The Trilogy of Fallot also called Fallot's trilogy is a rare

congenital heart disease A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular ...

consisting of the following defects:

pulmonary valve stenosis Pulmonary valve stenosis (PVS) is a heart valve disorder. Blood going from the heart to the lungs goes through the pulmonary valve, whose purpose is to prevent blood from flowing back to the heart. In pulmonary valve stenosis this opening is too ...

right ventricular hypertrophy Right ventricular hypertrophy (RVH) is a condition defined by an abnormal enlargement of the cardiac muscle surrounding the right ventricle. The right ventricle is one of the four chambers of the heart. It is located towards the lower-end of the h ...

and

atrial septal defect Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this d ...

. It occurs in 1.2% of all congenital heart defects. A 1960 case report of 22 patients who underwent surgery showed an excess of females with a ratio of 3:2, with the youngest person being 7 months old and the oldest being 50 years old.

Symptoms and signs

Mechanism

Trilogy of Fallot is a combination of three congenital heart defects:

pulmonary stenosis Pulmonic stenosis, is a dynamic or fixed obstruction of flow from the right ventricle of the heart to the pulmonary artery. It is usually first diagnosed in childhood. Signs and symptoms Cause Pulmonic stenosis is usually due to isolated valvula ...

, and an

. The first two of these are also found in the more common

tetralogy of Fallot Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are: *pulmonary stenosis, which is narrowing of the exit from the ri ...

. However, the tetralogy has a

ventricular septal defect A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one ...

instead of an atrial one, and it also involves an

overriding aorta An overriding aorta is a congenital heart defect where the aorta is positioned directly over a ventricular septal defect (VSD), instead of over the left ventricle. The result is that the aorta receives some blood from the right ventricle, causing ...

The Three Malformations

Diagnosis

Diagnosis is done via

echocardiography An echocardiography, echocardiogram, cardiac echo or simply an echo, is an ultrasound of the heart. It is a type of medical imaging of the heart, using standard ultrasound or Doppler ultrasound. Echocardiography has become routinely used in t ...

angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is performe ...

Treatment

It is treated using surgery to repair the atrial septal defect and pulmonary stenosis, once the

has been fixed the

will usually go away on its own.

Balloon valvuloplasty Heart valve repair is a cardiac surgery procedure, carried out to repair one or more faulty heart valves. In some valvular heart diseases repair where possible is preferable to valve replacement. A mechanical heart valve is a replacement valve th ...

is the most common treatment for pulmonary stenosis, a balloon is placed where the artery or valve is narrowed and is inflated, widening the artery or valve in the process, the balloon is then removed. It may cause valve regurgitation. If balloon valvuplasty is not an option

open heart surgery Cardiac surgery, or cardiovascular surgery, is surgery on the heart or great vessels performed by cardiac surgeons. It is often used to treat complications of ischemic heart disease (for example, with coronary artery bypass grafting); to corr ...

must be performed where the valve is either repaired or replaced with an artificial one.

History

It is named in honor of its discoverer: Etienne Fallot.

References

Congenital heart defects {{circulatory-disease-stub