What Is Tricuspid Atresia?

Throughout this article, we will explore Tricuspid Atresia to help provide you with a clear understanding of this particular genetic disorder. We will explore what Tricuspid Atresia is, any underlying causes, symptoms, diagnostic techniques, as well as available management options to ensure that you are well informed about this particular congenital heart condition and gain valuable insight to aid you in making informed decisions regarding your own care. 

Tricuspid atresia is a rare congenital heart condition in which the tricuspid valve is either severely underdeveloped or absent. The tricuspid valve is a key component in regulating the flow of blood between the right atrium and the right ventricle. This condition can disrupt the normal circulation of blood, resulting in complex anatomical changes in the heart.

Early diagnosis and timely interventions such as medications, surgical procedures or heart transplants are essential. The symptoms of tricuspid atresia include:

• cyanosis
• rapid breathing
• poor growth
• heart murmurs

Read on to discover the causes, symptoms, diagnosis and treatment options for congenital heart conditions like tricuspid atresia. Understanding tricuspid atresia is vital for those affected with this condition and their caregivers as it will empower you to make informed decisions regarding your own care.

Introduction

Tricuspid atresia is a rare inherited heart defect which is characterised by the absence of the tricuspid valve. This condition results in the disruption of blood flow between the right atrium and the right ventricle.¹

The estimated prevalence of this condition is approximately 1 in 10,000 births, however, the incidence of this condition varies between different regions and populations.² Understanding the signs, symptoms and causes of tricuspid atresia is essential for effective diagnosis and management of this rare congenital condition. 

Anatomy and physiology

Normal heart function

The heart is a crucial organ which is responsible for pumping blood around the body as well as providing the tissues with nutrients and oxygen. The heart consists of four chambers: two ventricles (left and right) and two atria (left and right).

When the heart functions normally, blood that is low in oxygen returns to the right atrium and is pumped into the right ventricle before flowing into the lungs via the pulmonary artery. Blood that is rich in oxygen returns to the left atrium and is pumped into the left ventricle before being distributed by the aorta to the rest of the body.

Electrical impulses help to coordinate the contraction of the heart to ensure efficient and rhythmic blood flow. This synchronised action between the ventricles and the atria is facilitated by various heart valves, such as the mitral valves and the tricuspid valve³, which enables the heart to maintain circulation and keep up with the body’s demands. 

Tricuspid valve

A key component of the heart is the tricuspid valve, which regulates the flow of blood between the right atrium and the right ventricle. The tricuspid valve opens to allow deoxygenated blood that returns from the body into the right atrium to flow into the right ventricle.

The right ventricle then contracts, which results in the tricuspid valve closing to prevent blood from flowing back into the atrium. This ensures that the blood flows one way into the pulmonary artery before it is carried to the lungs for oxygenation.⁴

The tricuspid valve is essential in maintaining the overall function of the heart. Any malfunction or malformation of this valve can result in serious cardiac conditions, such as tricuspid atresia. 

Tricuspid atresia in the heart

Tricuspid atresia is a rare heart defect which can be described as the severe underdevelopment or absence of the tricuspid valve. In a healthy functioning heart, the tricuspid valve helps to regulate the flow of deoxygenated blood from the right atrium to the right ventricle.

However, in tricuspid atresia, this valve is either poorly formed or missing, which disrupts normal blood circulation. Therefore, the blood is unable to flow from the right atrium to the right ventricle, resulting in the heart compensating with alternative pathways.² This condition typically requires surgical shunts or other interventions so patients can receive adequate oxygenation and blood circulation. 

Causes and risk factors

Congenital nature

Congenital conditions are typically present at birth and are the result of a combination of both genetic and environmental factors. Regarding tricuspid atresia, the primary cause is typically genetic factors.

However, the exact genetic mechanism can vary between individuals. The majority of cases of tricuspid atresia occur spontaneously without a family history; however, in some cases, specific genetic mutation of inheritance patterns may contribute to the development of this condition.²

Additionally, environmental factors such as the mother's exposure to particular infections, toxins or medications during pregnancy can play a role in the development of congenital heart defects.⁵ By understanding the congenital nature of tricuspid atresia, we can aid in early detection to ensure appropriate medical intervention when necessary. 

Genetic factors

Genetic factors can also play a key role in the development of congenital heart defects such as tricuspid atresia. The exact genetic causes can vary between individuals, with many cases being believed to result from complex interactions between genetic mutations and multiple genes. In particular circumstances, a family history of congenital heart defects can further increase the risk of developing heart defects, highlighting a genetic link.

Despite this, the majority of cases occur spontaneously with no clear family link and often result from random mutations that occur during foetal development.⁵ Understanding the genetic factors behind tricuspid atresia allows you to make more informed decisions regarding family planning and medical management for individuals affected by this condition. 

Environmental factors

Additionally, environmental factors can also contribute to the development of congenital heart defects such as tricuspid atresia. Exposure to certain environmental factors during pregnancy can further increase the risk of developing these conditions. These environmental factors include the maternal use of particular medications, infections, exposure to chemicals and toxins and alcohol consumption.

It is important to note that not all pregnancies that are exposed to these environmental factors result in congenital heart defects; however, by minimising the exposure to these factors, you can ensure optimal foetal development.⁶ Understanding the key role environmental factors have on the development of congenital heart defects provides comprehensive education and prenatal care for expectant mothers. 

