Polymyositis (PM) and dermatomyositis (DM) are rare idiopathic inflammatory myopathies (IIM). Myocardial involvement in patients with IIM is an unfavorable prognostic factor and one of the most common cause of mortality in this group of patients. The purpose of this review is to present current knowledge on cardiovascular manifestations observed in IIM. Data published in English until December 2021 were selected. Clinical symptoms suggesting cardiac involvement are non-specific and require a differential diagnosis in accordance with cardiological guidelines. Troponin I is specific to cardiac injury and should be preferred to other markers to evaluate the myocardium in IIM. Abnormalities in electrocardiography are common in IIM, especially non-specific changes of the ST-T segment. In standard echocardiography left ventricular diastolic dysfunction is reported frequently. New diagnostic technologies can reveal clinically silent myocardial abnormalities. However, the prognostic value of subclinical impairment of myocardial function require further studies.