Whether your heart is beating too fast, too slowly, or erratically, this condition can feel scary. We’ll walk you through it all, one beat at a time.
WHEN YOUR HEART beats normally, you probably don’t give it a second thought. But when that steady thump-thump changes, it could be a sign that something more is going on. There are numerous conditions that can cause your heart rate to speed up, slow down, or lose its regular rhythm. Some are nothing more than an annoyance. Others can be much more serious. We'll help you sort through the differences so you can get the treatment you need.
What Are Arrhythmias, Anyway?
We’ve all heard the sayings “my heart skipped a beat” and “my heart was pounding out of my chest!” Maybe that’s why so many of us think of irregular heart rhythms as occasional episodes that are triggered by unusual levels of happiness, fear, or excitement—and it’s true, they sometimes can be. But for people who live with irregular heartbeats, called arrhythmias, their symptoms occur for a variety of reasons, often triggered by a combination of factors, including genetics, underlying physical conditions, stimulants like cigarettes and alcohol, and/or those external stressors or high emotions.
So, let’s get to the details. Arrhythmias are abnormal heartbeats that interfere with your heart’s ability to pump blood efficiently and effectively. They can make your heart beat much faster or slower than it should, and sometimes it beats in an out-of-sync manner.
Most arrhythmias won’t harm you, but the more serious types can prevent your brain, heart, and other organs from getting the blood and oxygen they need to survive and thrive. Some arrhythmias can be fatal.
For example, one type of arrhythmia, called atrial fibrillation, can cause blood clots to form. Such clots can travel to your brain and trigger a stroke, or, less commonly, cause a pulmonary embolism, a blockage in one of the arteries in your lungs. As scary as this is, these conditions can be treated when they're detected in time.
Before we dive into the details, though, let’s start with how your heart beats when it’s doing its job the way it’s supposed to:
You know that your heart is a pump, and each beat or contraction moves blood through the body.
It has four chambers: On top are the right and left atria. On the bottom are the right and left ventricles.
To keep your blood flowing at a rate necessary to meet your body’s needs, the walls of each chamber contract and relax in a steady rhythm.
That’s your heart beating. It gets faster when you exercise or move around, as the demand for oxygen grows, and it slows down while you’re at rest.
What controls this complex process? The heart has its own pacemaker. Called the sinus node, it's located at the top of the right atrium. It sends electrical signals to each part of your heart telling it what to do and when. Here's how it works:
First, the signal instructs the atria to contract, which pushes blood into the ventricles.
Next, it pauses at the atrioventricular (AV) node, which is med-speak for the electrical connection between atria and the ventricles. That little time-out gives the ventricles a sec to fill up.
Finally, the signal tells the ventricles to contract. Blood in the right ventricle heads over to the lungs to pick up oxygen. Blood on the left flows out to the rest of the body.
This whole signalling system works thanks to your autonomic nervous system, which also controls your liver, kidneys, and other bodily organs. They all function without any input from you (imagine if you literally had to think through every heart beat!). When all works as it should, your heart will beat approximately 60 to 100 times each minute.
What Are the Types of Arrhythmias?
Arrhythmias can be grouped in a couple of different ways, including where in the heart they occur and how they affect your beat.
When an arrhythmia speeds up your heartbeat, it’s called a tachycardia or tachyarrhythmia.
Too slow, and it’s called a bradycardia or bradyarrhythmia.
Now, let’s break it down even further.
Let’s go back to the saying, “My heart skipped a beat!” You’ve probably had one of these before. In fact, nearly everyone experiences them on occasion. This can occur spontaneously or with stress, excessive exercise, smoking, or too many cups of coffee rather than from an underlying heart condition.
These types of arrhythmias, officially called premature atrial contractions (PACs) or premature ventricular contractions (PVCs), are the most common types and are rarely cause for concern. They can originate in either the atria or ventricles. They’re often found in children and teenagers. But if they happen frequently or they bother you, talk to your doctor. It’s rare, but they can be a sign of an underlying heart problem, such as injury to the heart, according to the American Heart Association (AHA).
Supraventricular Arrhythmias (SVTs)
This type of arrhythmia, which can sometimes be life-threatening, starts in the atria. When it occurs, your heart can beat faster than 100 beats per minute at rest (which is another way of saying you’re experiencing tachycardia).
Supraventricular arrhythmias include:
Atrial fibrillation (afib): This is the most common type of arrhythmia that requires medical intervention. Afib causes an erratic and often rapid heartbeat. During an episode, your heart can’t pump as well as it does normally, and blood may pool in your left atrium. Clots can form there, and if one gets into your bloodstream, it can travel to your brain and cause a stroke. Afib can also lead to heart failure.
