Although many episodes of a racing heart are associated with temporary triggers, some are caused by electrical disturbances within the heart.
These conditions are known as arrhythmias.
The heart normally follows an organized electrical pathway that coordinates contractions of its chambers.
When electrical signals develop abnormally or travel through an unusual pathway, the heartbeat may become too fast, too slow, or irregular.
Some arrhythmias are relatively harmless, while others can interfere with the heart's ability to pump blood effectively.
1. Supraventricular tachycardia
Supraventricular tachycardia, commonly called SVT, refers to a group of abnormal rhythms that originate above the heart's ventricles.
During an episode, the heart can suddenly begin beating very rapidly.
People with SVT may describe the sensation as an electrical switch being turned on and off.
Symptoms can include:
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Sudden rapid heartbeat.
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Strong palpitations.
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Dizziness.
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Shortness of breath.
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Chest discomfort.
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Weakness.
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Anxiety.
Some episodes last only a few minutes, while others may continue longer.
SVT can occur in people who otherwise appear healthy, including young adults.
Although many episodes are not immediately life-threatening, recurring symptoms should be evaluated.
An electrocardiogram may help identify the rhythm, particularly if it is recorded during an episode.
Treatment depends on the specific type of SVT, how often it occurs, and whether it causes significant symptoms.
Some patients benefit from medication, while others may be candidates for a procedure called catheter ablation.
2. Atrial fibrillation
Atrial fibrillation, often called AFib, is a common abnormal heart rhythm.
It occurs when the electrical activity in the upper chambers of the heart becomes disorganized.
Instead of contracting in a coordinated way, the atria quiver or beat irregularly.
This can cause an irregular and sometimes rapid heartbeat.
Possible symptoms include:
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A fluttering or racing sensation in the chest.
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Fatigue.
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Shortness of breath.
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Reduced exercise tolerance.
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Dizziness.
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Weakness.
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Chest discomfort.
Some people have no noticeable symptoms and discover the condition during a routine examination.
Atrial fibrillation is important because it can increase the risk of blood clots and stroke.
When the atria do not contract effectively, blood may collect in certain areas of the heart, increasing the possibility of clot formation.
A clot can travel to the brain and cause a stroke.
Treatment may involve medications to control heart rate or rhythm, and anticoagulants for people whose stroke risk warrants them.
The appropriate treatment depends on age, other medical conditions, symptoms, and individual risk factors.
3. Ventricular tachycardia
Ventricular tachycardia is a rapid heart rhythm that begins in the lower chambers of the heart.
It can be particularly dangerous because the ventricles are responsible for pumping blood to the lungs and the rest of the body.
When the ventricles beat too rapidly, they may not have enough time to fill properly between contractions.
This can reduce blood circulation and lead to dizziness, fainting, severe weakness, or cardiac arrest.
Ventricular tachycardia is more likely to occur in people with certain forms of heart disease, previous heart attacks, or structural abnormalities.
However, symptoms and risk vary depending on the specific condition.
A sustained episode requires emergency medical evaluation.
Sudden collapse, loss of consciousness, or a person who is unresponsive and not breathing normally should be treated as a medical emergency. Call emergency services and begin CPR if trained, using an automated external defibrillator if available.
4. Premature heartbeats
Some people experience extra heartbeats that originate earlier than expected.
These are called premature contractions.
Premature atrial contractions begin in the upper chambers, while premature ventricular contractions begin in the lower chambers.
They may feel like:
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A skipped heartbeat.
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A brief pause followed by a strong beat.
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A flutter in the chest.
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A sudden thump.
Occasional premature beats are common and may occur in people without significant heart disease.
They can become more noticeable after caffeine consumption, alcohol use, stress, poor sleep, or dehydration.
However, frequent premature beats or those accompanied by dizziness, fainting, chest pain, or shortness of breath should be assessed.
A doctor may recommend an ECG or ambulatory heart monitoring to determine how frequently they occur and whether treatment is needed.
5. Structural heart problems
Sometimes, an abnormal heartbeat is associated with an underlying structural problem.
Examples include certain heart valve disorders, cardiomyopathy, congenital heart conditions, and damage caused by previous heart attacks.
These conditions can affect the heart's ability to pump blood or disrupt its electrical system.
Possible symptoms include palpitations, fatigue, breathlessness, swelling in the legs, and reduced exercise tolerance.
An echocardiogram, which uses ultrasound to examine the heart, may help identify structural abnormalities.
A racing heartbeat alone does not prove that someone has heart disease. However, recurring symptoms combined with a history of cardiovascular problems deserve medical attention.
Why symptoms matter as much as heart rate
A heart rate of 110 beats per minute does not mean the same thing in every situation.
A person with a temporary increase caused by fever may have a different level of risk from someone experiencing a sudden, unexplained, irregular heartbeat accompanied by dizziness.
Doctors consider several factors:
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How quickly the heartbeat begins.
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Whether it starts and stops suddenly.
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Whether the rhythm feels regular or irregular.
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How long the episode lasts.
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Whether it occurs during sleep or physical activity.
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Whether chest pain, breathlessness, or faintness occurs.
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Whether the person has an existing heart condition.
This is why the pattern of symptoms can be more informative than a single pulse measurement.
CHAPTER 4: WARNING SIGNS YOU SHOULD NEVER IGNORE AND HOW DOCTORS INVESTIGATE THE PROBLEM
A racing heartbeat is not always an emergency, but certain accompanying symptoms may indicate that the heart is struggling to maintain adequate circulation.
Recognizing these warning signs is essential.
1. Chest pain or pressure
Chest discomfort occurring with a rapid heartbeat should be taken seriously.
Some people describe it as pressure, squeezing, heaviness, or tightness.
Pain may spread to the arm, shoulder, back, neck, or jaw.
Chest pain can have many causes, including muscle problems, digestive conditions, and anxiety. However, it may also indicate reduced blood flow to the heart or a heart attack.
If chest pain or pressure occurs with a racing heartbeat, especially if it is new, severe, or persistent, seek emergency medical attention.
Do not assume that it is simply stress or indigestion.
2. Shortness of breath
A fast heartbeat accompanied by difficulty breathing may indicate that the cardiovascular or respiratory system is under strain.
You may notice that you cannot take a full breath, feel unusually breathless while lying down, or struggle to perform activities that were previously easy.
Sudden or severe shortness of breath requires urgent medical evaluation.
If it occurs together with chest discomfort, faintness, or a racing heartbeat, treat the situation as an emergency.