Partial Anomalous Pulmonary Venous Return (PAPVR)
Information for teenagers and adults with partial anomalous pulmonary venous return
Partial anomalous pulmonary venous return (PAPVR) is a congenital heart condition in which one or more of the veins carrying oxygen-rich blood from the lungs connect to the right side of the heart or one of its major veins, rather than to the left atrium.
It is also sometimes called partial anomalous pulmonary venous connection (PAPVC).
Normally, all four pulmonary veins return oxygen-rich blood from the lungs to the left atrium. From there, blood passes into the left ventricle and is pumped around the body.
In PAPVR, some of this blood instead returns to the right side of the circulation and passes through the lungs again.
The significance of PAPVR varies considerably. Some people have only one small anomalous pulmonary vein and never require treatment. Others have a larger amount of abnormal blood flow that causes enlargement of the right side of the heart and may benefit from surgical repair.
PAPVR is sometimes diagnosed during childhood but is also commonly discovered for the first time in adulthood.
How does PAPVR affect the circulation?
Normally, oxygen-rich blood returning from the lungs travels through the pulmonary veins into the left atrium.
In PAPVR, one or more pulmonary veins instead drain into structures on the right side of the circulation, such as:
The superior vena cava (SVC)
The right atrium
The inferior vena cava (IVC)
Another large vein returning blood to the heart
This means that some oxygen-rich blood is redirected through the right side of the heart and back to the lungs.
This is called a left-to-right shunt.
If only a small amount of blood is redirected, the effect on the heart may be minimal.
If a larger amount of blood is redirected, the right atrium and right ventricle receive extra blood with every heartbeat and can gradually become enlarged.
Is PAPVR associated with an atrial septal defect?
Yes.
PAPVR is commonly associated with a sinus venosus atrial septal defect (ASD).
A sinus venosus ASD is an opening near the upper or lower part of the atrial septum, close to where the major veins enter the heart.
The most common combination is a superior sinus venosus ASD with abnormal drainage of one or more right upper pulmonary veins into the superior vena cava or the junction between the SVC and right atrium.
When both conditions are present, they contribute to additional blood flow through the right side of the heart.
PAPVR can also occur without an ASD.
Does PAPVR cause symptoms?
Many people with PAPVR have no symptoms, particularly when only a small amount of blood is being redirected.
The condition may be discovered incidentally during an echocardiogram, CT scan or cardiac MRI performed for another reason.
When the amount of abnormal blood flow is more significant, symptoms can include:
Shortness of breath during exercise
Reduced exercise capacity
Fatigue
Palpitations
Symptoms often develop gradually and may not become apparent until adulthood.
Does everyone with PAPVR need treatment?
No.
The decision to treat PAPVR depends on how much blood is being redirected and what effect this is having on the heart.
A person with a single anomalous pulmonary vein, a relatively small shunt and normal right ventricular size may simply require observation.
Surgical repair may be considered when there is a significant amount of abnormal blood flow causing enlargement of the right side of the heart, particularly when the right ventricle is substantially volume-loaded.
Other factors include:
Symptoms
The number of anomalous pulmonary veins
The anatomy of the abnormal connections
The presence of an ASD
Right ventricular size and function
Pulmonary artery pressure
Pulmonary vascular resistance
Your congenital cardiologist will consider all of these factors rather than deciding on treatment simply because an anomalous pulmonary vein is present.
How do you measure how much blood is being redirected?
Your cardiologist may describe the amount of abnormal blood flow using the term Qp:Qs.
This compares the amount of blood flowing through the lungs (Qp) with the amount flowing around the body (Qs).
Normally these amounts are approximately equal, giving a Qp:Qs of around 1:1.
In PAPVR, extra blood passes through the lungs, so pulmonary blood flow may be higher than systemic blood flow.
Cardiac MRI and, in selected cases, cardiac catheterisation can help measure this.
The shunt measurement is only one part of the assessment. Right ventricular enlargement, symptoms, pulmonary pressures and anatomy are also important when deciding whether treatment is appropriate.
How is PAPVR repaired?
When treatment is required, PAPVR is usually repaired surgically.
The aim is to redirect the anomalous pulmonary veins into the left atrium, allowing oxygen-rich blood to return to the correct side of the heart.
The exact operation depends on where the pulmonary veins connect.
If there is an associated sinus venosus ASD, the repair usually addresses both abnormalities at the same operation.
Warden procedure
When the right upper pulmonary veins drain relatively high into the superior vena cava, a Warden procedure may sometimes be used.
This operation redirects the pulmonary venous blood through the atrial septum into the left atrium and reconnects the upper part of the SVC to the right atrial appendage.
This allows blood from the upper body to continue reaching the right atrium while the pulmonary veins are redirected to the left atrium.
There are several variations of PAPVR repair, and your surgeon will choose the approach most suited to your anatomy.
What problems can occur after repair?
Most people do very well following PAPVR repair.
Potential problems after surgery are uncommon but can include:
Pulmonary vein narrowing
The pathway redirecting a pulmonary vein towards the left atrium can occasionally become narrowed.
This is called pulmonary venous obstruction.
Superior vena cava narrowing
After some types of sinus venosus ASD/PAPVR repair, particularly those involving the SVC, narrowing of the superior vena cava can occasionally occur.
Heart rhythm problems
Because surgery occurs close to the upper chambers of the heart and the heart’s natural pacemaker, some people can develop abnormal heart rhythms.
