The electrocardiogram

The electrocardiogram is likely to show us right axis deviation and right ventricular hypertrophy. I’ll make a comment now that if you throw the EKG of babies with cyanotic congenital heart disease, tetralogy or transposition into a batch of newborn electrocardiograms, you may not – in the first few days of life – be able to distinguish these because the normal newborn has a predominance of right ventricular forces.
The treatment for the transposition, and especially what can be done from the point of view of the primary care physician, would be to implement the prostaglandin. What the prostaglandin does here in this setting is to increase the ductal flow so that you have increased pulmonary flow via the ductus, bringing increased volumes of flow back to the left atrium, sort of stretching open this foramen ovale or ASD so that you end up with more saturated blood shunted to the right atrium, which then carries the blood out to the aorta. So in this fashion you can increase the oxygen saturation in a baby with a transposition. It’s not a typical ductal-dependent lesion as, for example, tetralogy of Fallot. The atrial mixing becomes quite key as well. Another part of the management, usually once it gets into my hands or my colleague’s hands, is to assess the atrial communication and if it is compromised at all, then to use the catheterization to effect a balloon atrial septostomy.
Horny goat weed information
Then the surgery of choice these days is the arterial switch operation which allows transection of the great arteries and re-anastomosis so that they come off the appropriate ventricle. Along with this it is important for us as a cardiologist to alert the surgeons of the coronary artery anatomy so that they will be able to re-implant these coronary arteries with a near aorta without compromise to coronary flow.

I put this up to remind you that before our surgeons were so skilled at arterial switch operations, we did venous switch and the names that are associated with the venous switch approach, i.e. redirecting the systemic venous flow to the pulmonary artery via the left ventricle, and redirecting the pulmonary venous flow to the right ventricle to the aorta; either by a stenting operation or a Mustard operation, and we still occasionally have reason to use one of these two approaches rather than arterial switch. If our baby has tricuspid atresia he might remind us that we are dealing with an atretic bicuspid valve here, no orifice, no communication from the right atrium to the right ventricle. And usually as a result, a very hypoplastic underdeveloped right ventricle, which is key to remember in your assessment of this baby with the potential of bicuspid atresia. They almost always present right in the early newborn period because of the cyanosis. One of the keys to your examination is the lack of a right ventricular impulse. In other words, these blue babies tend to have a predominant apical left ventricular impulse and they may or may not have murmurs. There’s nothing about the bicuspid atresia that presents a murmur. I really put this up for looking at the EKG because this is one of the blue babies where the EKG may be very helpful, in that this baby usually has a left axis deviation, a lack of the usual predominance of right forces that expect for a newborn, but in fact progression that looks more adult-like with a predominance of left ventricular forces. And that makes sense if you think about the fact that the right ventricle is hypoplastic; underdeveloped due to the lack of inflow.

What can you do about these babies as a primary care physician? Again, to effect pulmonary flow or to enhance it with the use of prostaglandin. When you refer that baby to the pediatric cardiologist then again we will assess the atrial septum to be sure that the defect is adequate. That’s the only way we decompress the right atrium in this setting. Then if not, then we do the balloon atrial septostomy. Then these babies require surgical intervention in the newborn period. Usually in the form of a aorticopulmonary shunt and to allow the baby to grow to several months of age, at which time we would bring the baby in for a Glenn shunt. The Glenn shunt, being an anastomosis of the superior vena cava to the right pulmonary artery so that systemic venous flow goes directly into the pulmonary bed. The Fontan is the second stage of the surgery and it completes the return of system venous return directly to the pulmonary bed by some kind of tunnel, if you will, within or nowadays external to the right atrium so that all systemic venous return goes directly into the pulmonary bed. Of course the reason this is not done earlier in life is that the pulmonary resistance is still relatively high in young infants and we have to wait until the pulmonary vascular resistance drops, so that you have essentially a passive venous flow into the pulmonary bed.

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