COVID-19’s Hidden Shield: How Post-Infection Hearts Safeguard Against Atrial Contractions

COVID-19’s Hidden Shield: How Post-Infection Hearts Safeguard Against Atrial Contractions | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article COVID-19’s Hidden Shield: How Post-Infection Hearts Safeguard Against Atrial Contractions Zinah Ahmed Almuttairi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4018774/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Ectopic atrial contractions, also known as premature atrial contractions (PACs), are abnormal heart rhythms originating from the atria (the upper chambers of the heart). These contractions occur earlier than expected during the cardiac cycle and can disrupt the normal rhythm. While they are generally benign, their presence can sometimes cause symptoms such as palpitations. The exact mechanisms linking COVID-19 and EACs are not fully understood, and some evidence suggests that COVID-19 infection can increase the risk of developing EACs or other types of arrhythmias. Objectives: Effects of the EAC on post-COVID-19 patients Materials and Methods: This is a case‒control study of middle-aged individuals of either sex involving 50 adult patients with post-COVID-19 infection (eight were excluded from the study because they were not cooperative), 23 females and 19 males with a mean age of 36.98 ± 12.2 years who were not vaccinated against COVID-19 after one month to two years of an acute episode of COVID-19 (confirmed by positive real-time reverse-transcription polymerase chain reaction (RT‒PCR)) according to the World Health Organization (WHO) selected randomly from those attending to the adult Holter and Echocardiography Laboratory in Al-Zahraa Hospital/Al-Hussein Medical City/Karbala Province after being referred by an internist during the period from the 12th of October 2022 to the end of January 2024 and divided into three groups: nonhospitalize, hospitalize and admitted to intensive care. The control group consisted of 40 healthy persons, 23 females and 17 males with a mean age of 33.28 ± 9.58 years, who were referred by an internist for ECG and echocardiography with no Hx of the previous infection of COVID-19. All of them underwent electrocardiographic evaluation via ECG and Holter ECG for 24 hours. Conclusion: Post-COVID-19 patients had a lower risk of EAC than control patients, indicating that it may have a protective effect on EAC and reduce the risk of cardiac arrhythmias. Physiology Cardiac & Cardiovascular Systems SARS-CoV-2 COVID-19 ECG EAC Introduction Ectopic atrial contractions, also known as premature atrial contractions (PACs), are abnormal heart rhythms originating from the atria (the upper chambers of the heart). These contractions occur earlier than expected during the cardiac cycle and can disrupt the normal rhythm. While they are generally benign, their presence can sometimes cause symptoms such as palpitations¹. A review of arrhythmias during COVID-19 revealed that the incidence of arrhythmias was greater in critically ill patients; for instance, 16.5% of ICU patients with COVID-19 experienced atrial tachyarrhythmias². EAC is usually benign and does not require treatment unless it is frequent or causes symptoms. EAC is not uncommon among patients with COVID-19, especially those who are hospitalized or have severe illness. EAC may be associated with inflammation, hypoxia, electrolyte imbalance, or cardiac injury caused by the virus⁴. Some studies have reported an increased risk of cardiac arrhythmias in COVID-19 patients, especially those with severe or critical illness or those with preexisting cardiovascular diseases, possibly due to direct or indirect effects of the virus on the heart, such as myocarditis, pericarditis, myocardial ischaemia, or autonomic dysfunction ⁵´⁶. There is some evidence that COVID-19 infection can increase the risk of developing EAC or other types of arrhythmias, either during the acute phase of the illness or in the post-COVID-19 period. This may be due to several factors, such as inflammation of the heart muscle or blood vessels, lack of oxygen, stress, or immune system overreaction ⁷. Dewland TA, Whitman IR, Win S, et al. found no evidence of malignant or sustained arrhythmias, such as atrial fibrillation, atrial flutter, or ventricular tachycardia. However, 92% of the participants reported palpitations, which were mostly due to sinus rhythm, sinus tachycardia, or isolated ectopy. Subjects and Methods The study population At the College of Medicine, Al-Nahrain University, Iraq, conducted a case–control study from October 2022 to February 2023. