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TRICUSPID ATRESIA

Tricuspid atresia is the third most common cyanotic congenital heart disease in which the non oxygenate blood can not flow from right artrium to right ventricle due to non development or agenesia of tricuspid valve. Right ventricle is small and pulmonary artery sometimes is stenotic.

Majority of infants with die in the first year of life without surgery. ASD is necessary for the blood flowing from right atrium to left system and with out them the infants will not survive.

Historical perspective

Tricuspid atresia was first discovered by friedrich ludwig kreysig in 1817, a german physician who found the obstruction between right atrium and right ventricle in tricuspid valve. The classic term of tricuspid atresia was used firstly by schuberg in 1861.

Pathophysiology

Inferior vena cava and superior vena cava collect venous non oxygenate blood into right atrium. Through ASD blood reach to left atrium and finally flow into left ventricle and via aorta artery goes into the rest of body. This blood is the mixture of saturated and unsaturated oxygen. If there is VSD, this mixed blood in left ventricle come into right ventricle via VSD , then via pulmonary artery flows into pulmonary bed and becomes oxygenate ,then returns back into left atrium with pulmonary venous oxygenate blood . In presence of PDA, the mixed blood in aora flow from this passage into pulmonary artery and pulmonary bed.

In the presence of pulmonary stenosis and normal positioning of great arteries cyanosis will increase by aggravating the right to left shunt in the level of VSD.TGA and subaortic stenosis and persistent left superior venacava are others accompanied anomaly.

Classification

Tricuspid atresia is classified according to connection between ventricles and aorta and pulmonary artery into two subgroups:

• ·        normal connection between ventricles and  aorta and pulmonary artery . this type is much more common  and Cyanosis is more common dependent on the size od VSD

• ·        Aorta comes from small  right ventricle and pulmonary artery comes from left ventricle ,.flow in aorta is dependent on VSD. Subaortic stenosis and aortic arch anomalies are common

Differentiating tricuspid atresia from other Diseases

• Tricuspid atresia must be differentiated from other diseases that cause lung olygemia and cyanosis , such as

• TS
• PS
• ASD

Epidemiology and Demographics[edit | edit source]

• The prevalence of tricuspid atresia is approximately 1.2 per 100,00 birth live.

Age

• tricuspid atresia is more commonly observed among infant less than one year old.

Gender

• Tricuspid atresia affects male and female equally.

Race

• There is no racial predilection for tricuspid atresia

Risk Factors[edit | edit source]

• there is no specific risk factors for occurance of tricuspid atresia during pregnancy .
• few cases were reported as inheritance autosomal recessive tricuspid atresia

Natural History, Complications and Prognosis[edit | edit source]

• The majority of patients with [disease name] remain asymptomatic for [duration/years].
• Early clinical features include [manifestation 1], [manifestation 2], and [manifestation 3].
• If left untreated, [#%] of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
• Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
• Prognosis is generally [excellent/good/poor], and the [1/5/10­year mortality/survival rate] of patients with [disease name] is approximately [#%].

Diagnosis[edit | edit source]

Diagnostic Criteria[edit | edit source]

• The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met:

• [criterion 1]
• [criterion 2]
• [criterion 3]
• [criterion 4]

Symptoms[edit | edit source]

• [Disease name] is usually asymptomatic.
• Symptoms of [disease name] may include the following:

• [symptom 1]
• [symptom 2]
• [symptom 3]
• [symptom 4]
• [symptom 5]
• [symptom 6]

Physical Examination[edit | edit source]

• Patients with [disease name] usually appear [general appearance].
• Physical examination may be remarkable for:

• [finding 1]
• [finding 2]
• [finding 3]
• [finding 4]
• [finding 5]
• [finding 6]

Laboratory Findings[edit | edit source]

• There are no specific laboratory findings associated with [disease name].

• A [positive/negative] [test name] is diagnostic of [disease name].
• is diagnostic of [disease name].
• Other laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].

Imaging Findings[edit | edit source]

• Echocardiography is the imaging modality of choice for tricuspid atresia and can show ASD, VSD, PDA, and aortic arch anomaly.
• On EKG, tricuspid atresia is characterized by left axis deviation, left ventricle hypertrophy, right atrium enlargment and left atrium enlargment in increment amount of of pulmonary blood flow.
• CXR may demonestrate situs solitus, left sided aortic arch ,levocardia, absent main pulmonary artery, heart size is dependent on pulmonary blood flow, right aortic arch in %25 of cases.
• Catheterization may demonestrate the gradient between left ventricle and right aventricle in subaortic stenosis.

Other Diagnostic Studies[edit | edit source]

• [Disease name] may also be diagnosed using [diagnostic study name].
• Findings on [diagnostic study name] include [finding 1], [finding 2], and [finding 3].

Treatment[edit | edit source]

Medical Therapy[edit | edit source]

• There is no treatment for [disease name]; the mainstay of therapy is supportive care.

• The mainstay of therapy for [disease name] is [medical therapy 1] and [medical therapy 2].
• [Medical therapy 1] acts by [mechanism of action 1].
• Response to [medical therapy 1] can be monitored with [test/physical finding/imaging] every [frequency/duration].

Surgery[edit | edit source]

• Surgery is the mainstay of therapy for [disease name].

Prevention[edit | edit source]

• There are no primary preventive measures available for [disease name].

• Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].

• Once diagnosed and successfully treated, patients with [disease name] are followed-up every [duration]. Follow-up testing includes [test 1], [test 2], and [test 3].

References

1.Svensson EC, Huggins GS, Lin H, et al. A syndrome of tricuspid atresia in mice with a targeted mutation of the gene encoding Fog-2. Nat Genet. 2000;25(3):353-356. doi:10.1038/77146