Summary
Aim. To highlight the key genetic, pathophysiological, and clinical differences between long QT syndome (LQTS) types and review treatment approaches.
Material and methods. A scientific literature review was conducted using PubMed, Google Scholar, and Science Direct databases with keywords: “congenital long QT syndrome,” “genetics,” “channelopathy,” “sudden cardiac death,” and “syncope.” The review included 11 fulltext articles in English, published between 2014 and 2024.
Literature review. Long QT syndrome is a rare primary electrical heart disease characterized by altered cardiomyocyte repolarization, manifesting as a prolonged QT interval on twel-lead electrocardiogram. Clinically, the syndrome may present with syncope, cardiac arrest, or sudden cardiac death due to ventricular arrhythmias. However, up to 40% of genetically confirmed patients may not display electrocardiographic changes, and some may remain asymptomatic all life. Mutations in genes encoding voltage-gated ion channel proteins may result in altered duration and shape of the ventricular action potential. Syndrome is classified into 17 types, with the three most common types being LQT1, LQT2, and LQT3. Depending on the type, clinical symptoms are more likely to manifest in response to different triggers. Patients require syndrome-specific lifestyle recommendations, and treatment involves long-term use of non-selective beta-adrenergic blockers. If symptoms persist despite optimal medical treatment, non-pharmacological interventions, such as implantable cardioverter-defibrillators or left cardiac sympathetic denervation, may be considered.
Conclusions. Long QT syndrome remains a rare but life-threatening condition leading to ventricular arrhythmias or sudden cardiac death. Most cases are associated with the three main types caused by specific genetic mutations. Treatment includes lifestyle recommendations, pharmacological therapy and interventional procedures, if needed.
