Symptoms of Cardiac Arrhythmias

Cardiac arrhythmias can produce a range of symptoms—from very mild, like lightheadedness, to life-threatening, including cardiac arrest.

These can be divided into a “classic” group of symptoms that are highly (though not exclusively) indicative of cardiac arrhythmia and an “other” group of symptoms that are just as likely to be caused by an arrhythmia as something else.

But many times, much to patients' surprise, cardiac arrhythmias may not produce any symptoms at all. This is especially true for arrhythmias that produce intermittent “extra” heartbeats—namely, premature atrial complexes (PACs) and premature ventricular complexes (PVCs).

arrhythmia symptoms
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Classic Symptoms

When a patient presents with classic symptoms, a healthcare provider should look specifically for a cardiac arrhythmia as the cause.

These classic symptoms include:

  • Palpitations
  • Lightheadedness
  • Syncope
  • Cardiac arrest

While there could be another cause to blame, arrhythmia is likely.


Palpitations are an unusual awareness of the heartbeat. They are commonly experienced as disturbing skips or pauses, intermittent heartbeats that feel too strong or pounding, episodes of rapid or “runaway” heartbeats, or heartbeats that are perceived to be irregular instead of steady.

Palpitations affect different people in different ways. Some people don’t find them particularly bothersome, while others find them extremely distressing and frightening.

Almost any cardiac arrhythmia can produce palpitations, including the many types of bradycardia (slow heart rate) and tachycardia (rapid heart rate), PACs and PVCs, and episodes of heart block.


If a cardiac arrhythmia is preventing the heart from pumping blood sufficiently to provide the body’s needs, episodes of lightheadedness may result.

When an arrhythmia is producing lightheadedness, it is more likely to do so when you are upright, or when you are doing something active. Resting or lying down tends to improve this symptom.

Lightheadedness is a common symptom that has many potential causes. But when an arrhythmia produces lightheadedness, it is a sign that the arrhythmia itself may be dangerous.

Because lightheadedness may be a sign of a potentially dangerous problem like syncope or cardiac arrest, this is a symptom that should always be evaluated by a healthcare provider.


Syncope, or transient loss of consciousness, is a fairly common problem that (like lightheadedness) has numerous potential causes, many of which are pretty benign.

But when syncope is caused by a cardiac arrhythmia, that’s a good sign that the arrhythmia itself is quite dangerous. It usually means that the arrhythmia is preventing the brain from receiving enough oxygen to maintain consciousness.

Episodes of syncope can result from either bradycardia (if the heart rate is slow enough) or tachycardia (if the heart rate is fast enough).

For this reason, an episode of unexplained syncope always requires a full medical evaluation to pinpoint the underlying cause.

Any arrhythmia that has caused syncope should be considered potentially life-threatening and should be treated aggressively.

Cardiac Arrest

cardiac arrest occurs when the heart stops beating. Although there may be other causes for this, the main consideration is the function of the electrical activity of the heart and the heart's rhythm.

While severe bradycardia may cause a cardiac arrest, most often this condition is produced by ventricular fibrillation or ventricular tachycardia.

Cardiac arrest invariably leads to rapid death (and is the main cause of sudden death) unless either the arrhythmia terminates by itself or effective cardiopulmonary resuscitation is administered within a very few minutes.

Anyone who has survived a cardiac arrest should be considered to be at high risk for subsequent episodes of cardiac arrest and should receive aggressive and effective therapy.

Most of these people will be strong candidates for an implantable defibrillator.

Cardiac system without and with arrhythmia.

Other Symptoms

In addition to these classic symptoms, cardiac arrhythmias may also produce several less specific symptoms that may not necessarily point a healthcare provider toward considering an arrhythmia as the cause.

Most of these “other” symptoms are related to an arrhythmia causing a relative reduction in the ability of the heart to pump blood to the body’s organs.

These symptoms are more likely to occur when a person is upright or exerting themself and in people who have other medical conditions in addition to the arrhythmia, such as heart failure, diabetes, lung problems, or coronary artery disease.

These symptoms include:

  • Fatigue
  • Dyspnea (shortness of breath)
  • Poor exercise tolerance
  • Generalized weakness
  • Confusion
  • Chest pain

When to See a Healthcare Provider

Any of these symptoms should prompt a visit to the healthcare provider. An episode of severe lightheadedness or unexplained syncope should be evaluated immediately and warrants a call to 911. 

Arrhythmia Healthcare Provider Discussion Guide

Get our printable guide for your next healthcare provider's appointment to help you ask the right questions.

Doctor Discussion Guide Old Man

While many cardiac arrhythmias are fairly common and usually benign, others are dangerous and need to be treated. This means it is important for your healthcare provider to identify whether an arrhythmia is producing your symptoms, and if so, which specific arrhythmia is causing the problem and how aggressive it should be treated.

Frequently Asked Questions

  • What does it feel like to have a cardiac arrhythmia?

    An arrhythmia may be barely noticeable—like a skipped heartbeat that happens only occasionally. It may also feel like a fluttering in your chest. Because an arrhythmia prevents the heart from effectively pumping blood to the body and brain, it can also cause shortness of breath, feelings of light-headedness or faintness, or even, in the most serious cases, loss of consciousness or death.

  • Does a cardiac arrhythmia always produce symptoms?

    No. In fact, sometimes you may not even know you have an arrhythmia. This is why it’s important to get regular health checkups, especially if you have risk factors for an arrhythmia or other forms of heart disease.

  • Are palpitations the same as an arrhythmia?

    No. Palpitations are a symptom that may be caused by an underlying arrhythmia, or they can be caused by stress or other factors. They can occur in healthy people and may not always indicate a more serious condition.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation. Journal of the American College of Cardiology. 2014;64(21):e1-e76. doi:10.1016/j.jacc.2014.03.022

  3. Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Circulation. 2018;138(13). doi:10.1161/CIR.0000000000000549

  4. Wexler RK, Pleister A, Raman SV. Palpitations: evaluation in the primary care setting. AFP. 2017;96(12):784-789.

  5. Kerber KA, Baloh RW. The evaluation of a patient with dizziness. Neurol Clin Pract. 2011;1(1):24-33. doi:10.1212/CPJ.0b013e31823d07b6

  6. Runser LA, Gauer R, Houser A. Syncope: evaluation and differential diagnosis. AFP. 2017;95(5):303-312.

  7. Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia. Circulation. 2016;133(14):e506-e574. doi:10.1161/CIR.0000000000000311

  8. American Heart Association. Arrhythmia tools and resources.

By Richard N. Fogoros, MD
Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology.