Objectives A significant proportion of COVID‐19 patients may have cardiac involvement including arrhythmias. Although arrhythmia characterisation and possible predictors were previously reported, there are conflicting data regarding the exact prevalence of arrhythmias. Clinically applicable algorithms to classify COVID patients' arrhythmic risk are still lacking, and are the aim of our study. Methods We describe a single‐centre cohort of hospitalised patients with a positive nasopharyngeal swab for COVID‐19 during the initial Israeli outbreak between 1/2/2020 and 30/5/2020. The study's outcome was any documented arrhythmia during hospitalisation, based on daily physical examination, routine ECG's, periodic 24‐hour Holter, and continuous monitoring. Multivariate analysis was used to find predictors for new arrhythmias and create classification trees for discriminating patients with high and low arrhythmic risk. Results Out of 390 COVID‐19 patients included, 28 (7.2%) had documented arrhythmias during hospitalisation, including 23 atrial tachyarrhythmias, combined atrial fibrillation (AF), and ventricular fibrillation, ventricular tachycardia storm, and 3 bradyarrhythmias. Only 7/28 patients had previous arrhythmias. Our study showed a significant correlation between disease severity and arrhythmia prevalence (P < .001) with a low arrhythmic prevalence amongst mild disease patients (2%). Multivariate analysis revealed background heart failure (CHF) and disease severity are independently associated with overall arrhythmia while age, CHF, disease severity, and arrhythmic symptoms are associated with tachyarrhythmias. A novel decision tree using age, disease severity, CHF, and troponin levels was created to stratify patients into high and low risk for developing arrhythmia. Conclusions Dominant arrhythmia amongst COVID‐19 patients is AF. Arrhythmia prevalence is associated with age, disease severity, CHF, and troponin levels. A novel simple Classification tree, based on these parameters, can discriminate between high and low arrhythmic risk patients.

At MA, SpO2 is approximately 0.4% lower compared with SL. Our study supports the AAP recommendation suggesting algorithm cut-offs may need adjustment in high-altitude nurseries and suggest broadening it to MA as well.

Healthy young female adults have a higher (1.5%) SpO than their male counterparts. This difference is not yet present at birth. Further studies are needed to determine the timing of sex-differences, and to better define the mechanism(s) behind this observation.

Objectives: A significant proportion of COVID-19 patients may have cardiac involvement including arrhythmias. Although arrhythmia characterization and possible predictors were previously reported, there are conflicting data regarding the exact prevalence of arrhythmias. Clinically applicable algorithms to classify COVID patients' arrhythmic risk are still lacking, and are the aim of our study. Methods: We describe a single center cohort of hospitalized patients with a positive nasopharyngeal swab for COVID-19 during the initial Israeli outbreak between 1/2/2020-30/5/2020. The study's outcome was any documented arrhythmia during hospitalization, based on daily physical examination, routine ECG's, periodic 24-hour Holter, and continuous monitoring. Multivariate analysis was used to find predictors for new arrhythmias and create classification trees for discriminating patients with high and low arrhythmic risk. Results: Out of 390 COVID-19 patients included, 28 (7.2%) had documented arrhythmias during hospitalization, including: 23 atrial tachyarrhythmias, combined atrial fibrillation (AF) and ventricular fibrillation, ventricular tachycardia storm, and 3 bradyarrhythmias. Only 7/28 patients had previous arrhythmias. Our study showed significant correlation between disease severity and arrhythmia prevalence (p<0.001) with a low arrhythmic prevalence among mild disease patients (2%). Multivariate analysis revealed background heart failure (CHF) and disease severity are independently associated with overall arrhythmia while age, CHF, disease severity, and arrhythmic symptoms are associated with tachyarrhythmias. A novel decision tree using age, disease severity, CHF, and troponin levels was created to stratify patients into high and low risk for developing arrhythmia. Conclusions: Dominant arrhythmia among COVID-19 patients is AF. Arrhythmia prevalence is dependent on age, disease severity, CHF, and troponin levels. A novel simple Classification tree, based on these parameters, can discriminate between high and low arrhythmic risk patients. WHAT'S KNOWN? • A significant proportion of COVID-19 patients may have cardiac involvement including arrhythmias. • There is a correlation between disease severity in general and cardiac involvement specifically to occurrence of cardiac arrhythmias. • Arrhythmia characterization and possible predictors. WHAT'S NEW? • Using a 24-hour Holter monitoring among hospitalized COVID-19 patients, for better arrythmias detection. • Among of all hospitalized COVID-19 patients, 7.2% had new arrhythmias during hospitalization. • Classification tree which discriminate between high and low arrhythmic risk patients

Background Heart failure with preserved ejection fraction (HFpEF) is common in elderly people and is increasing in prevalence. No specific treatment for this condition exists. Coenzyme Q10 (CoQ10) is an essential cofactor for energy production, with reduced levels being noted in HF. Previous studies have suggested a possible role for CoQ10 in the treatment of HF. This study examined the effect of CoQ10 supplementation on diastolic function in HFpEF patients. Methods We conducted a prospective, randomized, double-blind, placebo-controlled trial including patients aged > 55 years presenting with New York Heart Association class II-IV heart failure symptoms and left ventricular ejection fraction > 50%, with impaired diastolic function. Echocardiography and levels of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) were performed at baseline and following 4 months of CoQ10 or placebo supplementation. Results A total of 39 patients were enrolled-19 in the CoQ10 group and 20 in the placebo group. Baseline clinical characteristics were similar between groups, while compliance was high and also similar between the CoQ10 and placebo groups. There was no significant effect of treatment on indices of diastolic function (difference in the lateral E/e' ratio: −0.86 ± 6.57 in the CoQ10 group, +0.18 ± 3.76 in the placebo group; p = 0.561) or on serum NT-proBNP levels (− 72 pg/mL vs. − 42 pg/mL; p = 0.195). Conclusions In this pilot trial in elderly patients with HFpEF, treatment with CoQ10 did not significantly affect echocardiographic indices of diastolic function and serum NT-proBNP levels. Trial Registration This trial was registered in the US National Institutes of Health Clinical Trials Registry (ClinicalTrials. gov identifier: NCT02779634).