From the Guidelines
Dilated cardiomyopathy (DCM) is caused by a variety of factors, including genetic mutations, viral infections, chronic alcohol abuse, and other conditions that damage the heart muscle, leading to enlargement of the heart chambers and impaired pumping function, as highlighted in a recent systematic review of clinical practice guidelines and recommendations 1. The causes of DCM can be categorized into several groups, including:
- Genetic mutations, which account for about 30-40% of cases and can be inherited in autosomal dominant, recessive, or X-linked patterns 1
- Viral infections, such as coxsackievirus, adenovirus, and HIV, which can directly damage heart muscle cells and trigger an inflammatory response leading to DCM
- Chronic alcohol abuse, which is directly toxic to heart muscle cells
- Other causes, including certain medications (particularly some chemotherapy drugs like doxorubicin), toxins (such as cocaine and heavy metals), nutritional deficiencies (especially thiamine, selenium, and carnitine), and systemic diseases like thyroid disorders, sarcoidosis, and hemochromatosis
- Pregnancy-related DCM (peripartum cardiomyopathy), which can occur in the last month of pregnancy or within five months after delivery
- Chronic uncontrolled hypertension and coronary artery disease, which can lead to DCM over time as the heart muscle weakens from prolonged stress It is essential to note that in many cases, despite thorough evaluation, the exact cause of DCM remains unknown, which is termed idiopathic dilated cardiomyopathy. The therapeutic management of DCM has traditionally overlapped with heart failure (HF) treatment, sharing primary therapeutic options, from optimal decongestion to appropriate risk stratification for arrhythmias, as stated in a recent review of current guidelines and recommendations 1. The diagnosis and management of DCM should be guided by current clinical practice guidelines and recommendations, which emphasize the importance of individualized treatment and targeting the underlying cause, in addition to standard systolic HF therapies, as highlighted in a scientific statement from the American Heart Association 1.
From the Research
Causes of Dilated Cardiomyopathy
The causes of dilated cardiomyopathy can be categorized into two main types: genetic and acquired factors.
- Genetic factors, also known as primary dilated cardiomyopathy, involve mutations in genes that encode structural components of the sarcomere and desmosome 2, 3, 4, 5.
- Acquired factors, also known as secondary dilated cardiomyopathy, include:
- Infections, such as myocarditis 2, 3, 4, 5
- Toxins, such as exposure to alcohol, drugs, or other toxins 2, 3, 4, 5
- Cancer treatment 2
- Endocrinopathies 2, 3, 4, 5
- Pregnancy 2
- Tachyarrhythmias 2
- Immune-mediated diseases 2
- Cocaine use, which can induce vasospasm, promote intracoronary thrombosis, and stimulate atherosclerosis 6
Prevalence of Genetic and Acquired Factors
- Genetic mutations can be identified in up to 35% of patients with dilated cardiomyopathy 3, 5
- Acquired factors, such as myocarditis and exposure to toxins, account for a significant proportion of cases 3, 4, 5
- In some cases, patients with acquired dilated cardiomyopathy may also harbor a likely pathogenic or pathogenic gene variant 2