What are the other Names for this Condition? (Also known as/Synonyms)

• DORV (Double Outlet Right Ventricle)
• DORV Syndrome
• Double Outlet Right Ventricle (DORV)

What is Double Outlet Right Ventricle Syndrome? (Definition/Background Information)

• Double Outlet Right Ventricle (DORV) Syndrome is a rare cono-truncal anomaly in which both the aorta and pulmonary artery originate, either entirely or predominantly, from the morphologic right ventricle
• DORV Syndrome accounts for about 2-3% of all congenital heart defects, with a birth prevalence rate of 1/ 10,000 neonates as reported in Germany
• Double Outlet Right Ventricle Syndrome is classified into sub-types, based on the relationship of the ventricular septal defect (subaortic, doubly-committed, subpulmonary or non-committed) with the great arteries
• Other cardiac anomalies frequently associated with DORV Syndrome include pulmonary stenosis (DORV Fallot type, DORV with non-committed VSD), various degrees of left and right ventricular hypoplasia, atrioventricular (AV) septal defects, and straddling AV valves 
• Extracardiac anomalies, such as heterotaxy (polysplenia, asplenia, situs ambiguous) and intestinal malrotation, are frequent

(Source: Double Outlet Right Ventricle; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Who gets Double Outlet Right Ventricle Syndrome? (Age and Sex Distribution)

• Double Outlet Right Ventricle Syndrome is a rare congenital disorder, occurring at a frequency of approximately 1 in 5,000 to 10,000 individuals
• The presentation of symptoms may occur at birth 
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Double Outlet Right Ventricle Syndrome? (Predisposing Factors)

• A positive family history may be an important risk factor, since Double Outlet Right Ventricle Syndrome can be inherited

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Double Outlet Right Ventricle Syndrome? (Etiology)

• Double Outlet Right Ventricle Syndrome results from an error in formation of the cono-truncus, which is the primary outlet of the heart during embryonic development. The cono-truncal anomalies result in neural crest and second heart field dysfunction
• Cardiac progenitor cells are controlled by various genes, such as GDF1 (19p13.11) and CFC1 (2q21.2), which when mutated can result in Double Outlet Right Ventricle Syndrome 
• Double Outlet Right Ventricle Syndrome is associated with chromosomal anomalies such as 22q11.2 deletion syndrome, trisomy 13, trisomy 18 and CHARGE syndrome as well

(Source: Double Outlet Right Ventricle; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

What are the Signs and Symptoms of Double Outlet Right Ventricle Syndrome?

The signs and symptoms of Double Outlet Right Ventricle Syndrome vary widely, depending on the combination of the abnormalities present and may include:

• Cyanosis 
• Tachypnea or breathlessness
• Poor feeding 
• Slow weight gain 
• Tachycardia and/or heart murmur 
• Ventricular septal defect (VSD) that allows blood to drain from the left ventricle
• Polysplenia (multiple small spleens)
• Asplenia (absence of spleen function)
• Situs ambiguous (abnormal arrangement of organs in the viscera)
• Malrotation of intestine

(Source: Double Outlet Right Ventricle; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

How is Double Outlet Right Ventricle Syndrome Diagnosed?

The diagnosis of Double Outlet Right Ventricle Syndrome is based on the following:

• Echocardiography showing both great arteries arising from the right ventricle
• In complex forms, cardiac catheterization-angiography, magnetic resonance imaging (MRI) and/or computed tomography (CT) scan are required

(Source: Double Outlet Right Ventricle; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Double Outlet Right Ventricle Syndrome?

The complications of Double Outlet Right Ventricle Syndrome may include:

• Breathing difficulties
• Pulmonary hypertension
• Cyanosis
• Abnormal heart function
• Congestive heart failure

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Double Outlet Right Ventricle Syndrome Treated?

The treatment methods for Double Outlet Right Ventricle Syndrome are as follow:

• In the presence of two viable ventricles, biventricular repair is the optimal treatment and it is quite safely achieved in the simple forms (DORV-VSD type, DORV-Fallot type and DORV-TGA type)
• In the complex forms (DORV with non-committed VSD, DORV-atrioventricular septal defect-pulmonary stenosis-heterotaxy), univentricular repair (Fontan operation) is often preferred by a number of teams, while biventricular repair is performed in selected cases in advanced pediatric heart surgery centers

(Source: Double Outlet Right Ventricle; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

How can Double Outlet Right Ventricle Syndrome be Prevented?

• Currently, Double Outlet Right Ventricle Syndrome may not be preventable, since it is a genetic disorder
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Double Outlet Right Ventricle Syndrome? (Outcomes/Resolutions) 

• Without treatment, the prognosis for Double Outlet Right Ventricle Syndrome is poor due to severe cyanosis, congestive heart failure or pulmonary hypertension
• With biventricular repair, patients have, on average, a normal life expectancy
• All patients that have received surgery for a DORV require life-long surveillance by a cardiologist. Univentricular palliation requires a very close follow-up

(Source: Double Outlet Right Ventricle; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Additional and Relevant Useful Information for Double Outlet Right Ventricle Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/