en عمومى General پژوهشي Research <strong>Background:</strong>&nbsp; COVID-19 patients with cardiovascular underlying disease have more severe problems.<br> <strong>Methods and Materials</strong><strong>:</strong>&nbsp;This is a retrospective descriptive-analytical cross-sectional study based on the information in patients&#39; medical records. From March 2020 to the end of April, patients with COVID 19 hospitalized in Razi and Fatemeh Zahra teaching hospitals were included in the study.<br> <strong>Results:</strong> In this study, 1501 patients were evaluated. Patients ranged in age from 21 to 76 years with a mean and standard deviation of 54&plusmn;18.4 which 766 cases (51.0%) were female. Forty cases (2.7%) developed a severe form of the disease, and 1461 cases (97.3%) had a mild form of COVID-19. The final diagnosis of a heart disorders was acute myocarditis in 5.7%, arrhythmia in 9.5% and myocardial infarction in 3.6% cases respectively, which also had a statistically significant difference between severe and mild groups P<0.0001.<br> <strong>Conclusion:</strong>&nbsp;Underlying cardiovascular diseases are associated with a higher severity in COVID-19 patients. COVID-19, Myocarditis, Myocardial Infarction, Arrhythmia 173 182 http://intjmi.com/browse.php?a_code=A-10-1-396&slc_lang=en&sid=1 Narges Najafi 10031947532846004506 10031947532846004506 No Associate Professor, Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran Mousa Javadian 10031947532846004507 10031947532846004507 No Resident of Infectious Diseases and Tropical Medicine , Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran Alireza Davoudi 10031947532846004508 10031947532846004508 Yes Associate Professor, Antimicrobial Resistance Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran