Infants with congenitally corrected transposition of the great arteries have many different symptoms because many additional heart abnormalities occur along with the switched heart chambers.
Long-term problems due to weakening of the heart muscle are likely to develop in adulthood due to the right ventricle supplying blood to the body.
The diagnosis is based on findings from a doctor's physical examination, electrocardiography (ECG), chest imaging, and cardiac catheterization.
Treatment is with medication to control symptoms, surgery to correct the defects, and pacemakers or implantable cardioverter-defibrillators if the abnormality causes an abnormal heart rhythm.
(See also Overview of Heart Defects Overview of Heart Defects About one in 100 babies is born with a heart defect. Some are severe, but many are not. Defects may involve abnormal formation of the heart's walls or valves or of the blood vessels that enter... read more .)
Congenitally corrected transposition of the great arteries is relatively rare. Most affected infants have other heart abnormalities as well, such as ventricular septal defect Atrial and Ventricular Septal Defects Atrial and ventricular septal defects are holes in the walls (septa) that separate the heart into the left and right sides. Holes can be present in the walls of the heart between the upper heart... read more 
, pulmonic stenosis Pulmonary Valve Stenosis in Children Pulmonary valve stenosis is a narrowing of the pulmonary valve (sometimes called the pulmonic valve), which opens to allow blood to flow from the right ventricle to the lungs. The heart valve... read more , and Ebstein anomaly Ebstein Anomaly Ebstein anomaly is an abnormality of the tricuspid valve that causes malfunction of the valve with regurgitation (blood leaking backward into the atrium) or stenosis (obstruction to blood flowing... read more .
Symptoms
These abnormalities result in a wide range of symptoms. An abnormally slow heart rhythm due to heart block Overview of Heart Block Heart block is a delay in the conduction of electrical current as it passes through the conduction system of the heart, including the atrioventricular node, bundle of His, or both bundle branches... read more may develop. In heart block, the electrical signals that control the heartbeat are partially or completely blocked between the upper and lower chambers of the heart. Heart block is treated with a pacemaker. In addition to the symptoms caused by any of the associated abnormalities, all people with congenitally corrected transposition are likely to develop symptoms secondary to having the circulation to the body supported by the right ventricle.
Infants may have a heart murmur due to pulmonic stenosis or a ventricular septal defect. If stenosis is severe and a ventricular septal defect is present, the skin and lips may appear bluish (cyanosis) because not enough oxygen is reaching the tissues. If a large ventricular septal defect is present, symptoms of heart failure, such as difficulty breathing and poor feeding, may occur. Symptoms may develop gradually during childhood and adolescence depending on the severity of the defects.
As children reach adulthood, the function of their right ventricle, which has taken on the work of the left ventricle, may begin to worsen, leading to an enlarged heart (cardiomyopathy) Overview of Cardiomyopathy Cardiomyopathy refers to progressive impairment of the structure and function of the muscular walls of the heart chambers. There are three main types of cardiomyopathy: Dilated cardiomyopathy... read more 
or heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more 
. Often tricuspid regurgitation Tricuspid Regurgitation Tricuspid regurgitation is leakage of blood backward through the tricuspid valve each time the right ventricle contracts. Tricuspid regurgitation is caused by disorders that enlarge the right... read more occurs, in which blood leaks backward through the tricuspid valve each time the right ventricle contracts.
Diagnosis
Stethoscope examination of the heart
Electrocardiography (ECG) and chest x-ray
Echocardiography (ultrasonography of the heart)
Magnetic resonance imaging (MRI) and computed tomography (CT)
Cardiac catheterization
Doctors are able to diagnose abnormalities of the heart by listening to the chest with a stethoscope. Doctors might hear a heart murmur or heart sounds might be louder on the right side if the chest than on the left. Subsequently, they usually perform an ECG and imaging studies.
Echocardiography Echocardiography and Other Ultrasound Procedures Ultrasonography uses high-frequency (ultrasound) waves bounced off internal structures to produce a moving image. It uses no x-rays. Ultrasonography of the heart (echocardiography) is one of... read more 
(ultrasonography of the heart) and, sometimes, CT or MRI is used to show details of the anatomy and to evaluate the function of the ventricles.
Electrocardiography Electrocardiography Electrocardiography (ECG) is a quick, simple, painless procedure in which the heart’s electrical impulses are amplified and recorded. This record, the electrocardiogram (also known as an ECG)... read more 
(ECG) may show heart block or other abnormalities, and chest x-rays X-Rays of the Chest Anyone thought to have a heart disorder has chest x-rays taken from the front and the side. Typically, the person is standing upright, but chest x-rays can be done with people lying in bed if... read more 
show a change in the shape and position of the heart.
Treatment
Medication
Surgery
Pacemaker or implantable cardioverter defibrillator
Medication may be needed if heart failure develops.
Surgical treatment is often necessary for ventricular defects or tricuspid regurgitation.
Pacemakers or implantable cardioverter defibrillators may be needed if the congenital transposition causes abnormal heart rhythms.
More Information
The following English-language resources may be useful. Please note that The Manual is not responsible for the content of these resources.
American Heart Association: Common Heart Defects: Provides overview of common congenital heart defects for parents and caregivers
American Heart Association: Infective Endocarditis: Provides an overview of infective endocarditis, including summarizing prophylactic antibiotic use, for patients and caregivers
