Fragmentation of the QRS Complex Is Associated with Right Ventricular Dilatation and Mortality in Critically Unwell Coronavirus Disease 2019 Patients

Background: QRS fragmentation (fQRS) is a depolarization disorder that can be detected on routine electrocardiography (ECG). Current evidence suggests that fQRS is a prognosticator of adverse cardiovascular events. This study aimed to assess the relationship between fQRS and all-cause mortality in critically unwell coronavirus disease 2019 (COVID-19) patients and to investigate the significance of associated abnormalities on echocardiography.

Methods: A retrospective cohort study of COVID-19 patients in a critical care setting was performed. Electrocardiography was performed on presentation to hospital, admission to the critical care unit, and at subsequent points according to clinical need. Transthoracic echocardiography was performed at clinical discretion to assess for structural and functional cardiac abnormalities. Primary outcome was in-hospital mortality and secondary outcome was the need for mechanical invasive ventilation.

Results: Totally, 212 consecutive patients were included of which 120 (57%) exhibited fQRS and inferior leads were involved in 88% of the patients. Overall, fQRS was a significant predictor of mortality [65% vs. 44% P =.003; multivariate odds ratio = 2.96, 95% confidence interval (CI): 1.42-6.40, P =.005] and inferior fQRS itself was a significant predictor of mortality (P =.03). There was no significant association between fQRS and the need for invasive mechanical ventilation. A total of 112 patients underwent echocardiography. There was a greater incidence of right ventricular (RV) dilatation in the fQRS group (16%
vs. 2% respectively, P =.02) and pulmonary hypertension (33% vs. 14% respectively, P =.03) based on echocardiographic criteria.

Conclusion: Our study demonstrates that fQRS is significantly associated with RV dilation, pulmonary hypertension, and mortality in critically unwell COVID-19 patients.