An abnormal heartbeat, also called an arrhythmia, is a condition where the heart beats in an irregular rhythm. This happens when the electrical signals that control the heartbeat do not work normally.
Because of this, the heart may beat:
-
Too fast (tachycardia)
-
Too slow (bradycardia)
-
Too early (premature beat)
-
Very irregular or shaky (fibrillation)
About 1.5% to 5% of people experience some type of arrhythmia.
Some arrhythmias are harmless, while others can be dangerous if they affect the flow of blood to vital organs like the:
-
Brain
-
Lungs
-
Heart
-
Kidneys
If not treated, a severe arrhythmia can be life-threatening.
Table of Contents
Arrhythmia vs. Dysrhythmia
The words arrhythmia and dysrhythmia are often used to mean the same thing: an irregular heartbeat.
In medical terms, there is a slight difference, but in normal use, they are used interchangeably.
Types of Arrhythmias
Arrhythmias are classified based on:
-
Heart rate speed – slow or fast
-
Where they start – in the atria (upper chambers) or ventricles (lower chambers)
-
Whether the rhythm is regular or irregular
Normally, the heart follows a smooth electrical pathway.
When this pathway is interrupted, the heartbeat becomes irregular.
1. Bradycardia (Slow Heartbeat)
Bradycardia is when the heart beats less than 60 times per minute.
Possible causes:
-
Heart block
-
Problems with the sinus node
-
Congenital heart disease
-
Sleep apnea
Bradycardia may cause weakness, dizziness, or fainting because the heart is not pumping enough oxygen-rich blood.
2. Tachycardia (Fast Heartbeat)
Tachycardia is when the heart beats over 100 times per minute.
If it lasts only a few minutes, it may be harmless.
If it lasts more than 30 minutes, especially with chest pain or shortness of breath, it needs emergency care.
3. Ventricular Arrhythmias
These start in the ventricles (lower chambers).
Some can be life-threatening.
Common types:
-
Ventricular Tachycardia (VT) – fast heartbeat from the ventricles
-
Ventricular Fibrillation (VF) – rapid and chaotic heartbeat that stops blood flow (medical emergency)
-
Premature Ventricular Contractions (PVCs) – extra early beats
Ventricular Fibrillation is very dangerous
It can cause sudden cardiac arrest if not treated immediately.
4. Supraventricular (Atrial) Arrhythmias
These start in the atria (upper chambers).
Examples include:
-
Atrial Fibrillation (AF) – fast, irregular beating
-
Atrial Flutter – fast but more regular pattern
-
Supraventricular Tachycardia (SVT) – sudden episodes of fast heartbeat
Atrial Fibrillation
-
Can reach up to 400 beats per minute
-
Increases stroke risk
-
Common in people over age 65
5. Premature Heartbeats
These feel like the heart “skipped a beat.”
They are usually harmless, but if frequent, they may need evaluation.
Symptoms of an Arrhythmia
Some people do not feel anything.
Others may notice:
-
Heart fluttering or pounding
-
Slow or fast heartbeat
-
Chest discomfort
-
Dizziness or lightheadedness
-
Weakness or fatigue
-
Shortness of breath
-
Fainting
Seek emergency help if there is:
-
Chest pain
-
Trouble breathing
-
Sudden collapse
Causes of Arrhythmia
Arrhythmias may be caused by:
Medical conditions
-
High blood pressure
-
Diabetes
-
Thyroid problems
-
Electrolyte imbalance (low potassium, magnesium, calcium)
-
Heart disease or heart attack
-
Sleep apnea
Lifestyle and triggers
-
Stress or anxiety
-
Caffeine
-
Alcohol
-
Smoking
-
Recreational drugs (like cocaine or amphetamines)
Medications
Some medicines for asthma, depression, allergies, or colds can also trigger arrhythmias.
Risk Factors
You are more likely to develop an arrhythmia if you:
-
Are older
-
Have heart disease
-
Have high blood pressure
-
Have diabetes
-
Smoke or drink alcohol frequently
-
Take stimulant medications
-
Have a family history of arrhythmia
Diagnosis
Doctors may use:
-
Electrocardiogram (ECG) – main test to measure heart rhythm
-
Holter Monitor – wearable device that records heartbeat for 24–48 hours
-
Echocardiogram – ultrasound of the heart
-
Stress Test – evaluates heart under exercise
-
Blood tests – check electrolytes and thyroid levels
Prevention and Lifestyle Care
To help prevent arrhythmias:
-
Reduce stress
-
Limit caffeine and alcohol
-
Stop smoking
-
Exercise regularly
-
Maintain a healthy weight
-
Eat a heart-friendly diet (low salt, low fat)
-
Manage blood pressure and cholesterol
Always consult your doctor before taking new medication or supplements.
Home and Complementary Support
Some supportive practices may help:
-
Yoga – may reduce heart rate and stress
-
Meditation – helps calm the nervous system
-
Magnesium-rich foods – support heart rhythm
(Only take supplements after asking a doctor.)
Bottom Line
Arrhythmias are common, and many are not serious.
But some can be dangerous and require treatment.
If you feel constant palpitations, chest pain, dizziness, or fainting, seek medical attention immediately.
Understanding your condition and managing risk factors can help protect your heart health.