Most people who develop afib already have underlying heart disease and are 65 or older, though this condition can occur in young, healthy people as well. Episodes tend to be short and infrequent at first, coming and going on their own. However, as the disease progresses, episodes happen more often and will eventually require medical intervention to stop. For example, your doctor may have to shock your heart to correct its beating.
People with afib commonly take medications to prevent stroke, such as blood thinners. Other drugs and procedures may be needed to correct the heart’s rhythm and rate. The Centres for Disease Control and Prevention (CDC) estimate that between about 3 and 6 million people in the U.S. have atrial fibrillation.
Atrial flutter: Similar to atrial fibrillation but rarer, it causes a super-fast heartbeat—sometimes more than 300 beats per minute—that’s regular rather than erratic. Because the same type of pooling and clotting can occur, atrial flutter can also lead to a stroke or heart failure. However, such complications can usually be avoided with proper treatment.
Paroxysmal supraventricular tachycardia (PSVT): This is another very rapid heartbeat (up to 250 beats per minute) that starts and stops suddenly. It’s often not dangerous. However, some PSVTs are cause for concern. People with Wolff-Parkinson-White syndrome, for example, are born with an extra electrical pathway that connects the heart’s upper and lower chambers. While this PSVT only rarely causes cardiac arrest, it can cause fainting.
These arrhythmias, which can also cause fast and irregular heartbeats, start in the ventricles, your heart’s lower chambers. While they can be life-threatening without treatment, there are procedures and medications available that restore a normal heart rate when it occurs.
Ventricular tachycardia: This type of rapid heartbeat—often greater than 170 beats per minute—disrupts the ventricles’ ability to fill and pump properly. When this type of arrhythmia lasts only a handful of heartbeats, it does not cause problems; however, if it lasts longer, it can cause dizziness, shortness of breath, fainting or, in extreme cases, cardiac arrest.
Ventricular fibrillation: The most serious of the arrhythmias, ventricular fibrillation is a medical emergency requiring an immediate call to 911. When this arrhythmia strikes, it causes the lower chambers (venticles) to quiver instead of contract, which stops the heart from pumping blood. If the heartbeat is not corrected within minutes, ventricular fibrillation leads to cardiac arrest and death.
This type of arrhythmia causes your heart to beat too slowly. For the average adult, that means under 60 heart beats a minute at rest or while doing non-strenuous activities (although a slowed rate during sleep is not unusual or always cause for alarm, according to the American Heart Association).
Your heart's natural pacemaker (remember, it's called the sinus node), is located in the right atrium. It sends electrical impulses across the atria, triggering them to pump blood into the ventricles. Bradyarrhythmias occur when those signals are blocked. This slowing or blockage can be caused by tissue damage from aging, previous heart procedures, inflammatory diseases, birth defects, and more.
In some people, slow heartbeats are perfectly normal. Athletes, for example, are very physically fit and therefore have hearts that work super efficiently, both when they’re working out and, say, sitting behind a desk. That’s because people who are in top physical condition can pump sufficient blood with fewer heart beats at rest—as few as 50 each minute.
Still, for regular Joes and Janes who are not daily gym bunnies or Olympic track stars, when the heart beats too slowly to meet the body and brain’s needs, there is a risk of passing out. The lack of oxygen may also cause confusion and shortness of breath. In extreme cases, cardiac arrest can occur.
Sick Sinus Syndrome
This arrhythmia compromises the ability of your heart’s pacemaker, or sinus node, to properly control your heart rate, causing it to swing from too slow to too fast or to wildly erratic. It can lead to stroke, heart failure, and cardiac arrest.
Your heart’s electrical signals travel a route from their origin in the sinus node to their destination, such as your ventricles. If the route gets blocked, the signals may slow down, causing a dip in your heart rate.
What Causes Arrhythmias?
Most arrhythmias occur in people who already have some form of heart disease. They can also occur in people who possess structurally “normal” hearts with no sign of disease, but rather have issues with how the electrical pathways in their hearts are working.
Having had a heart attack, for example, can increase your odds of an arrhythmia because the scarring that results can form along the path that the electrical signals interfering with transmission. Arrhythmias can also occur during a heart attack, as cells die off and scar tissue develops.
