what are some diseses that can accure in fetal heart circulation?

1 ANSWERS

1. amomipais82
   

   Hi,
   Approximately 1 percent of all live-born infants have a heart defect. This means that in the United States, approximately 25,000 to 30,000 babies are born each year with some type of congenital heart disease. Cardiac development occurs very early in gestation, during the first seven weeks. The cause of most heart defects is unknown. Sometimes an infection during pregnancy, such as rubella (German Measles), can interfere with heart development. Other times a genetic or chromosomal abnormality such as Down syndrome will result in a heart defect. And still other times a chronic health issue with the mother such as insulin dependent diabetes seems to cause an increased incidence of heart defects in their fetus. However, for most families no cause is determined.
   
   Prenatal diagnosis of congenital heart disease
   The prenatal (before birth) diagnosis of most congenital heart diseases (CHD) may be suspected during a routine ultrasound. If your obstetrician sees something on routine ultrasound that looks unusual, he or she may refer you to a specialist that handles high-risk pregnancies. These doctors are called perinatologists. More tests will be done to determine if there is a disorder of the heart and evaluate for any associated anomalies (birth defects).
   
   You may also need to see a pediatric cardiologist. This doctor will do another type of ultrasound that looks specifically at the heart, its chambers, valves and vessels. This ultrasound is called a fetal echocardiogram. With this type of ultrasound a diagnosis of congenital heart disease can usually be confirmed or ruled out.
   
   How does the diagnosis of congenital heart disease affect the pregnancy?
   For most women the pregnancy will continue normally. You will have your regular visits with your obstetrician to have your blood pressure and urine checked and your weight monitored. More ultrasounds may be done to check on the baby's growth and to monitor the heart's function. If the baby is positioned in a way that makes it difficult to see all areas of the heart, you may be asked to have more than one echocardiogram to confirm the diagnosis or just to get a better look at another area of the heart that was not viewed well on the initial exam.
   
   Congenital heart disease may or may not be associated with other anomalies or with genetic syndromes or chromosomal abnormalities. The need for an amniocentesis to evaluate the baby's chromosomes will be determined by the perinatologist after the targeted ultrasound.
   
   Labor and delivery are not affected by the diagnosis of congenital heart disease. Most babies will tolerate labor and delivery without any problems. There is no need to do a Caesarean section for a baby with congenital heart disease except for those reasons that would affect any pregnancy such as maternal pelvis size that is too small for the size of the baby, failure for labor to progress, position of the baby other than head down, or a baby that is not tolerating labor as evidenced by their heart rate. The cardiothoracic surgeons prefer bigger babies to operate on so it is best to try to go as close to full term as you can. If your labor is induced, it will be done a week or two before your due date.
   
   Depending on the diagnosis, it may be recommended for you to deliver at a hospital that has a level III Neonatal Intensive Care Unit (NICU), pediatric cardiologist, and cardiothoracic surgeons on staff to confirm the diagnosis and care for the baby after delivery. This means the baby would go to the NICU after delivery and have an echocardiogram to evaluate his/her heart anatomy more clearly. For some heart diseases the administration of prostaglandins is necessary to keep the heart circulation more like it was before birth with special openings that allow for communication between the heart's chambers. The echocardiogram will confirm the diagnosis and then the neonatologist will order the special medication that is needed.
   
   Knowing that your baby has a heart disorder prior to delivery gives your baby the best chances of getting the treatment he/she needs in the most timely manner.
   
   Who treats congenital heart disease?
   Pediatric cardiologists are the specialists that take care of infants and children with congenital heart disease. With the fetal (unborn baby) diagnosis of congenital heart disease you will meet with a pediatric cardiologist who will perform a fetal echocardiogram to confirm the diagnosis and begin to develop a plan of care for after the baby is born. Fetal "echo" is an ultrasound of your baby's heart and its circulation. Pediatric cardiothoracic or cardiovascular surgeons are the specialists who do surgery on infants and children with CHD. You may also meet with these specialists before your baby is born to discuss surgical options. Neonatologists are pediatricians who have received extra training in the care of newborns with special problems. At birth, your baby will be cared for by a neonatologist.
   
