A Member of the University of Maryland Medical System | In Partnership with the University of Maryland School of Medicine

Maryland Heart Center

Patient Conditions

UMMC's Heart and Heart Surgery Program ranked as one of the nation's 50 best by U.S. News & World Report's 2011 "Best Hospitals" survey.

Read how Maryland Heart Center cardiologists are treating ventricular tachycardia by using new imaging techniques.

Arrhythmias

Ask the Expert

Get answers to your Arrhythmia questions.

Dr. Shorofsky’s Bio | Q&A Archive

Note: This is for informational purposes only. Doctors cannot provide a diagnosis or individual treatment advice via e-mail. Please consult your physician about your specific health care concerns.

Related Content

Arrhythmias are abnormal heart rhythms, which cause the heart to beat too fast (tachycardia) or too slow (bradycardia) and to pump blood less effectively.

Arrhythmias are very common, affecting millions of people worldwide. They are the main cause of sudden cardiac death in the United States, accounting for more than 400,000 deaths each year.

Arrhythmias are caused by either a disruption of the normal electrical conduction system of the heart, or heart disease.

Normally, the four chambers of the heart (two atria and two ventricles) contract in a very coordinated manner:

The signal for the heart to contract in a synchronized manner is an electrical impulse that begins in the "sinoatrial node" (also called the SA node), which is the body's natural pacemaker.
The signal leaves the sinoatrial node and travels through the two atria, stimulating them to contract. Then, the signal passes through another node (the AV node), and finally travels to the ventricles and stimulates them to contract in synchrony.

Problems can occur anywhere along the conduction system, causing various arrhythmias. There can also be a problem in the heart muscle itself, causing it to respond differently to the signal, or causing the ventricles to contract in an uncoordinated manner.

An arrhythmia occurs when:

the heart's natural pacemaker develops an abnormal rate or rhythm
the normal conduction pathway is interrupted
another part of the heart takes over as pacemaker
disease in the heart muscle allows electricity to travel in a circuit generating a rapid and often dangerous heart rhythm

Intrinsic conduction system of the heart

Please call if you would like to make an appointment or talk to someone about our services. Patients dial 1-800-492-5538 or 410-328-5842, physicians dial 410-328-6622 or 1-800-318-1019.

Connect with UMMC

© 2011 University of Maryland Medical Center (UMMC). All rights reserved. UMMC is a member of the University of Maryland Medical System, 22 S. Greene Street, Baltimore, MD 21201. 1.800.492.5538 TDD: 1.800.735.2258
Physician Referral: 1.800.373.4111