Trilogy of Fallot

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
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Trilogy of Fallot
Synonyms
Pronounce	N/A
Specialty	N/A
Symptoms	Cyanosis, dyspnea, fatigue
Complications	Heart failure, arrhythmia
Onset	Infancy
Duration	Chronic
Types
Causes	Congenital heart defect
Risks	Genetic factors, maternal diabetes
Diagnosis	Echocardiogram, chest X-ray, cardiac MRI
Differential diagnosis	Tetralogy of Fallot, ventricular septal defect
Prevention
Treatment	Surgical repair, medication
Medication	Beta blockers, diuretics
Prognosis	Variable, depends on severity and treatment
Frequency	Rare
Deaths

left ventricular hypertrophy

Congenital heart defect

Trilogy of Fallot is a rare congenital heart defect characterized by three primary cardiac anomalies: pulmonary valve stenosis, right ventricular hypertrophy, and an atrial septal defect. This condition is related to, but distinct from, the more well-known Tetralogy of Fallot.

Anatomy and Pathophysiology

Pulmonary Valve Stenosis

Pulmonary valve stenosis is a narrowing of the pulmonary valve opening, which restricts blood flow from the right ventricle to the pulmonary artery. This obstruction increases the workload on the right ventricle, leading to right ventricular hypertrophy.

Right Ventricular Hypertrophy

Diagram of right ventricular hypertrophy

Right ventricular hypertrophy refers to the thickening of the muscular walls of the right ventricle. This occurs as a compensatory mechanism in response to the increased pressure required to overcome the obstruction caused by pulmonary valve stenosis.

Atrial Septal Defect

An atrial septal defect (ASD) is a hole in the wall (septum) that separates the two upper chambers of the heart (atria). This defect allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood in the right atrium, potentially leading to increased blood flow to the lungs and further strain on the right side of the heart.

Diagnosis

The diagnosis of Trilogy of Fallot is typically made through a combination of physical examination, echocardiography, and other imaging techniques such as cardiac MRI or CT scan. A heart murmur is often detected during a physical exam, prompting further investigation.

Treatment

Treatment for Trilogy of Fallot usually involves surgical intervention to correct the defects. This may include procedures to relieve the pulmonary stenosis, repair the atrial septal defect, and address any associated anomalies. In some cases, a balloon valvuloplasty may be performed to widen the pulmonary valve.

Prognosis

With appropriate surgical treatment, individuals with Trilogy of Fallot can lead relatively normal lives. However, they require regular follow-up with a cardiologist to monitor heart function and detect any potential complications.

See also

• Tetralogy of Fallot
• Congenital heart defect
• Pulmonary valve stenosis