Dilated cardiomyopathy

Dilated cardiomyopathy is an abnormal widening ( dilation ) of the heart muscle, especially the left ventricle. By a systolic pump failure it comes to progressive loss of cardiac output.

The disease is also known in veterinary medicine, there, however, usually hereditary. See Dilated cardiomyopathy ( veterinary medicine)

Causes

A distinction is made between primary forms of cardiomyopathy, the cause of which is unknown, and secondary forms with the following causes:

• Infectious: viral ( Coxsackie virus, influenza viruses, adenoviruses, echoviruses ), bacteria ( staphylococci, enterococci, Borrelia burgdorferi ), fungi or protozoa ( toxoplasmosis, Chagas disease )
• Toxic ( alcohol, anthracyclines, phosphorus)
• Ischemic (recurrent infarctions, microangiopathy )
• Metabolically ( beri- beri, malnutrition )
• Immunologically (systemic lupus erythematosus, polyarteritis nodosa, progressive systemic sclerosis, dermatomyositis )
• Endocrine (hypothyroidism, hyperthyroidism, pheochromocytoma, acromegaly)
• Valvular: cardiac dysfunction in advanced heart defects
• Neuromuscular Duchenne muscular dystrophy, Becker muscular dystrophy, myotonic dystrophy Curschmann Steinert

Symptoms / Diagnosis

In the foreground are the symptoms of heart failure (especially dyspnea ) are due to a decrease in the ejection fraction of the left ventricle up to 30 percent. The enlargement of the heart, there is a relative mitral or tricuspid regurgitation. At the end of diastole occurs by contraction of the atrium to a third heart sound, which one perceives a gallop rhythm on auscultation. The pulse amplitude is small.

ECG

The ECG is often found a left bundle branch block and signs of enlargement of the left ventricle. Often there is an atrial fibrillation with absolute arrhythmia.

Echo

Echocardiography can see a strong expansion of the ventricles. The wall of the left ventricle is usually diluted, transformed the left ventricle spherical and well- reduced movable ( contractile ). The ejection fraction is reduced, increasing the distance between the anterior mitral leaflet and septum, mitral regurgitation and tricuspid regurgitation is often a front.

Biopsy

In the heart muscle biopsy can not fibrosing diffuse fibrosing and focal fibrosing the different types. Furthermore, one sees narrow heart muscle cells with large nuclei. Major complications include heart failure, cardiac arrhythmias, and thrombus formation in the advanced cardiac cavities.

Therapy

In the secondary forms the causative disease is treated. Otherwise, heart failure and cardiac arrhythmias are medically treated with ACE inhibitors and beta - blockers. Furthermore, indexed prophylaxis of thrombosis. A more recent therapeutic approach is the use of autologous stem cell transplantation myocardial regeneration, its effectiveness has yet to be occupied in larger studies. With further progression of the disease, the heart transplant may be considered.

In veterinary medicine, the Inodilatator pimobendan is the first choice. In addition, the regularly encountered, triggered by atrial fibrillation ( supraventricular ) tachycardia by means of equally positive inotropic digitalis is treated. In addition, ACE inhibitors and beta - blockers are also used here.