What is cardiac arrhythmia?

If you have a cardiac arrhythmia it means that you have an abnormal heart rhythm.

Normal heart rhythm

A normal heart rhythm ranges between 60-100 beats per minute. That means that your heart beats around 100,000 times a day!

Your heart rate is controlled by electrical impulses that coordinate your heart’s contractions. These electrical impulses begin at the sinoatrial node – also called the sinus node or SA node – and are usually steady and consistent.

The heart is made up of two upper chambers, called the atria, and two lower chambers, called the ventricles. When the atria contract, oxygen-rich blood flows into the ventricles. When the ventricles contract, blood is pumped out of the heart into the body.

Abnormal heart rhythm

Sometimes the flow of electrical impulses does not operate properly. The sinus node may send out signals too quickly, or it may send out too many signals.

In other cases, the signals may reverberate inside one of your heart's chambers instead of moving on in a regular pattern.

The result is a fast or irregular heartbeat. It can sometimes feel like a flutter. These abnormal rhythms are called arrhythmias or cardiac arrhythmias.

When your heart beats erratically, it does not pump blood as efficiently as it should. You may feel ill because oxygen isn’t being properly delivered to all parts of your body.

What is atrial fibrillation?

Atrial fibrillation is sometimes also referred to as atrial fib, Afib and AF. It is a relatively common condition in which the upper chambers of your heart, the atria, beat rapidly or in an uncontrolled manner.

This uncoordinated, fast heartbeat is what causes atrial fibrillation. It affects your blood flow, resulting in an irregular pulse and sometimes a fluttering feeling in your chest.

Atrial fibrillation is not life threatening in itself. But it is important that it is treated, not only to control the symptoms of atrial fibrillation but also because atrial fibrillation may be responsible for up to 20% of all strokes.

There are three main classifications of atrial fibrillation. These classifications are based on the frequency of your episodes and how quickly they end:

  • Paroxysmal (intermittent) atrial fibrillation – Atrial fibrillation that terminates spontaneously or with intervention within 7 d of onset. • Episodes may recur with variable frequency.
  • Persistent atrial fibrillation – Continuous Atrial fibrillation that is sustained >7 d.
  • Longstanding persistent atrial fibrillation – Continous Atrial fibrillation of >12 mo duration.
  • Permanent atrial fibrillation - Permanent Atrial fibrillation is used when there has been a joint decision by the patient and clinician to cease further attempts to restore and/or maintain sinus rhythm.
    • Acceptance of Atrial fibrillation represents a therapeutic attitude on the part of the patient and clinician rather than an inherent pathophysiological attribute of the Atrial fibrillation.
    • Acceptance of Atrial fibrillation may change as symptoms, the efficacy of therapeutic interventions, and patient and clinician preferences evolve.
  • Nonvalvular atrial fibrillation - Atrial fibrillation in the absence of rheumatic mitral stenosis, a mechanical or bioprosthetic heart valve, or mitral valve repair.

The good news is that advances in medicine have made it possible for your atrial fibrillation to be treated effectively. Your doctor can explain your treatment options to you.

If medications are not effective in controlling your atrial fibrillation, nonsurgical procedures, such as catheter ablation, have proven effective and can eliminate the cause of your atrial fibrillation. Learn more about catheter ablation »

What is atrial flutter?

Atrial flutter is an uncomfortable fluttering sensation in your chest. Atrial flutter occurs when a single electrical signal circulates rapidly in one of your heart's chambers.

When does atrial flutter occur?

Atrial flutter can occur if you have heart disease, heart attack or chest trauma. Although not life threatening, your atrial flutter needs to be controlled to prevent more serious types of arrhythmia, like atrial fibrillation, from developing.

How do you treat atrial flutter?

Cardiac ablation is one treatment for atrial flutter. An electrophysiologist, a cardiologist who specializes in the treatment of arrhythmias, performs this noninvasive procedure. Cardiac ablation has been extremely successful in helping patients find relief from their symptoms.

