WHAT IS POTS?
Dysautonomia is an umbrella-term used to define conditions caused by a malfunctioning autonomic nervous system. Postural Orthostatic Tachycardia Syndrome (POTS) is a form of Dysautonomia. POTS is most often seen in women of child-bearing age but can and does affect people of all different ages, genders, and races. Just like all chronic illnesses, the degree of severity can range from mild to completely disabling. Approximately 25% of patients with POTS cannot work, go to school, or keep up with daily tasks due to their condition. The autonomic nervous system is responsible for every bodily function you do not have to think about at this very moment. You do not have to tell your heart to beat, nor do you have to instruct your lungs to inhale or exhale, as both are done automatically. With POTS, there is dysfunction with these automatic functions. The autonomic nervous system is responsible for so many bodily functions which is why no two patients with POTS are ever exactly the same.
The symptoms seen in POTS can vary greatly but an increase in 30+ bpm (40+ in adolescents), or a HR that goes above 120bpm, within the first 10 minutes of standing is seen in all patients. This increase in heart rate is responsible for the "T" in POTS: Tachycardia. Tachycardia is defined as an abnormally high heart rate. The average resting heart rate is anywhere from 60-90 (some athletes experience bradycardia, or low heart rate). This average resting heart rate would remain the same when going from sitting to standing in a healthy individual, or would change slightly. With POTS, the heart rate increases as the body's way of trying to compensate for the blood that is starting to pool in the lower extremities. Our heart rates increase to try to work extra hard to pump our blood back to our heads, with little success.
This increase in heart rate is diagnostic criteria for POTS and is seen with or without a decrease in blood pressure. It is a common myth that patients with POTS always have low blood pressure but that's not accurate. In fact, the increase in heart rate can be accompanied with a stable blood pressure, a drop in blood pressure, or even an increase in blood pressure. Orthostatic hypotension is a different form of Dysautonomia in which the blood pressure drops when standing but the heart rate remains the same.
Although POTS is often characterized as a fainting disorder, it can more accurately be described as a presyncope (the feeling of lightheadedness, dizziness, and confusion experienced right before one faints) condition. In fact, fainting and a decrease in blood pressure are not diagnostic criteria for POTS.
POTS was termed in 1993 but several medical and historical documents describe patients with POTS symptoms under different diagnoses including "soldier's heart." Current research is suggesting that POTS is an autoimmune condition. An autoimmune condition means that the body's immune system is attacking the body itself instead of intruding threats. More research is necessary in order to understand more about POTS and eventually find a cure!
Check out my blog post "31 Facts about Dysautonomia" to learn more.