From the Guidelines
Dilated cardiomyopathy (DCM) is diagnosed by the presence of left ventricular or biventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to explain these changes, as defined by the European Association of Cardiovascular Imaging in 2019 1. The diagnostic criteria for DCM include:
- Left ventricular dilation and systolic dysfunction
- Absence of abnormal loading conditions or coronary artery disease that could explain the changes
- A multimodality imaging approach, including echocardiography and cardiac MRI, is recommended for diagnosis and prognostic assessment 1 Key considerations in the diagnosis of DCM include:
- Clinical context, including symptoms such as dyspnea, fatigue, and edema
- Physical examination findings, such as S3 gallop, elevated jugular venous pressure, and peripheral edema
- Laboratory testing, including natriuretic peptides, cardiac troponins, and genetic testing in cases with family history 1 The use of multimodality imaging in DCM diagnosis allows for a comprehensive evaluation of the disease, including the assessment of cardiac structure and function, and the identification of potential causes and comorbidities 1. In clinical practice, the diagnosis of DCM should be made based on a combination of clinical, laboratory, and imaging findings, with a focus on identifying the underlying cause of the disease and guiding therapy 1.
From the Research
Diagnostic Criteria for Dilated Cardiomyopathy (DCM)
The diagnostic criteria for DCM involve the presence of left ventricular dilatation and contractile dysfunction, as defined in the study 2. The left ventricular ejection fraction (LVEF) is a key parameter in diagnosing DCM, with reduced LVEF (<40%) being a common criterion, as mentioned in the studies 3, 4, and 5.
Key Parameters for Diagnosis
- Left ventricular dilatation
- Contractile dysfunction
- Reduced left ventricular ejection fraction (LVEF) (<40%)
- Presence of symptoms related to congestive heart failure, such as circulatory collapse, arrhythmias, and thromboembolic events, as mentioned in the study 2
Additional Factors
- Genetic mutations involving genes that encode cytoskeletal, sarcomere, and nuclear envelope proteins, among others, which account for up to 35% of cases, as stated in the study 2
- Acquired causes, including myocarditis and exposure to alcohol, drugs, and toxins, and metabolic and endocrine disturbances, as mentioned in the study 2
- Secondary neurohormonal changes that contribute to reverse remodelling and ongoing myocyte damage, as discussed in the study 2
Prognosis and Treatment
- The prognosis is worst for individuals with the lowest ejection fractions or severe diastolic dysfunction, as mentioned in the study 2
- Treatment of chronic heart failure comprises medications that improve survival and reduce hospital admission, such as angiotensin converting enzyme inhibitors and β blockers, as stated in the study 2
- Other interventions include enrolment in a multidisciplinary heart failure service, and device therapy for arrhythmia management and sudden death prevention, as mentioned in the study 2