Congenital Absent Pulmonary Valve - An Insight

Introduction

An uncommon congenital cardiac defect known as pulmonary valve agenesis is characterized by the complete or partial lack of pulmonary valve leaflets, which is linked to pulmonary artery orifice stenosis and pulmonary artery aneurysmal dilatation. It can happen as part of a syndrome or often coexist with other cardiovascular abnormalities such as ventricular septal defect or tetralogy of Fallot. The clinical symptoms, which include pulmonary insufficiency, bronchial obstruction (due to compression by aneurysmally dilated pulmonary arteries), pulmonary stenosis, cyanosis, and cardiac failure, are dependent upon the existence of concomitant cardiac abnormalities.

What Is Congenital Absence of Pulmonary Valve?

The pulmonary valve can be absent or poorly developed in an absent pulmonary valve defect, an uncommon condition. Via this valve, blood deficient in oxygen leaves the heart and enters the lungs, where it is replenished with oxygen. This illness is congenital, meaning it exists from birth.

What Pathology Associated With Congenital Absence of Pulmonary Valve?

Ventricular septal defects are typically linked to the congenital absence of the pulmonary valve. Infancy is a crucial time for survival. The most common causes of symptoms are persistent cardiac failure, respiratory distress, or infection resulting from airway blockage caused by the dilated pulmonary artery squeezing the bronchus.

What Are the Types of Congenital Absent Pulmonary Valve?

It has been characterized as two sorts.

• Fallot - Fallot type is linked to the Fallot tetralogy.

• Non-Fallot - It is characterized by an absent pulmonary valve, an intact ventricular septum, and perhaps tricuspid atresia.

What Heart Defect is Associated With Absent Pulmonary Valve?

The pulmonary arteries that bring blood to the lungs for oxygen uptake are also greatly expanded or dilated in the case of a missing pulmonary valve. The bronchi, the tubes that carry oxygen into the lungs, may be compressed by them when they grow big. This results in respiratory issues.

A missing pulmonary valve might also result in further cardiac abnormalities, such as:

• Tricuspid valve anomaly.

• Defective atrial septum.

• Double ventricle right outlet.

• Arteriosis ductus.

• Defective endocardial cushion.

• Marfan condition.

• Atresia tricuspid.

• Leaky pulmonary artery absence.

Gene abnormalities may cause heart issues associated with nonexistent pulmonary valves.

What Are the Symptoms Associated With Congenital Absent Pulmonary Valve?

The infant's other flaws will determine the symptoms, which might include any of the following:

• Calicosis, or blue coloring of the skin.

• Coughing up.

• Inability to prosper.

• Low appetite.

• Fast breathing.

• Lack of respiration.

• Sniffling.

How To Diagnose Congenital Absent Pulmonary Valve?

Echocardiography, a test that utilizes sound waves to build a picture of the heart, can be used to identify absent pulmonary valves before the baby is born. The baby's chest may murmur during an examination.

Examinations for pulmonary valve absence consist of the following:

• An examination to gauge the heart's electrical activity (electrocardiogram).

• Cardiovascular CT imaging.

• Radiology of the chest.

• Echocardiography.

• An MRI of the heart using magnetic resonance imaging.

1. Antenatal Ultrasound

A characteristic that may be symptomatic of a balloon-like or bow-tie-shaped arrangement of pulmonary arteries is pulmonary aneurysmal dilatation. It may also exhibit severe pulmonary valve regurgitation +/- the existence of an overriding aorta or a VSD.

2. CT/ MRI

CT or MRI might make it possible to see a dilated main pulmonary artery with or without branch dilatation, as well as a primitive or non existent pulmonary valve, directly.

What Are the Treatment Modalities That Are Associated With An Absent Pulmonary Valve?

Reproductively symptomatic infants usually require early surgical intervention. Surgery is often performed within the first three to six months of life or later for infants who do not exhibit significant symptoms.

The operation may entail the following, depending on the sort of additional cardiac abnormalities the baby has:

• Shutting the ventricular septal defect is a hole in the wall separating the heart's left and right ventricles.

• Cutting off the blood vessel known as the ductus arteriosis that joins the aorta and the pulmonary artery.

• The right ventricle's flow to the lungs is increased.

The following surgical procedures are used to treat missing pulmonary valves:

• Repositioning the pulmonary artery so that it is in front of the aorta and out of the airways.

• Rebuilding the lung's arterial wall (pulmonary plication and reduction arterioplasty) to relieve airway pressure.

• Repairing the lungs' breathing passages and windpipe.

• Substituting a pulmonary valve from animal or human tissue for the defective one.

• Before and after surgery, infants with severe respiratory difficulties might need to be given oxygen or put on a ventilator.

What Are the Complications Associated With an Absent Pulmonary Valve?

Possible complications include:

• Abscess or brain infection.

• Fall in the lungs (atelectasis).

• Pneumonia.

• Heart failure on the right side.

How to Prevent Congenital Absent Pulmonary Valve?

Families may be assessed to determine their risk for congenital malformations, even though no method exists to avoid this problem.

What Is The Prognosis Of an Absent Pulmonary Valve?

Absent pulmonary valve still has a dismal prognosis. Other than heart issues, the majority of newborns have respiratory distress-related difficulties. The main cause of respiratory discomfort is often dilated pulmonary artery compression of the bronchi, which can result in extensive lobar emphysema. The orientation of their infundibulum likewise governs the pulmonary arteries' preferred dilatation.

A short, vertical infundibulum is typical. In absent pulmonary valve syndrome, aneurysmal dilatation of the right pulmonary artery results from an infundibulum oriented towards the right and horizontal, further compressing the middle lobe bronchus. The left-oriented infundibulum causes the left pulmonary artery to dilate aneurysmically, compressing the bronchus of the left main and upper lobes.

Conclusion

An uncommon condition known as an absent pulmonary valve occurs when the pulmonary valve is either absent or poorly developed. Through this valve, blood with low oxygen content travels from the heart to the lungs, where it is replaced with oxygen. This illness is congenital, meaning it exists from birth. In general, the prognosis is seen as bad. Numerous surgical techniques have been used, such as valve less repair, replacing with a mono cusp valve, and replacing with a valved conduit.