Total anomalous pulmonary venous return

If our patient turns out to have total anomalous pulmonary venous return, let’s remember what that means. First of all, there are four different types of total anomalous pulmonary venous return. The majority of which are super-cardiac type. The intracardiac type accounts for the second category and the infradiaphragmatic – which is usually the most problematic – accounts for 10-20%. And then there is a form in which you may have a mixture of these different forms of return of individual veins. The super-cardiac type is one in which the pulmonary is … looking at the back of the heart, so that the pulmonary veins are here collected into a common vessel, which drains superiorally. A vertical vein, or sometimes we call it a left superior vena cava, then joins the innominate vein to go over to the right superior vena cava. So the super-cardiac from pulmonary venous drainage.

The infradiaphragmatic is one in which the pulmonary veins collect again behind the heart but drain inferiorally through the diaphragm and the porta cava system to return then via the inferior vena cava. The presentation of these babies is quite variable, again. If they present within the first few hours of life then it’s usually with severe cyanosis with significant pulmonary edema. This is usually the infradiaphragmatic form and these babies are very difficult to manage. The more common forms of total anomalous are the super-cardiac or the cardiac form which drains to the coronary sinus. Another form in fact is when the pulmonary veins collect behind the heart again and actually drain into a dilated coronary sinus and therefore into the right atrium.

So the super-cardiac, the intracardiac forms usually don’t present in the immediate newborn period but actually get out a week or two before they are recognized, usually having mild – mild almost always – as much as moderate cyanosis and usually with some degree of congestive heart failure. They are usually impressive in their examination too, in having these multiple sounds. Multiple murmurs which represent the increased blood flow through the right heart and out the pulmonary outflow tract. So often we will have systolic and diastolic murmurs as well as wide fixed splitting of the second heart sound. Now in the first type, the ones that present within the first few hours of life, the x-ray is likely to look like this. And if you think you are not seeing much, you are right. It’s hard to distinguish the cardiac border here because there is a lot of pulmonary edema. If we saw the heart it would actually be fairly normal in size, but this is an x-ray that we often see with the infradiaphragmatic type of total anomalous pulmonary venous return. The problem being that the long tract of venous return presents resistance to this low velocity flow and therefore results in significant pulmonary edema.

On the other hand, the baby who presents a few weeks out with mild cyanosis and a low congestive heart failure may have an x-ray that looks like this. And this is a “snowman” that we talk about in blue babies, associated with total anomalous pulmonary venous return. This leftward shadow represents the dilated venous channel, the vertical vein or the left superior vena cava which has collected the pulmonary veins here, drains the return in this way across the innominate vein to a now dilated superior vena cava, because of the pulmonary venous return is systemic venous return as well. With some increased pulmonary vascular markings. So this x-ray can be helpful in distinguishing the total anomalous super-cardiac type.

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