Heart arrhythmias—abnormal heart rhythms—affect millions of people worldwide. While some arrhythmias are harmless, others can be serious or even life-threatening. This guide will help you understand what arrhythmias are, how they affect your body, and when you should be concerned.
What Is an Arrhythmia?
An arrhythmia is any abnormality in your heart’s electrical system that causes it to beat too fast, too slow, or with an irregular pattern. To understand arrhythmias, it helps to first understand how your heart normally works.
The Heart’s Electrical System
Your heart has its own built-in electrical system that controls your heartbeat. This remarkable system:
- Generates electrical impulses that signal your heart muscles to contract
- Coordinates the timing of contractions between the upper chambers (atria) and lower chambers (ventricles)
- Adjusts your heart rate based on your body’s needs
The normal electrical pathway begins in the sinoatrial (SA) node‚Äîyour heart’s natural pacemaker‚Äîlocated in the right atrium. The impulse travels through the atria, causing them to contract and push blood into the ventricles. The impulse then reaches the atrioventricular (AV) node, which briefly delays the signal before sending it to the ventricles, causing them to contract and pump blood throughout your body.
When Things Go Wrong
Arrhythmias occur when there’s a problem with this electrical system. The issue might be:
- An electrical impulse that starts in the wrong place
- A blocked or delayed electrical pathway
- An electrical signal that travels along an abnormal pathway
- The natural pacemaker firing too quickly or too slowly
These electrical disturbances result in heartbeats that are too fast, too slow, or irregular, which can affect how efficiently your heart pumps blood.
Types of Arrhythmias
Arrhythmias are typically categorized based on:
- Where in the heart they originate (atria or ventricles)
- How they affect your heart rate (too fast or too slow)
- Whether they cause regular or irregular rhythms
The main categories include:
Tachycardias (Fast Heart Rhythms)
Tachycardias are arrhythmias that cause your heart to beat faster than normal (generally over 100 beats per minute at rest). These include:
- Atrial fibrillation (AFib): The most common serious arrhythmia, characterized by chaotic, irregular electrical signals in the atria, leading to an irregular and often rapid heart rate.
- Atrial flutter: Similar to AFib but with a more organized electrical pattern, typically causing a regular but rapid heart rate.
- Supraventricular tachycardia (SVT): A rapid heart rate that starts in the atria, often beginning and ending suddenly.
- Ventricular tachycardia (VT): A potentially serious rapid heart rhythm originating in the ventricles.
- Ventricular fibrillation (VFib): A life-threatening condition where the ventricles quiver instead of pumping, requiring immediate emergency treatment.
Bradycardias (Slow Heart Rhythms)
Bradycardias are arrhythmias that cause your heart to beat slower than normal (generally under 60 beats per minute). These include:
- Sinus bradycardia: A slow heart rhythm starting from the sinus node.
- Heart block: A delay or blockage of electrical impulses as they travel from the atria to the ventricles.
- Sick sinus syndrome: A condition where the heart’s natural pacemaker doesn’t function properly.
Premature (Extra) Beats
These are extra heartbeats that occur earlier than the next expected regular beat:
- Premature atrial contractions (PACs): Extra beats originating in the atria.
- Premature ventricular contractions (PVCs): Extra beats originating in the ventricles.
These premature beats are very common and often harmless, though they may feel like a skipped beat or heart “flip-flop.”
What Causes Arrhythmias?
Many factors can contribute to the development of arrhythmias:
Heart-Related Causes
- Coronary artery disease: Reduced blood flow to the heart can damage heart tissue and affect electrical pathways.
- Heart attack: Damage from a previous heart attack can disrupt normal electrical signals.
- Heart failure: A weakened heart can trigger arrhythmias.
- Heart valve problems: Valve disease can lead to enlargement of heart chambers and affect electrical conduction.
- Congenital heart defects: Some people are born with abnormalities in their heart’s structure or electrical system.
