Polymyositis/Dermatomyositis and the Heart

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Muscle weakness, characteristic skin lesions

• Arrhythmias or conduction disturbances

• Myocarditis, pericarditis, coronary arteritis, and valve disease

GENERAL CONSIDERATIONS

• Polymyositis/dermatomyositis is a chronic inflammatory myopathy that presents as symmetric proximal muscle weakness and a rash, usually over the extensor surfaces of the hands and the face, neck, and chest

• The incidence is about 1–5 new cases per million per year in the United States

• It strikes adults in their fourth to sixth decades

• African-American women are more often affected

• Occasionally the condition is associated with other connective tissue diseases

• Cardiovascular disease is a common cause of mortality

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Palpitation due to ectopic beats

• Congestive heart failure findings, such as dyspnea on exertion and edema

• Chest pain due to pericarditis

PHYSICAL EXAM FINDINGS

• Pericardial rub, elevated jugular venous pressure

• Pulmonary rales, S_3, enlarged apical impulse

• Right ventricular lift, loud P₂

• Murmur of mitral regurgitation

• Skin manifestations

DIFFERENTIAL DIAGNOSIS

• Other connective tissue diseases

• Other causes of cardiac disease

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Elevated brain natriuretic peptide or troponins

ELECTROCARDIOGRAPHY

• ST-T–wave abnormalities in about 50%

• Fascicular and bundle branch blocks

• Atrioventricular blocks

• Premature atrial and ventricular beats

IMAGING STUDIES

• Chest x-ray:

  • – Cardiomegaly

  • – Pulmonary congestion

• Echocardiography:

  • – Pericardial effusion

  • – Left ventricular wall motion abnormalities and reduced ejection fraction

  • – Enlarged right heart and Doppler evidence of increased pulmonary pressure

  • – Mitral valve prolapse in about 50%

  • – Hyperkinetic heart syndrome in some

• Myocardial perfusion imaging with technetium-99m pyrophosphate shows myocardial uptake

• Cardiac MRI with late gadolinium enhancement of the epicardium and mid-wall of the lateral and septal walls

DIAGNOSTIC PROCEDURES

• Cardiac catheterization or CT coronary angiography may be required if coronary vasculitis is suspected

TREATMENT

CARDIOLOGY REFERRAL

• Suspected heart disease

HOSPITALIZATION CRITERIA

• Pericarditis

• Heart failure

• Significant arrhythmias or heart block

MEDICATIONS

• Specific anti-inflammatory pharmacotherapy

• Specific cardiac therapy as indicated

• Pulmonary vasodilators in selected cases

THERAPEUTIC PROCEDURES

• Percutaneous coronary intervention may be required

• Pericardiocentesis may be required.

SURGERY

• Valve, coronary, or pericardial surgery is rare

MONITORING

• ECG monitoring in hospital as appropriate

DIET AND ACTIVITY

• Low-sodium diet if heart failure

• Restricted activity if heart ...