Overview of POTS Syndrome

Woman fainting with POTSThis handout is written by Dr. Marc Le Gras. The intent of this handout is to enhance the information provided to you at the consultation and on follow-up visits. It is provided for education and help with your condition. The more you know about POTS, the better you will do.

What is POTS?

POTS is an abbreviation for Postural Orthostatic Tachycardia Syndrome. In plain English, this means an abnormal rise in heart rate along with symptoms mainly consisting of dizziness or feeling weak and lightheaded when going from lying down or sitting down to standing up or walking. People with POTS syndrome may be unable to stand or walk for long periods of time, or even briefly. There can be a drop in blood pressure with these symptoms, called hypotension. At times, people can lose consciousness or faint – this is called “syncope.” The medical definition of POTS disease in pediatrics is a persistent rise in heart rate of more than 30-40 beats per minute when standing, or a standing heart rate of greater than 120 beats per minute. There may be a drop in blood pressure as well. The medical definition sometimes includes a duration of at least six months of symptoms, but we don’t need to wait that long to start making you feel better. POTS is not a deadly or lethal condition.

But doesn't everyone get dizzy at times when they stand up?

Yes, normal healthy people can get brief symptoms occasionally when they stand up. When we stand, there is a normal shift in blood distribution from our chest to our abdomen and legs of up to 1 liter and this can cause brief symptoms of lightheadedness and an increase in heart rate. Usually the cardiovascular system adapts to this quickly and symptoms of an increased heart rate will resolve within 30 seconds. These brief episodes are called orthostatic hypotension.

So why do I faint?

There are times where the blood pressure drops so much that there isn't enough blood going to the brain. The blood pressure drop alone can be enough to cause fainting, but it also triggers an increased heart rate – there are areas in the brain that receive the signal of a fast heart rate and cause an abnormal response in which a brain nerve (called the vagal nerve) slows or stops the heart. This type of fainting is called vasovagal or neurocardiogenic syncope.

Read more: Overview of POTS Syndrome

Vasovagal Syncope or Neurocardiogenic NCS

What is vasovagal syncope or neurocardiogenic syncope?

Vasovagal syncope or neurocardiogenic syncope (NCS) is caused by a drop in blood pressure, quickly followed by faster then slower heart rate resulting in poor blood and oxygen flow to the brain which results in temporary loss of consciousness.

Neurocardiogenic syncope is also referred to as neurally mediated syncope. It is also called fainting.

Read more: Vasovagal Syncope or Neurocardiogenic NCS

Screenings for Critical Congenital Heart Defects

congenital heart defects

by James P Kyser, M.D.

Critical congenital heart defects (CCHDs) are serious structural heart defects that occur in a very small number of newborns (the CDC estimates about 7,200 each year in the U.S.). CCHDs are the culprit of about 30 percent of infant deaths.

CCHDs make up around 25 percent of all congenital heart defects, and often require surgery very early in life. The diagnosis of CCHDs requires the right kinds of screening. Without proper screening, newborns might be misdiagnosed or not diagnosed at all. CCHDs can be picked up on routine obstetrical ultrasounds that almost all pregnant women have.

Additionally, there are particular screenings that can be done prenatally, like a Fetal Echocardiogram.

Prenatal Screenings

by Douglas H. King, M.D.

One of the fastest growing areas within the discipline of pediatric cardiology is the study of fetal echocardiography. This particular discipline has evolved with the advent of improved imaging techniques, especially that of computer enhancement which now allows us to evaluate the cardiac anatomy and fetuses as young as 16-18 weeks. The purpose of this discussion is to review the indications for fetal echocardiography and to explore the use of fetal echocardiography in both the evaluation and treatment of congenital heart disease and fetal dysrhythmias.

Indications for fetal scanning include those groups of patients who would be considered to be at high risk for having a child with a cardiac malformation. These groups include those with:

1. Positive family history.
2. Maternal conditions such as diabetes mellitus, which does increase the likelihood of having a congenital heart defect.
3. Those fetuses who are the product of in vitro fertilization, which does increase the incidence of congenital heart disease.
4. Exposure to potentially teratogenic drugs such as lithium or Dilantin.

