There may be combinations of different valvular and blood vessel abnormalities. The effects of different cardiovascular anomalies vary. It may occur in various ways but is particularly common when there is shunting of blood from the right to the left side of the heart, for example due to Tetralogy of Fallot. It projects from the ventral thoracic wall and may be covered by the skin and subcutaneous tissues.
Dysplasia is a general term implying abnormal development.
It is often used in relation to various valvular anomalies. Examples of stenotic lesions in which there is a familial incidence in dogs include pulmonic stenosis and subaortic stenosis. Valvular stenosis leads to pressure overload within the ventricle affected, which leads to concentri c hypertrophy of the ventricle muscle. This may lead to subendocardial ischaemia and fibrosis , resulting in dysrythmias , furthermore, the A-V valve may become incompetent leading to congestive heart failure. There may be post-stenotic dilatation of the pulmonic or aortic outflow tracts. . . .