A cardiomyopathy (CMP) is a condition of the myocardium in which the heart muscle is structurally and functionally abnormal that cannot be explained by underlying coronary artery disease , arterial hypertension, valvular disease or congenital heart disease. However, patients with a CMP may also have coronary artery disease , arterial hypertension, valvular disease or congenital heart disease.
A cardiomyopathy can occur in families due to genetic defects or can be acquired. According to the structural cardiac abnormalities, there are different clinical pictures or phenotypes. The same phenotype can sometimes arise from different causes.
To reach the diagnosis, all patients with suspected or confirmed cardiomyopathy should undergo a comprehensive cardiac examination including clinical evaluation, family tree analysis, ECG, rhythm monitoring, laboratory tests and multimodal imaging (echocardiographic, cardiac MRI, etc.). ).
See diagnostic setup.
Once a diagnosis has been reached, a diagnosis- and patient-specific approach will have to be provided. A detailed discussion of all these aspects is beyond the scope of this website. The treating cardiologist will adequately inform the patient, the family and the other treating physicians about this.
We also provide clinically relevant, specific points of attention regarding the most common cardiomyopathies :
Most genetically determined cardiomyopathies have an autosomal dominant inheritance pattern with variable penetrance. This means that:
Genetic research is sometimes indicated if a familial cardiomyopathy is suspected. However, a negative genetic test does not rule out a genetic cause for the cardiomyopathy. Good cardiological follow-up of family members remains indicated. If a pathological mutation is found, genetic testing can be done within the family to demonstrate or rule out carrier status of this mutation. This then has an important impact on the need for good cardiological follow-up and possible inheritance of the mutation to children.
Before genetic testing, the patient is best referred to a cardiogenetics consultation so that correct counseling can take place in advance.
Indications for genetic research:
Based on morphological and functional features of the myocardium, 5 phenotypes of cardiomyopathies are described:
A thickened, hypertrophic heart muscle (thickness > 12 mm) causes stiffening of the myocardium, usually leading to heart failure with preserved LVEF ( HFpEF ).
The main causes are:
A non-thickened, normotrophic heart muscle with a dilated LV (end-diastolic diameter > 50 mm) causes reduced contraction of the myocardium, usually leading to heart failure with mildly reduced or reduced LVEF ( HFmrEF or HFrEF).
A non-thickened, normotrophic heart muscle with regional or diffuse hypokinesia of the LV, but without dilation of the LV, with an increased risk of ventricular arrhythmias and usually a picture of heart failure with mildly reduced or reduced LVEF (HFmrEF or HFrEF ).
Dilation and/or dysfunction of the right ventricle (RV) with increased risk of ventricular arrhythmias and/or right heart failure. Sometimes there may be biventricular involvement with also LV dysfunction.
A non-thickened, normotrophic and non-dilated heart muscle with normal systolic contractility and a picture of heart failure with preserved LVEF ( HFpEF ). Classically this is caused by a stiffened endocardium .
Cardiac amyloidosis is an infiltrative cardiomyopathy and is characterized by the extracellular deposition of misfolded proteins in the myocardium. These proteins stick together to form insoluble amyloid fibrils. This causes thickening and stiffening of the myocardium with a picture of diffuse, concentric hypertrophic cardiomyopathy.
Amyloidosis has become more frequently diagnosed in recent years and is an increasingly important cause of heart failure with preserved LVEF ( HFpEF ).
It is very important that the diagnosis is made at the earliest possible stage to enable rapid treatment of the cause and slow down further disease progression. Sometimes an image suspicious for cardiac amyloidosis is accidentally seen on a bone scan that was done for another indication . These patients must then be referred quickly for further diagnosis and therapy.
Amyloidosis can be caused by different types of proteins with different underlying disease processes that cause these proteins.
The 2 most frequent and clinically most important forms are:
Among other things:
For more information: https://www.tvcjdc.be/nl/article/13305027/
There is usually an asymmetric LV hypertrophy, most pronounced in certain segments of the myocardium, usually the septum.
Sometimes there is LVOT obstruction (LV outflow tract ) due to hypertrophy of the basal septum and/or systolic anterior movement (SAM) of the anterior mitral valve leaflet . This is then called a hypertrophic obstructive cardiomyopathy. This LVOT obstruction can already be present at rest, but sometimes only during exercise.
There are different patterns of LV hypertrophy: