Question: Which abnormal heart rhythms are more dangerous/less dangerous?
Answer :When we talk about arrhythmias, there are some that are very innocuous -- they really don't cause any harm at all. Very frequently in young people who drink a lot of Coca-Cola, or a lot of caffeinated products, they will have extra or skipped heart beats. And those are very minor and really cause no problems.
In older people the most common arrhythmia is a rhythm called atrial fibrillation. This is an erratic function of the heart that really isn't dangerous. It can produce a lot of symptoms. And again it needs further evaluation. It's really not life threatening.
We are mainly concerned about life threatening arrhythmias in people that have underlying heart disease -- the heart is not working normally either because they've had a previous heart attack or had muscle problems that cause weakening of the heart muscle. If the heart muscle is very weakened or very damaged from previous heart attacks, then these arrhythmias can become life threatening. And those are the ones we are most concerned about.