Page 88 - Medicine and Surgery

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84 Chapter 2: Cardiovascular system

Aetiology Sex
Two-thirds are attributable to chronic venous insuffi- M > F
ciency. Aggravating factors include old age, obesity, re-
current trauma, immobility and joint problems. Aetiology
The aetiology of most congenital heart disease is un-
Pathophysiology known, and associations are as follows:
Chronic venous ulceration is the last stage of lipo- Genetic factors: Down, Turner, Marfan syndromes.
dermatosclerosis(the skin changes of oedema, fibrosis Environmental factors: Teratogenic effects of drugs
around veins and eczema, which occurs in venous sta- and alcohol.
sis). Maternal infections such as rubella, toxoplasmosis.

Pathophysiology
Clinical features
Normally in postnatal life the right ventricle pumps de-
Distinguishable from arterial ulcers by clinical features
oxygenated blood to lungs and the left ventricle pumps
and a history of chronic venous insufficiency (see Table
oxygenatedbloodatsystemicbloodpressuretotheaorta,
2.11 page 76).
with each ventricle morphologically adapted for its task.
The pulmonary circulation normally has low resistance.
Investigations
Congenital heart lesions can be considered according
Phlebography is performed to assess the underlying state
to one or more of
of the veins.
Abnormal shunting of blood back to the lungs (left
to right). Blood from the left side of the heart is re-
Management
turned to the lungs instead of going to the systemic
Healing often takes weeks, possibly months. Conserva-
circulation.
tive treatment consists of application of an absorbent
Abnormal shunting of blood from the lungs (right to

nonadherent dressing, preferably under a compression
left) in which de-oxygenated blood bypasses the lungs
bandage, which reduces venous stasis. Local antibiotics
and enters the systemic circulation.
are contraindicated as they do not prevent colonisation Narrowed cardiac outflow channels or valves.
and are often irritant and reduce healing rates. Abnormal connections or positions of chambers.
Skin grafts may speed healing, but only if venous pres-
Clinically lesions can be divided into two categories:
sure is reduced, e.g. by leg elevation. Surgery to remove Acyanotic heart disease, which include the left to right
incompetent veins before ulceration occurs.
shunts (atrial septal defects, ventricular septal de-
fects and persistent ductus arteriosus) and obstruc-
tive lesions (aortic stenosis, right ventricular outflow
Congenital heart disease tract obstruction, coarctation of the aorta and mitral
stenosis).
Introduction to congenital Cyanotic heart disease including tetralogy of Fallot
heart disease and transposition of the great arteries.
Definition
Ventricular septal defects
Developmental abnormalities of the heart.
Definition
Prevalence Abnormal defect in the ventricular septum allowing pas-
Up to 1% of live born infants are affected by some form sage of blood flow between the ventricles.
of congenital heart disease.
Incidence
Age 1in 500 live births, the commonest of all heart defects
Congenital. accounting for around 40%.