Beyond the Virus: QTc Interval Changes in COVID-19 Survivors (preprint)

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses angiotensin-converting enzyme-2 receptors on host cells to enter the cells. These receptors are expressed on heart muscle tissue and the tissues of other major organs, which supports the primary accepted theory for the direct cardiac cell injury of coronavirus disease 2019 (COVID-19) and the associated cardiorespiratory manifestations. The SARS-CoV-2 infection leads to unstable myocardial cell membranes due to hypoxia, myocarditis, myocardial ischemia, and abnormal host immune response. This is the main reason behind arrhythmia and electrocardiogram (ECG) changes during COVID-19. However, the specific effect on QTc after Covid 19 infection has not been studied well. Therefore, this study aimed to examine the association between post COVID-19 infection and QTc changes.Objectives: Examine the association between post COVID-19 infection and QTc changes.Materials and Methods: This is a case control study conducted on middle age of either sex involves 50 adult patients with post-COVID-19 infections (eight were defaulted from the study because they were not cooperative), 23 females and 19 males with mean age (36.98 ± 12.2 years) who were non-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)) test according to the World Health Organization (WHO) selected randomly from those attending to the adult Holter and Echocardiography lab in Al-Zahraa Hospital/ Al-Hussein Medical City/ Karbala Province after being referred by Internist during the period from the 12th of October 2022 to the end of January 2024 and divided in to three groups : non hospitalize, hospitalize and admitted to intensive care while control group consisted of 40 healthy persons 23 females and 17 males with mean age (33.28 ± 9.58 years), whom referred by Internist for ECG with no Hx of the previous infection of covid 19. All of them have electrocardiographic evaluation by taking ECG.Conclusion That post COVID-19 patients had prolonged QT and QTc intervals increase the risk for cardiac arrhythmias.

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

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 patientsMaterials 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.