INTRODUCTION
The on-going pandemic of coronavirus disease 2019 (COVID-19) has created a worldwide emergency:1 on March 8th, Italy became the second most affected country in the world after China, and specific rules for restricting social contacts in the whole country were applied by the Italian Government in order to contain the epidemic spread. These emergency measures were in force until May 4th, 2020. At the end of June 2020, 240.000 cases were registered in Italy with more than 34.000 deaths.2
As restrictions included the reduction or the interruption of several routine public health and hospital services, as out-patient clinics and office visits and routine hospital admissions for chronic disease, there was widespread major concern regarding also the management of non-COVID patients, such as patients with advanced cardiac disease, and its prognostic implications during the lockdown period.
Recently a significant reduction of 47% in diagnosis of new-onset cases of atrial fibrillation (AF) was observed in the danish adult population during national lockdown in Denmark, suggesting that the risk of complications of non-diagnosed AF could rise significantly and influence the outcome unfavourably3. Furthermore an increase of admissions to emergency department caused by rhythm disturbances has ben recently observed in our region during lockdown period, despite a reduction in dysrhythmia-related urgent unplanned hospitalization4.
The aim of our study was to evaluate the risk of clinically relevant cardiac arrhythmias during lockdown period in a study population with advanced cardiac disease and high risk of cardiac arrhythmias and mortality. In particular, we studied the impact of lockdown restrictions on the incidence of new onset of AF and ventricular tachycardia (VT) and fibrillation (VF) in patients with Implantable cardioverter-defibrillators (AICD) and Cardiac Resynchronization Therapy-defibrillators (ICD/CRT-Ds) for primary and secondary prevention of sudden cardiac death.