Recurrent risks for congenital heart disease in families with a congenital heart defect vary according to various studies. In a family who has given birth to a previous child with congenital heart disease, the recurrence risk ranges between 2 and 3%. A particularly high-risk group would include the fetus of a parent who has congenital heart disease. The recurrence risk for these fetuses is approximately 4%.

Fetuses who are the product of in vitro fertilization have a recurrence risk as high as 7-8% and should be screened for congenital heart disease. Parents with genetic syndromes, such as velocardiofacial syndrome, may have a recurrence risk as high as 50% for having a child with a congenital heart defect. Consequently, the fetuses born to a parent with a deletion of the 22nd chromosome should have a fetal echocardiogram.

Fetal echocardiography should be considered for conditions which put the fetus at risk for structural or functional cardiac malformations. Mothers with diabetes have a 13% chance of giving birth to a child with a major congenital anomaly and there is approximately a 6% chance of giving birth to an infant with congenital heart disease.

The most common heart defects associated with maternal Type I diabetes include transposition of the great arteries, VSD, coarctation of the aorta, and abnormal septal hypertrophy. Mothers with connective tissue disease are at risk for giving birth to a child with complete heart block, as well as other congenital abnormalities. Mothers with isoimmunization secondary to RH incompatibility are at risk for having children with congestive heart failure secondary to severe anemia. Finally, mothers of advanced maternal age are at risk for giving birth to infants with chromosomal abnormalities. These mothers of course should be given the option of both amniocentesis and fetal ultrasound scanning.

Among the many teratogenic agents that have been associated with congenital heart disease is phenytoin. This medication has been associated with septal defects, coarctation of the aorta, patent ductus arteriosus, as well as pulmonary and aortic stenosis. Mothers taking lithium during the first trimester of pregnancy are at risk for giving birth to a child with Ebstein’s anomaly of the tricuspid valve. Those mothers who have ingested large amounts of alcohol put their fetuses at risk for both atrial and ventricular septal defects. Isotretinoin, used for acne, has been associated with congenital heart defects causing both abnormalities of the great vessels as well as atrioseptal defects. Mothers taking oral contraceptives during their first trimester of pregnancy have given birth to infants with septal defects as well as children with tetralogy of Fallot. In those mothers in whom a fetal arrhythmia is noted, a fetal echocardiogram should be seriously considered. Fetuses with either sustained tachycardia, i.e., heart rates equal to or greater than 180 or those with sustained bradycardia, i.e., heart rates less than 90-100, should be thoroughly evaluated.

If a congenital heart defect is found in a fetus, there should be serious consideration towards amniocentesis, especially if there are any other associated congenital anomalies. The risk of genetic defects may be as high as 40% for congenital cardiac malformations detected at 18-20 weeks. This figure of 40% is much higher than is seen in liveborn infants with congenital heart defects where chromosomal or other syndromes are noted in approximately 10% of children with congenital heart defects. The risk for higher association in the 18-20 week-old fetus stems from the fact that many fetuses with congenital malformations may be spontaneously aborted during the second and third trimester.

The echocardiographic evaluation of fetal dysrhythmias is one area in which considerable strides have been made, in both evaluation and management. Many fetuses with persistent dysrhythmias will present with fetal hydrops and the treatment following delivery carries with it a high risk of morbidity and mortality. Fetal echocardiography and fetal Doppler permits an accurate in utero diagnosis of fetal dysrhythmias and is helpful in monitoring treatment with maternally administered medications.