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Institute Review Board (IRB) of Al-Nahrain University/College of Medicine on October 2022 (191/2022), and participants provided informed consent. This study included 90 patients, 50 adult patients with post-COVID-19 infections (eight were excluded from the study because they were not cooperative), and the control group consisted of forty healthy persons. The remaining 90 patients who agreed to participate in this research were selected randomly from among those attending the adult Holter and Echocardiography Laboratory in Al-Zahraa Hospital/Al-Hussein Medical City/Karbala Province after being referred by an internist. Sample Collection Group I (Patients Post-COVID-19 Infection Group) This group consisted of forty-two patients, 23 females and 19 males with a mean age of 36.98 ± 12.2 years, who were not vaccinated against COVID-19 after one month to two years of an acute episode of COVID-19 (confirmed by positive real-time reverse-transcription polymerase chain reaction (RT‒PCR)) according to the World Health Organization (WHO). The patients were divided into three groups: nonhospitalized (those with mild or moderate illness and any of the various signs or symptoms of COVID-19 but who did not require hospital admission), hospitalized (those with severe illness), and admitted to intensive care. Age, sex, body mass index, heart rate, and Holter ECG for 24 hours were recorded for each study participant; ECG was used to assess and assess the EAC. The inclusion criteria included patients aged > 18 to 60 years, nonvaccinated patients after 30 days to 2 years of acute episodes of COVID-19, and exclusion criteria included any patient with any one of the following: asymptomatic or presymptomatic infection (positive PCR but no symptoms of COVID-19), vaccinated, less than 30 days after an acute episode of COVID-19, < 18 years old, IHD, valvular heart disease, positive family history of heart disease, diabetes mellitus, stroke, renal failure, or connective tissue disease. Group II (Control Group) This group consisted of forty healthy people, 23 females and 17 males with a mean age of 33.28 ± 9.58 years, who were referred by an internist for ECG and echocardiography with no Hrs. of previous COVID-19 infection. On examination, it shows no underlying problem; this is proven by cardiac electrophysiological and echocardiographic investigation. Materials and Instruments Standard twelve-lead ECG was performed for every patient in our study using a Philips Pagewriter TC20 ECG device from Philips Medical Devices. ECG was performed while the patient was lying in a supine position in a quiet room in the Holter and Echocardiography Laboratory at Al-Zahraa Hospital. All ECG traces were assessed by a professional specialist. A Holter 24-hr study was performed for each patient in our study (MARS. model: 8200 W. Tower Avenue Milwaukee Wisconsin 53223, USA). The device's software analysed the records (three channels, lead II, AVL, V1) to detect arrhythmia and conduction issues. Statistical analysis All analyses were performed by using SPSS software version 25.0 (SPSS, Chicago). Continuous data are presented as the mean and standard deviation and were analysed with Student’s t test. Categorical variables are expressed as numbers and percentages and were analysed with the chi-square test. A p value less than 0.05 was considered to indicate a statistically significant difference. Results The mean age of the patients was 36.98 ± 12.2 years, which was slightly greater than that of the controls (33.28 ± 9.58 years), with no significant difference. Likewise, the two groups were comparable in terms of sex distribution, weight, height and BMI, with no significant differences (Table 1 ). Table 1 Demographic characteristics and clinical data of the study population Variables Patients (n = 42) Controls (n = 40) p- value Age, years Mean ± SD Range 36.98 ± 12.2 19–60 33.28 ± 9.58 19–49 0.132 Sex Male Female 19(45.24%) 23(54.76%) 18(45%) 22(55%) 0.893 Weight, kg Mean ± SD Range 75.93 ± 11.98 56–110 74.18 ± 15.58 43–115 0.568 Height, cm Mean ± SD Range 165.62 ± 8.0 142–181 163.35 ± 13.0 100–185 0.340 BMI, k/m 2 Mean ± SD Range 27.78 ± 4.73 20.76–42.97 28.23 ± 7.82 15.79-66.0 0.754 HR, beats/min Mean ± SD Range 94.24 ± 31.57 60–169 106.95 ± 32.39 65–164 0.076 Rare and frequent EAC were more common among the controls (32.5% and 20%, respectively) than among the patients (16.67% and 0%, respectively), with a significant difference (Table 2 ). Table 2 Holter parameters in patients and controls Variables Patients (n = 42) Controls (n = 40) p- value EAC, b/h Negative Rare Frequent 35(83.33%) 7(16.67%) 0(0%) 19(47.5%) 13(32.5%) 8(20%) 0.004 No demographic characteristics were significantly associated with disease severity, and none of the included demographic characteristics were significantly associated with COVID-19 severity. Although the mean BMI was greater in nonhospitalized patients (28.43 ± 4.83 kg/m2) than in hospitalized patients (25.0 ± 3.19 kg/m2), the difference exceeded the acceptable limit of Table 3 . Table 3 Association of demographic characteristics with disease severity Variables Nonhospitalized (n = 34) Hospitalized (n = 8) p- value Age, years Mean ± SD Range 37.97 ± 12.57 19–60 32.75 ± 10.04 19–50 0.281 Gender Male Female 15(44.12%) 19(55.88%) 4(50%) 4(50%) 0.764 Weight, kg Mean ± SD Range 76.97 ± 12.15 58.0-110 71.5 ± 10.84 56.0–88.0 0.250 Height, cm Mean ± SD Range 164.85 ± 8.6 142–181 168.88 ± 3.27 161–171 0.204 BMI, k/m 2 Mean ± SD Range 28.43 ± 4.83 20.96–42.97 25.0 ± 3.19 30.76–30.09 0.064 EAC had no significant association with COVID-19 severity (Table 4 ). Table 4 Association between Holter monitoring and disease severity Variables Nonhospitalized (n = 34) Hospitalized (n = 8) p- value EAC Negative Rare 20(58.82%) 14(41.18%) 5(62.5%) 3(37.5%) 0.849 Discussion This study is one of the few case‒control studies that assessed the long-term impact of COVID‒19 on the EAC, as most of the existing studies focused on the acute phase or short-term follow-up. However, this study revealed a lower risk of EAC in post-COVID‒19 patients than in the control group, which is contrary to the above findings. This may suggest that post-COVID-19 status has a protective effect on the EAC, possibly by modulating the immune system, reducing inflammation, or enhancing cardiac autonomic function ⁹. COVID-19 infection can trigger a dysregulated immune response, leading to excessive inflammation and tissue damage ¹⁰. However, some studies suggest that post-COVID-19 patients may have a more balanced and regulated immune system, as they produce antibodies and memory cells that can recognize and neutralize the virus ¹¹. In addition, COVID-19 infection can cause systemic inflammation, which can impair the function of various organs, including the heart, lungs, kidneys, and brain ¹². However, post-COVID-19 patients may have lower levels of inflammation, as they clear the virus and resolve tissue damage¹³. Moreover, post-COVID-19 patients may have increased levels of anti-inflammatory molecules, such as interleukin-10 and transforming growth factor-beta, which can modulate the inflammatory response and promote tissue repair¹⁴. According to cardiac autonomic function, COVID-19 infection can affect cardiac autonomic function (the ability of the heart to adjust its rate and rhythm), and COVID-19 can impair cardiac autonomic function by causing direct damage to the heart muscle, nerve fibres, or receptors or by inducing stress, anxiety, or depression. However, post-COVID-19 patients may have improved cardiac autonomic function, as they recover from the acute phase and restore their cardiac health. Furthermore, post-COVID-19 patients may have enhanced cardiac autonomic function by engaging in physical activity, relaxation techniques, or cardiovascular rehabilitation programs, which can stimulate the parasympathetic nervous system and improve heart rate variability. Conclusion Post-COVID-19 patients had a lower risk of EAC than did those in the control group, indicating that EAC may have a protective effect on cardiac arrhythmias. Declarations Data availability The datasets used and/or analysed during the current study are available from the corresponding author upon reasonable request. Funding and support This research received no specific funding from public, commercial, or nonprofit funding agencies. Conflict of interest statement: The authors declare that there are no conflicts of interest. Author contributions References Rupert, F.G., Jessica Langtree, Andrew R.J., 2017. Ectopic Beats: How Many Count? EMJ Cardiol. 2017;5[1]:88-92. Turagam, M. K., Musikantow, D., Goldman, M. E. and others, 2020. Malignant Arrhythmias in Patients With COVID-19: Incidence, Mechanisms, and Outcomes. Circulation: Arrhythmia and Electrophysiology, 13(11), e008920. Heaton, J., & Yandrapalli, S. (2023, August 8). Premature Atrial Contractions. In StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. Available from: StatPearls - Premature Atrial Contractions. Dewland, T.A., Whitman, I.R., Win, S. and others, 2022. Prospective arrhythmia surveillance after a COVID-19 diagnosis. Open Heart, 9(1), p.e001758. Chang, S.E., Feng, A., Meng, W. and others, 2021. SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans. Nature Communications, 12(1), p.5417. Larsen, N.W., Stiles, L.E., Shaik, R., Schneider, L., Muppidi, S., Tsui, C. and Miglis, M., 2022. Characterization of autonomic symptom burden in long COVID: a global survey of 2,314 adults. medRxiv, p.22274300. Emadi-Baygi, M., Ehsanifard, M., Afrashtehpour, N., Norouzi, M. and Joz-Abbasalian, Z., 2021. Corona Virus Disease 2019 (COVID-19) as a System-Level Infectious Disease with Distinct Sex Disparities. Frontiers in Immunology, 12, p.778913. Dillon, G.A., Joyner, M.J. and Baker, S.E., 2023. Closing the window on COVID-19 case‒control studies. American Journal of Physiology - Heart and Circulatory Physiology, 324(2), pp.H364-H365. Greenhalgh, T., Knight, M., A’Court, C., Buxton, M. and Husain, L., 2020. Management of postacute covid-19 in primary care. BMJ, 370, p.m3026. Tahaghoghi-Hajghorbani, S., Zafari, P., Masoumi, E. and others, 2020. The role of dysregulated immune responses in COVID-19 pathogenesis. Virus Research, 290, p.198197. Sun, Y., Zou, Y., Wang, H., Cui, G., Yu, Z. and