The outbreak of the novel coronavirus epidemic changed how healthcare systems around the globe act. Until today, we took for granted the ability to do multiple laboratory tests, such as long-term ECG monitoring or echocardiography. Now access to these facilities has been radically restricted as they are now being used for another purpose – to serve as a weapon in the uneven battle with the virus.
SARS-Cov-2 pathogenetic insight
The first patients were diagnosed with COVID-19 in the first days of December 2019 in the Chinese city of Wuhan, until then known for its Institute of Virology. After the worldwide spread of the pathogen, the majority of cases developed acute respiratory distress syndrome (ARDS), but many health centers have also reported the presence of heart muscle involvement1 resulting in acute cardiac injury, heart failure, and arrhythmia. Patients with preexisting cardiovascular disease, such as hypertension, heart failure, coronary disease, and arrhythmic conditions are reported to have a poor prognosis and higher Intensive Care Unit (ICU) admission rates than the rest of the population2. There are numerous pathogenetic hypotheses for myocardial injury caused by SARS-Cov-2, including molecular binding to ACE2 receptors present not only on pulmonary alveoli, but also on cardiomyocytes, and the invasion of them3; cytokine storms secondary to lung infection resulting in a dramatic increase in inflammatory signals which harm other organs4, 5; and adverse responses to proposed treatments.
Cardiac involvement in COVID-19
Observational studies conducted before today have shown that direct cardiac involvement in COVID-19 can contribute to symptoms presented by patients and long-term results due to heart tissue destruction6, 7. Reports from Italian researchers7 herald that many people with the confirmed presence of SARS-Cov-2 died while being quarantined, which can be attributed to sudden cardiac death (SCD) and arrhythmic events. Both features pose serious questions if the real face of the virus is a cardiac serial killer. Moreover, there are even more endangered groups who should be meticulously monitored while in non-hospital settings – patients with preexisting arrhythmic diseases, such as in groups suggested by an international group of arrhythmologists8. The use of long-term Holter monitoring seems to be a potentially useful tool for these patients. First of all, a Holter-ECG does not need to be performed with the patient’s on-site presence and can be performed using remote techniques. What is more, it seems to be a reliable tool with which to assess arrhythmia risk not only in the acute phase, but also as an assessment of long-term complications due to heart muscle fibrosis.
Many centers have proposed treatment options for the novel disease. Until now, there is no pathogen-specific cure and the proposed medications involve numerous pharmacologic agents targeted mainly at blocking an inflammatory response and thus attenuating the ongoing cytokine storm. Substances experimentally used in clinics around the world most often include potent agents used in rheumatology such as quinine derivates: chloroquine and hydroxychloroquine, macrolide antibiotic azithromicine9 and direct antiviral agents: ribavirin, remdesivir, oseltamivir, lopinavir/ritonavir, and others10. Antimalarials are reported to be successful in preventing acute respiratory distress syndrome, but their side effect spectrum includes QT interval prolongation, and heart conduction system malfunction due to increased depolarization length duration. Azithromycin has established a potential for causing potentially lethal arrhythmias resulting in sudden cardiac death11. In a regular clinical setting, combining these agents would pose serious questions, but facing a lethal and previously unknown disease puts us in a completely different situation. In a web-based communication supported by the American College of Cardiology, Simpson et al. propose a harm and risk reduction algorithm for physicians using these medical agents12. Nevertheless, it should be underlined that the risk is serious, and patients should be subjected to regular ECG interrogations13. Possible solutions also include Holter-ECG, which is a confirmed and easy to use tool to monitor both arrhythmic events and QT segment changes. Novel devices, such as adhesive patches and design-friendly recorders used for long-term monitoring provide an easy-to-use way of communicating with medical professionals. Medical algorithms can support a scarcity of doctors in the assessment of recorded signals. Their use should definitely be considered as the disease spreads and beings to require even closer cooperation of the medical industry and medical professionals.
The spread of COVID-19 is a threat posed to healthcare systems worldwide, not only due to its acute presentation, but also its long-term damage. Arrhythmic complications are one of the presentations of the disease and should be taken into consideration in diagnostic and treatment algorithms. Holter-ECG monitoring seems to be a feasible way of managing heart rhythm disorders encountered in patients affected by SARS-Cov-2.
 Bansal M: Cardiovascular disease and COVID-19. Diabetes Metab Syndr 2020; 14:247-250.
 Wu Z, McGoogan JM: Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72 314 cases from the Chinese Center for Disease Control and Prevention. Jama 2020.
 Xiong T-Y, Redwood S, Prendergast B, Chen M: Coronaviruses and the cardiovascular system: acute and long-term implications. European heart journal 2020.
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 Inciardi RM, Lupi L, Zaccone G, Italia L, Raffo M, Tomasoni D, Cani DS, Cerini M, Farina D, Gavazzi E, Maroldi R, Adamo M, Ammirati E, Sinagra G, Lombardi CM, Metra M: Cardiac Involvement in a Patient With Coronavirus Disease 2019 (COVID-19). JAMA Cardiology 2020.
 Kochi AN, Tagliari AP, Forleo GB, Fassini GM, Tondo C: Cardiac and arrhythmic complications in Covid-19 patients. Journal of cardiovascular electrophysiology 2020.
 Wu CI, Postema PG, Arbelo E, Behr ER, Bezzina CR, Napolitano C, Robyns T, Probst V, Schulze-Bahr E, Remme CA, Wilde AAM: SARS-CoV-2, COVID-19 and inherited arrhythmia syndromes. Heart Rhythm 2020.
 Gautret P, Lagier JC, Parola P, Hoang VT, Meddeb L, Mailhe M, Doudier B, Courjon J, Giordanengo V, Vieira VE, Dupont HT, Honoré S, Colson P, Chabrière E, La Scola B, Rolain JM, Brouqui P, Raoult D: Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents 2020:105949.
 Zhou M, Zhang X, Qu J: Coronavirus disease 2019 (COVID-19): a clinical update. Frontiers of Medicine 2020.
 Ray WA, Murray KT, Hall K, Arbogast PG, Stein CM: Azithromycin and the risk of cardiovascular death. The New England journal of medicine 2012; 366:1881-1890.
 Simpson TF, Kovacs RJ, Stecker EC: Ventricular Arrhythmia Risk Due to Hydroxychloroquine-Azithromycin Treatment For COVID-19. Cardiology Magazine: American College of Cardiology, 2020, pp.
 Roden DM, Harrington RA, Poppas A, Russo AM: Considerations for Drug Interactions on QTc in Exploratory COVID-19 (Coronavirus Disease 2019) Treatment. Circulation 2020.