Dilated cardiomyopathy: the left ventricle (and sometimes the right) are dilated and / or the contractile force (ejection fraction) is reduced
Dilated Cardiomyopathy (DCM) is a myocardial disease characterized by expansion of the left ventricle (LV) and / or reduction of its force of contraction (" systolic dysfunction") or release ("diastolic dysfunction").
In about 50% of patients the DCM has a genetic cause and in about 25% it is caused by mutations in the gene for Titin, an important heart cell protein, which can be analyzed with NGS genetic analysis. In other patients it is caused by mutations in genes that produce sarcomeric proteins (eg Myosin, Myosin binding Protein C, Troponin), which in this case are responsible for dilation, rather than hypertrophy. Some patients have mutations in the Foil A / C, or the Desmoplachin, or ion channels, and all of these have a higher likelihood of complications such as life-threatening arrhythmias (Ventricular tachycardia and / or Fibrillation).
When other family members of the patient have had or have cardiomyopathy, heart failure, or even sudden death at a young age, DCM it probably has a genetic cause. In these patients thegenetic analysis is essential to identify the mutation and the causative gene and allow the administration of a more targeted and effective therapy.
A form of DCM is also often present in patients who have "neuromuscular” genetic diseases, such as dystrophies (e.g. Duchenne muscular dystrophy).
But Dilated cardiomyopathy can also have many other causes:
- heart infections (myocarditis) almost always from viruses, but also bacterial
- chemotherapy and / or radiotherapy to treat cancer
- exposure to toxic substances, such as alcohol abuse
- fast and prolonged supraventricular / ventricular arrhythmias ("tachycardiomyopathy")
- from food deficiency, (e.g. in patients with "anorexia" or during a famine)
- after childbirth ("postpartum")
- autoimmune diseases (e.g. rheumatoid arthritis, etc)
Some of these forms, such as dilated cardiomyopathy by alcohol abuse or from food deficiency, are reversible.
In the early stages, symptoms may be absent or scarce even for many years, and are represented by palpitations, arrhythmias, or shortness of breath during exertion.
Fundamental objectives for the cardiologist are the recognition of the cause, the control of symptoms, avoiding the progression of heart disease and possible thrombus formation if the heart chamber is very dilated, and the prevention of arrhythmias, including those that can cause cardiac arrest.
Over the last 30 years there have been many advances in treatment for DCM, with a significant improvement in survival and quality of life, thanks to the use of numerous medications available, implantation of defibrillators (ICD), biventricular pacemakers ("resynchronization" CRT) and to heart transplants.