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.
Arrhythmia â A variation in the normal rhythm of the heart beat. Atrial fibrillation and flutter are two types of arrhythmia. Atria â The two small upper chambers of the heart that receive blood from the lungs and the body.