Funding Acknowledgements Type of funding sources: None. Background - Introduction: The COVID-19 pandemic has generated serious repercussions on the health system, reducing the number of all cardiology procedures worldwide. Objectives Describe the impact of the COVID-19 pandemic on the procedures performed by the electrophysiology department in a national referral center.  Methods We made a retrospective review of our data base and we compared procedures made in the last 3 years since 2017 to 2019 with the procedures made in the 2020. We divide the procedures into two large groups: Cardiac Implantable Electronic Devices (CIED) related procedures (which included implants, revisions, changes, upgrades and extractions) and electrophysiological studies and ablations (which included conventional and complex procedures). Other types of procedures were no included. Results There was a significant reduction in all procedures, the average of procedures performed in the last 3 previous years was 467 (there were 479 in 2017, 411 in 2018 and 511 in 2019), while in 2020 we performed only 319 (p = 0.01); this represents a reduction of 33.4% in the total number of procedures performed in our center. There was no statistical difference regarding the CIED related procedures, the average of procedures of the last 3 previous years was 174 (there were 186 in 2017, 148 in 2018 and 188 in 2019), and in 2020 we performed 189 procedures, this value is near to the average of the last 3 previous years and very close to the value of the 2019 (p = 0.46). Regarding the electrophysiological studies and ablations, the average of procedures of the last 3 previous years was 293 (there were 293 in 2017, 263 in 2018 and 323 in 2019), while in 2020 we performed only 129 procedures, considerably decreasing compared to the previous years (p < 0.01). The reduction in the electrophysiological studies and ablations was 55.97%. The most affected months were April, May and June. Conclusions The COVID-19 pandemic considerably affected the number of electrophysiological procedures in our center, reducing it by 33.4% compared to the previous years. The reduction of procedures fundamentally affected the electrophysiological studies and ablations, reducing them by 55.97%. The number of CIED related procedures were no affected. Electrophysiological procedures Procedures2017201820192017-2019 average2020CIED related procedures186148188174189Electrophysiological studies and ablations293263323293129Total479411511467319Comparative table of the electrophysiological procedures performed in our center in recent years.Abstract Figure. Comparison of the procedures.

Abstract. To control the spread of COVID-19, in March 2020 exceptional restrictive measures were taken imposing a radical change in the lifestyle of millions of citizens around the world, albeit for a short period of time. The national lockdown, which in Italy lasted from 10 March to 18 May 2020, was a unique opportunity to observe the variation in air quality in urban environments in a condition of almost total traffic block and a strong reduction in work activities. In this paper, the data from seventeen urban monitoring sites in Tuscany are presented by comparing PM and NO2 of the two months before the start of the lockdown and the two after with the corresponding months of the previous three years. The results show that the total load of PM2.5 and PM10 decreased but it did not exhibit significant changes compared to previous years, while NO2 undergoes a drastic reduction. For three of these sites, the chemical composition of the collected samples was measured by thermo-optical, ion chromatography and PIXE analysis, and the application of multivariate PMF analysis allowed the PM10 source identification and apportionment. Thanks to these analyses it was possible to explain the low sensitiveness of PM10 to the lockdown effects as due to different, sometimes opposite, behaviors of the different sources that contribute to PM. The results clearly indicated a decline in pollution levels related to urban traffic and an increase in the concentration of sulfate for all sites during the lockdown period.