An arrhythmia is any disorder of your heart rate or heart rhythm, such as beating too fast (tachycardia), too slow (bradycardia), or irregularly.
Normally, the 4 chambers of the heart (2 atria and 2 ventricles) contract in a very specific, coordinated manner.
The electrical impulse that signals your heart to contract in a synchronized manner begins in the sinoatrial node (SA node), which is your heart's natural pacemaker.
The signal leaves the SA node and travels through the 2 upper chambers (atria). Then the signal passes through another node (the AV node), and finally, through the lower chambers (ventricles). This path enables the chambers to contract in a coordinated fashion.
Problems can occur anywhere along this conduction system, causing various arrhythmias. Examples include:
The risks of getting a tachycardia or bradycardia varies greatly, depending on the condition of your heart, prior heart attack, blood chemistry imbalances, or endocrine abnormalities.
Arrhythmias may also be caused by some substances or drugs, including beta blockers, psychotropics, sympathomimetics, caffeine, amphetamines, and cocaine. Sometimes antiarrhythmic medications -- prescribed to treat one type of arrhythmia -- can actually cause another type of arrhythmia.
Some types of arrhythmias may be life-threatening if not promptly and properly treated.
The person may not have symptoms.
A doctor will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal.
The following tests may be performed to identify arrhythmias:
If an arrhythmia is detected, various tests may be done to confirm or rule out suspected causes. EPS testing may be performed to locate the origin of the arrhythmia and determine the best treatment, especially if a pacemaker implantation or catheter ablation procedure is being considered.
When an arrhythmia is serious, urgent treatment may be required to restore a normal rhythm. This may include intravenous medications, electrical "shock" therapy (defibrillation or cardioversion), or implanting a temporary pacemaker to interrupt the arrhythmia.
Supraventricular arrhythmias may be treated with anti-arrhythmic drugs. However, most supraventricular arrhythmias can be treated and cured with radiofrequency ablation, eliminating the need for lifelong drug therapy.
Increasingly, most ventricular tachycardias are treated with an implantable cardioverter-defibrillator (ICD). As soon as arrhythmia begins, the ICD sends a shock to terminate it, or a burst of pacing activity to override it.
Bradycardias that cause symptoms can be treated by implanting a permanent pacemaker.
The outcome is dependent on several factors:
With bradycardias treated with a permanent pacemaker, the outlook is usually good.
Call your provider if you develop any of the symptoms of a possible arrhythmia. Also call your provider if you have been diagnosed with an arrhythmia and your symptoms worsen or do not improve with treatment.
Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia. These steps include not smoking; eating a well-balanced, low-fat diet; and exercising regularly.