- Inflammation: Conditions like myocarditis (inflammation of the heart muscle) can trigger arrhythmias.
Non-Heart-Related Causes
- Electrolyte imbalances: Abnormal levels of potassium, sodium, calcium, or magnesium in your blood can affect heart rhythm.
- Thyroid problems: Both overactive and underactive thyroid can lead to arrhythmias.
- Sleep apnea: This sleep disorder has been linked to various arrhythmias, particularly atrial fibrillation.
- Diabetes: Can damage nerves that control heart rate.
- Medications: Certain prescription and over-the-counter medications can trigger arrhythmias in some people.
- Stimulants: Caffeine, nicotine, alcohol, and recreational drugs can affect heart rhythm.
- Stress and anxiety: Can trigger or worsen certain arrhythmias.
Symptoms of Arrhythmias
Arrhythmia symptoms vary widely. Some people experience no symptoms at all, while others may have severe symptoms that significantly impact their quality of life.
Common symptoms include:
- Palpitations: Feelings of a racing, pounding, fluttering, or “skipping” heartbeat
- Fatigue: Feeling unusually tired during normal activities
- Lightheadedness or dizziness: Due to reduced blood flow to the brain
- Shortness of breath: Especially during physical activity or when lying down
- Chest discomfort or pain: May feel like pressure, squeezing, or fullness
- Fainting (syncope): Complete loss of consciousness, usually brief
- Anxiety: Often triggered by awareness of heart rhythm abnormalities
More serious symptoms that require immediate medical attention include:
- Severe chest pain
- Severe shortness of breath
- Fainting or near-fainting
- Weakness or inability to exercise
- Confusion or difficulty thinking clearly
It’s important to note that the severity of symptoms doesn’t always correlate with the seriousness of the arrhythmia. Some potentially dangerous arrhythmias cause few or no symptoms, while some harmless arrhythmias can cause significant discomfort.
When to See a Doctor
You should consult a healthcare professional if:
- You experience any symptoms of arrhythmia, especially if they’re new or worsening
- You have risk factors for heart disease and are concerned about arrhythmias
- You’ve been diagnosed with an arrhythmia and notice changes in your symptoms
- You have a family history of serious arrhythmias or sudden cardiac death
Seek emergency medical attention if you experience:
- Chest pain lasting more than a few minutes
- Difficulty breathing
- Fainting or severe dizziness
- A very fast heartbeat (more than 120-150 beats per minute) accompanied by shortness of breath, chest pain, or dizziness
Risk Factors for Arrhythmias
Certain factors increase your risk of developing an arrhythmia:
- Age: The risk of arrhythmias increases as you get older
- Genetics: Family history of arrhythmias or conditions that cause arrhythmias
- Lifestyle factors: Smoking, excessive alcohol or caffeine consumption, drug use, high stress levels
- Existing heart conditions: Coronary artery disease, heart failure, congenital heart disease
- High blood pressure: Can lead to structural changes in the heart that promote arrhythmias
- Diabetes: Affects the heart’s electrical system and increases risk of coronary artery disease
- Sleep apnea: Associated with several types of arrhythmias
- Medications: Some prescription and over-the-counter medications can trigger arrhythmias
- Electrolyte imbalances: Often due to dehydration, kidney problems, or certain medications
Living with Arrhythmias
Many people with arrhythmias lead normal, active lives with proper management. Depending on the type and severity of your arrhythmia, management may include:
- Lifestyle modifications to reduce triggers
- Medications to control heart rate or rhythm
- Procedures to correct the arrhythmia
- Regular monitoring by healthcare professionals
In future posts, we’ll explore the different types of arrhythmias in more detail, discuss diagnosis and treatment options, and provide strategies for living well with arrhythmias.
Remember, understanding your condition is the first step toward managing it effectively. If you have concerns about your heart rhythm, don’t hesitate to speak with a healthcare provider.