Electrocardiographic Manifestations of COVID-19: Effect on QRS and QTc

Introduction: Prolonged QT intervals have been reported in patients with COVID-19. Virus particles have been demonstrated in heart tissue and direct effects on cardiac function have been noted. We hypothesize that cardiac electrophysiologic abnormalities may be a direct effect of COVID-19.Methods: 814 patients with RT-PCR proven COVID-19 were admitted and 614 discharged home from St. Francis Hospital Emergency Room (ER) between March-May 2020. Corrected QT (QTc) and QRS intervals were measured from ECG’s performed in the ER prior to intervention or administration of QT prolonging drugs. QTc and QRS intervals were evaluated as a function of disease severity (patients admitted versus discharged home; inpatients admitted to medical vs critical care unit) and cardiac involvement (troponin elevation >0·03 ng/ml, elevated B-natriuretic peptide (BNP) or NT pro-BNP >500 pg/ml). Multivariable analysis was used to test for significance (p<0·05) of disease severity and cardiac involvement in baseline QTc and QRS. Logistic regression was used to generate odds ratio for predictors of disease severity and mortality.Results: Average age was 66 ± 16 years, 45% female, 46% hypertensive, 28% diabetic, average body mass index of 28·7 ± 6·4 kg/m 2 . Baseline QTc of inpatients was prolonged compared to patients discharged home (450·1 ± 30·2 msec versus 423·4 ± 21·7msec, p<0·0001). In inpatients with either elevated troponin or abnormal BNP (34·4%), both baseline QTc and QRS were prolonged compared to those with normal levels (troponin - QTc: 460·9 ± 34·6 msec versus 445·3 ± 26·6 msec, p<0·0001, QRS: 98·7 +- 24·6 vs 90.5 ± 16.9 msec; p<0·0001; BNP - QTc: 465·9 ± 33·0 msec versus 446·0 ± 26·2 msec, p<0·0001, QRS: 103·6 ± 25·3 versus 90·6 +- 17·6, p<0·0001). Findings were confirmed with multivariable analysis (QTc: inpatient vs discharged, p<0·0001, elevated troponin, p=0·0007, abnormal BNP, p=0·0014; QRS: elevated troponin p=0.0506, abnormal BNP p<0·0001). Baseline QTc ≥500 msec was found to be an independent predictor of mortality (OR 2·03, CI [0·967, 4·27], p=0·06). QTc prolongation was associated with increased mortality (8·3% for every 10 msec increase in QTc; OR 1·083, CI [1·002, 1·171], p=0·04).Conclusion: Abnormalities of cardiac activation (QRS) and repolarization (QTc) are direct manifestations of COVID-19 and early markers for progression to severe disease. The ECG, a readily accessible tool, identifies cardiac involvement and can be used to predict disease course and mortality.Funding Statement: Funding provided by the research foundation at Catholic Health of Long Island.Declaration of Interests: None.Ethics Approval Statement: The study was submitted for expedited Internal Review Board Review and received a waiver given its retrospective nature of data analysis in anonymized subjects.