These can include:
Atrial flutter
Atrial fibrillation
A slower heart rhythm due to sinus node dysfunction
The risk is influenced by age at repair, anatomy and the type of operation performed.
What is scimitar syndrome?
Scimitar syndrome is a particular and less common form of anomalous pulmonary venous return.
In scimitar syndrome, some or all of the veins from the right lung typically drain into the inferior vena cava rather than the left atrium.
The anomalous vein can have a curved appearance on a chest X-ray resembling a traditional curved sword called a scimitar, which gives the condition its name.
Scimitar syndrome can also be associated with:
A smaller right lung
Abnormal position of the heart towards the right side of the chest
Abnormal blood supply to part of the right lung
Other congenital heart abnormalities
The severity varies considerably. Some people are diagnosed during infancy, while others have a milder form that is not discovered until adulthood.
Assessment and treatment of scimitar syndrome are individualised and may differ from more typical forms of PAPVR.
Pulmonary hypertension
Significant PAPVR causes increased blood flow through the lung circulation.
Over many years, a large untreated shunt can occasionally contribute to pulmonary hypertension.
Severe pulmonary vascular disease is uncommon in people with isolated PAPVR but is important to identify before considering surgery.
If pulmonary hypertension is suspected, additional assessment — sometimes including cardiac catheterisation — may be required before deciding whether repair is appropriate.
How to stay well
Keep up with your heart checks
The amount of follow-up required depends on your anatomy, the size of the shunt and whether you have undergone repair.
People with a small unrepaired PAPVR and normal right ventricular size may need only occasional surveillance.
People with significant right heart enlargement, pulmonary hypertension, previous surgery or residual abnormalities require more regular congenital heart disease follow-up.
Stay active
Most people with mild PAPVR and normal heart function can undertake normal physical activity without restriction.
People who have had successful repair and have normal heart function can also usually return to normal recreational exercise.
Exercise recommendations may be different if you have significant pulmonary hypertension, right ventricular dysfunction or an important abnormal heart rhythm.
If you participate in competitive or very high-intensity exercise, discuss this with your cardiologist.
Look after your teeth
Good dental hygiene and regular dental care are important for overall cardiovascular health.
PAPVR alone does not usually require antibiotics before dental procedures.
Your cardiologist can advise you if another aspect of your congenital heart condition means antibiotic prophylaxis is required.
Don’t smoke or vape
Avoid smoking and vaping. Maintaining a healthy weight, blood pressure and cholesterol also helps reduce additional cardiovascular stress.
Pregnancy
Most women with mild or successfully repaired PAPVR, normal right ventricular function and normal pulmonary artery pressure can have a successful pregnancy with relatively low cardiovascular risk.
Pregnancy may require more specialised assessment if there is:
Significant unrepaired PAPVR
Marked right ventricular enlargement
Pulmonary hypertension
Reduced heart function
An important abnormal heart rhythm
Women with significant PAPVR should ideally have congenital cardiology assessment before pregnancy.
Symptoms to tell your doctor about
Contact your doctor or cardiology team if you develop:
New or increasing shortness of breath
A noticeable reduction in exercise capacity
Frequent or prolonged palpitations
Dizziness or near-fainting
Unexplained fainting
New swelling of your ankles or abdomen
Increasing fatigue
A significant change in your usual symptoms
Emergency — get help immediately if
Seek urgent medical attention or call 000 if you develop:
Severe or rapidly worsening shortness of breath
Fainting associated with exercise or sustained palpitations
A sustained rapid heartbeat associated with dizziness, chest pain or feeling very unwell
Severe chest pain
A sudden significant deterioration in your condition
Your regular check-ups
Follow-up for PAPVR may include:
Clinical review
Your cardiologist will ask about exercise capacity, breathlessness, palpitations and other symptoms and examine your heart and circulation.
ECG
An electrocardiogram records the electrical activity and rhythm of your heart.
Echocardiogram
An ultrasound can assess right heart size and function, pulmonary artery pressure and associated abnormalities such as an ASD. The anomalous pulmonary veins themselves are not always easily seen on a routine adult echocardiogram.
Cardiac MRI
Cardiac MRI is particularly useful in PAPVR. It can show where the pulmonary veins drain, accurately measure right ventricular size and function and quantify the amount of additional blood flow through the lungs.
Cardiac CT
CT provides very detailed images of the pulmonary veins and their relationship to surrounding structures and can be particularly useful when planning treatment.
Exercise testing
Exercise testing can objectively assess exercise capacity if symptoms or the significance of the condition are uncertain.
Heart rhythm monitoring
A Holter monitor or longer-term rhythm monitor may be recommended if you experience palpitations, dizziness or fainting.
Cardiac catheterisation
Catheterisation is not required for everyone. It may be used when more accurate measurement of pulmonary artery pressure, pulmonary vascular resistance or blood flow is required.
Questions for your doctor
Which of my pulmonary veins drain abnormally, and where do they connect?
Do I also have a sinus venosus ASD?
How large is the left-to-right shunt?
Is my right ventricle enlarged or under increased strain?
Are my pulmonary artery pressures normal?
Does my PAPVR need surgery, or can it simply be monitored?
If I have already had surgery, are the pulmonary veins and SVC unobstructed?
Do I have any restrictions on exercise, work, travel or pregnancy?
How often should I have congenital heart follow-up?
This information is intended as a general guide for teenagers and adults with partial anomalous pulmonary venous return. The anatomy and significance of PAPVR vary considerably between individuals, and your congenital cardiologist can provide advice specific to your pulmonary veins, heart function and current health.
