Coronavirus Disease: Epidemiology, Aetiology, Pathophysiology and Involvement of the Cardiovascular System

Since the emergence in China of coronavirus disease (COVID-19) in December 2019; the virus causing the pandemic has infected the human population in almost every country and territory on the globe. At the time of writing there are over 84 million confirmed cases of infection and over 1.8 million deaths globally. Rates of infection differ as does the number of severe cases and subsequent deaths between countries and continents. This is due in part to lockdown measures, social distancing and wearing of face coverings. It is also reflected by how healthcare systems record coronavirus deaths along with access to testing as well as tracking and tracing of infected individuals. Symptoms of COVID-19 include a novel persistent cough, fever and anosmia (loss of smell). In most cases, such symptoms are mild. A small proportion of those who become infected however, have a severe reaction to the disease affecting multiple organ systems and often require respiratory support in the intensive care setting. One such physiological system affected is the cardiovascular system. This is likely due to the increased number of ACE2 receptors in co-morbid cardiac pathologies. ACE2 receptors serve as the entry port for the coronavirus into human cells. Those individuals with underlying cardiovascular risk factors are therefore disproportionately at risk of COVID-19 infection. This chapter reviews the aetiology and epidemiology of the coronavirus infection; potential pathophysiological mechanisms of disease involving the cardiovascular system including the clinical utility of biomarkers, electrocardiography and echocardiography as well as autopsy cardiac pathology and histopathology.