Zipcodes in Twentynine Palms, CA (San Bernardino County) Cities in San Bernardino County, CA. * Not found in the U.S. Census 2000 data. Location may not be an incorporated place or boundary may be approximate.
About Arrhythmia. An arrhythmia is an abnormal heart rhythm. Learn about the heart's structure and why abnormal heart rhythms may cause problems. Read more.
An arrhythmia describes an irregular heartbeat - the heart may beat too fast (tachycardia), too slowly (bradycardia), too early (premature contraction), or irregularly (fibrillation). Arrhythmias occur when the electrical signals to the heart that coordinate heartbeats are not working properly. Many heart arrhythmias are harmless.