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.
Types of Arrhythmia. There are many types of arrhythmias. Arrhythmias are identified by where they occur in the heart (in the atria or ventricles) and by what happens to the heart's rhythm when they occur. Arrhythmias that begin in the atria are called atrial or supraventricular (above the ventricles) arrhythmias. Ventricular arrhythmias begin in the ventricles. In general, ventricular arrhythmias caused by heart disease are the most serious. Premature beats are the most common type of heart arrhythmia.