Specifically, the heart disease-related causes of arrhythmia include:
Coronary Artery Disease (CAD)
This build-up of plaque narrows and stiffens the heart's arteries. As blood flow and oxygen to the heart is reduced, the way it responds to electrical signals may change. This can cause atrial fibrillation.
CAD also frequently leads to heart attack, and the scarring can increase your risk of both ventricular tachycardia and ventricular fibrillation. Both can both also occur during a heart attack due to the sudden loss of blood flow in the heart.
This disease weakens your heart and alters the way electrical signals travel through your heart, setting you up for arrhythmias including atrial fibrillation, atrial flutter, sick sinus syndrome, and ventricular tachycardia.
When your heart’s system of valves does not work properly, it can put extra strain on your heart. That causes the heart—your most important muscle—to enlarge and stiffen. Heart-valve disorders are among the most common causes of atrial fibrillation. They can also trigger ventricular tachycardia.
Rheumatoid arthritis, lupus, and other autoimmune disorders often affect the heart and can cause arrhythmias, likely due to the chronic inflammation that occurs in such diseases. For example, lupus raises the risk of faster than normal heartbeats (above 100 beats per minute) as well as atrial fibrillation. Atrial fibrillation is the most common arrhythmia in people with rheumatoid arthritis.
What Are the Risk Factors for Arrhythmias?
In addition to these causes, many risk factors—some in your control, others not—up your odds of developing an arrhythmia. Many of them also increase your risk of heart disease more broadly. They include:
High Blood Pressure
Hypertension makes your heart work harder. As a result, your left ventricle grows thick and stiffens, which interferes with your heart’s electrical wiring. Electrical signals can no longer move as easily, which increases your risk of atrial fibrillation.
This disease significantly boosts your odds of developing HBP and CAD, and people with diabetes have as much as 40% higher risk of atrial fibrillation. Inflammation associated with diabetes is once again the likely culprit.
Excess weight makes the heart work harder, and that extra strain can cause the heart to enlarge, making it more susceptible to atrial fibrillation. Obesity also often accompanies other arrhythmia risk factors, such as HBP, sleep apnoea, and diabetes.
When your breathing is repeatedly interrupted during sleep, your heart gets less oxygen. Left untreated, sleep apnoea can lead to atrial fibrillation and other usually less serious arrhythmias, including premature contraction.
If your body produces too much thyroid hormone, your heart may beat harder and faster. When left untreated, this can trigger afib.
As we get older, our heart’s internal pacemaker loses cells, which causes it to slow down. Age-related heart changes can also affect the pathways that electricity follows. And with age we become more prone to diseases that affect the heart, like CAD, heart failure, and diabetes. Arrhythmias among the elderly include atrial fibrillation, bradycardias (slow heart beats), sick sinus syndrome, and other atrial and ventricular arrhythmias.
You can be born with structural abnormalities of the heart that affect the way it conducts electricity, leading to atrial tachycardias as well as life-threatening ventricular arrhythmias.
The genes that you inherit from your parents play a role in the development of some types of arrhythmias, called cardiac channelopathies. They can cause your heart to beat too fast, too slow, or irregularly whether or not you have other forms or heart disease.
The most common inherited arrhythmia is long QT syndrome, in which the lower chambers of the heart develop a rapid and irregular rhythm that can lead to ventricular fibrillation, a life-threating arrhythmia. Many people have no symptoms until they experience fainting, seizure, or even sudden cardiac arrest. Most first episodes occur before age 40. If you have a family history of this heart condition, ask your doctor for screening tests, which may include genetic testing, wearing event monitoring devices, and an electrocardiogram (ECG).
Other examples of arrhythmias that you can be born with include:
Brugada syndrome is a rare inherited arrhythmia that causes irregular heartbeats. Sudden death may be the first sign of its presence.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a deadly form of arrhythmia that strikes young people primarily during exercise. It can cause fainting, dizziness, and light-headedness, often beginning in childhood. Untreated, it can lead to often fatal ventricular tachycardia.
What Are the Symptoms of Arrhythmias?
Will you feel your heart speed up or slow down? Not always. Arrhythmias cause a variety of symptoms, but you may have no symptoms at all. Often, people learn they have an arrhythmia such as atrial fibrillation by chance.
Maybe you get a required heart exam prior to knee surgery, for example, and your doctor discovers a problem. Or a diagnosis of atrial fibrillation may come after you’ve already had a stroke. For others, a rapidly beating or erratic heartbeat is both noticeable and uncomfortable. Every person is different.
