Congenital Heart Defect Test Preparation

I have three opening comments to this episode. 1. This episode will help you to prepare for exam questions related to congenital heart defects. The goal of this recording is not to fully describe every concept, instead I hope to explain or at least identify many of the most commonly tested concepts and the most common areas of confusion. 2. This episode will focus so closely on the details that set a particular congenital heart defect apart from the others, and because of this in your very narrow focus, this recording will not cover most of what nursing care looks like for these different congenital heart defects. That information can be found in the book on the subsections, clinical consequences of congenital heart disease, and nursing care of the family and child with congenital heart disease. 3. Both congenital heart defect and congenital heart disease refer essentially to the same thing and both are abbreviated CHD. I will be using the abbreviation CHD for the rest of this episode, and it will not matter at all whether you think the disease stands for disease or defect. CHDs with increased pulmonary blood flow. This first group includes several of the most common and simplest defects. These defects all share two things in common. 1. Each of these defects is caused by a single unnatural connection between the systemic circulation going to the body and the pulmonary circulation going to the lungs. Because the pressure in the systemic circulation is generally higher, the flow will go from high pressure to low pressure, that is, from the systemic circulation into the pulmonary circulation. 2. By definition, all of these defects cause increased blood flow to the lungs. This can directly cause difficulty breathing, but in serious cases, or even in my cases over the course of many years, this can also lead to pulmonary artery hypertension. Pulmonary artery hypertension is noteworthy for being limiting, irreversible, and eventually fatal unless they are able to get a lung transplant. 4. The atroceptal defect, or ASD, is a hole in the atroceptum. This hole can be filled with a patch or device, either by surgically opening the chest or with a cardiac catheter, but they can close spontaneously on their own as well. This CHD stands out as the one most likely to be virtually asymptomatic. This is typically a good thing, but it also means it is more likely to go undiagnosed and untreated, and over time, this can lead to dysrhythmia or even a stroke. The most characteristic clinical manifestation of the ASD is a split S2 heart sound. Ventricular septal defect. The ventricular septal defect, or VSD, is a hole in the ventricular septum. Like the ASD, the hole can be closed with a patch or device, and it may spontaneously close as well. The most characteristic clinical manifestation of the VSD is a loud, hollow, systolic murmur. 8. Atroventricular canal defect. The atroventricular canal defect, or AV canal defect, is one hole that spans both the atrole and ventricular septum, a kind of combined ASD and VSD. This defect stands out as the most severe among the CHDs with increased pulmonary blood flow. It is the only one in the category that causes synosis, and it is the most likely to put the child at risk of pulmonary artery hypertension, and is therefore the most likely to require a pallet of measure such as pulmonary artery banding, which slows the blood flow to the lungs. 8. Peyton ductus arteriosus. The Peyton ductus arteriosus, or PDA, is a connection between the aorta and pulmonary artery. The PDA has a unique murmur that is continuous and is described as machinery-like. They also present with a widened pulse pressure, which causes a bounding pulse. The PDA also stands out as the only CHD that can be fixed pharmacologically, by giving a prostate gland and inhibitor, such as endomethocin or ibuprofen. This concludes our discussion of the CHDs with increased pulmonary blood flow. Obstructive defects. The next category of CHDs are obstructive defects caused by an abnormal narrowing. The scientific name for narrowing is stenosis. Three things are true of all the CHDs within this category. 1. A possible treatment option for all of these defects is to balloon and stand via cardiac catheterization. 2. All of these CHDs will cause a murmur as blood is squeezed through the abnormal narrowing. 3. The other clinical manifestations will be caused by slower blood flow distal to the defect, or by increased pressure proximal to the defect. Aortic stenosis. Aortic stenosis is a narrowing at or near the aortic valve. So a question, what is distal to the defect? Answer, the entire body. Because the entire body is receiving slow blood flow, the child will be pale and weak with weak pulses and a low blood pressure all over their body. So a question, what is proximal to the defect? Answer, the left ventricle. Because the left ventricle is proximal to the defect, it's going to have to work harder and it's going to have left ventricular hypertrophy. Coractation of the aorta. Coractation of the aorta is also a narrowing of the aorta, but this time around the aortic arch. So question, what is distal to the defect? Answer, the lower half of the body. When looking at the legs, the clinical manifestations will be roughly identical to those of aortic stenosis. Question again, what is proximal to the defect? Answer, the upper half of the body. Blood pressure to the arms will actually be increased, and the increased pressure in the head can cause headaches and nosebleeds. This is why it is very important to get blood pressures on all four extremities for children with coroctation of the aorta. Pomonic stenosis. Pomonic stenosis is a narrowing of the pulmonary artery. The pathophysiology for this is a bit more complicated, but long story short, this is the only obstructive defect that causes cyanosis. A-synotic and cyanotic heart defects. All of the CHDs I've discussed so far fall under the larger category of A-synotic heart defects. What is possible to see cyanosis with the CHDs I've already discussed? The cyanosis is generally either mild or does an unusual finding. Most of the nursing care for a child with a cyanotic CHD has to do with managing the hypoxemia, which is discussed in your book. As a side note, the cyanotic heart defects are further subdivided in the book, but I don't find that these subdivisions are particularly useful at least for this recording. The T-O-F-L-O is the most common cyanotic heart defect, so you can expect it on any CHD exam. Here are the four defects that make up T-O-F in order of importance. Pomonic stenosis, ventricular septal defect, right ventricular hypertrophy, and overriding aorta. Some infants with T-O-F will receive a medication called Prostiglandin E1 to keep the ductus arteriosus open, as well as a bloodlactastic shun. These are only palliative measures to keep the babies alive until they have grown enough for surgical repair. Tri-Cuspidatrizia and hypoplastic left heart syndrome. An infant born with tricuspidatrizia has only one functioning ventricle, the left ventricle. An infant born with hypoplastic left heart syndrome, or HLHS, has only one functioning ventricle, the right ventricle. Either way, these children only have one functioning ventricle. Overall, these children are very sick and require a lot of support in order to survive. For those born with HLHS, the surgical repair will happen as three different surgeries, the norwood, the glen, and the fontan. Babies with tricuspidatrizia will only need the glen and the fontan. Transposition of the Great Arteries Transposition is a science-y way to say switching, so children with transposition of the Great Arteries, or TGA, are born with their pulmonary artery and Iorta, switched. The surgical repair for this is simple enough, at least from a conceptual standpoint, switch the arteries back to their usual place. While waiting for the surgery, the goal will be to cause as much mixing of blood as possible. This can be done by keeping the patent ductus arteriosus open, but prostate gland in E1, or by performing a balloon atrial subtostomy. Total anomalous pulmonary venous connection, or TAPVC, happens when the pulmonary veins drain into the right atrium instead of the left atrium, surgeries required to connect the pulmonary veins to where they should go. Troncas arteriosus In troncas arteriosus, the aorta and pulmonary artery are combined into one big artery. There is a holostostolic murmur as the ventricle squeezed blood into this one artery. The surgical repair for this is a new artificial pulmonary artery, but because this artificial artery won't grow along with the child, this will need to be replaced as the child grows.