From the Guidelines
The four most common congenital electrical cardiology pathologies are Wolff-Parkinson-White Syndrome, Long QT Syndrome, Brugada Syndrome, and Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). These conditions are associated with significant morbidity and mortality, and their management is crucial to improve quality of life and prevent sudden cardiac death.
Key Characteristics of Each Condition
- Wolff-Parkinson-White Syndrome: characterized by the presence of an accessory electrical pathway between the atria and ventricles, leading to pre-excitation and supraventricular tachycardias 1.
- Long QT Syndrome: involves delayed cardiac repolarization, resulting in prolonged QT intervals on ECG and increased risk of torsades de pointes, a life-threatening ventricular arrhythmia.
- Brugada Syndrome: presents with characteristic ST-segment elevation in right precordial leads, increasing the risk of sudden cardiac death.
- Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT): causes exercise-induced ventricular arrhythmias due to abnormal calcium handling in cardiac cells.
Management and Treatment
- Wolff-Parkinson-White Syndrome: catheter ablation is the definitive treatment, with success rates exceeding 95% 1.
- Long QT Syndrome: treatment typically includes beta-blockers, with implantable cardioverter-defibrillators (ICDs) for high-risk patients.
- Brugada Syndrome: ICD implantation is the primary treatment for symptomatic patients.
- CPVT: treatment includes beta-blockers, exercise restriction, and sometimes flecainide as adjunctive therapy.
Importance of Genetic Counseling
All these conditions require genetic counseling for family members, as they often have autosomal dominant inheritance patterns.
Clinical Considerations
It is essential to consider the clinical context and individual patient characteristics when managing these conditions, as outlined in the 2018 AHA/ACC guideline for the management of adults with congenital heart disease 1.
From the Research
Congenital Electrical Cardiology Pathologies
The following are some of the most common congenital electrical cardiology pathologies:
- Wolff-Parkinson-White (WPW) syndrome, which results from the congenital presence of impulse-conducting fascicles, known as accessory pathways (APs) or bypass tracts, that connect atria and ventricles across the annulus fibrosis 2, 3
- Congenital long QT syndrome (LQTS), a familial cardiac ion channelopathy characterized by prolonged ventricular repolarisation, ventricular arrhythmias, and associated syncope or sudden cardiac death 4
- Atrioventricular (AV) nodal reentrant tachycardia, the most common regular supraventricular arrhythmia in humans, which can be challenging to treat in patients with congenital heart disease due to abnormal venous access and intracardiac anatomy 5
- Atrial fibrillation with an accessory pathway, which has the morphology of VT but is differentiated because the rhythm is irregular and the rate is more than 200 beats per minute, often associated with WPW syndrome 6
Characteristics and Treatment
These pathologies have distinct characteristics and treatment options:
- WPW syndrome: characterized by a short PR interval, presence of a delta wave, widened QRS complex, and ST-T wave changes, treated with medications, surgical or catheter ablation 2, 3
- LQTS: diagnosed by prolonged ventricular repolarisation on electrocardiography, treated with antiarrhythmic therapy and other management options 4
- AV nodal reentrant tachycardia: treated with catheter ablation of the slow AV nodal pathway, which can be challenging in patients with congenital heart disease 5
- Atrial fibrillation with an accessory pathway: treated with emergency procedures such as blocking the accessory pathway with procainamide or breaking the reentry circuit at the AV node 6