What is atrial tachycardia?

When your abnormal heartbeat creates a heart rate that is faster than normal, it is called tachycardia. (A bradycardia is a heartbeat that is slower than normal.)

Tachycardias have different names depending on the origin of the abnormal signal. Ventricular tachycardia starts in the ventricles, in the lower chambers of your heart. Atrial tachycardia starts in the upper chambers of your heart, above the ventricles.

What are the types of atrial tachycardia?

Supraventricular tachycardia (SVT), also referred to as atrial tachycardia, is a general name for arrhythmias that start above your ventricles. It is sometimes called paroxysmal supraventricular tachycardia (PSVT) because it occurs intermittently, or from time to time.

AV Nodal Re-entrant Tachycardia (AVNRT) is a type of abnormal rhythm that arises from malfunctioning of the atrial ventricular (AV) node.

When does atrial tachycardia occur?

SVTs usually begin and end suddenly. An episode can last anywhere from seconds to hours. SVT may cause your heart to beat 160–200 times per minute.

AVNRT confuses the electrical signals traveling from atria to ventricles. As a result, both your atria and ventricles beat at the same time instead of in sequence. This creates a fast heart rate, around 120–250 beats per minute. Although your resulting heartbeat is typically regular, rather than erratic, your heart is not pumping efficiently. Most AVNRT patients do not have underlying heart disease.

Is atrial tachycardia life threatening?

SVTs are generally not life threatening, unless you have an additional existing heart problem. Your symptoms can vary in severity, and more severe forms may require treatment with medications or catheter ablation.

Ventricular tachycardia

Ventricular tachycardia causes your ventricles to contract before they have had a chance to completely fill with blood, impairing blood flow to your body.

What causes ventricular tachycardia?

Ventricular tachycardia occurs in people with underlying heart abnormalities. If you have had a heart attack, for example, your scar tissue from the heart attack can cause irregular electrical pathways. These alternate pathways can create abnormal electrical conduction within your heart, causing ventricular tachycardia.

Is ventricular tachycardia dangerous?

Ventricular tachycardia is a serious disorder and requires prompt treatment. It poses a serious danger in that it may evolve into the more serious, life-threatening condition, ventricular fibrillation. This is a condition wherein the ventricles quiver, pumping very little blood out of your heart. Ventricular fibrillation is the primary cause of sudden cardiac death. Death can result if your normal heart rhythm is not restored within 3–5 minutes.

How do you treat ventricular tachycardia?

Regular treatment of ventricular tachycardia includes medications to slow your heart rate. High-risk patients are treated with an implantable cardioverter defibrillator (ICD). This device, inserted under the skin of your chest like a pacemaker, senses irregular rhythms and automatically shocks your heart back into normal rhythm.

Cardiac ablation is increasingly being used to interrupt the abnormal pathways that cause ventricular tachycardia. With current technology, a cardiologist that specializes in the treatment of arrhythmias can accurately locate the irregular pathway, thus enabling your physician to eliminate the abnormal signals causing your tachycardia.

What is Wolff-Parkinson-White syndrome?

Wolff-Parkinson-White (WPW) syndrome occurs when you have a second, or ancillary, pathway within your heart that conducts electrical signals between your atria and ventricles.

In this situation your electrical signals skip your AV node and instead use the extra pathway. Your signals reach your ventricles too soon and reverberate back to your atria, causing a very fast heartbeat.

What causes WPW?

Most cases of Wolff-Parkinson-White are hereditary or associated with congenital (present at birth) or acquired heart defects.

Is WPW life threatening?

Most people with WPW have no symptoms, but in some people, it can be extremely dangerous and even pose a serious risk for sudden death.

How do you treat WPW?

Cardiac ablation is a treatment option in cases where your WPW symptoms put you at risk of sudden death. Cardiac ablation can eliminate the symptoms of the disorder in most (85%–95%) cases, depending on the location of the ancillary pathway.

Questions
for your
doctor

Prepare for your next visit with these important questions.

View Checklist