ECG characteristics associated with adverse outcomes in COVID-19, a tertiary centre experience
Authors: Bistrovic P , Manola S , Delic-Brkljacic D , Lucijanic M 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
COVID-19 is a systemic disease with dominantly respiratory symptoms, however numerous other presentations involving practically any organ system have been described. Older patients and those with other comorbidities are at higher risk for critical COVID, increased respiratory requirements and death. (1) Those with cardiovascular comorbidities seem to be at a particular risk of detrimental outcomes. (2)

Purpose
The aim of our research was to see if certain ECG characteristics at admission could be predictive of unfavourable events in severe and critical COVID-19 patients.

Methods
We analyzed patient data and available ECG records at admission for 1752 consecutively hospitalized patients with severe and critical COVID-19 at our institution from March 2020 to June 2021. ECG records were obtained from our institution's medical archives, while patient data and outcomes were analyzed through electronic medical records. We analyzed the available ECGs recorded at admission for rhythm abnormalities, heart rate, ST segment changes, presence and localisation of Q waves, interventricular conduction abnormalities, AV conduction, PR, QRS and QTc interval duration, P, QRS and T wave axis, QRS-T angle and Sokolow-Lyon hypertrophy criteria. We defined primary outcomes as mechanical ventilation requirement and intrahospital death.

Results
Our results show that patients who required mechanical ventilation were significantly (P&lt;0.05) more likely to have atrial fibrillation at admission, be tachycardic, have ST depression, have prolonged PR and QTc intervals, as well as pathological T wave axis and QRS-T angle. In multivariate analysis atrial fibrillation (OR 1.55, CI 1.07-2.23), tachycardia (OR 1.45, CI 1.17-1.80), prolonged PR interval (OR 1.88, CI 1.12-3.15) were independently associated with increased need for mechanical ventilation. Intrahospital mortality was significantly (P&lt;0.05) increased in patients who had atrial fibrillation, were tachycardic, had ST depression or elevation, right bundle branch block, left bundle branch block, prolonged PR interval and QRS duration, short and long QTc interval, pathological T wave axis and QRS-T angle. Following multivariate adjustment, atrial fibrillation (OR 2.30, CI 1.59-3.32), tachycardia (OR 1.30, CI 1.05-1.61), ST depression (OR 1.91, CI 1.34-2.72), prolonged PR interval (OR 2.55, CI 1.53-4.25), short QTc interval (OR 8.64, CI 0.95-78.57) and pathological T wave axis (OR 0.71, CI 0.47-1.07) and QRS-T angle (OR 1.85, 1.25-2.73) independently significantly increased mortality.

Conclusion
Specific ECG changes seen already at admission seem to be associated with the need for mechanical respiratory support and increased mortality in COVID-19 patients. This readily available and easily utilised method can potentially help in early identification of those at risk in order to monitor patients more carefully and potentially alter early treatment approach.