**7. Cardiovascular involvement**

The epicenter of COVID-19 infection is pulmonary complication, however, accompanied cardiovascular complications contributes to mortality [34–45].

Cardiovascular complications commonly found to be associated with COVID-19 are myocardial injury, myocarditis, dysrhythmias, heart failure, acute myocardial infarction (AMI) and venous thromboembolic events (VTE). Myocarditis as the cause of death was reported in 7% of 68 fatal COVID-19 of total 150 cases studied [35]. Another study of 191 patients from Wuhan reported 54 deaths; of which 28 (52%) had heart failure, overall prevalence being 23% (44 of 191) [36].

Various mechanisms are postulated for CVS manifestations like destabilization of vascular plaques due to systemic inflammation, viral infection induced increase in cytokine activity leading to increased cardiac demand and direct damage to the heart by utilizing ACE2 receptors of cardiac tissue by virus [37, 38].

Many patients already may have pre-existing cardiovascular disease like coronary artery disease, hypertension and others which leads to greater severity of COVID-19 infection. A meta-analysis of 1527 patients of COVID-19 infection, showed that the prevalence of hypertension and cardiac disease was 17.1% and16.4% respectively, and all of them were more likely to develop more severe illness requiring ICU care [39]. Previous viral infections, including Middle East respiratory syndrome coronavirus (MERS-CoV), have been linked with myocardial injury and myocarditis with increased troponin concentration [40]. Acute cardiac injury can be recognised by increased troponin levels which were reported to be present in 7 to 17 % patients who are admitted with COVID-19. Cardiovascular complications are life threatening; proper monitoring by following trend of troponin level can be useful. Many such patients may require admission to intensive cardiac care unit [30, 36, 41]. Knowing such complication as part of multi-organ involvement is important for clinicians, as it may improve outcomes [42]. Palpitations may manifest as initial symptom in around 7% of patients with COVID-19 [43]. Patients with COVID-19 are also has increased risk of venous thrombo-embolisms (VTEs) [44, 45].