Ren, Z., 2022. Immune response induced by novel coronavirus infection. Frontiers in Cellular and Infection Microbiology, 12, p.988604. Jain, U., 2020. Effect of COVID-19 on the organs. Cureus, 12(8), p.e9540 Newell, K.L. and Waickman, A.T., 2022. Inflammation, immunity, and antigen persistence in postacute sequelae of SARS-CoV-2 infection. Current Opinion in Immunology, 77, p.102228. Allendes, F.J., Díaz, H.S., Ortiz, F.C., Marcus, N.J., Quintanilla, R., Inestrosa, N.C. and Del Rio, R., 2023. Cardiovascular and autonomic dysfunction in long-COVID syndrome and the potential role of noninvasive therapeutic strategies on cardiovascular outcomes. Frontiers in Medicine, 10, p.1. Skow, R.J., Garza, N.A., Nandadeva, D., Stephens, B.Y., Wright, A.N., Grotle, A.K., Young, B.E. and Fadel, P.J., 2022. Impact of COVID-19 on cardiac autonomic function in healthy young adults: potential role of symptomatology and time since diagnosis. American Journal of Physiology - Heart and Circulatory Physiology, 323(6), p.H1206-H1211. Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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These contractions occur earlier than expected during the cardiac cycle and can disrupt the normal rhythm. While they are generally benign, their presence can sometimes cause symptoms such as palpitations\u0026sup1;. A review of arrhythmias during COVID-19 revealed that the incidence of arrhythmias was greater in critically ill patients; for instance, 16.5% of ICU patients with COVID-19 experienced atrial tachyarrhythmias\u0026sup2;. EAC is usually benign and does not require treatment unless it is frequent or causes symptoms. EAC is not uncommon among patients with COVID-19, especially those who are hospitalized or have severe illness. EAC may be associated with inflammation, hypoxia, electrolyte imbalance, or cardiac injury caused by the virus⁴. Some studies have reported an increased risk of cardiac arrhythmias in COVID-19 patients, especially those with severe or critical illness or those with preexisting cardiovascular diseases, possibly due to direct or indirect effects of the virus on the heart, such as myocarditis, pericarditis, myocardial ischaemia, or autonomic dysfunction ⁵\u0026acute;⁶. There is some evidence that COVID-19 infection can increase the risk of developing EAC or other types of arrhythmias, either during the acute phase of the illness or in the post-COVID-19 period. This may be due to several factors, such as inflammation of the heart muscle or blood vessels, lack of oxygen, stress, or immune system overreaction ⁷. Dewland TA, Whitman IR, Win S, et al. found no evidence of malignant or sustained arrhythmias, such as atrial fibrillation, atrial flutter, or ventricular tachycardia. However, 92% of the participants reported palpitations, which were mostly due to sinus rhythm, sinus tachycardia, or isolated ectopy.\u003c/p\u003e"},{"header":"Subjects and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eThe study population\u003c/h2\u003e \u003cp\u003eAt the College of Medicine, Al-Nahrain University, Iraq, conducted a case\u0026ndash;control study from October 2022 to February 2023. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Institute Review Board (IRB) of Al-Nahrain University/College of Medicine on October 2022 (191/2022), and participants provided informed consent. This study included 90 patients, 50 adult patients with post-COVID-19 infections (eight were excluded from the study because they were not cooperative), and the control group consisted of forty healthy persons. The remaining 90 patients who agreed to participate in this research were selected randomly from among those attending the adult Holter and Echocardiography Laboratory in Al-Zahraa Hospital/Al-Hussein Medical City/Karbala Province after being referred by an internist.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eSample Collection Group I (Patients Post-COVID-19 Infection Group)\u003c/h2\u003e \u003cp\u003eThis group consisted of forty-two patients, 23 females and 19 males with a mean age of 36.98\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2 years, who were not vaccinated against COVID-19 after one month to two years of an acute episode of COVID-19 (confirmed by positive real-time reverse-transcription polymerase chain reaction (RT‒PCR)) according to the World Health Organization (WHO). The patients were divided into three groups: nonhospitalized (those with mild or moderate illness and any of the various signs or symptoms of COVID-19 but who did not require hospital admission), hospitalized (those with severe illness), and admitted to intensive care.\u003c/p\u003e \u003cp\u003eAge, sex, body mass index, heart rate, and Holter ECG for 24 hours were recorded for each study participant; ECG was used to assess and assess the EAC. The inclusion criteria included patients aged\u0026thinsp;\u0026gt;\u0026thinsp;18 to 60 years, nonvaccinated patients after 30 days to 2 years of acute episodes of COVID-19, and exclusion criteria included any patient with any one of the following: asymptomatic or presymptomatic infection (positive PCR but no symptoms of COVID-19), vaccinated, less than 30 days after an acute episode of COVID-19, \u0026lt;\u0026thinsp;18 years old, IHD, valvular heart disease, positive family history of heart disease, diabetes mellitus, stroke, renal failure, or connective tissue disease.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eGroup II (Control Group)\u003c/h2\u003e \u003cp\u003eThis group consisted of forty healthy people, 23 females and 17 males with a mean age of 33.28\u0026thinsp;\u0026plusmn;\u0026thinsp;9.58 years, who were referred by an internist for ECG and echocardiography with no Hrs. of previous COVID-19 infection. On examination, it shows no underlying problem; this is proven by cardiac electrophysiological and echocardiographic investigation.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003eMaterials and Instruments\u003c/h2\u003e \u003cp\u003eStandard twelve-lead ECG was performed for every patient in our study using a Philips Pagewriter TC20 ECG device from Philips Medical Devices. ECG was performed while the patient was lying in a supine position in a quiet room in the Holter and Echocardiography Laboratory at Al-Zahraa Hospital. All ECG traces were assessed by a professional specialist. A Holter 24-hr study was performed for each patient in our study (MARS. model: 8200 W. Tower Avenue Milwaukee Wisconsin 53223, USA). The device's software analysed the records (three channels, lead II, AVL, V1) to detect arrhythmia and conduction issues.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAll analyses were performed by using SPSS software version 25.0 (SPSS, Chicago). Continuous data are presented as the mean and standard deviation and were analysed with Student\u0026rsquo;s t test. Categorical variables are expressed as numbers and percentages and were analysed with the chi-square test. A p value less than 0.05 was considered to indicate a statistically significant difference.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe mean age of the patients was 36.98\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2 years, which was slightly greater than that of the controls (33.28\u0026thinsp;\u0026plusmn;\u0026thinsp;9.58 years), with no significant difference. Likewise, the two groups were comparable in terms of sex distribution, weight, height and BMI, with no significant differences (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDemographic characteristics and clinical data of the study population\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePatients\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;42)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControls\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep- value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, years\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.98\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2\u003c/p\u003e \u003cp\u003e19\u0026ndash;60\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.28\u0026thinsp;\u0026plusmn;\u0026thinsp;9.58\u003c/p\u003e \u003cp\u003e19\u0026ndash;49\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.132\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003cp\u003eMale\u003c/p\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19(45.24%)\u003c/p\u003e \u003cp\u003e23(54.76%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18(45%)\u003c/p\u003e \u003cp\u003e22(55%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.893\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWeight, kg\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e75.93\u0026thinsp;\u0026plusmn;\u0026thinsp;11.98\u003c/p\u003e \u003cp\u003e56\u0026ndash;110\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e74.18\u0026thinsp;\u0026plusmn;\u0026thinsp;15.58\u003c/p\u003e \u003cp\u003e43\u0026ndash;115\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.568\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHeight, cm\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e165.62\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0\u003c/p\u003e \u003cp\u003e142\u0026ndash;181\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e163.35\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e \u003cp\u003e100\u0026ndash;185\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.340\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBMI, k/m\u003c/b\u003e\u003csup\u003e\u003cb\u003e2\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.78\u0026thinsp;\u0026plusmn;\u0026thinsp;4.73\u003c/p\u003e \u003cp\u003e20.76\u0026ndash;42.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.23\u0026thinsp;\u0026plusmn;\u0026thinsp;7.82\u003c/p\u003e \u003cp\u003e15.79-66.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.754\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHR, beats/min\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e94.24\u0026thinsp;\u0026plusmn;\u0026thinsp;31.57\u003c/p\u003e \u003cp\u003e60\u0026ndash;169\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e106.95\u0026thinsp;\u0026plusmn;\u0026thinsp;32.39\u003c/p\u003e \u003cp\u003e65\u0026ndash;164\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.076\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eRare and frequent EAC were more common among the controls (32.5% and 20%, respectively) than among the patients (16.67% and 0%, respectively), with a significant difference (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eHolter parameters in patients and controls\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePatients\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;42)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControls\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep- value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEAC, b/h\u003c/b\u003e\u003c/p\u003e \u003cp\u003eNegative\u003c/p\u003e \u003cp\u003eRare\u003c/p\u003e \u003cp\u003eFrequent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35(83.33%)\u003c/p\u003e \u003cp\u003e7(16.67%)\u003c/p\u003e \u003cp\u003e0(0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19(47.5%)\u003c/p\u003e \u003cp\u003e13(32.5%)\u003c/p\u003e \u003cp\u003e8(20%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.004\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eNo demographic characteristics were significantly associated with disease severity, and none of the included demographic characteristics were significantly associated with COVID-19 severity. Although the mean BMI was greater in nonhospitalized patients (28.43\u0026thinsp;\u0026plusmn;\u0026thinsp;4.83 kg/m2) than in hospitalized patients (25.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.19 kg/m2), the difference exceeded the acceptable limit of Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAssociation of demographic characteristics with disease severity\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNonhospitalized\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;34)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHospitalized\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;8)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep- value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, years\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37.97\u0026thinsp;\u0026plusmn;\u0026thinsp;12.57\u003c/p\u003e \u003cp\u003e19\u0026ndash;60\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.75\u0026thinsp;\u0026plusmn;\u0026thinsp;10.04\u003c/p\u003e \u003cp\u003e19\u0026ndash;50\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.281\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003cp\u003eMale\u003c/p\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15(44.12%)\u003c/p\u003e \u003cp\u003e19(55.88%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(50%)\u003c/p\u003e \u003cp\u003e4(50%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.764\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWeight, kg\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e76.97\u0026thinsp;\u0026plusmn;\u0026thinsp;12.15\u003c/p\u003e \u003cp\u003e58.0-110\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e71.5\u0026thinsp;\u0026plusmn;\u0026thinsp;10.84\u003c/p\u003e \u003cp\u003e56.0\u0026ndash;88.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.250\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHeight, cm\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e164.85\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6\u003c/p\u003e \u003cp\u003e142\u0026ndash;181\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e168.88\u0026thinsp;\u0026plusmn;\u0026thinsp;3.27\u003c/p\u003e \u003cp\u003e161\u0026ndash;171\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.204\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBMI, k/m\u003c/b\u003e\u003csup\u003e\u003cb\u003e2\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.43\u0026thinsp;\u0026plusmn;\u0026thinsp;4.83\u003c/p\u003e \u003cp\u003e20.96\u0026ndash;42.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.19\u003c/p\u003e \u003cp\u003e30.76\u0026ndash;30.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.064\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eEAC had no significant association with COVID-19 severity (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAssociation between Holter monitoring and disease severity\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNonhospitalized\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;34)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eHospitalized\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;8)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep- value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEAC\u003c/b\u003e\u003c/p\u003e \u003cp\u003eNegative\u003c/p\u003e \u003cp\u003eRare\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e20(58.82%)\u003c/p\u003e \u003cp\u003e14(41.18%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5(62.5%)\u003c/p\u003e \u003cp\u003e3(37.