What is a Heart Arrhythmia?

What is a Heart Arrhythmia?

A heart arrhythmia is an irregular heartbeat. Arrhythmias occur when the electrical signals in the heart are abnormal, causing the heart to beat too quickly or slowly or have an irregular rhythm. Certain medications and lifestyle choices can put someone at a higher risk of developing arrhythmias. Their symptoms can be bothersome and uncomfortable and typically feel like the heart is racing, fluttering, or skipping beats, resulting in lightheadedness or syncope.

While many arrhythmias are harmless, some can be serious and even life-threatening in certain cases. People whose arrhythmias are accompanied by chest pain, difficulty breathing, fainting, or prolonged heart palpitations should seek immediate medical attention.

Types of Heart Arrhythmias


There are two types of arrhythmias, each having a different effect on heart rate.

  • Tachycardia is an arrhythmia in which the heart beats too quickly. A faster heart rate means that blood may not fill the heart's chambers between beats, which can impair blood flow to other body parts. Tachycardia is often caused by misfiring and interfering electrical signals between different heart parts.
  • Bradycardia is an arrhythmia in which the heart beats too slowly. Bradycardia is more common in older adults and can be caused by certain medications, damage to the heart from a heart attack or heart disease, and malfunctioning electrical impulses in the heart. Frequently, bradycardia is considered normal. For example, athletes and physically active adults often have a resting heart rate lower than 60 bpm due to physical conditioning, and it can be normal to have bradycardia while sleeping.

Stages of Heart Arrhythmias


Heart arrhythmias are often categorized into four groups:

  • Extra beats (ectopy). The extra beats disrupt normal heart rhythm, causing sensations of fluttering in the heart or skipped beats. Extra beats are usually harmless, though you should consult a doctor if they occur frequently or are highly symptomatic, as this may indicate an underlying heart condition.
  • Supraventricular tachycardias are fast heart rates that affect the heart's upper chambers, known as the atria. When the heart beats too quickly, it cannot properly pump blood around the body. While supraventricular tachycardias are usually not life-threatening, there is a very small chance they cause fainting or cardiac arrest.
  • Ventricular arrhythmia are irregular heart rhythms that affect the lower chambers of the heart, known as ventricles. Ventricular arrhythmias can cause the ventricles to beat abnormally fast, produce extra beats, or twitch rather than contract and relax fully. The ventricles are crucial in pushing blood out of the heart to other parts of the body, so they can have serious effects on the body when they function abnormally.
  • Bradyarrhythmias, occur when the heart rate is abnormally slow and has an irregular rhythm. Sometimes, bradyarrhythmias produce no symptoms. However, since they can reduce the amount of blood flow to the brain and other body parts, they can lead to fainting, dizziness, shortness of breath, or other symptoms.

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Signs & Symptoms of Heart Arrhythmias


Heart arrhythmias sometimes do not cause any signs or symptoms. Heart arrhythmia symptoms may go unnoticed until a doctor detects an irregular heart rhythm when performing a physical examination for another health reason.

If arrhythmia symptoms do occur, they can include:

  • Heart palpitations
  • Racing heartbeat
  • Slowed heartbeat
  • Shortness of breath
  • Chest discomfort or pain
  • Fatigue
  • Sweating
  • Anxiety
  • Dizziness or lightheadedness
  • Fainting or nearly losing consciousness

Seek immediate medical attention if your symptoms include shortness of breath, dizziness or lightheadedness, fainting, or chest discomfort and pain.

What Causes Heart Arrhythmias?


The heart is made up of four chambers. The two upper chambers are called atria, and the two lower chambers are called ventricles. When blood first enters the heart, it flows into the atria and then into the ventricle. Valves in the heart open and close to regulate blood flow between the chambers.

The sinus node in the upper right chamber controls your heart's rhythm. The body's natural pacemaker is responsible for sending an electrical signal to the atria, causing the heart muscle to contract and pump blood into the ventricles. This signal is controlled at the AV (atrioventricular) node, which gives the ventricles time to fill with blood before contracting and pumping blood to the rest of the body.

Arrhythmias, or irregular heartbeats, are caused when the electrical signals that regulate the rhythm of your heartbeat are created abnormally or do not transmit properly. This can be caused by a variety of factors, including:

  • Heart attack
  • Damage or scarring from previous heart attacks
  • Coronary artery disease
  • Cardiomyopathy
  • Changes to the heart's structure
  • High blood pressure
  • Valve disorders
  • Electrolyte imbalance
  • Hyperthyroidism (overactive thyroid gland)
  • Hypothyroidism (underactive thyroid gland)
  • Healing and recovery from previous heart surgery
  • Sleep apnea
  • Genetic conditions
  • Consumption of too much alcohol or caffeine
  • Diabetes
  • Infection with COVID-19
  • Drug abuse
  • Smoking
  • Anxiety or stress

Risk Factors

Risk Factors

Several risk factors can increase the risk of heart arrhythmias. These include:

  • Coronary artery disease
  • Heart attack
  • Abnormal heart valves
  • Heart failure
  • Cardiomyopathy
  • Narrowed heart arteries
  • Previous heart surgery
  • High blood pressure
  • Congenital heart disease
  • Thyroid disease
  • Obstructive sleep apnea
  • Electrolyte imbalance
  • Certain prescription and over-the-counter drugs
  • Certain nutritional supplements
  • Excessive alcohol consumption
  • Caffeine
  • Nicotine
  • Illegal drug use



Arrhythmias can cause various health complications such as dizziness, lightheadedness, or fainting. In severe cases, they can also cause heart failure and cardiac arrest. If an arrhythmia causes stagnant blood, it can increase the risk of blood clots. This can result in a stroke. Arrhythmias are the most common cause of sudden cardiac death (SCD). When the electrical signals in the heart are severely misfiring, and the heart cannot pump blood, this can result in death within minutes without treatment.



Certain lifestyle choices can reduce the risk of heart disease and help prevent arrhythmias. Many of these preventative measures involve fundamental decisions related to maintaining overall health. Arrhythmia prevention methods include:

  • Maintain a heart-healthy diet. Avoid saturated and trans fats, and instead eat fruit, vegetables, and lean proteins
  • Maintain a healthy weight
  • Engage in regular physical activity
  • Limit caffeine
  • Limit alcohol consumption
  • Avoid or quit smoking
  • Manage stress
  • Use medication as directed, ensure you take the correct dosages, and inform your doctor of all medications you take, including prescriptions and over-the-counter medicines
  • Participate in routine checkups and r screenings for arrhythmias and cardiac conditions
Get Care

Trust NewYork-Presbyterian for Heart Arrhythmia Care

NewYork-Presbyterian's team of dedicated healthcare specialists is knowledgeable in treating individuals experiencing heart arrhythmias. Our team also offers a wide range of cardiovascular care services for various heart conditions, including advanced heart disease, aortic disease, cardiac amyloidosis, cardiac sarcoidosis, coronary artery disease, congenital heart disease, pulmonary hypertension, valvular heart disease, and more.