Long QT interval syndrome: etiology, diagnostic and treatment

Indrė Sasnauskaitė1, Vilija Grumuldytė1, Kamilė Gerulytė1

1Lithuanian University of Health Sciences, Academy of Medicine, Faculty of Medicine, Kaunas, Lithuania 


Long QT syndrome (LQTS) is a genetic or acquired condition characterized by a prolonged QT interval due to increased action potential and is associated with lethal ventricular tachyarrhythmias, such as Torsades de Pointes [1]. The primary symptoms in patients with LQTS include palpitations, syncope, seizures, and sudden cardiac death in an otherwise healthy young individual with a structurally normal heart [2]. Rapid progress of genetic technology has significantly improved our understanding of molecular and genetic mechanisms of LQTS [3,4]. The vast majority of acquired LQTS is the result of the adverse effect of drugs and electrolyte imbalance [5]. For instance, hydroxychloroquine and azithromycin prolong QT interval and nowadays they are both used to treat COVID – 19. These medications can lead to dangerous consequences for the patients [6]. Therefore, ECG should be carefully monitored for patients who use certain drugs that prolong QT interval [7]. This article will outline the current knowledge about the congenital and acquired LQTS causes and provide essential diagnostic and clinical data.


Keywords: long QT syndrome, genetic testing, drug-induced QT prolongation.