What Happened to Electrocardiogram as a Screening Test to Recognize Cardiovascular Complications in COVID-19 Patients?

We read with great interest the paper from Lala et al. (1). The authors must be congratulated for focusing attention on the clinical relevance of troponin I as a marker of myocardial injury in patients with coronavirus disease 2019 (COVID-19) and on the strong prognostic implications of this simple and easily available biomarker. Unfortunately, troponin is a generic marker of myocardial damage and cannot provide any valuable insight into the pathophysiological mechanism of the damage. We believe that this limitation could have been partly resolved by the systematic evaluation of standard electrocardiogram (ECG). Paradoxically and unexpectedly, 5 months after the beginning of the “COVID-19 era,” data on standard ECG as a screening tool for cardiovascular complications are almost completely missing in the literature—1 recently published and 1 in-press paper (2,3)—whereas ECG details are available only for selected patients diagnosed with myocarditis or acute coronary syndrome. The extreme lack of ECG data is all the stranger considering it is a broadly available, low-cost diagnostic test that can be quickly performed without exposing a large number of personnel to the virus. This ECG eclipse has contributed to generate the misconception that “myocardial injury” diagnosed by elevated serum troponin is synonymous with myocarditis or acute coronary syndrome, neglecting the fact, for instance, that acute pressure overload of the right ventricle can also cause an increase of this biomarker. Indeed, compared to troponin, ECG can provide not only a generic diagnosis of myocardial injury or damage but can also orient to the specific pathophysiological mechanism and foster suspicion of pulmonary thromboembolic or in situ thrombosis of the pulmonary circulation, which are being described with increasing frequency (4).

In conclusion, the high frequency and the prognostic implications of increased troponin I reported by Lala et al. support the importance of a systematic screen of the full spectrum of cardiovascular complications of COVID-19 infection, including events threatening the right and not only the left ventricle. Standard ECG is fundamental in this strategy, so systematic studies on this issue are urgently needed.