A normal heart beats in a steady, even rhythm; about 60 to 100 times each minute (that’s about 100,000 times each day). Cardiac arrhythmias are disturbances in the normal rhythm of the heartbeat. An occasional palpitation or fluttering is usually not serious, but a persistent arrhythmia may be life threatening.
There are many different types of cardiac arrhythmias. The heart may beat too rapidly, known as atrial tachycardia, or too slowly, known as bradycardia, or it may beat irregularly. Atrial fibrillation and atrial flutter are common cardiac arrhythmias, which lead to an irregular and sometimes rapid heart rate.
These atrial arrhythmias may interfere with the heart’s ability to pump blood properly from its upper chambers (atria). The atria may not always empty completely, and blood remaining there too long may stagnate and potentially clot. Such clots may travel to other parts of the body, where they may cause blockages in the blood supply to the limbs, brain or heart.
In ventricular fibrillation, the lower chambers of the heart (ventricles) quiver feebly instead of contracting powerfully. This is the most severe type of arrhythmia, causing death in minutes unless medical assistance is obtained immediately.
When to Call an Ambulance
An arrhythmia may be “silent” and not cause any symptoms. A doctor can detect an irregular heartbeat during a physical exam by taking your pulse, listening to your heart or by performing diagnostic tests. If you do experience symptoms of cardiac arrhythmia, they may include:
There are many causes for arrhythmias, however a fast or slow heart rate does not always mean your heart rhythm is abnormal. Your heart rate is also related to anxiety, activity, medications or other normal causes. Arrhythmias can be caused by:
Risk increases with smoking, excess consumption of caffeine or alcohol, advancing age, high blood pressure, kidney disease and stress.
You can help reduce your risk for arrhythmia by engaging in regular aerobic exercise, and by avoiding cigarettes, illegal drugs and excessive amounts of alcohol and caffeine. You should also be aware that emotional stress can sometimes cause irregularities with your heartbeat. If you are taking prescription medication, it is important that you carefully follow instructions and be aware of possible side effects.
Physicians at Johns Hopkins have been leaders in the field of electrophysiology — the study of the heart’s electrical activity — since the early 1970s. Dr. Hugh Calkins has been director of the Arrhythmia Service since 1992.
Evaluation for an abnormal heart rhythm begins with an examination by one of our physicians at our Outpatient Center (satellite facility) at Green Spring Station. Your doctor may recommend one or more tests to diagnose the arrhythmia and determine if it is causing your symptoms. Exercise treadmill tests and electrocardiograms are performed at the outpatient locations. The others are done in the electrophysiology laboratory located in the hospital’s Cardiovascular Diagnostic Laboratory.
The electrophysiology lab provides state-of-the-art biplane fluoroscopy equipment that facilitates complex catheter ablation procedures and reduces the amount of X-ray exposure that patients receive. The doctor routinely checks in with the patient before the procedure to answer any questions.
Based on your diagnostic exam and test results, the doctor will work with you on a treatment plan that may include one or more of the following options:
Treatment is also likely to include possible prevention-based lifestyle changes that can help reduce your risk. Your family may also want to learn to recognize your symptoms so that cardiopulmonary resuscitation (or CPR) can be applied in an emergency situation.
Content Resource: http://www.hopkinsmedicine.org/heart_vascular_institute/conditions_treatments/conditions/arryhthmias.html