Letter to the Editor

Before attributing sick sinus syndrome to increased intracerebral pressure, all other causes must be carefully excluded

Abstract

We read with interest the article by Al-Attas et al. about a 47-year-old man with venous sinus thrombosis (VST) complicated by increased intracerebral pressure (ICP) and sick sinus syndrome (SSS) [1]. The patient made a full recovery with heparinization and implantation of a pacemaker [1]. The report is noteworthy, but several points should be discussed.
The first point is that causes of SSS other than increased ICP have not been adequately ruled out [1]. SSS can be primary (hereditary) or acquired. Primary SSS is due to mutations in SCN5A, MYH6, KCNG2, MECP2, LMNA or HCN4. Since no genetic testing was performed, primary SSS cannot be definitively ruled out. It was also not mentioned whether or not there was a consanguinity between the parents of the index patient. Secondary causes of SSS include advanced age, infections (e.g. Chagas, typhoid, SARS-CoV-2), inflammation, hypoxia, muscular dystrophy, infiltrative diseases, hyperthyroidism, trauma, previous cardiac surgery, refeeding syndrome or medication [2]. To rule out secondary SSS, it would have been useful to perform a magnetic resonance imaging (MRI) of the heart with contrast, especially to determine whether the patient had myocarditis. As the case occurred during the pandemic, it must be ruled out that the patient was infected with SARS-CoV-2, which can be complicated not only by myocarditis but also by VST [3, 4].