Overview

A missing tricuspid valve that prevents blood flow from the right atrium to the right ventricle is a congenital heart disease, and it is called tricuspid atresia.¹ There are required routes that the blood will have to follow to reach the lungs and circulate throughout the body because of the disfigurement.² They're routed through atrial septal defect (ASDs) and ventricular septal defect( VSDs), ensuring sufficient rotation and oxygen pressure.

Since it's a cyanotic congenital heart deformity, tricuspid atresia yields superior blood oxygen that can induce cyanosis, or blue wear and tear of the skin.³ How much deoxygenated and oxygenated blood will be able to mix will depend on whether an ASD or VSD exists and how severe the problem is. Opinion and treatment must be addressed before that.⁴

Causes

Tricuspid atresia results from an abnormal formation of the tricuspid valve during embryonic growth. Although the pathogenesis is unknown, several reasons may be intertwined in its etiology.^{5 6}

Some genes involved in the formation of the heart may have mutations that may be a risk factor for congenital heart conditions such as tricuspid atresia. Holt-oram syndrome and Noonan syndrome are two genetic syndromes linked with the condition.⁷

Chromosome Abnormalities Trispid 21( Down syndrome) and other chromosomal diseases have been intertwined with tricuspid atresia and other congenital cardiac malformations.⁸

Motherly medical conditions during pregnancy, poorly controlled diabetes, lupus, and viral diseases like rubella are risk factors that are reported to potentially inhibit fetal cardiac development.⁹

Maternal diseases during pregnancy, such as uncontrolled diabetes, lupus, and some viral infections, such as rubella, have been suggested as risk factors for impairing fetal heart development.

Environmental Causes exposure to drugs( such as retinoic acid and anticonvulsants), alcohol, cigarettes, and other bad drugs during pregnancy has the ability to disrupt normal heart conformation and increase the risk of congenital heart disease.¹⁰

Mother's Age Older mothers (above 35) have been associated with an elevated frequency of natural heart disease in babies.

Abnormalities of Fetal Development during the initial stages of gestation, any disruption of normal development of septal structures and endocardial cushions can lead to tricuspid atresia.

Signs and symptoms

Symptoms of tricuspid atresia depend on the extent of disfigurement and whether or not other congenital heart defects like ASD and VSD exist. Symptoms and signs listed below are typical

In cyanotic infants, because of oxygenation, the nail beds, skin, and lips become blue. The cause for this is the flow of blood with lower oxygen content through the body.

Physicians can detect irregular cardiac murmurs with a stethoscope from the turbulent flow of blood through the deformed openings of a heart.

1. Dyspnea lack of a child's heart to supply adequate oxygen-enriched blood, causes reproducing breathing difficulties, especially on exertion or feeding
2. Failure to feed and grow tricuspid atresia makes it primarily exhausting for children to feed, and they end up being undernourished and gaining weight progressively, generally described as failure to thrive
3. Failure of the heart to effectively circulate well-oxygenated blood makes tricuspid atresia children frail and tired³
4. Swelling of the toes and fingers and their rounding due to regular low oxygen is referred to as" digital clubbing"^{2 6} 
5. Water retention or oedema can result in some infants with tricuspid atresia if heart failure develops

Diagnosis

A combination of imaging, clinical evaluation, and laboratory tests is applied in tricuspid atresia to determine the fact of the existence of the disfigurement and its degree. These are some individual methods that are commonly used

1. Fetal echocardiogram and antenatal ultrasound - Through detailed evaluation of the structure and rotation of the fetal heart in utero, fetal echocardiography can sometimes identify tricuspid atresia in utero. Preterm webbing might be suspected in a high-risk pregnancy with a family history of naturally occurring cardiac defects⁵
2. Postnatal Physical test: Neonates with tricuspid atresia always present with heart murmurs and cyanosis following birth, which warrants further investigation¹
3. Electrocardiography( ECG) is a recording of the electrical activity of the heart and can detect abnormal atrial dimensions, left ventricular hypertrophy, and left axis deviation, all of which are suggestive of tricuspid atresia⁷
4. Cardiac catheterization is an invasive procedure in which a catheter is placed inside the heart to observe blood pressure and oxygen status inside the chambers. It yields useful hemodynamic information that aids in assessing the severity of the issue and in surgical planning⁸
5. Palpitation Oximetry is a straightforward, non-invasive test that gauges blood oxygen saturation. Tricuspid atresia low oxygen levels because of their impaired blood inflow to the lungs⁶
6.  Chest X-ray Though less educational than echocardiography, a chest X-ray can pick up on elevated pulmonary vascular markings and cardiomegaly, which are signs of abnormal blood inflow patterns³
7. Genetic Testing or chromosome testing can be advised to identify the genetic cause of tricuspid atresia if it is suspected to be caused by an inherited condition⁹

 Risk factors

 Increased risk of tricuspid atresia is produced by different factors

1. Congenital history of natural cardiac complaints may be due to genetic predilection²
2. Diabetes or viral infection during pregnancy, poorly controlled diabetes, and infections like rubella can impact fetal cardiac development¹⁰
3. Pregnancy with some drugs or substances pregnancy with some drugs, like retinoic acid and seizure-specifics, is associated with natural heart anomalies⁴
4. Multicomplex heart disease, e.g., tricuspid atresia, has nothing to do with chromosomal runs, e.g., Down syndrome⁸
5. Motherly alcohol or motherly smoking medicine toxins due to alcohol or tobacco use during pregnancy can hinder the normal formation of the heart⁹

Complications

Tricuspid atresia may have adverse outcomes when the cure is not administered

• Cardiac failure accumulation of fluids, shortness of breath, and decreased capacity for exercise characterize heart failure that may be a consequence of an overloaded left ventricular workload through fearful rotation⁵
• Arrhythmias may be treated with specific therapy or placement of a pacemaker due to structural abnormalities or postoperative changes⁶
• Thromboembolism, Stroke, and other vascular complications can occur due to the possibility of developing blood clots as a result of abnormal blood flow⁷
• Exercise intolerance: Both children and adults with tricuspid atresia have exertion issues because of low oxygenation⁸
• Pulmonary hypertension: Abnormal blood flow patterns can lead to elevated pressure in the pulmonary arteries, which puts additional strain on the heart³

Treatment

Managing tricuspid atresia requires surgical intervention. The primary procedures include, 

• Blalock- Taussig Shunt: A palliative procedure that links the pulmonary and subclavian highways to circulate more blood into the lungs⁹
• Glenn Procedure: This procedure, done when the child is four to six months old, links the pulmonary artery to the superior vena cava, lowering the heart's workload and raising oxygenation⁵
• Fontan Procedure: It is performed in children progressing 2- 4 times and by-passes the right ventricle by re-diverting blood from the lower half to the lungs⁶
• Heart Transplant: Heart transplant can be performed in severe cases where surgery alone is not sufficient⁷
• Medical Management: For management of symptoms and prevention of complications, doctors may set parameters like oxygen therapy, diuretics, and anticoagulants³

FAQ's

What is tricuspid atresia?

Tricuspid atresia is a congenital defect in which the tricuspid valve is absent, and consequently, no blood is circulated from the right atrium to the right ventricle ¹

How do ASDs and VSDs help tricuspid atresia?

ASDs are an opening where the blood coming from the right atrium can flow to the left ventricle, and VSDs are a passage to enables the blood to cross the pulmonary circulation to receive oxygen and systemic circulation. ⁴

Is tricuspid atresia curable?

Yes, surgical interventions like the Blalock-Taussig shunt, Glenn procedure, and Fontan procedure can be used in an attempt to cure the disease and enhance the quality of life.⁹

What happens to cases with tricuspid atresia?

A majority of persons with tricuspid atresia are suitable to have healthy, productive lives with proper surgical intervention and follow-up.⁷

Will there be changes in life after the cure?

The patient will have to wait for strenuous efforts, come back regularly for monitoring, and cling to structured traditional treatments. 

Can tricuspid atresia be diagnosed during pregnancy?

Yes, prenatal echocardiography can identify cardiac abnormalities during pregnancy, allowing early planning of the operation.⁵

What are the post-operative survival rates?

The mortality rate has improved considerably with the development of individuals who live well into their majority with relevant care.⁶

Summary

Tricuspid atresia is a congenital heart condition in which normal blood flow is impeded by the absence of the tricuspid valve. For circulation to be maintained, the body depends on ASDs and VSDs. Environmental factors, chromosomal abnormalities, maternal health issues, and genetic mutations are among the causes. Among the symptoms are exhaustion, breathing problems, heart murmurs, cyanosis, and stunted growth. Imaging, ECG, and genetic tests are used in the diagnosis process. Heart failure, arrhythmias, and pulmonary hypertension are among the complications. Heart transplants are necessary in extreme circumstances, and treatment entails surgical techniques such as the Fontan and Glenn surgeries. Patients can lead healthy lives under constant observation with the right help.^{1 3 5 7}