Supraventricular tachycardia is the most frequent dysrhythmia noted in utero. The decision to administered medications to the mother depends on the age of the fetus and the overall clinical situation. If the supraventricular tachycardia is not sustained and there is no evidence of fetal hydrops, then the infant can be followed expectantly, observing the serial ultrasounds for signs of hydrops or persistent tachycardia. If hydrops is present and the tachycardia is sustained, then the decision for early delivery depends on fetal lung maturity and the overall age of the fetus. In infants less than 34 weeks with an immature lung status, serious consideration should be given towards administration of medications to the mother.

The most frequently used medication for fetal tachycardia is digoxin. A maternal digoxin level of 2 ng/mL is usually required for conversion and this typically requires a maintenance dose in the mother of at least 0.75 mg per day. A second-line drug used for treatment of fetal supraventricular tachycardia is flecainide. The success rate with a combination of digoxin and flecainide is as high as 80% for conversion of fetal tachycardia.

The in utero treatment of fetal dysrhythmias highlights the importance of a team approach and treatment of critically ill fetuses. Generally a pediatric cardiologist works closely with a perinatologist in making decisions with regards to optimum treatment of the fetal dysrhythmia. If fetal treatment is not successful, the perinatologist and neonatologist will work closely together in terms of determining the optimal time for delivery of the premature fetus.

Prenatal screening for fetuses with congenital heart disease provides both the physician and parents with valuable information. If a congenital heart defect is present, the parents can make informed choices as to whether to continue the pregnancy or whether to terminate the pregnancy prior to 24 weeks. If a pregnancy is carried to term, the parents can be prepared for the outcome of the pregnancy and the infant can be delivered appropriately in a center equipped to deal with infants with cardiac problems. Many studies have highlighted improved morbidity and decreased mortality in those children with complex congenital heart disease who were identified in utero and were delivered at a tertiary care center. In the future, prenatal therapy of selected congenital heart defects will become more commonplace, including pulmonary and aortic valvotomies in fetuses with severe right and left ventricular outflow tract obstruction.

Screenings Postpartum

But not all CCHDs are obvious before or after delivery, and it’s possible that a newborn could leave the hospital without being diagnosed. The consequences of this can be disastrous. Depending on the type and severity of the CCHD, these defects can be fatal or lead to serious problems.

Utilizing pulse oximetry screening, more infants can be diagnosed with a range of CCHDs before they get sick. These screening looks at seven major defects: hypoplastic left heart syndrome, tetralogy of Fallot, pulmonary atresia with intact septum, transposition of the great arteries, total anomalous pulmonary venous return, truncus arteriosus and tricuspid atresia. Five additional, secondary, diagnoses include double outlet right ventricle, coarctation of the aorta, Ebstein’s anomaly, single ventricle and interrupted aortic arch.

Read more: Screenings for Critical Congenital Heart Defects

Exercise is Safe for Most Children with Heart Disease

children exercising

by Andrew W. Hoyer, M.D.

Most children with congenital heart disease (CHD) will go on to lead normal healthy lives. Often, the condition is well-managed or corrected, even permanently. But what should parents do in regards to their child's activity levels?

While most recreational physical activity is safe for most children born with congenital heart disease, there is no one right answer for what is best for everyone. Just as CHD describes a wide variety of cardiac health issues, the best approach to physical activity in your child is varied as well.

In some cases, the level of activity the child takes on needs to be monitored or kept to a minimum (such as those with heart rhythm disorders). But rather than focusing on what can't be done, think about what your child can do.

Physical activity is recommended just like it would be for any other child: not just for the sake of enjoyment and "acting like a kid," but as a way of improving cardiac function and reducing the problems that come with inactivity.

Read more: Exercise is Safe for Most Children with Heart Disease

A Review of Fetal Echocardiography

fetal heart test

by Douglas H. King, M.D.

One of the fastest growing areas within the discipline of pediatric cardiology is the study of fetal echocardiography. This particular discipline has evolved with the advent of improved imaging techniques, especially that of computer enhancement which now allows us to evaluate the cardiac anatomy and fetuses as young as 16-18 weeks. The purpose of this discussion is to review the indications for fetal echocardiography and to explore the use of fetal echocardiography in both the evaluation and treatment of congenital heart disease and fetal dysrhythmias.

