Myocarditis and cardiomyopathies
Inflammatory heart muscle diseases (myocarditis) can be triggered by viruses, bacteria or other pathogens. In Europe, myocarditis is mostly caused by viruses such as Coxsackie, Echo, Cytomegalovirus, but also rubella, mumps, measles, HIV and influenza viruses. However, bacteria and fungi are also possible causes in our part of the world. In addition to pathogens, diseases of the heart muscle can also be caused by toxins, autoimmune diseases or collagen diseases.
Clinically, myocarditis presents itself very differently, and the signs are usually rather unspecific. The main symptoms are usually those of heart failure: Tachycardia, tachy- and dyspnoea, extrasystole, large liver and grey skin colour. Laboratory chemistry shows increased signs of inflammation. Other important diagnostic tools are the ECG, lung X-ray and echocardiography. In order to obtain clear evidence of myocarditis, it is necessary to perform a heart muscle biopsy.
The most important therapeutic measure is bed rest, in addition to the administration of afterload-lowering agents, diuretics and digitalis preparations. Severe cases require intensive medical treatment with ventilation and mechanical circulatory support (e.g. Berlin Heart). If the heart muscle cannot recover with all these measures, a heart transplant is possible.
Cardiomyopathies are a separate group of diseases that occur independently of congenital heart defects, coronary heart disease or systemic diseases. Cardiomyopathies are essentially divided into 3 groups. They can be divided into three groups: 1. dilated cardiomyopathy, 2. hypertrophic cardiomyopathy and 3. restrictive cardiomyopathy. These three types differ in terms of haemodynamics and each requires different treatment.
Dilated cardiomyopathy, the only one of the three forms, can be the result of myocarditis. One or both chambers are massively dilated (enlarged) and have limited contractility (pumping function). The musculature is moderately hypertrophied (thickened). Due to the pronounced enlargement of the heart cavities, thrombi can form in them. The main clinical signs are fatigue, weakness, failure to thrive and signs of heart failure with dyspnoea, cyanosis and an enlarged liver. Echocardiography and ECG are also helpful in the diagnosis. The therapeutic approach is similar to that for myocarditis: Heart failure therapy with diuretics, ACE inhibitors, beta blockers, catecholamines and phosphodiesterase inhibitors support the heart in the acute phase of the disease. At the end of the therapeutic spectrum is heart transplantation, preceded by the artificial heart (Berlin Heart), which can bridge the waiting time until transplantation.
Hypertrophic cardiomyopathy is a genetically determined disease, half of which is familial and the other half sporadic. The main problem with this disease is hypertrophy (thickening) of the heart muscle. The ventricular septum is particularly affected, resulting in a significant narrowing of the heart cavities and outflow tracts. A distinction is made here between hypertrophic obstructive and hypertrophic non-obstructive cardiomyopathy. Clinically, most children present without symptoms; occasionally palpitations can lead to a clarification. Echocardiography is crucial in making the diagnosis. The main complication of this form of cardiomyopathy is sudden cardiac death caused by arrhythmias and myocardial ischaemia. Therapeutically, beta-blockers and calcium anatgonists can prevent the progression of hypertrophy and alleviate symptoms. Heavy physical exertion should be avoided in this disease. It is also possible to surgically eliminate the hypertrophy by performing a transaortic myectomy.
Restrictive cardiomyopathy is characterised by diastolic dysfunction with normal systolic function. This form is characterised by severe dilatation of the atria with normal-sized ventricles. The causes of this disease are essentially unclear. Clinically, it is characterised by fatigue and reduced performance. In severe cases, a heart transplant must be considered.