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.849\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study is one of the few case‒control studies that assessed the long-term impact of COVID‒19 on the EAC, as most of the existing studies focused on the acute phase or short-term follow-up. However, this study revealed a lower risk of EAC in post-COVID‒19 patients than in the control group, which is contrary to the above findings. This may suggest that post-COVID-19 status has a protective effect on the EAC, possibly by modulating the immune system, reducing inflammation, or enhancing cardiac autonomic function ⁹. COVID-19 infection can trigger a dysregulated immune response, leading to excessive inflammation and tissue damage \u0026sup1;⁰. However, some studies suggest that post-COVID-19 patients may have a more balanced and regulated immune system, as they produce antibodies and memory cells that can recognize and neutralize the virus \u0026sup1;\u0026sup1;. In addition, COVID-19 infection can cause systemic inflammation, which can impair the function of various organs, including the heart, lungs, kidneys, and brain \u0026sup1;\u0026sup2;. However, post-COVID-19 patients may have lower levels of inflammation, as they clear the virus and resolve tissue damage\u0026sup1;\u0026sup3;. Moreover, post-COVID-19 patients may have increased levels of anti-inflammatory molecules, such as interleukin-10 and transforming growth factor-beta, which can modulate the inflammatory response and promote tissue repair\u0026sup1;⁴. According to cardiac autonomic function, COVID-19 infection can affect cardiac autonomic function (the ability of the heart to adjust its rate and rhythm), and COVID-19 can impair cardiac autonomic function by causing direct damage to the heart muscle, nerve fibres, or receptors or by inducing stress, anxiety, or depression. However, post-COVID-19 patients may have improved cardiac autonomic function, as they recover from the acute phase and restore their cardiac health. Furthermore, post-COVID-19 patients may have enhanced cardiac autonomic function by engaging in physical activity, relaxation techniques, or cardiovascular rehabilitation programs, which can stimulate the parasympathetic nervous system and improve heart rate variability.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003ePost-COVID-19 patients had a lower risk of EAC than did those in the control group, indicating that EAC may have a protective effect on cardiac arrhythmias.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding and support\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific funding from public, commercial, or nonprofit funding agencies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest statement:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that there are no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eRupert, F.G., Jessica Langtree, Andrew R.J., 2017. Ectopic Beats: How Many Count? EMJ Cardiol. 2017;5[1]:88-92. \u003c/li\u003e\n\u003cli\u003eTuragam, M. K., Musikantow, D., Goldman, M. E. and others, 2020. Malignant Arrhythmias in Patients With COVID-19: Incidence, Mechanisms, and Outcomes. Circulation: Arrhythmia and Electrophysiology, 13(11), e008920.\u003c/li\u003e\n\u003cli\u003eHeaton, J., \u0026amp; Yandrapalli, S. (2023, August 8). Premature Atrial Contractions. In StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. Available from: StatPearls - Premature Atrial Contractions.\u003c/li\u003e\n\u003cli\u003eDewland, T.A., Whitman, I.R., Win, S. and others, 2022. Prospective arrhythmia surveillance after a COVID-19 diagnosis. Open Heart, 9(1), p.e001758.\u003c/li\u003e\n\u003cli\u003eChang, S.E., Feng, A., Meng, W. and others, 2021. SARS-CoV-2 infection induces long-lived bone marrow plasma cells in humans. Nature Communications, 12(1), p.5417.\u003c/li\u003e\n\u003cli\u003eLarsen, N.W., Stiles, L.E., Shaik, R., Schneider, L., Muppidi, S., Tsui, C. and Miglis, M., 2022. Characterization of autonomic symptom burden in long COVID: a global survey of 2,314 adults. medRxiv, p.22274300.\u003c/li\u003e\n\u003cli\u003eEmadi-Baygi, M., Ehsanifard, M., Afrashtehpour, N., Norouzi, M. and Joz-Abbasalian, Z., 2021. Corona Virus Disease 2019 (COVID-19) as a System-Level Infectious Disease with Distinct Sex Disparities. Frontiers in Immunology, 12, p.778913.\u003c/li\u003e\n\u003cli\u003eDillon, G.A., Joyner, M.J. and Baker, S.E., 2023. Closing the window on COVID-19 case‒control studies. American Journal of Physiology - Heart and Circulatory Physiology, 324(2), pp.H364-H365.\u003c/li\u003e\n\u003cli\u003eGreenhalgh, T., Knight, M., A\u0026rsquo;Court, C., Buxton, M. and Husain, L., 2020. Management of postacute covid-19 in primary care. BMJ, 370, p.m3026.\u003c/li\u003e\n\u003cli\u003eTahaghoghi-Hajghorbani, S., Zafari, P., Masoumi, E. and others, 2020. The role of dysregulated immune responses in COVID-19 pathogenesis. Virus Research, 290, p.198197.\u003c/li\u003e\n\u003cli\u003eSun, Y., Zou, Y., Wang, H., Cui, G., Yu, Z. and Ren, Z., 2022. Immune response induced by novel coronavirus infection. Frontiers in Cellular and Infection Microbiology, 12, p.988604.\u003c/li\u003e\n\u003cli\u003eJain, U., 2020. Effect of COVID-19 on the organs. Cureus, 12(8), p.e9540\u003c/li\u003e\n\u003cli\u003eNewell, K.L. and Waickman, A.T., 2022. Inflammation, immunity, and antigen persistence in postacute sequelae of SARS-CoV-2 infection. Current Opinion in Immunology, 77, p.102228.\u003c/li\u003e\n\u003cli\u003eAllendes, F.J., D\u0026iacute;az, H.S., Ortiz, F.C., Marcus, N.J., Quintanilla, R., Inestrosa, N.C. and Del Rio, R., 2023. Cardiovascular and autonomic dysfunction in long-COVID syndrome and the potential role of noninvasive therapeutic strategies on cardiovascular outcomes. Frontiers in Medicine, 10, p.1.\u003c/li\u003e\n\u003cli\u003eSkow, R.J., Garza, N.A., Nandadeva, D., Stephens, B.Y., Wright, A.N., Grotle, A.K., Young, B.E. and Fadel, P.J., 2022. Impact of COVID-19 on cardiac autonomic function in healthy young adults: potential role of symptomatology and time since diagnosis. American Journal of Physiology - Heart and Circulatory Physiology, 323(6), p.H1206-H1211.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Al Nahrain university/ College of Medicine/ Department of Physiology","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"SARS-CoV-2, COVID-19, ECG, EAC","lastPublishedDoi":"10.21203/rs.3.rs-4018774/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4018774/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003eBackground:\u003c/b\u003e\u003c/p\u003e \u003cp\u003eEctopic atrial contractions, also known as premature atrial contractions (PACs), are abnormal heart rhythms originating from the atria (the upper chambers of the heart). These contractions occur earlier than expected during the cardiac cycle and can disrupt the normal rhythm. While they are generally benign, their presence can sometimes cause symptoms such as palpitations. The exact mechanisms linking COVID-19 and EACs are not fully understood, and some evidence suggests that COVID-19 infection can increase the risk of developing EACs or other types of arrhythmias.\u003c/p\u003e\u003cp\u003e\u003cb\u003eObjectives:\u003c/b\u003e\u003c/p\u003e \u003cp\u003eEffects of the EAC on post-COVID-19 patients\u003c/p\u003e\u003cp\u003e\u003cb\u003eMaterials and Methods:\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThis is a case‒control study of middle-aged individuals of either sex involving 50 adult patients with post-COVID-19 infection (eight were excluded from the study because they were not cooperative), 23 females and 19 males with a mean age of 36.98\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2 years who were not vaccinated against COVID-19 after one month to two years of an acute episode of COVID-19 (confirmed by positive real-time reverse-transcription polymerase chain reaction (RT‒PCR)) according to the World Health Organization (WHO) selected randomly from those attending to the adult Holter and Echocardiography Laboratory in Al-Zahraa Hospital/Al-Hussein Medical City/Karbala Province after being referred by an internist during the period from the 12th of October 2022 to the end of January 2024 and divided into three groups: nonhospitalize, hospitalize and admitted to intensive care. The control group consisted of 40 healthy persons, 23 females and 17 males with a mean age of 33.28\u0026thinsp;\u0026plusmn;\u0026thinsp;9.58 years, who were referred by an internist for ECG and echocardiography with no Hx of the previous infection of COVID-19. All of them underwent electrocardiographic evaluation via ECG and Holter ECG for 24 hours.\u003c/p\u003e\u003cp\u003e\u003cb\u003eConclusion:\u003c/b\u003e\u003c/p\u003e \u003cp\u003ePost-COVID-19 patients had a lower risk of EAC than control patients, indicating that it may have a protective effect on EAC and reduce the risk of cardiac arrhythmias.\u003c/p\u003e","manuscriptTitle":"COVID-19’s Hidden Shield: How Post-Infection Hearts Safeguard Against Atrial Contractions","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-07 08:45:55","doi":"10.21203/rs.3.rs-4018774/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c15b2c00-69c3-418f-9f91-7954a4bc8a40","owner":[],"postedDate":"March 7th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":29155932,"name":"Physiology"},{"id":29155933,"name":"Cardiac \u0026 Cardiovascular Systems"}],"tags":[],"updatedAt":"2024-03-07T08:45:55+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-07 08:45:55","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4018774","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4018774","identity":"rs-4018774","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}