   The normal heart
   The normal heart has a right and left atrium (filling chambers) and a right and left ventricle (pumping chambers). The valves of the heart are the aortic valve, mitral (sometimes referred to as bicuspid) valve, pulmonary valve and tricuspid valve. These valves are one-way "gates" that allow blood to flow into an area but not to flow back into the area it has just left.
   
   The normal circulation of the heart is as follows:
   Blood returns to the heart, from the body, via two large veins. The upper body's blood returns via the superior vena cava and the lower body's blood returns via the inferior vena cava. Both of these vessels return blood to the right atrium. From the right atrium it passes through the tricuspid valve into the right ventricle. From the right ventricle the blood is pumped through the pulmonary valve into the pulmonary artery, and right and left arteries feed the blood into the right and left lungs. In the lungs, the carbon dioxide is removed and oxygen is added to the blood. The lungs normally have a low pressure/low resistance so the blood flows easily throughout. Next, the blood is returned to the heart via the pulmonary veins into the left atrium. From the left atrium the blood passes through the mitral (or bicuspid) valve into the left ventricle. The left ventricle is the powerhouse or muscle of the heart. The left ventricle is very strong, thick and muscular to pump the blood out through the aortic valve into the aorta and ultimately to the rest of the body.
   
   Normally there is no direct communication between the right and left side of the heart. The right side handles the unoxygenated blood. The left side handles oxygenated blood.
   
   Fetal circulation
   The normal circulation of a fetus while in the uterus follows a slightly different path than after a baby is born. While in the uterus the placenta acts as the lungs, therefore less blood passes into the actual fetal lungs. There are two structures within a fetal heart that allow this "bypass". One is the patent ductus arteriosus or PDA. The PDA allows mixing between the pulmonary artery and the aorta as it is a passageway between these two major vessels. The other is the patent foramen ovale (PFO). The PFO is a hole between the two atriums. It allows mixing of blood between the two right and left atrium. The PDA and PFO allow a right to left shunt, which directs blood away from the lungs and directs this more oxygenated blood to travel to the body.
   
   The pressure in the lungs of a fetus is higher than that in the body. This increased pressure encourages the right to left shunt also. After a baby is born the pressure in the lungs decreases as the vessels in the lungs begin to relax. The pressure in the body increases after birth. This change in the pressures allows more blood to flow into the lungs. These factors, the changes in pressure, are what cause the PDA and PFO to eventually close. The final closure usually takes several days.
   
   Keeping the PDA open
   Some congenital heart diseases are dependent on the fetal circulation remaining intact and the PDA remaining patent to provide the mixing of oxygenated with unoxygenated blood. To keep the PDA patent we can give prostaglandins (PGE). PGE is a medication that will keep the PDA open so there is mixing of blood. This medication can cause side effects that we do not desire. However, the benefit of the medication far outweighs the risks of the side effects. Some side effects of PGE may include rash, apnea (stop breathing for a prolonged period), thickened secretions, and fever. If a fever should develop, blood cultures will be drawn to evaluate for an infection because fever can also be a sign of infection. Once the blood work has been drawn, antibiotics will be started as a precaution. If apnea becomes significant there are a couple things to help. The first thing to try is the medication caffeine. This will stimulate the baby and encourage them to breath more regularly. If caffeine is not enough to control the apnea and the heart rate is being affected, the next treatment would be intubation and ventilation. Intubation means a special tube is placed in the baby's windpipe to help with breathing. This tube is called an endotracheal tube or ETT. A ventilator would be attached to this tube to help the baby breathe. The ETT triggers production of secretions so the nursing staff will suction the tube to keep it patent or open, because thickened secretions is another side effect of prostaglandins.
   
   Keeping the PFO open
   Some congenital heart diseases are dependent on the fetal circulation remaining intact and the PFO remaining patent to provide mixing of oxygenated with unoxygenated blood. There are means by which to ensure that this opening remains patent to help these particular babies.
   
   To ensure the PFO remains patent a balloon atrial septostomy will be performed. This is a surgical procedure done in the NICU. This would be done shortly after birth. While observing via ultrasound, a special catheter is inserted into a major vessel in the groin area. The catheter is then threaded through this vessel and eventually into the heart via the inferior vena cava. The catheter is then passed through the PFO and a balloon is inflated. This inflated balloon is pulled back through the PFO. This will "tear" open the PFO and make it larger. This larger hole allows for more mixing between the two sides of the heart.

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