Demographics, Clinical Features and Genetics of Common Inherited Arrhythmias in Oman.

Objectives: Inherited arrhythmia syndromes (IAS) are a group of rare disorders that result from genetic mutations in several genes including congenital long QT syndrome, Brugada syndrome (BrS), short QT syndrome, and Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). Affected individuals may have various symptoms including sudden cardiac death (SCD). Few reports have highlighted long QT syndrome from the Arbian Gulf region. The current study aims to describe demographics of children and adults with inherited arrhythmia syndromes; report the presenting clinical features, genetic mutations and management strategies.

Material and method: This is a descriptive retrospective study that included Omani children and adults with inherited arrhythmia syndromes who were diagnosed and treated at the National Heart Centre (NHC) of the Royal Hospital, between 2006 and 2022. Data collected include patient demographics, geographical distribution, clinical features, genetic reports and management strategies.

Result: A total of one hundred and six Omani patients were included. Sixty-six (62.3 %) were males, and 71 (67 %) were adults at diagnosis and 35 (33 %) were children. Three inherited arrhythmia syndromes were found including Long QT, Brugada and catecholaminergic polymorphic ventricular tachycardia (CPVT) and these accounted for 58 (54.7 %), 39 (36.8 %) and 9 (8.5 %), respectively. Seventy-six (71.7 %) of the patients were from consanguineous families. The clinical features varied based on the type of arrhythmia. The treatment modalities constituted of beta blockers and antiarrhythmics, implantable cardioverter defibrillators (ICDs), pacemakers, and left sympathetic ganglionectomy (LSGs). Seventy-one individuals (66.9 %) underwent genetic testing. It is important to highlight that 36 (50.7 %) individuals were with pathogenic or likely pathogenic variants and 13 (18.3 %) individuals were with variants of uncertain significance (VUS) in different IAS related genes.

Conclusion: The current study is the first comprehensive study on the inherited arrhythmia syndromes in Oman and the Arabian Gulf countries. It provides insight about the demographic, clinical and genetic profile of the most common IAS in the region, hence helping in early detection of different types of IAS types and prevention of sudden cardiac death in patients and their relatives. Continuous research efforts in the genetic and cellular mechanisms underlying these disorders will help to identify potential targets for improved disease-specific treatments.