What Is Ebstein's Anomaly

Overview

The tricuspid valve is one of the four valves of the heart located¹ between the right atrium and the right ventricle, consisting of three leaflets- septal, anterior, and posterior. In Ebstein’s anomaly, the position of the tricuspid valve is compromised, and the leaflets are malformed.²

Causes of ebstein's anomaly

In Ebstein’s anomaly, the tricuspid valve is lower than its original position in the right ventricle, making it a part of the right atrium. This leads to an enlargement of the right atrium.

Ebstein’s anomaly occurs due to many factors, but most of the time, it happens by chance. The improper development of the tricuspid valve in the first eight weeks of fetal growth can cause it. Genetic factors may contribute to congenital heart defects, either due to a defect in a gene, a chromosomal abnormality, or environmental exposure, causing heart problems to occur more often in certain families.

The malformed leaflets may lead to tricuspid valve regurgitation (backward blood leaking.) The severity varies from person to person.³

Signs and symptoms of ebstein's anomaly

Symptoms may be similar to other heart or respiratory conditions, including :

• Difficulty in breathing
• Fatigue
• Palpitations (pounding heart) 
• Arrhythmia (irregular heartbeat) 
• Exertional dyspnoea (sensation of running out of air) 
• Oedema (fluid buildup) of the lower extremity

Management and treatment for ebstein's anomaly

Medical management

Supportive treatment is to help reduce pulmonary vascular resistance and hypoxemia (low blood oxygen) in infants.

In symptomatic infants with cyanosis (skin discolouration), inhalation of nitric oxide can help reduce pulmonary vascular resistance. Inotropes (drugs that induce changes in heartbeat) for newborns with heart failure and cardiogenic shock (when the heart can not pump enough blood).

Loop diuretics (used to treat excessive fluid), guideline-directed medical therapy, and beta-blockers are a few choices of drugs used in the medical management of Ebstein’s anomaly.

Surgical management

Indications for surgery in neonates, children, and adults are:

• Right heart failure due to severe tricuspid regurgitation and cyanosis
• A cardiothoracic ratio of greater than 80 per cent
• Heart failure symptoms
• Right ventricular dysfunction or progressive dilation
• Evidence of paradoxical emboli
• Tricuspid regurgitation

Surgical procedures are:

• Atrial septal defect surgery
• Tricuspid valve repair or replacement
• Ablation therapy (destroying abnormal tissue)
• Maze procedures (treats irregular heartbeat) 

Prophylactic management

Antibiotic prophylaxis (giving antibiotics before surgery) for infective endocarditis (heart infection)  is recommended for patients with Ebstein’s anomaly.

Managing Ebstein’s anomaly becomes smooth with:

• A timely visit to the doctor
• Self-care
• Staying active

Diagnosis of ebstein's anomaly

In infants and neonates, the most common physical examination finding is the presence of cyanosis, and in adults, it is the murmuring sound of the heart due to tricuspid regurgitation.

A heart murmur is a turbulence in the blood flow from the right ventricle to the pulmonary artery.

Your cardiologist (heart specialist) may ask for the following tests:

Cardiothoracic imaging- An X-ray examining the chest and surrounding area. Some findings may include: 

• Cardiomegaly (enlargement of the heart) 
• Right atrial enlargement causing an increase in cardiothoracic ratio
• Tricuspid regurgitation (can also be diagnosed with colour Doppler ultrasound)
• Electrocardiogram- An echo is one of the fastest ways to evaluate the heart. Any irregular electrical activity helps to detect heart damage.

Echo findings will show:

• Right bundle branch block
• Delta waves due to pre-excitation
• Tall P waves suggesting right atrial enlargement
• First-degree AV block
• Supraventricular tachyarrhythmias

Exercise echocardiogram

A stress TMT (Treadmill test) is done when a patient walks on a treadmill or pedals a stationary cycle to monitor the heart during stress. It also monitors breathing and blood pressure rates.

Cardiac MRI- Cardiac magnetic resonance imaging is an effective way to know more about the tricuspid leaflet anatomy. Quantifies the right ventricular ejection fraction.

Cardiac catheterization- A catheter is inserted from a blood vessel in the groin or arm through the aorta into the heart and is used to measure the pressure of different chambers of the heart.

Risk factors

There are several risk factors for Ebstein’s anomaly including:⁴

• Maternal exposure to second-hand cigarette smoke 
• Family genetic history of congenital heart disorder^.
• Environmental history

Complications

The complications of Ebstein’s anomaly are

• Heart failure right and biventricular
• Atrial arrhythmias (the most common)
• Paradoxical emboli
• Sudden cardiac death 

FAQs

Can Ebstein's anomaly be prevented

Since there are several factors contributing to Ebstein’s anomaly, a single causative factor is difficult to identify. However, taking necessary precautions before becoming pregnant may help prevent complications.

Depending on your signs and symptoms, your doctor might recommend avoiding certain competitive sports or ballistic activities.

Since pregnancy, labour, and delivery put a strain on your heart, it is advised to visit your doctor once you have planned for your baby. With adequate monitoring and updated health checkups, it may be possible to prevent Ebstein’s anomaly. 

How common is Ebstein's anomaly

Ebstein’s anomaly is a rare congenital heart condition that occurs in 1 per 200,000 live births.

When should I see a doctor?

If you find difficulty in breathing during rest or exertion or notice any other symptoms of heart failure like palpitations, fatigue, or if the skin around the lips and nails looks blue or you feel sudden cramps or swelling of your legs, it is advised not to delay and talk to your doctor. Your general practitioner (GP) might refer you to a cardiologist for further diagnosis.

Summary

Ebstein’s anomaly is a rare congenital heart condition that occurs due to the displacement of the tricuspid valve and can be treated with surgery and/or medications. While the cause is unknown, it can be present at birth or develop during childhood. Without treatment, it can lead to serious complications like heart failure, arrhythmias, and even death. With the right care, it is possible to improve symptoms, quality of life, and long-term outcomes.