IMPORTANCECritical illness, a marked inflammatory response, and viruses such as SARS-CoV-2 may prolong corrected QT interval (QTc). OBJECTIVE To evaluate baseline QTc interval on 12-lead electrocardiograms (ECGs) and ensuing changes among patients with and without COVID-19. DESIGN, SETTING, AND PARTICIPANTS This cohort study included 3050 patients aged 18 years and older who underwent SARS-CoV-2 testing and had ECGs at Columbia University Irving Medical Center from March 1 through May 1, 2020. Patients were analyzed by treatment group over 5 days, as follows: hydroxychloroquine with azithromycin, hydroxychloroquine alone, azithromycin alone, and neither hydroxychloroquine nor azithromycin. ECGs were manually analyzed by electrophysiologists masked to COVID-19 status. Multivariable modeling evaluated clinical associations with QTc prolongation from baseline. EXPOSURES COVID-19, hydroxychloroquine, azithromycin. MAIN OUTCOMES AND MEASURES Mean QTc prolongation, percentage of patients with QTc of 500 milliseconds or greater.RESULTS A total of 965 patients had more than 2 ECGs and were included in the study, with 561 (58.1%) men, 198 (26.2%) Black patients, and 191 (19.8%) aged 80 years and older. There were 733 patients (76.0%) with COVID-19 and 232 patients (24.0%) without COVID-19. COVID-19 infection was associated with significant mean QTc prolongation from baseline by both 5-day and 2-day multivariable models 15.29 to 26.33] milliseconds;

Introduction Electrocardiographic characteristics in COVID‐19‐related mortality have not yet been reported, particularly in racial/ethnic minorities. Methods and Results We reviewed demographics, laboratory and cardiac tests, medications, and cardiac rhythm proximate to death or initiation of comfort care for patients hospitalized with a positive SARS‐CoV‐2 reverse‐transcriptase polymerase chain reaction in three New York City hospitals between March 1 and April 3, 2020 who died. We described clinical characteristics and compared factors contributing toward arrhythmic versus nonarrhythmic death. Of 1258 patients screened, 133 died and were enrolled. Of these, 55.6% (74/133) were male, 69.9% (93/133) were racial/ethnic minorities, and 88.0% (117/133) had cardiovascular disease. The last cardiac rhythm recorded was VT or fibrillation in 5.3% (7/133), pulseless electrical activity in 7.5% (10/133), unspecified bradycardia in 0.8% (1/133), and asystole in 26.3% (35/133). Most 74.4% (99/133) died receiving comfort measures only. The most common abnormalities on admission electrocardiogram included abnormal QRS axis (25.8%), atrial fibrillation/flutter (14.3%), atrial ectopy (12.0%), and right bundle branch block (11.9%). During hospitalization, an additional 17.6% developed atrial ectopy, 14.7% ventricular ectopy, 10.1% atrial fibrillation/flutter, and 7.8% a right ventricular abnormality. Arrhythmic death was confirmed or suspected in 8.3% (11/133) associated with age, coronary artery disease, asthma, vasopressor use, longer admission corrected QT interval, and left bundle branch block (LBBB). Conclusions Conduction, rhythm, and electrocardiographic abnormalities were common during COVID‐19‐related hospitalization. Arrhythmic death was associated with age, coronary artery disease, asthma, longer admission corrected QT interval, LBBB, ventricular ectopy, and usage of vasopressors. Most died receiving comfort measures.

Objectives: Increases in emergency department (ED) visits may place a substantial burden on both the ED and hospital-based laboratories. Studies have identified laboratory turnaround time (TAT) as a barrier to patient process times and lengths of stay. Prolonged laboratory study results may also result in delayed recognition of critically ill patients and initiation of appropriate therapies. The objective of this study was to determine how ED patient volume itself is associated with laboratory TAT.Methods: This was a retrospective cohort review of patients at five academic, tertiary care EDs in the United States. Data were collected on all adult patients seen in each ED with troponin laboratory testing during the months of January, April, July, and October 2007. Primary predictor variables were two ED patient volume measures at the time the troponin test was ordered: 1) number of all patients in the ED ⁄ number of beds (occupancy) and 2) number of admitted patients waiting for beds ⁄ beds (boarder occupancy). The outcome variable was troponin turnaround time (TTAT). Adjusted covariates included patient characteristics, triage severity, season (month of the laboratory test), and site. Multivariable adjusted quantile regression was carried out to assess the association of ED volume measures with TTAT.Results: At total of 9,492 troponin tests were reviewed. Median TTAT for this cohort was 107 minutes (interquartile range [IQR] = 73-148 minutes). Median occupancy for this cohort was 1.05 patients (IQR = 0.78-1.38 patients) and median boarder occupancy was 0.21 (IQR = 0.11-0.32). Adjusted quantile regression demonstrated a significant association between increased ED patient volume and longer times to TTAT. For every 100% increase in census, or number of boarders over the number of ED beds, respectively, there was a 12 (95% confidence interval [CI] = 9 to 14) or 33 (95% CI = 24 to 42)-minute increase in TTAT.Conclusions: Increased ED patient volume is associated with longer hospital laboratory processing times. Prolonged laboratory TAT may delay recognition of conditions in the acutely ill, potentially affecting clinician decision-making and the initiation of timely treatment. Use of laboratory TAT as a patient throughput measure and the study of factors associated with its prolonging should be further investigated.ACADEMIC EMERGENCY MEDICINE 2010; 17:501-507 ª