It is seen predominantly in males, and 30–50% of cases have a familial distribution. Signs and symptoms
Those affected by arrhythmogenic cardiomyopathy may not have any symptoms at all despite having significant abnormalities in the structure of their hearts. If symptoms do occur, the initial presentation is often due to abnormal heart rhythms (arrhythmias) which in arrhythmogenic cardiomyopathy may take the form of palpitations, or blackouts. Sudden death may be the first presentation of ACM without any preceding symptoms. These symptoms often occur during adolescence and early adulthood, but signs of ACM may rarely be seen in infants. As ACM progresses, the muscle tissue within the ventricles may dilate and weaken. The right ventricle typically weakens first, leading to fatigue and ankle swelling. In the later stages of the disease in which both ventricles are involved shortness of breath may develop, especially when lying flat.The first clinical signs of ACM are usually during adolescence and early adulthood. However, rarely, signs of ACM have been demonstrated in infants. Causes
Genetics
ACM is usually inherited in an autosomal dominant pattern, with variable expression. Only 30% to 50% of individuals affected by ACM will test positive to one of the known genetic mutations in chromosomal loci associated with the disease. Novel studies showed that mutations (point mutations) in genes encoding for desmosomal proteins (see intercalated disc) are the main causatives for the development of this disease. Recently it has been shown, that mutations in the desmin DES gene could cause ACM.
Complications
Children with this condition are at a higher risk of developing the following complications:
Failure to thrive
Recurrent chest infections
Endocarditis
Epilepsy
Stroke
Arrhythmia
Heart failure
Premature deathChildren whose PAVSD is caused by DiGeorge syndrome (also known as 22q11.2 deletion syndrome) are more likely to suffer from the post-surgical complications (especially respiratory ones) associated with surgeries that treat this defect.Women with PAVSD are at a slightly higher risk of being infertile and having miscarriages or children with a congenital heart defect.Airway hyperresponsiveness is a commonly seen co-morbidity among those afflicted with PAVSD. Pathogenesis
Pulmonary atresia in PAVSD takes place during the first 8 weeks of fetal life, when the pulmonary valve that is supposed to form, fails to form, this doesnt allow blood to flow through the pulmonary artery from the right ventricle. The ventricular septal defect associated with PAVSD lets the right ventricule form.In some cases of PAVSD, major aortopulmonary collateral arteries develop; in a normal fetus, these arteries usually develop but then start deteriorating after pulmonary arteries grow, in fetuses with PAVSD, the pulmonary arteries dont develop, and this gives a chance to the major aortopulmonary collateral arteries to develop fully. Pathophysiology
The mildest variant of pulmonary atresia with ventricular septal defect involves pulmonary atresia with normally developed main pulmonary artery and branch pulmonary arteries, the blood that flows to the lungs from the right side of the heart goes to the left side of the heart through the ventricular septum which then flows through the patent ductus arteriosus.