What are the causes of dilated cardiomyopathy?

From the Guidelines

Dilated cardiomyopathy (DCM) is caused by a variety of factors, including genetic mutations, viral infections, chronic alcohol abuse, toxins, medications, nutritional deficiencies, autoimmune disorders, and pregnancy-related conditions, as well as idiopathic causes when no specific cause can be identified. The causes of DCM can be categorized into several groups, including:

• Genetic causes, which account for about 30-40% of cases and can be inherited in autosomal dominant, recessive, or X-linked patterns 1
• Infectious causes, such as viral infections like coxsackievirus, adenovirus, and HIV, which can directly damage heart muscle cells and trigger an inflammatory response leading to DCM 1
• Toxic causes, including chronic alcohol abuse, which requires consumption of more than 80g of alcohol daily for at least five years, and various medications like chemotherapy drugs, cocaine, and certain antipsychotics 1
• Nutritional deficiencies, particularly thiamine, selenium, and carnitine, which can compromise heart function 1
• Autoimmune disorders, such as lupus and rheumatoid arthritis, which may cause DCM through inflammatory mechanisms 1
• Pregnancy-related DCM (peripartum cardiomyopathy), which typically occurs in the last month of pregnancy or within five months after delivery 1
• Chronic tachycardia and severe hypertension, which can lead to DCM through persistent mechanical stress on the heart 1 It is essential to identify the underlying cause of DCM, as treatment should be individualized and target the underlying cause, in addition to standard systolic heart failure therapies, to improve morbidity, mortality, and quality of life outcomes 1.

From the Research

Causes of Dilated Cardiomyopathy

The causes of dilated cardiomyopathy (DCM) are multifactorial and can be categorized into genetic and acquired factors.

• Genetic factors:
  • Mutations in genes encoding sarcomere, cytoskeletal, and nuclear proteins, as well as proteins involved in Ca(2+) metabolism 2, 3, 4, 5, 6
  • Filamin C (FLNC) variant has been associated with DCM 4
• Acquired factors:
  • Infections, such as viral myocarditis 3, 5, 6
  • Toxins, such as alcohol and drugs 3, 5, 6
  • Cancer treatment 3
  • Endocrinopathies, such as metabolic or endocrine disturbances 3, 5, 6
  • Pregnancy 3
  • Tachyarrhythmias 3
  • Immune-mediated diseases 3
  • Exposure to allergens 5
  • Systemic autoimmune diseases 5

Genetic and Acquired Factors

It is estimated that 5-15% of patients with acquired DCM harbor a likely pathogenic or pathogenic gene variant 3.

• The diagnostic approach should consider both genetic and acquired factors 3
• Genetic testing can identify disease-causing mutations in 20-35% of DCM cases 4, 6
• A thorough assessment is necessary to risk stratify and identify patients who may benefit from primary prevention implantable cardioverter defibrillator therapy 4