Palpitations are the awareness of heartbeats. The sensation may feel like pounding, fluttering, racing, or skipping beats. Other symptoms—for example, chest discomfort or shortness of breath—may be present depending on the cause of the palpitations.
Palpitations are common. Some people find them unpleasant and alarming, but they rarely indicate a life-threatening heart disorder. Many people without heart disease also have palpitations.
Causes of Palpitations
Ordinarily, people do not notice the beating of their heart. However, many people can feel their heart beating when something causes it to beat more forcefully or rapidly than usual. Such rapid, forceful beats are usually a normal response by the heart (sinus tachycardia). Causes include the following:
Exercise
Strong emotions (such as anxiety, fear, pain)
Low blood count (anemia)
Fever
In other cases, palpitations result from a disturbance of heart rhythm (arrhythmia).
Types of arrhythmias
Arrhythmias range from harmless to life threatening.
The most common arrhythmias include
Both of these arrhythmias usually occur in people without a heart disorder and are harmless. The premature beat itself is not felt. What is felt is the following normal heartbeat, which occurs after a slight delay and is slightly stronger than usual. Although people feel as if their heart skipped a beat, it actually did not.
Other arrhythmias that cause palpitations and may be caused by serious heart disorders include
Atrioventricular nodal reentrant tachycardia
These other arrhythmias involve the heart beating much faster than normal. Arrhythmias in which the heart beats too slowly rarely cause palpitations, although some people do feel the slow rate.
Causes of arrhythmias
Some arrhythmias (for example, atrial premature beats, ventricular premature beats, or PSVT) often occur in people who have no serious underlying disorders. Others are often caused by a serious heart disorder or a disorder elsewhere in the body.
Serious heart disorders include angina, heart attack (acute coronary syndrome), congenital heart diseases (for example, the Brugada syndrome or congenital long QT syndrome), disorders of heart valves, and conduction system disturbances (for example, Wolff-Parkinson-White syndrome).
Disorders not related to the heart that may cause arrhythmias include
Overactive thyroid gland (hyperthyroidism)
Low level of oxygen in the blood (hypoxia)
Low level of potassium in the blood (hypokalemia)
Low level of magnesium in the blood (hypomagnesemia)
High levels of hormones produced by a tumor of the adrenal glands (pheochromocytoma)
Complications
Arrhythmias that cause the heart to beat too fast can cause complications (particularly in older people). If the heart goes too fast, it may not be able to pump blood adequately, and people may feel faint or pass out or develop heart failure. Heart failure occurs mainly in people who have previously had heart failure or a heart attack, although it can occur in other people if the heart rate is very fast or if the heart beats too fast for a long time. A rapid heart rate also increases the oxygen needs of the heart muscle. People who have narrowing of the arteries to the heart muscle (coronary artery disease) can develop chest pain due to angina or a heart attack (which may be fatal).
Some arrhythmias, particularly ventricular tachycardia, are unstable and can lead directly to cardiac arrest.
Evaluation of Palpitations
Although not all palpitations are caused by a heart disorder, the consequences of some heart disorders are so serious that people with palpitations should usually be evaluated by a doctor. The following information can help people decide when to see a doctor and help them know what to expect during the evaluation.
Warning signs
In people with palpitations, certain symptoms and characteristics are cause for concern. They include
Light-headedness or fainting
Chest pain or pressure
Shortness of breath
Pulse rate over 120 per minute or less than 45 per minute
Having heart disease or a family history of sudden death, recurrent fainting, or unexplained seizure disorder
Symptoms occur during exercise, particularly if they cause loss of consciousness
When to see a doctor
People who have palpitations and any warning signs should go to an emergency department right away, as should those who have continuous, ongoing palpitations. Those who have fainting, chest pain, or shortness of breath should call emergency services.
People without warning signs who have occasional palpitations or had an episode that stopped should call their doctor. The doctor will determine how quickly they need to be seen based on their age, underlying conditions, and other symptoms.
What the doctor does
Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination helps determine the possible cause.
Doctors ask
How often palpitations occur
How long palpitations last
Sometimes doctors ask the person to tap out the rate and cadence of palpitations because the pattern of beats can help them determine the cause.
