Background - COVID-19 has led to over 1 million deaths worldwide and has been associated with cardiac complications including cardiac arrhythmias. The incidence and pathophysiology of these manifestations remain elusive. In this worldwide survey of patients hospitalized with COVID-19 who developed cardiac arrhythmias, we describe clinical characteristics associated with various arrhythmias, as well as global differences in modulations of routine electrophysiology practice during the pandemic. Methods - We conducted a retrospective analysis of patients hospitalized with COVID-19 infection worldwide with and without incident cardiac arrhythmias. Patients with documented atrial fibrillation (AF), atrial flutter (AFL), supraventricular tachycardia (SVT), non-sustained or sustained ventricular tachycardia (VT), ventricular fibrillation (VF), atrioventricular block (AVB), or marked sinus bradycardia (HR<40bpm) were classified as having arrhythmia. De-identified data was provided by each institution and analyzed. Results - Data was collected for 4,526 patients across 4 continents and 12 countries, 827 of whom had an arrhythmia. Cardiac comorbidities were common in patients with arrhythmia: 69% had hypertension, 42% diabetes mellitus, 30% had heart failure and 24% coronary artery disease. Most had no prior history of arrhythmia. Of those who did develop an arrhythmia, the majority (81.8%) developed atrial arrhythmias, 20.7% developed ventricular arrhythmias, and 22.6% had bradyarrhythmia. Regional differences suggested a lower incidence of AF in Asia compared to other continents (34% vs. 63%). Most patients in in North America and Europe received hydroxychloroquine, though the frequency of hydroxychloroquine therapy was constant across arrhythmia types. Forty-three percent of patients who developed arrhythmia were mechanically ventilated and 51% survived to hospital discharge. Many institutions reported drastic decreases in electrophysiology procedures performed. Conclusions - Cardiac arrhythmias are common and associated with high morbidity and mortality among patients hospitalized with COVID-19 infection. There were significant regional variations in the types of arrhythmias and treatment approaches.

Physical activity (PA) is a cornerstone of prevention to decrease mortality in patients with chronic cardiovascular disease, including heart failure. 1,2 Implantable cardiac devices offer the opportunity to monitor PA and data derived from implantable devices have been associated with shortand long-term outcomes. 3,4 During the severe acute respiratory syndrome coronavirus 2 pandemic, restrictions to outdoor activity were imposed by national authorities. In Italy, after the first case of coronavirus disease-2019 (COVID-19) on February 21, the so-called lockdown act was passed on March 8, 2020. 5 These rigorous measures decreased the impact of COVID-19 pandemic on the National Health System, 6 but likely resulted in changes in the ability of patients to maintain PA levels. In the current study, we examined the impact of the COVID-19 and regulatory movement restrictions on the PA of patients with an implantable cardioverter defibrillator.

Highlights: Takotsubo cardiomyopathy was more common in women and the mortality rate was 2.2%. Ventricular arrhythmias were the strongest predictor of mortality. Age was associated with increased mortality in women with takotsubo cardiomyopathy.

Background: Predicting an accessory pathway location is extremely important in pediatric patients. Aims:We designed a study to compare previously published algorithms by Arruda, Boersma, and Chiang.Methods: This multicenter study included patients who had undergone successful ablation of one accessory pathway. Analysis of resting 12-lead electrocardiograms was carried out. An aggregated prediction score was constructed on the basis of algorithm agreement, and a structured workflow approach was proposed. Results:The total population was 120 patients (mean age, 12.7 [± 3.6] years). The algorithm by Boersma had the highest accuracy (71.7%). The inter-rater agreement among the 3 reference algorithms, according to left-sided accessory pathway (AP) identification, was good between Boersma and Chiang (κ = 0.611; 95% confidence interval [CI], 0.468-0.753) but moderate between Arruda and Chiang and between Arruda and Boersma (κ = 0.566; 95% CI, 0.419-0.713 and κ = 0.582; 95% CI, 0.438-0.727, respectively). Regarding locations at risk of atrioventricular (AV) block, agreement was fair between Arruda and Chiang and between Boersma and Chiang (κ = 0.358; 95% CI, 95% CI, respectively) but moderate between Arruda and Boersma (κ = 0.45; 95% CI, 0.304-0.597). On applying a first-step diagnostic evaluation, when concordance was achieved, we were able to correctly identify left-sided or non-left-sided ablation sites in 96.4% (n = 80) of cases. When concordance was achieved, correct prediction of risk/no risk of AV block was achieved in 92.2% (n = 59) of cases.Conclusions: An aggregated prediction score based on 3 reference algorithms proved able to predict an accessory pathway location very precisely and could be used to plan safely invasive procedures.

Background Cardiac implantable electronic device (CIED) implantation rates, as well as the clinical and procedural characteristics and outcomes in patients with known active COVID-19 are unknown. Objective To gather information regarding CIED procedures during active COVID-19, performed with personal protective equipment, based on an international survey. Methods Fifty-three centers from 13 countries across 4 continents provided information on 166 patients with known active COVID-19 who underwent a CIED procedure. Results CIED procedure rate in 133,655 hospitalized COVID-19 patients ranged from 0 to 16.2 per 1000 patients (p<0.001). Most devices were implanted due to high degree / complete AV block (112, 67.5%) or sick sinus syndrome (31, 18.7%). Of the166 patients surveyed, the 30-day complication rate was 13.9% and the 180-day mortality rate was 9.6%. One patient had a lethal outcome as a direct result of the procedure. Differences in patient and procedural characteristics and outcomes were found between Europe and North America. An older population (76.6 vs. 66 years, p<0.001) with a non-significant higher complication rate (16.5% vs. 7.7%, p=0.2) were observed in Europe, while a higher rate of critically ill patients (3.3% vs. 33.3%, p<0.001) and mortality (5% vs. 26.9%, p=0.002) were observed in North America. Conclusion CIED procedure rates during known active COVID-19 disease varied greatly from 0 to 16.2 per 1000 hospitalized COVID-19 patients worldwide. Patients with active COVID-19 infection who underwent CIED implantation had high complication and mortality rates. Operators should take into consideration these risks prior to proceeding with CIED implantation in active COVID-19 patients.