The heart in dermatomyositis and polymyositis
Rheumatology Unit, Department of Medicine, Karolinska Institutet At Karolinska University Hospital, Solna Stockholm, Sweden.
Correspondence to: I. E. Lundberg, Rheumatology Unit, Karolinska University Hospital, SE-17176 Stockholm, Sweden. E-mail: Ingrid.lundberg{at}ki.se
Cardiovascular manifestations constitute a major cause of death in myositis. Despite this, clinically manifest cardiac involvement in polymyositis and dermatomyositis is relatively rare. In contrast, subclinical manifestations are frequently reported and are predominated by conduction abnormalities and arrhythmias detected by ECG. The most frequently reported clinically overt manifestations are congestive heart failure, conduction abnormalities, that may lead to complete heart block, and coronary artery disease. The underlying pathophysiological mechanisms that may cause cardiac manifestations involve myocarditis and coronary artery disease as well as involvement of the small vessels of the myocardium.