Most irregular heartbeats are not serious. Many people experience occasional skipped beats or fluttering sensations that are completely harmless and need no treatment. But some types of irregular heartbeat can raise your risk of stroke, heart failure, or cardiac arrest, so the answer depends entirely on which kind you have and what else is going on with your heart.
The key distinction is where in the heart the irregular rhythm starts, how long it lasts, and whether you have underlying heart disease. Some arrhythmias come and go in response to everyday triggers and disappear on their own. Others require lifelong management.
Types That Are Usually Harmless
The most common irregular heartbeat most people notice is a premature beat, sometimes called a premature ventricular contraction (PVC) or premature atrial contraction. It feels like your heart skipped a beat or did a little flip. These extra beats are generally not a concern and rarely signal a more serious condition. Almost everyone has them from time to time. They can be triggered by caffeine, stress, poor sleep, or dehydration, and they typically stop on their own.
That said, very frequent PVCs (thousands per day over months) can gradually weaken the heart muscle. So while the occasional skipped beat is nothing to worry about, a pattern that feels constant or worsening is worth mentioning to a doctor.
Types That Require Attention
Atrial Fibrillation (AFib)
AFib is the most common type of arrhythmia in the United States. It happens when chaotic electrical signals in the heart’s upper chambers cause an irregular and often very fast heartbeat. Some people feel it as a quivering or racing sensation in the chest; others don’t notice it at all. AFib can be temporary, starting and stopping on its own, or it can become persistent and require treatment to resolve.
The biggest concern with AFib is stroke. When the upper chambers quiver instead of contracting fully, blood can pool and form clots. If a clot travels to the brain, it causes a stroke. This is why people diagnosed with AFib are often prescribed blood thinners. Current guidelines recommend direct oral anticoagulants as the first-line therapy, with the decision based on your individual stroke risk calculated through a scoring system that accounts for age, sex, blood pressure, diabetes, and history of prior stroke or heart failure.
AFib is classified by how long it lasts. Paroxysmal AFib comes and goes, resolving within seven days. Persistent AFib lasts longer than seven days and typically needs intervention. Long-standing persistent AFib has been continuous for over 12 months. Each stage carries increasing risk if left unmanaged.
Ventricular Tachycardia (VT)
Ventricular tachycardia starts in the heart’s lower chambers and produces a rapid heartbeat that prevents the ventricles from filling properly with blood. When the heart can’t pump enough blood to the body, you may feel dizzy, lightheaded, or faint. In people with otherwise healthy hearts, VT may not cause serious problems. But in people with existing heart disease, it can be a medical emergency and may deteriorate into cardiac arrest.
Warning Signs That Need Immediate Help
An irregular heartbeat on its own, without other symptoms, is rarely an emergency. The situation changes when it’s accompanied by chest pain, fainting or near-fainting, severe shortness of breath, or a sudden feeling that something is very wrong. These symptoms suggest the heart isn’t pumping enough blood to meet the body’s needs and warrant a call to emergency services.
Fainting during an arrhythmia is particularly concerning because it means your brain briefly lost adequate blood flow. If you’ve had fainting spells, your doctor may recommend a tilt-table test, which monitors how your heart rate and blood pressure respond when you move from lying down to standing.
Common Triggers for Palpitations
Many episodes of irregular heartbeat are triggered by things you can identify and manage. Caffeine is a well-known culprit, particularly if you drink more than three cups of coffee per day. Large amounts of energy drinks high in caffeine can, in rare cases, actually cause arrhythmias rather than just palpitations. Alcohol is another trigger and has been directly linked to episodes of atrial fibrillation.
Stress and anxiety are among the most frequent non-cardiac causes. So are dehydration, low potassium levels, and anemia. Even certain foods can set off palpitations: high-sodium processed foods, very sugary meals (especially if you’re prone to low blood sugar), spicy foods, and chocolate, which contains a compound that naturally increases heart rate. Some dietary supplements, including bitter orange, ephedra, and ginseng, can also cause palpitations.
What Happens If It Goes Untreated
The consequences of ignoring an arrhythmia depend on the type. Occasional PVCs left alone are almost always fine. AFib left untreated raises stroke risk significantly and, over time, can weaken the heart muscle, potentially leading to heart failure. The heart is essentially working harder than it should for months or years, and that takes a toll.
Ventricular tachycardia in someone with heart disease can escalate to ventricular fibrillation, where the heart quivers uselessly instead of pumping. This is cardiac arrest, and it’s fatal within minutes without treatment.
Current clinical guidelines emphasize early rhythm control for AFib, meaning the goal is to restore and maintain a normal heart rhythm rather than simply managing the heart rate. For some patients, catheter ablation, a procedure that targets the tissue causing faulty electrical signals, is now recommended as a first-line option.
How Irregular Heartbeats Are Diagnosed
The standard starting point is an EKG, which records your heart’s electrical activity for about 10 seconds. The limitation is obvious: if your arrhythmia comes and goes, a brief snapshot might miss it entirely. For intermittent symptoms, a Holter monitor records your heart rhythm continuously for 24 to 48 hours. You’ll typically keep a diary of your activities and symptoms so your doctor can match what you felt to what the monitor recorded.
If your episodes are even less frequent, a cardiac event recorder can be worn for a month or two using patches, bracelets, or finger clips. You activate it when you feel symptoms, capturing the rhythm at the exact moment something feels off.
For arrhythmias suspected to be triggered by exercise, a stress test has you walk on a treadmill or ride a stationary bike while your heart is monitored, sometimes provoking the irregular rhythm so it can be studied. An echocardiogram, which uses ultrasound to image the heart’s structure and movement, helps determine whether structural problems are contributing to the rhythm issue.
What Smartwatches Can and Can’t Tell You
Consumer smartwatches with single-lead EKG capability can detect atrial fibrillation with roughly 94% sensitivity, meaning they catch most true cases. However, their specificity is lower, around 82% to 91%, which means they also flag rhythms as abnormal when they’re actually fine. The positive predictive value in one major study was only about 55%, so roughly half the “AFib detected” alerts in a general population are false positives.
A smartwatch notification is a reasonable prompt to schedule an appointment, not a diagnosis. Any alert still needs to be confirmed with a clinical-grade recording reviewed by a professional. A normal resting heart rate falls between 60 and 100 beats per minute. Consistently reading above 100 at rest, or below 60 if you’re not a trained athlete, is worth discussing with your doctor regardless of what your watch says about rhythm.