Anomalous pulmonary venous connection (or anomalous pulmonary venous drainage or anomalous pulmonary venous return) is a congenital heart defect of the

pulmonary vein The pulmonary veins are the veins that transfer Blood#Oxygen transport, oxygenated blood from the lungs to the heart. The largest pulmonary veins are the four ''main pulmonary veins'', two from each lung that drain into the left atrium of the h ...

s. It can be a total anomalous pulmonary venous connection, wherein all four pulmonary veins are incorrectly positioned, or a partial anomalous pulmonary venous connection, wherein only some of the pulmonary veins are incorrectly positioned.

Signs and symptoms

* Right ventricular heave * Loud S1 * Fixed

split S2 A split S2 is a finding upon auscultation of the S2 heart sound. It is caused when the closure of the aortic valve (A2) and the closure of the pulmonary valve (P2) are not synchronized during inspiration. The second heart sound (S2) is cause ...

* S3 gallop * Systolic ejection murmur at left upper sternal border *

Cardiomegaly Cardiomegaly (sometimes megacardia or megalocardia) is a medical condition in which the heart becomes enlarged. It is more commonly referred to simply as "having an enlarged heart". It is usually the result of underlying conditions that make the h ...

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 right lower chambe ...

and right axis deviation on ECG *

Cyanosis Cyanosis is the change of Tissue (biology), tissue color to a bluish-purple hue, as a result of decrease in the amount of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Cyanosis is apparent usually in the Tissue (bi ...

tachypnea Tachypnea, also spelt tachypnoea, is a respiratory rate greater than normal, resulting in abnormally rapid and shallow breathing. In adult humans at rest, any respiratory rate of 1220 per minute is considered clinically normal, with tachypnea b ...

and

dyspnea Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that ...

, since the overloaded pulmonary circuit can cause pulmonary edema * ''Cottage-loaf sign'', that is,

chest X-ray A chest radiograph, chest X-ray (CXR), or chest film is a Projectional radiography, projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common fi ...

appearance similar to a cottage loaf, also known as the 'snow man' sign or 'figure of 8' sign.

Total anomalous pulmonary venous connection (TAPVR)

''Total anomalous pulmonary venous connection'', also known as total ''anomalous pulmonary venous return'', is a rare

cyanotic Cyanosis is the change of tissue color to a bluish-purple hue, as a result of decrease in the amount of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Cyanosis is apparent usually in the body tissues covered with ...

congenital A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...

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

in which the pulmonary veins drain into the right side of the heart instead of the left, as is usually seen. This can happen within the heart (intracardiac) where it drains into the coronary sinus or right atrium, or below it (infracardiac) where it drains into the liver at the portal or hepatic vein. The anomalous connection causes low blood oxygenation and limitation of venous return to the heart.

Diagnosis

The diagnosis of TAPVC is dependent upon whether or not there is an obstruction. TAPVC with obstruction will clinically present with cyanosis, tachypnea, dyspnea, and hypoxemia. Chest x-ray may show a ground-glass appearance due to pulmonary edema resulting from increased pressure in the obstructed pulmonary veins.

Treatment

Cases of TAPVC with obstruction are considered a surgical emergency. In TAPVC without obstruction, surgical redirection can be performed within the first month of life. The operation is performed under general anesthesia. The four pulmonary veins are reconnected to the left atrium, and any associated heart defects such as atrial septal defect, ventricular septal defect, patent foramen ovale, and/or patent ductus arteriosus are surgically closed. With obstruction, surgery should be undertaken urgently. PGE1 should be given because a

patent ductus arteriosus Patent ductus arteriosus (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after childbirth, birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs from the aorta, which has a h ...

allows oxygenated blood to go from the circulation of the right heart to the systemic circulation.

Partial anomalous pulmonary venous connection (PAPVR)

A ''Partial anomalous pulmonary venous connection'' (or ''Partial anomalous pulmonary venous drainage'' or ''Partial anomalous pulmonary venous return'') is a congenital defect where the

left atrium The atrium (; : atria) is one of the two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular mitral and tricuspid heart valves. ...

is the point of return for the blood from some (but not all) of the

s. It is less severe than total anomalous pulmonary venous connection which is a life-threatening anomaly requiring emergent surgical correction, usually diagnosed in the first few days of life. Partial anomalous venous connection may be diagnosed at any time from birth to old age. The severity of symptoms, and thus the likelihood of diagnosis, varies significantly depending on the amount of blood flow through the anomalous connections. In less severe cases, with smaller amounts of blood flow, diagnosis may be delayed until adulthood, when it can be confused with other causes of pulmonary hypertension. There is also evidence that a significant number of mild cases are never diagnosed, or diagnosed incidentally. It is associated with other vascular anomalies, and some genetic syndromes such as

Turner syndrome Turner syndrome (TS), commonly known as 45,X, or 45,X0,Also written as 45,XO. is a chromosomal disorder in which cells of females have only one X chromosome instead of two, or are partially missing an X chromosome (sex chromosome monosomy) lea ...

Diagnosis

It can be diagnosed with

CT scan A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

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 perfo ...

, transesophageal

echocardiography Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an ec ...

, or cardiac MRI.

Treatment

It is sometimes treated with surgery, which involves rerouting blood from the right atrium into the left atrium with a patch or use of the Warden procedure. However, interest is increasing in catheter-based interventional approaches, as well as medical therapy for less severe cases.

Pathophysiology

To understand the different types of anomalous pulmonary venous connection, it is important to establish the background in which normal fetal vasculature develops. During embryonic development, the lungs start as outgrowths from the foregut and share its splanchnic vascular plexus. At around 25 to 27 days of gestation, there are no direct links to the heart. By 27 to 29 days of gestation, the primitive pulmonary vein begins to form as an outgrowth from the left atrium and eventually connects with the primitive pulmonary venous system.

References

External links

{{Congenital vascular defects Congenital vascular defects