Indications for fetal scanning include those groups of patients who would be considered to be at high risk for having a child with a cardiac malformation. These groups include those with:

1. Positive family history.
2. Maternal conditions such as diabetes mellitus, which does increase the likelihood of having a congenital heart defect.
3. Those fetuses who are the product of in vitro fertilization, which does increase the incidence of congenital heart disease.
4. Exposure to potentially teratogenic drugs such as lithium or Dilantin.

Recurrent risks for congenital heart disease in families with a congenital heart defect vary according to various studies. In a family who has given birth to a previous child with congenital heart disease, the recurrence risk ranges between 2 and 3%. A particularly high-risk group would include the fetus of a parent who has congenital heart disease. The recurrence risk for these fetuses is approximately 4%.

Fetuses who are the product of in vitro fertilization have a recurrence risk as high as 7-8% and should be screened for congenital heart disease. Parents with genetic syndromes, such as velocardiofacial syndrome, may have a recurrence risk as high as 50% for having a child with a congenital heart defect. Consequently, the fetuses born to a parent with a deletion of the 22nd chromosome should have a fetal echocardiogram.

Read more: A Review of Fetal Echocardiography

Sudden Cardiac Arrest

Sudden Cardiac Death in a young person is a tragic and devastating event.  There are about 3,000 such deaths in the US every year, most of which are due to SIDS (sudden infant death syndrome).  The incidence of SIDS decreased with the recognition that we need to put infants to sleep on their backs ("Back to Sleep"), but infants still die at about the same rate now as they did 10 years ago for various reasons, including maternal smoking and genetic factors.  For older children, the five most common causes of sudden cardiac death are hypertrophic cardiomyopathy, commotio cordis, coronary artery anomalies, myocarditis, and a ruptured aortic aneurysm from Marfan syndrome.

Read more: Sudden Cardiac Arrest

Marfan syndrome

Do you know the signs of Marfan syndrome? It is a connective tissue disorder that can involve many parts of the body, including the heart.  If left undetected, it could result in life threatening problems such as aortic dissection (a tear in the wall of the biggest artery in the body).   

Marfan syndrome occurs equally in males and females, and all ages can be affected. There are many outward physical attributes that suggest the presence of Marfan syndrome.  These findings include tall stature with a short torso, long arms and legs, long fingers, a chest bone that caves inward or bows outward, and scoliosis.  Also, the skin can show stretch marks and someone with Marfan syndrome may have flat feet or hammer toes.

Read more: Marfan syndrome

Down syndrome and heart disease

Do children with Down syndrome (Trisomy 21) need cardiology evaluation and what are some of the cardiac problems they may encounter?

Children with Down syndrome can have multiple malformations.  Up to 50% of them can have a malformation of the heart and so it is recommended that all children with Down syndrome undergo an echocardiogram or see a pediatric cardiologist early in life. This first assessment should be done in the first month or two of life since some children with Down syndrome may have significant cardiac malformations without having any obvious murmur.  If heart disease is not recognized early in life, there is a higher risk of developing pulmonary hypertension, a condition in which the pressure in the lungs and right side of the heart are elevated.  Pulmonary hypertension can become irreversible if found late and could preclude surgical correction of the cardiac malformation.

Read more: Down syndrome and heart disease

Learn about our Single Ventricle Monitoring Program

I would like to let you know that we have just started our Single Ventricle Monitoring Program.  We are excited to get this rolling because we think it will improve outcomes for our babies with single ventricle physiology during their most fragile time- when they're at home before their second stage surgery.  This type of program has been shown to improve survival and is now part of a national quality improvement project for pediatric cardiology.  Our Program is a joint effort between Randall Children's Hospital, Cardiac case managers, Dr. John Iguidbashian and his Physician's Assistant, Jason Lines, and the Pediatric Cardiology Center of Oregon.  

Read more: Learn about our Single Ventricle Monitoring Program