Home Faculty and Staff Hospitals and Offices Education / Fellowships Make an Appointment
Keck School of Medicine of USC - University of Southern California
Department of Surgery
Department links
Home Physicians Locations Education Society of Graduate Surgeons Contact Us Divisions and Institutes
CardioVascular Thoracic Institute
image map
Areas of Expertise Diseases & Treatments Clinical Trials Research News & Articles Videos Web Links
Patient Guides & Programs Visitor's Guide Forms & Downloads About CVTI Make a Gift Contact Us

Glossary of Terms


The heart beats or pumps at a certain speed and in a certain way, depending on the needs of the patient's body. When the heart is pumping normally, the heart is said to be in a normal (sinus) rhythm. Any deviation from a normal rhythm is defined as an arrhythmia, where the heart is beating too fast, too slow, beating irregularly or a combination of these abnormal rhythms. Arrhythmias are generally divided between atrial arrhythmias such as atrial fibrillation and ventricular arrhythmias. Most arrhythmias can be treated with medications, but some require surgery. While most arrhythmias are not life-threatening, some, such as ventricular fibrillation, are fatal if not treated quickly. Arrhythmias can be secondary to many causes, such as heart attack, medications, and electrolyte imbalances.

Related terms: Bradycardia, Tachycardia

Share this page:
Call us for an Appointment at (323) 442-5849
Patient Guides & Programs
Department of Surgery Home Divisions Physicians Locations Contact Us Education Society of Graduate Surgeons Keck School of Medicine of USC University of Southern California