Biventricular pacing has been the gold standard for cardiac resynchronization therapy in patients with left bundle branch block and severely reduced left ventricular ejection fraction for decades. However, in the past few years, this role has been challenged by the promising results of conduction system pacing in these patients, which has proven non-inferior and, at times, superior to biventricular pacing regarding left ventricular function outcomes. One of the most important limitations of both procedures is the long fluoroscopy times. Case description: We present the case of a 60-year-old patient with non-ischemic dilated cardiomyopathy and left bundle branch block in whom conduction system pacing was chosen as the first option for resynchronization therapy. A 3D electro-anatomical mapping system was used to guide the lead to the His bundle region, where correction was observed at high amplitudes, and afterward to the optimal septal penetration site. After reaching the left endocardium, left bundle branch pacing achieved a narrow, paced QRS complex with low fluoroscopy exposure. The three-month follow-up showed a significant improvement in clinical status and left ventricular function. Conclusion: Since conduction system pacing requires a great deal of precision, targeting specific, narrow structures inside the heart, 3D mapping is a valuable tool that increases the chances of success, especially in patients with complex anatomies, such as those with indications for cardiac resynchronization therapy

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

Catheter ablation for ventricular arrhythmias using remote magnetic navigation in patients with reduced ejection fraction

Цел: Радиофреквентната катетърна аблация е ефективен метод на лечение на сърдечни аритмии, вкл. комплексни и камерни аритмии. Дистанционната магнитна катетърна навигация (RMN) беше разработена като нов подход с цел подобряване на резултатите и намаляване на честотата на усложнения, както и намаляване на лъчевото натоварване за оператора и пациентите. Целта ни беше да сравним честотата на успех и усложнения при пациенти със или без тежко намалена левокамерна фракция на изтласкване (ФИЛК). Методи: Анализирахме ретроспективно всички пациенти с RMN в нашия център от 2015 до 2021 г. (n = 98). Не са прилагани специални критерии за подбор на пациентите за RMN. Бяха събрани всички клинични, параклинични и процедурни данни. Пациентите бяха разделени в 2 групи – със или без тежко намалена ФИЛК >/= 35%. Система CARTO беше използвана за 3D електроанатомичен мепинг. RMN беше осъществена посредством система Niobe ES и магнитен аблационен катетър с отворена иригация. Успехът беше дефиниран като пълно елиминиране на клиничната аритмия. Неиндуцируемостта след аблация беше оценена при всички пациенти с какъвто и да било вид камерна аритмия извън камерни екстрасистоли. Тестването на индуцируемост беше направено с програмирана камерна стимулация с до 4 екстрастимула. Статистическият анализ беше извършен със софтуерен пакет SPSS. Стойност на р Резултати: Успешна аблация с пълно елиминиране на клиничната аритмия, беше постигната при 92,3% от пациентите с тежко намалена ФИЛК и при 88,1% от пациентите с ФИЛК > 35% (р = 0,73). Общата честота на малки усложнения беше 2,04% със спонтанна резолюция. Не бяха регистрирани тежки усложнения. Неиндуцируемост беше постигната в 56,4% от пациентите с ФИЛК >/=35% и в 79,2% от пациентите с ФИЛК > 35% (р = 0,023). Заключение: Радиофреквентната катетърна аблация чрез RMN е ефективна и безопасна, независимо от наличието или не на тежко намалена ФИЛК.  Objective. Radiofrequency catheter ablation is an effective treatment option for cardiac arrhythmias including complex and ventricular arrhythmias. Remote magnetic catheter navigation (RMN) has been developed as a novel way of approach aiming to improve outcome and reduce complication rate, and reduce radiation exposure for both operator and patient. Our aim was to compare success and complication rate in patients with or without severely reduced left ventricular ejection fraction (LVEF). Methods. We retrospectively analyzed all the patients (n = 98) which have undergone RMN in our center between 2015-2021. No selection criteria for RMN procedure have been applied. All clinical and paraclinical, as well as procedural data were collected. Patients were divided into two groups, with or without severely reduced LVEF ≤ 35%. CARTO system was used for 3D electroanatomic mapping. RMN was done using Niobe ES system and an open-irrigated magnetic ablation catheter. Success rate was defi ned by complete elimination of clinical arrhythmia. Non-inducibility following ablation was assessed in all patients presenting with any type of ventricular arrhythmia other than premature ventricular contractions. Testing for inducibility was done by ventricular programmed pacing with up to four extra-stimuli. The statistical analysis was performed using SPSS software. P-value Results. Successful ablation with complete elimination of the clinical arrhythmia was achieved in 92.3% of the patients with severely reduced LVEF and in 88.1% of patients with LVEF > 35% (p = 0.73). Overall minor complication rate was 2.04% with spontaneous resolution. No major complications were reported. Non-inducibility was achieved in 56.4% of the patients with LVEF ≤ 35% and in 79.2% of the patients with LVEF >35% (p = 0.023). Conclusion. Radiofrequency catheter ablation using RMN is effective and safe regardless of the presence or not of a severely reduced LVEF