Something else to keep in mind: Having mild symptoms or no symptoms does not indicate that you have a less serious arrhythmia. And the opposite is also true. You could have severe symptoms but have a harmless arrhythmia. Here are some of the common symptoms:
These can feel differently for different people, but you may experience a pounding sensation in your chest, or you may feel like your heart’s racing that famous “mile a minute.”
Remember from above: Some arrhythmias can cause your heart to beat to more than 100 times each minute—and sometimes much faster than that. You may also feel like your heart has skipped a beat or a beat has come earlier than usual. Again, though, that you may not feel any abnormal beating during an episode of arrhythmia.
Shortness of Breath, Fatigue, Light-headedness, and Chest Pain
Some or all of these can occur when your heart rate’s off and your heart can’t pump blood efficiently. That can reduce the amount of oxygen your heart delivers to the rest of your body, resulting in shortness of breath. Both fast and slow heartbeats can cause these symptoms, according to the AHA.
People can faint from dehydration, emotional distress, or even standing up a little too quickly, and then quickly recover. Fainting from an arrhythmia, however, is caused when your blood pressure drops—sometimes to dangerously low levels. Such drops in blood pressure are medical emergencies, so if you have a history of arrhythmias, be sure to carry or wear a medical ID card, necklace, or bracelet so others know to call 911.
How Do Doctors Diagnose Arrhythmias?
You likely will see an electrophysiologist, a specialized type of cardiologist who focuses on heart-rhythm disorders. Early treatment may lead to better treatment outcomes. This is particularly true of atrial fibrillation, which may cause a stroke if left untreated.
In addition to a physical exam and a discussion of your family health history, your doctor will record your heart’s electrical activity with an electrocardiogram (ECG or EKG), a painless test that lasts about ten minutes. It will reveal any abnormalities with your heart’s electrical wiring that take place during the test.
However, arrhythmias often come and go, and yours may not occur during your ECG at your doctor’s office. If that happens, there are options:
Holter Monitors or Event Recorders
These wearable devices will monitor your heart’s activity while you go about your normal daily routine. If you are given an event recorder, you will turn it on when your symptoms begin, and it will start recording your heart’s activity. Holter monitors, on the other hand, are worn 24/7 (except when you’re in the shower), for anywhere from a few days to a few weeks. These smart-phone-sized devices automatically begin recording as soon as a change is detected. They’re considered to be more effective because they capture irregularity during its first stages.
If your arrhythmia most often occurs during physical exertion, your doctor may order a stress test, in which you will get your heart rate going on a treadmill or exercise bike (or with medication if you can’t exercise).
Electrophysiology (EP) Test
During this invasive surgical procedure, a catheter, or thin wire, is inserted through a vein, often in your groin, and threaded to your heart. Electrodes at the catheter’s tip stimulate the heart so that your doctor can evaluate its electrical function. This test helps find the cause of your arrhythmia and also helps guide treatment decisions. You will be awake but sedated for this one- to four-hour test. Often, you’ll go home the same day, but your doctor may decide to monitor you overnight.
Tilt Table Test
Strapped onto a table in a horizontal position, you are slowly raised until you are vertical. This shows how your blood and heart rhythm respond to gravity and changes in position. This test is often done to trigger symptoms like light-headedness, which can be caused by a heartbeat that’s too slow or too fast.
What Is the Best Treatment for Arrhythmias?
A wide variety of treatments exist to help you manage your arrhythmia. Your doctor will determine which therapeutic approach is best for you depending on your specific symptoms.
Medications to Treat Arrhythmias
For some arrhythmias, medications can be used to restore your heart beat to normal. They include:
Beta blockers, calcium channel blockers, and digitalis
These medications slow the heart and may be prescribed if your arrhythmia causes your heart to race.
Anticoagulants and antiplatelets
These include drugs such as warfarin and aspirin. They prevent clots and reduce your risk of stroke.
These medications help correct your heart beat and to keep your heart beating normally. If your doctor prescribes one of these, you may start it in the hospital, where you can be observed to be sure it’s effective and safe for you at the prescribed dose. They include:
Nexterone and Pacerone (Amiodarone): One of the most commonly prescribe drugs for arrhythmia, it’s often taken for atrial fibrillation. It can also treat other arrhythmias, including dangerous ventricular arrhythmias like ventricular fibrillation.
Tambocor (Flecainide): Used for irregular heartbeats, to slow a fast heart rate, and to maintain a normal rhythm, it works by relaxing the heart to improve how well it pumps blood. It’s used to treat some types of supraventricular tachycardia as well as atrial fibrillation and atrial flutter. It also may be used for dangerous arrhythmias called sustained ventricular tachycardias, which are too-fast rhythms that require medical intervention to restore a normal heartbeat.
