Is T-Wave Alternans a Repolarization Abnormality Marker in COVID-19? an Investigation on the Potentialities of Portable Electrocardiogram Device

Background: Cardiac arrhythmias are significantly associated with poor outcomes in coronavirus disease 2019 (COVID-19) patients. Microvolt T-wave alternans (TWA) can be automatically quantified and has been recognized as a representation of repolarization hetero-geneity and linked to arrhythmogenesis in various cardiovascular dis-eases. This study aimed to explore the correlation between microvolt TWA and COVID-19 pathology. Methods: Patients suspected of COVID-19 in Mohammad Hoesin General Hospital were consecutively evaluated using Alivecor (R) Kar-diamobile 6LTM portable electrocardiogram (ECG) device. Severe COVID-19 patients or those who are unable to cooperate in active ECG self-recording were excluded from the study. TWA was detected and its amplitude was quantified using the novel enhanced adaptive match filter (EAMF) method. Results: A total of 175 patients, 114 COVID-19 patients (polymer-ase chain reaction (PCR)-positive group), and 61 non-COVID-19 pa -tients (PCR-negative group) were enrolled in the study. PCR-positive group was subdivided according to the severity of COVID-19 pathol-ogy into mild and moderate severity subgroups. Baseline TWA levels were similar between both groups during admission (42.47 +/- 26.52 mu V vs. 44.72 +/- 38.21 mu V), but higher TWA levels were observed during discharge in the PCR-positive compared to the PCR-negative group (53.45 +/- 34.42 mu V vs. 25.15 +/- 17.64 mu V, P = 0.03). The correlation between PCR-positive result in COVID-19 and TWA value was sig-nificant, after adjustment of other confounding variables (R2 = 0.081, P = 0.030). There was no significant difference in TWA levels between mild and moderate severity subgroups in patients with COVID-19, both during admission (44.29 +/- 27.14 mu V vs. 36.75 +/- 24.46 mu V, P = 0.34) and discharge (49.47 +/- 33.62 mu V vs. 61.09 +/- 35.99 mu V, P = 0.33). Conclusions: Higher TWA values can be observed on follow-up ECG obtained during discharge in the PCR-positive COVID-19 patients.