Signs and symptoms

Cyanosis

A prominent clinical symptom associated with congenital heart defects such as tricuspid atresia is cyanosis. This refers to a bluish discolouration of the nail beds, lips and skin, which is due to reduced levels of oxygen in the blood.¹ In individuals that are affected with tricuspid atresia, blood that is low in oxygen is unable to pass through the defective heart valve, resulting in the mixing of oxygen-poor and oxygen-rich blood in the body.

Therefore, insufficiently oxygenated blood is circulated throughout the body, which manifests as cyanosis. The discolouration known as cyanosis is most noticeable in the lips (particularly when a baby exerts themselves or cries).² Cyanosis requires prompt medical attention and intervention as it is a critical clinical indicator of oxygen deprivation. 

Heart murmurs

Another common clinical symptom associated with tricuspid atresia is heart murmurs. Heart murmurs are extra sounds that are heard during a heartbeat and are the results of turbulent blood flow within the heart. In regards to tricuspid atresia, the underdevelopment or absence of the tricuspid valve can result in irregular blood flow patterns, resulting in heart murmurs.²

During a physical examination, healthcare professionals can detect these heart murmurs using a stethoscope. These heart murmurs are essential diagnostic indicators of congenital heart defects and require further testing and evaluation to determine the underlying heart condition’s characteristics and severity to aid in determining the appropriate treatment. 

Rapid breathing

Rapid breathing is another common symptom associated with tricuspid atresia, which is commonly displayed in infants and young children.⁷ Rapid breathing results from the heart's inability to pump oxygenated blood around the body, resulting in reduced oxygen levels in the body.

In order to compensate for this oxygen deficit, the body naturally tries to increase the intake of oxygen by breathing rapidly. Rapid breathing is often most noticeable when the affected individual is crying, feeding or during physical activity.²

Rapid breathing is a significant clinical sign that indicates potential heart problems. Healthcare professionals will often consider rapid breathing in combination with other symptoms to assess the potential severity of the heart condition.

Poor growth

Failure to thrive or poor growth is often a common sign of congenital heart conditions like tricuspid atresia. Poor growth is often the result of the heart’s compromised ability to deliver adequate nutrients and oxygen to the body’s organs and tissues.

As a consequence of reduced oxygen, individuals may struggle to develop or gain weight at the expected rate. This symptom is most noticeable in children and infants and can further manifest as stunted height and weight gains, delayed physical development and overall failure to meet growth milestones.⁸

Poor growth serves as a significant diagnostic marker for healthcare professionals, who can then produce appropriate strategies to address the growth challenges faced by individuals affected by tricuspid atresia. 

Diagnosis

Physical examination

Diagnosing congenital heart conditions like tricuspid atresia typically begins with a physical examination in which a healthcare professional will listen for abnormal heart sounds with a stethoscope. Healthcare professionals will also look for additional symptoms such as poor growth, cyanosis or rapid breathing, which can indicate a potential heart problem.² A physical examination can also prompt further diagnostic testing, such as an echocardiography. 

Echocardiography

A key method in the diagnosis of tricuspid atresia is a non-invasive imaging technique known as an echocardiography.¹ An echocardiogram utilises high-frequency sound waves to create a detailed image of the heart's function and structure. An echocardiogram aids healthcare professionals by providing vital information regarding the size, presence and function of the tricuspid valves, in addition to the heart's overall structure and blood flow. It also allows healthcare professionals to monitor the condition over time, making echocardiography a vital tool in the overall care of individuals affected.² 

Treatment

Medications

Medications used in the treatment of tricuspid atresia are mostly aimed at managing symptoms as well as improving the overall heart function.⁹ Individuals affected by tricuspid atresia may require medications to lower the workload of the heart, alleviate symptoms and prevent blood clots.

Medications such as anticoagulants may be prescribed to prevent the formation of blood clots.² Medications are an important part of the comprehensive treatment plan, which often works together with surgical procedures to improve the overall quality of life for individuals with tricuspid atresia. 

Surgery

The main treatment option for individuals affected by tricuspid atresia is surgery. This approach depends on the severity and specific characteristics of the condition.¹ Surgery is often required to correct the abnormal blood flow patterns associated with tricuspid atresia.

Additionally, certain surgical procedures may be performed to create alternative pathways for blood circulation when the tricuspid valve is absent. Furthermore, a heart transplant may be considered when the individual's heart abnormalities are too severe to be treated during surgery.¹⁰ Healthcare professionals will base treatment decisions on the careful evaluation of each patient’s particular circumstances. 

Summary 

Tricuspid atresia is a rare congenital heart condition in which the tricuspid valve is severely underdeveloped or missing. This condition is rather rare, with an estimated prevalence of around 1 in 10,000 births.

This condition results in oxygen-low blood not being able to flow directly into the right ventricle and circulate effectively. In order to compensate, the body will form alternative pathways for blood flow.

Tricuspid atresia requires timely medical intervention through a physical examination in which the healthcare professional will look for symptoms such as cyanosis, rapid breathing and poor growth. Treatment options for tricuspid atresia are often in the form of medications to manage the symptoms, as well as surgery.