Drakopoulou M, et al. - Considering the common occurrence of arrhythmias among adults with congenital heart disease (CHD) developing pulmonary arterial hypertension (PAH) patients, researchers sought for its incidence and impact on outcomes. They followed all adult patients with PAH associated with CHD (PAH-CHD) seen in a tertiary centre between 2007 and 2015 for new-onset atrial or ventricular arrhythmia and identified that arrhythmia is common in PAH-CHD. It was observed to be associated with an adverse long-term outcome, even when managed in a specialist centre.