The physical examination begins with the doctor checking the vital signs (pulse, temperature, and blood pressure). The pulse rate and whether the pulse is regular or irregular help suggest causes. An elevated temperature suggests fever is the cause. A low blood pressure does not suggest a cause but indicates extreme urgency.
Doctors listen to the heart for abnormal sounds that might indicate a valve disorder or heart inflammation. They listen to the lungs for sounds that indicate heart failure. They look at and feel the front of the neck to see if the thyroid gland is enlarged or inflamed.
Palpitations that occur with other symptoms, such as shortness of breath, chest pain, weakness, fatigue, or fainting, are more likely to result from an abnormal heart rhythm or a serious disorder.
Testing
Even though most causes of palpitations are not serious, testing typically is done.
Electrocardiography (ECG), sometimes with ambulatory monitoring
Laboratory testing
Sometimes imaging studies, stress testing, or both
Sometimes electrophysiologic testing
ECG is done. If the ECG is done while the person is having palpitations or an abnormal pulse rate, the diagnosis is usually clear. However, only a few of the possible causes produce an abnormal ECG when people are not having palpitations. Thus, people who have intermittent palpitations may need to wear an ECG monitor for a day or two (Holter monitoring—see figure Holter Monitor) or for a longer period (event recorder) to detect brief or irregularly occurring abnormal rhythms. In some people, doctors may insert a device underneath the skin to monitor the heart beat. This device is called a loop recorder, and it continuously monitors the person's heartbeat. Doctors can then use an external monitor to check the loop recorder for abnormal heart rhythms. Some commercially available products such as fitness trackers, which monitor heart rate, and other trackers that monitor track heart rhythms, are available for smart phones and watches but provide more limited information.
Laboratory testing is needed. Doctors do a complete blood count and measure serum electrolytes, including potassium, magnesium, and calcium. Doctors may measure other substances in the blood (cardiac markers) if the person has other symptoms that suggest a possible acute coronary syndrome. Doctors measure levels of thyroid hormone in the blood if they suspect an overactive thyroid and measure levels of other hormones in people who may have pheochromocytoma. Other tests may be done, depending on what other causes doctors suspect.
Imaging is sometimes needed. In people with ECG findings that suggest heart disease, doctors do echocardiography and sometimes magnetic resonance imaging (MRI) of the heart. People with symptoms during activity require stress testing sometimes with stress echocardiography or nuclear scanning.
Electrophysiologic (EP) testing is done when people's symptoms are severe and doctors suspect a dangerous heart rhythm problem that was not found with other tests. In this test, doctors pass small electrodes through a vein into the heart. The electrodes record the heart's electrical activity in more detail than an ECG does.
Treatment of Palpitations
Doctors usually simply provide reassurance for people with atrial premature beats or ventricular premature beats that are not caused by a heart disorder. If such harmless palpitations are very bothersome, doctors sometimes give a beta-blocker (a type of antiarrhythmic drug). Other identified rhythm disturbances and underlying disorders
For certain arrhythmias (for example, atrial flutter, PSVT, and atrioventricular nodal reentrant tachycardia), radiofrequency ablation, a more invasive treatment, is often the best option. In addition, if drugs are not effective or if people have certain dangerous rhythm disturbances, doctors may use invasive treatments such as direct current cardioversion or implantation of a combination pacemaker and defibrillator. The choice of procedure depends on the specific condition causing the disturbance.
Essentials for Older People
Older people are at particular risk of side effects due to antiarrhythmic drugs. Older people are likely to have several health problems and take several drugs, and these drug combinations may put them at risk of side effects. In older people, the kidneys are less effective at filtering drugs from the blood, which contributes to the risk of side effects. Some older people may even need a pacemaker before they can take antiarrhythmic drugs.
Key Points
Palpitations are common, and they have many causes that range from harmless to life-threatening.
People who have other symptoms such as light-headedness, chest pain or pressure, or shortness of breath may have a serious problem and should see a doctor quickly.
ECG, certain blood tests, and often other specialized cardiac tests are done.
Treatment depends on the cause.
