


The term arrhythmia is usually used to encompass a wide range of abnormal
heart rhythms (cardiac dysrhythmias).  Some of them are very serious
while others are completely benign.  Having "a few irregular beats"
on an EKG could be serious depending on what those beats were and
when they occurred, or could be of no significance.

Low blood potassium levels probably predispose people with underlying
heart disease to develop arrhythmias.  Very low potassium levels are
clearly dangerous, but it is not clear how much of a problem
low-end-of-normal levels are:  a lot of cardiologists seem to treat
anyone with even a mildly low-normal potassium level.
