arrhythmogene

Arrhythmogene is a term used to describe factors, conditions, or processes that predispose to arrhythmias, abnormal heart rhythms. In clinical use it encompasses inherited channelopathies, cardiomyopathies with an arrhythmogenic substrate, and acquired factors that alter cardiac electrophysiology.

Mechanisms: Arrhythmogenesis results from disturbances in impulse generation or conduction and from the tissue substrate that supports reentry or dispersion of repolarization. Ion channel defects can prolong or shorten the cardiac action potential and create afterdepolarizations; structural abnormalities such as fibrosis or fatty infiltration produce heterogeneous conduction. Genetic mutations in sodium, potassium, and calcium channel genes (for example SCN5A, KCNQ1, KCNH2, CACNA1C) and in desmosomal proteins (PKP2, DSP, DSC2, DSG2, JUP) underlie many inherited arrhythmogenic conditions.

Clinical examples: Inherited channelopathies include long QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Arrhythmogenic right ventricular cardiomyopathy is a cardiomyopathy with fatty/fibrous replacement of the right ventricle that predisposes to ventricular arrhythmias. Other diseases may acquire an arrhythmogenic substrate through aging, ischemia, or inflammatory processes.

Diagnosis and management: Evaluation combines ECG, ambulatory monitoring, exercise testing, and imaging (often cardiac MRI) to detect structural disease, with genetic testing when indicated. Management focuses on risk stratification and reducing arrhythmia burden: beta-blockers for many channelopathies; avoidance of triggering drugs; antiarrhythmic drugs in selected cases; catheter ablation for focal triggers; and implantable cardioverter-defibrillators for high-risk individuals. Lifestyle modifications may be advised in certain conditions.

Prognosis and research: Prognosis depends on the specific disorder and timeliness of treatment. Ongoing genetic and translational research aims to improve risk prediction and develop targeted therapies.