As we continue to learn more about the effects COVID-19 has on the body, cases of individuals experiencing symptoms such as heart palpitations, low blood pressure and dizziness are on the rise. If these complications sound familiar, it could be a disorder known as autonomic dysfunction. Mark O’Shaughnessy, MD, PPG – Cardiology, shares his knowledge of this complex condition, the role it plays in your cardiovascular health and its likely connection to the coronavirus.
Understanding the autonomic nervous system
The autonomic nervous system is a part of the body that controls involuntary functions, meaning you don’t have to think about them, they happen automatically. Your breathing, heart rate, blood pressure, body temperature, sweating, digestion, sensations, etc., are all part of this complex system. When you have a dysfunction in the system, you can experience problems with any one of those actions.
Different instances of autonomic dysfunction
Autonomic dysfunction is an overarching term for anything affecting the autonomic nervous system. It affects the whole body from top to bottom, but the issues we see in cardiology usually deal with a person’s heart rate and/or blood pressure.
We often take the regulation of these two functions for granted, but they are extremely important. For instance, when sitting down, your heart rate is at a certain level, but as soon as you get up to walk across the room, it increases automatically. When you exercise, it goes even higher. You don’t even have to think about it. The same thing happens from a blood pressure standpoint. During activity, the systolic pressure, or top number, goes up, and the bottom number goes down because you’re increasing the blood flow or pulse pressure through the muscles.
However, when these systems malfunction, your heart rate can increase or decrease to an unacceptable level for the activity you’re performing. Your blood pressure can do the same (rise or plummet). A classic example is when you go from sitting to standing. Normally, gravity pulls blood down toward the floor, and your body is supposed to respond by squeezing on those blood vessels to push it back toward your head. But if the autonomic nervous system isn’t doing its job, the blood vessels don’t squeeze down, your blood pressure drops, and you can become dizzy, lightheaded, and even pass out. This drop in blood pressure with a change in position is called orthostasis or orthostatic hypotension.
There’s also a condition called postural orthostatic tachycardia syndrome (POTS), an autonomic dysfunction abnormality where there’s a drop in blood pressure, but an increase in heart rate. This is similar to orthostatic hypotension. There’s still a drop in blood pressure when a change in position occurs, but the heart rate increases in this case. This happens because your body is desperately trying to remedy the dip in your blood pressure by increasing the heart rate to help maintain blood flow to the head and heart. This compensatory response or shift often leads to dizziness and fainting.
Signs and symptoms
While autonomic dysfunction can affect just one part of the entire autonomic nervous system, the most common symptoms we tend to see as a result of the condition, from a cardiovascular standpoint, typically include:
- Elevated heart rate
- Racing or pounding of the heart
- Low blood pressure
- Near fainting (near syncope)
- Passing out (syncope)
If it’s cardiovascular, we will do an assessment, get a health history and perform a physical exam to see what your symptoms are based on your symptom complex and how it’s presenting. Sometimes we will have people wear a Holter or event monitor for 24-48 hours to see what their heart rate is doing with activity.
A normal resting heart rate is between 50 and 100 beats per minute. A heart rate slightly over 100 can be normal, but if it’s consistently over that and staying in the 120s or higher, that suggests something is driving your heart rate up, making it go faster. Then, if you get up and move around, and it goes from 100 to 200 with minimal activity, that tells us there’s something else going on and needs further investigating.
If that’s the case, we will have you wear a heart monitor in the office to see what happens when being active. We’ll also test your blood pressure while lying, sitting and standing. Your blood pressure should drop slightly when standing, but not drastically. If it drops significantly and you’re having symptoms, that’s telling us your blood vessels aren’t behaving or doing what they’re supposed to. The bottom line, there aren’t any drugs, blood tests or imaging to diagnose cardiovascular autonomic dysfunction. We base it on a clinical diagnosis and a patient’s symptoms.
Ultimately, we aim to treat the underlying issue for the patient, and from a cardiac standpoint, we can do several things. The most important thing we can do for most of our patients is to have them exercise, which is great for many reasons. First, it makes you feel better and helps your cholesterol, along with a host of other health benefits. But exercising also helps teach your blood vessels and heart rate to do the right thing and to act or behave appropriately.
With that said, many people have difficulty exercising because the heart rate is fast, but you have to keep at it. Now, you don’t need to go all out. I’m not talking about marathon running. You can do any kind of walking or exercise to retrain the body and heart rate.
If that doesn’t work, or you’re passing out all the time because of low blood pressure, the first thing I’m going to tell you to do is the simplest. Start with your diet. Liberalize your salt and water intake because salt causes you to retain fluid. Think of it like this, if you are walking around relatively dehydrated, especially in the summer months, your tank isn’t full. So, when you stand up, your blood vessels will constrict, but that blood is being pulled away from your head by gravity, and if your tank isn’t full, it will never make it back to your head and cause you to feel dizzy and lightheaded. That’s why increasing your intravascular volume (how much blood and water are in your system) is vital to help fill that tank.
If dietary measures don’t work, we also suggest using support stockings. They help keep your blood vessels compressed, so when you stand up, your blood pressure doesn’t drop as low as it would without them. If we exhaust those options, then we can look at medications. We can use several to increase your blood pressure, but we want to try the easy options first before moving to more complex forms of treatment.
COVID’s connection to autonomic dysfunction
We’ve definitely seen an uptick in this condition since COVID-19. The interesting thing about COVID is it’s an unpredictable disease. It has many neurologic effects. Many people with long-COVID are experiencing symptoms like brain fog, fatigue, a loss of taste and smell, and much more. We’re seeing its effect on the brain and other systems, including the autonomic nervous system. So, for the past few years, we’ve seen lots of tachycardia (fast heart rate), bradycardia (slow heart rate) and blood pressure lability with the virus in the acute and the long haul or long-term phases.
Because of this, we often ask ourselves, “How do we treat it?” Honestly, we treat it the same way we do all other autonomic dysfunction – with time. We don’t know how long autonomic dysfunction due to COVID will last; we have to wait and see. That also goes with many other long-haul issues. We don’t know exactly how to treat everything that comes with long-COVID. We don't have any specific therapies for it yet. It will take time.
With that said, autonomic dysfunction isn’t causing any permanent damage or injury to the heart, but it can certainly affect your lifestyle. If you can’t stand up without being dizzy or lightheaded, or you can’t exercise because your heart rate is so fast, that will take a toll. But those things are lifestyle modifications. The dysfunction itself won’t cause any permanent injury to the heart itself.
Realistic recovery for autonomic dysfunction
Unfortunately, some people never do. I have younger patients we encourage to keep active and exercise, and often they’ll outgrow it. Other individuals will get it, especially older individuals, and it will never go away. However, most people experiencing COVID-related dysfunction can exercise, be patient and give it time; it will typically get better on its own.
When to seek medical intervention
If you’re having problems with daily activities like walking across the room or getting dressed and you notice your heart rate getting faster or you have reoccurring symptoms, you should get checked out. There’s also a chance that it may not be autonomic dysfunction. There are a number of things outside of autonomic dysfunction that could cause your heart rate to increase, including anemia, thyroid abnormalities, various diseases, conditions, illnesses and viruses such as COVID-19. For instance, your heart rate will be faster if you’re sick with an upper respiratory infection or have a fever. That’s a normal physiological reaction. But if your symptoms last for an extended period and affect your daily life, you should speak with your primary care provider or a cardiologist. We can help figure out what’s driving the condition.
I want people to understand that autonomic dysfunction, from a cardiovascular standpoint, is not life-threatening. It’s life-altering for some people and can affect their quality of life, but it’s not fatal. We have treatment for it, but it’s not like taking a pill for high blood pressure - you take it, and it goes away. Autonomic dysfunction is different; it requires more lifestyle modifications to treat the symptoms. Making these changes, being patient and following your physician's treatment plan will get you back to the quality of life you deserve.