and dissecting haemotoma of the aorta

Chapter 39 Cardiomyopathies and dissecting haematoma of the aorta




Questions


image What is a cardiomyopathy and what are the most common causes?

image How may cardiomyopathies present clinically?

image What is a dissecting haematoma of the aorta and what are its complications?



Cardiomyopathies


The term cardiomyopathy does not have a precise definition, but it is generally used to describe three conditions: hypertrophic, dilated and restrictive cardiomyopathy. Dilated cardiomyopathy is the commonest.



Dilated cardiomyopathy


The definition of dilated cardiomyopathy (also known as congestive cardiomyopathy) is progressive cardiac hypertrophy with dilatation affecting all chambers and associated with progressive systolic dysfunction. It is caused by diffuse damage to the myocardium and can have a number of aetiologies, including:


image viral infections, e.g. coxsackievirus B

image drugs and toxins, e.g. alcohol abuse

image hereditary abnormalities of cytoskeletal proteins.

The systolic dysfunction produces heart failure, which is often fatal. In some cases, mural thrombi form in the flabby cardiac chambers. If they break off, they give rise to embolic complications.



Hypertrophic cardiomyopathy


This condition is characterized by a hypertrophic left ventricle that can contract strongly, but it is stiff and diastolic filling is impaired. This stiffness is more precisely described as reduced ventricular compliance. A number of different genetic defects can produce this condition; the genes involved code for a variety of sarcomeric proteins. Although some cases arise sporadically, approximately half of patients inherit the condition as an autosomal dominant trait with variable penetrance and expression. There are a number of clinical features (Fig. 3.39.1):


image heart failure, which can result from the diastolic dysfunction of the thick, rigid ventricle, or from ventricular outflow obstruction during systole; the latter results from the narrow gap between the anterior mitral valve leaflet and the hypertrophic interventricular septum

image ischaemic heart disease, which occurs because the hypertrophic mass of muscle requires a large blood supply; angina can occur even in the absence of coronary artery stenosis
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Jul 3, 2016 | Posted by in MUSCULOSKELETAL MEDICINE | Comments Off on and dissecting haemotoma of the aorta
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