Pulmonary Atresia with Intact Ventricular Septum - An Overview

What Is Pulmonary Atresia With Intact Ventricular Septum?

A rare birth defect called pulmonary atresia with intact ventricular septum (PAIVS) affects the heart. It is marked by the right ventricle developing unevenly, an imperforate pulmonary valve, and probably long connections between the ventricles and the coronary arteries. The prognosis and treatment plan depend on how bad the right ventricular hypoplasia is. This includes the unfavorable and underdeveloped tricuspid valve, and the quantity of the myocardium depends on blood flow problems between the right ventricle and the coronary arteries.

What Are the Diagnostic Methods?

History:

Typically, infants with pulmonary atresia with an intact ventricular septum (PAIVS) are born during a period during which a fetus develops within, and cyanosis (bluish discoloration of the skin) is visible within hours of birth. A prenatal diagnosis can be obtained for the condition using a fetal medical imaging technique that utilizes ultrasound waves to visualize and assess (echocardiography). The premature closure of the patent ductus arteriosus in these infants is related to the development of early progressive cyanosis as well as tachypnea.

Investigation of the Body:

1. Central cyanosis, which includes both the perioral and periorbital regions, is the finding that occurs most frequently during a physical examination. After the ductal openings have been closed, profound generalized cyanosis will be seen.

2. The apical left ventricular surge may be pronounced.

3. There is a single beat for both the initial and second heart sounds.

4. A murmur associated with tricuspid regurgitation can frequently be heard near the left lower sternal boundary during the pan-systolic phase of the heartbeat. In severe cases, tricuspid regurgitation might be accompanied by a thrill with a diastolic rumbling and the murmur it produces.

5. A systolic ejection murmur of the patent arteriosus can sometimes be detected at the left side of the second or third intercostal gap, particularly after the beginning of a prostaglandin infusion.

6. In most cases, normal arterial pulses are detectable; nevertheless, in the presence of an enormous patent ductus arteriosus with increased pulmonary blood flow, these pulses may appear to be bounding.

7. Hepatomegaly is unusual and only occurs when an atrial septal defect is restricted.

Investigation from the Laboratory:

1. When measured with pulse oximetry, the upper and lower extremities will show identical hypoxemia levels.

2. In a patient who has cyanotic congenital heart disease (CCHD) with a fixed right-to-left shunt, an arterial blood gas (ABG) analysis will most likely reveal hypoxemia and hypercarbia that are resistive to inspired oxygen concentration.

Studies in Imaging

1. Electrocardiography: Left ventricular dominance, normal sinus rhythm, and an enlarged right atrium are frequently seen on electrocardiography (ECG). Additionally, patients with coronary artery stenosis or ventricular-coronary connections frequently experience ST-T wave anomalies, which are indicative of subendocardial ischemia.

2. Echocardiography: Pulmonary atresia diagnosis relies on echocardiography and angiography. Pulmonary atresia with an intact ventricular septum is diagnosed by two-dimensional echocardiography. (PAIVS). Anatomic pulmonary atresia, tricuspid valve, right ventricular architecture, and size are seen in subcostal and precordial views.

Absolute right ventricular volume measurements are frequently unreliable. According to the Congenital Heart Surgeons Study findings, the right ventricular cavity size was highly linked with the tricuspid valve z-value. In addition, retrospective results indicate right ventricular hypoplasia was the most critical variable in a single-ventricle versus two-ventricle repair.

1. Doppler: Also, color-flow continuous-wave Doppler ultrasonographic examinations show the degree of tricuspid regurgitation, estimate right ventricular pressure, which is usually supra systemic, and show interatrial communication constraint. (uncommon).

Doppler echocardiography and imaging show branch pulmonary artery volume, configuration (generally within reference ranges), and ductal patency. Echocardiography can detect right ventricular–dependent coronary flow and ventricular-coronary sinusoids but not coronary artery stenosis.

1. Angiocardiography: PAIVS neonates' prognosis depends on ventricular-coronary connections and right ventricular–dependent coronary circulation. Angiocardiography helps plan PAIVS treatment, while echocardiography diagnoses it. Right ventricular angiocardiography determines ventricular-coronary connections and right ventricle size and architecture. Balloon occlusion aortography shows proximal coronary arteries and stenosis.

2. Radiography: Chest radiography usually shows mild cardiomegaly and reduced or normal pulmonary vascular patterns. Right atrial enlargement can cause substantial cardiomegaly in patients with severe tricuspid regurgitation and dysplastic valves.

3.Findings of Histology: Individuals with pulmonary atresia with intact ventricular septum (PAIVS) may exhibit a variety of right ventricular myocardial abnormalities, such as ischemia, fibrosis, infarction, perforation, fiber disarray, spongy myocardium, and endocardial fibroelastosis. The extent of endocardial fibroelastosis is inversely proportional to the level of ventricular-coronary connections.

What Is the Treatment Method?

Medical Care

1. Initial treatment for pulmonary atresia with intact ventricular septum (PAIVS) comprises a continuous intravenous prostaglandin E1 infusion to maintain ductal patency.

2. To treat metabolic acidosis in neonates, it is necessary to administer sodium bicarbonate and replace lost fluids. While acidity persists and apnea develops due to prostaglandin E1, ventilatory support may be necessary.

3. Before hospital discharge, individuals eventually require medical palliation or therapeutic catheterization.

Surgical Intervention: For pulmonary atresia with intact ventricular septum (PAIVS), surgical or catheter-based interventional strategies are determined by the size and shape of the tricuspid valve in the right ventricle and also by the presence of aberrant coronary artery anatomy: right ventricular hypoplasia and moderate-to-severe tricuspid valve disease without ventricular-coronary connections.

1. Perform a transcatheter valvotomy with patent ductus arteriosus stenting, a surgical valvotomy, a transannular patch using a systemic-to-pulmonary artery shunt, or a transannular valvotomy. A future univentricular (Fontan) or 1.5-ventricle repair is likely.

2. Right ventricular hypoplasia with moderate-to-severe tricuspid valve disease with ventricular coronary interconnections but no stenosis or stoppage. Perform a transcatheter valvotomy with patent ductus arteriosus stenting, a surgical valvotomy, a transannular patching using a systemic-to-pulmonary artery shunt, or a transannular valvotomy. A future univentricular (Fontan) or 1.5-ventricle repair is likely.

3. Right ventricular hypoplasia with ventricular-coronary connections, proximal stenosis, and moderate-to-severe tricuspid valve disease. Stent the patent ductus arteriosus or conduct a systemic-to-pulmonary artery shunt. Heart transplantation or univentricular (Fontan) repair in the future is likely.

Conclusion

There is a spectrum of severe congenital heart disease known as pulmonary atresia with intact ventricular septum (PAIVS), and the severity of the condition varies greatly from patient to patient. Individuals with simple plate-like pulmonary atresia who have relatively normal RV anatomy and geometry and who can receive biventricular therapy are at one end of the severity spectrum. In contrast, patients with "hypoplastic right heart syndrome" are at the other end and must undergo single-ventricle palliation. Patients with a basic plate-like form of pulmonary atresia and a generally normal architecture and geometry of the right ventricle can tolerate a treatment pathway involving both ventricles. Patients who rely on the RV for coronary circulation and who have RV sinusoids and coronary artery fistulae have an elevated chance of passing away before their natural time—an important approach to transplantation for these exceedingly weak individuals. A hybrid treatment strategy for early palliation for patients whose anatomical makeup permits the option of one-and-a-half or two-ventricle routes. The early and interim outcomes of this treatment method have been remarkable. A sizable fraction of the patient population cannot participate in activities requiring physical movement.