Coronavirus disease 2019 (COVID-19) patients with pre-existing cardiovascular disease (CVD) or with cardiovascular complications have a higher risk of mortality. The main cardiovascular complications of COVID-19 include acute cardiac injury, acute myocardial infarction (AMI), myocarditis, arrhythmia, heart failure, shock, and venous thromboembolism (VTE)/pulmonary embolism (PE). COVID-19 can cause cardiovascular complications or deterioration of coexisting CVD through direct or indirect mechanisms, including viral toxicity, dysregulation of the renin–angiotensin–aldosterone system (RAAS), endothelial cell damage and thromboinflammation, cytokine storm, and oxygen supply–demand mismatch. We systematically review cardiovascular manifestations, histopathology, and mechanisms of COVID-19, to help to formulate future research goals and facilitate the development of therapeutic management strategies.