Betapace, Betapace AF, Sorine, and Sotylize (Solatol): Prescribed for atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation, this medication, which comes in various brands names, is used primarily in patients with life-threatening arrhythmias.
Surgeries and Procedures to Treat Arrhythmias
When medications can’t do the job, your doctor may recommend a procedure.
A catheter is threaded to your heart via the groin. Once there, your doctor will apply heat or extreme cold to small areas of your heart, creating tiny scars. These block the pathway of the electrical signal that’s causing your arrhythmia. Most often, it’s used to treat supraventricular tachycardia, but it can also treat both atrial fibrillation and atrial flutter.
When your heart beats irregularly or too fast, your doctor may have to shock it in order to get it back to normal. While sedated, two paddles—one on your chest, the other on your back—deliver brief electrical shocks to right your heart. The procedure takes about 30 minutes.
If your arrhythmia can’t be managed sufficiently with medication and/or procedures, you may require a different kind of solution: a device that helps control the electrical signalling of your heart.
Pacemaker: A small device is implanted under your skin below one of your collarbones. Wires from the device run through a vein and attach to the heart. They deliver signals that tell your heart to beat faster and are used for bradycardias, or arrhythmias that slow your heart beat. Some pacemakers connect directly to your heart without the need for wires.
Cardioverter-defibrillator: Implanted like a pacemaker but slightly larger, this device monitors your heart constantly. It can sense when a life-threatening arrhythmia, such as ventricular fibrillation or ventricular tachycardia, occurs. It shocks the heart to restore a normal heartbeat.
What Are the Best Lifestyle Changes for Arrhythmias?
In addition to sticking with your treatment plan—if your arrhythmia requires treatment, that is—you’ll need to focus on a healthy lifestyle to protect your heart and help prevent symptoms.
Eat well: Focus on foods that support heart health, such as fruits and vegetables, whole grains, legumes, lean meats, and fish. Avoid foods with saturated and trans fats, limit red meat, and choose whole foods over highly processed foods, which are often loaded with sodium and sugar.
Exercise: After getting your doctor’s OK, your goal should be 30 minutes a day five days a week. You and your doctor can discuss the right workout for you. To start, it may be something as mild as a daily walk around your neighbourhood.
Weight loss: If you’re overweight or obese, slimming down will help your heart. Losing weight can lower blood pressure, which reduces the risk of stroke.
Limit alcohol: Booze can stress your heart and make it beat faster. It can also trigger arrhythmias. Your doctor can help you decide if you need to cut it out altogether.
Quit smoking: Your heart’s health will improve dramatically, and you’ll be less likely to have an arrhythmia if you break this habit. Visit the American Heart Association to get help to stop smoking today.
Sleep well: If you have sleep apnoea, which disturbs your breathing constantly as you sleep, you will likely benefit from a device known as a C-PAP, which helps open your airways during the night and keeps you breathing normally. Good sleep will also help improve your blood pressure.
Tackle stress: Too much worry and anxiety can up blood pressure, boost cortisol levels, and increase your risk for arrhythmias. Try daily mediation, a walk with a loved one or friend outside, or focusing on doing the things you love to better manage stress.
Pay attention to side effects: Monitoring how you feel while on a medication is super important—it might not be the best medication for you, and in some cases, medication can actually trigger an arrhythmia. You may need a dose adjustment or a different medication altogether. Share all your symptoms with your doctor.
What Is Life Like for People With Arrhythmias?
There’s no doubt that living with an abnormal heartbeat can be stressful, even frightening. Fortunately, there’s plenty that you can do to help ease your worries, which is especially important because stress can be a trigger for an episode of arrhythmia.
First, make sure that you carefully follow your doctor’s treatment plan, which is designed to keep your heart beating as it should.
Medications work only if you take them. And if your meds don’t agree with you for some reason, speak up! There are different therapeutic approaches, and your doctor wants what’s best for you.
Also, staying active can help you decompress and release tension. In addition to exercises like walking, yoga may be particularly helpful for stress relief. In fact, a 2016 study in the European Journal of Cardiovascular Nursing found that this gentle form of exercise lowered blood pressure and heart rate in people with atrial fibrillation. It also likely improves quality of life.
And, don’t underestimate the value of connecting with others who are walking the same path as you. Check out the American Heart Association’s support groups, or ask your doctor for local resources and in-person group meetings.