Flutter: Flutter is a rapid vibration or pulsation. The difference between flutter and fibrillation is that flutter is well organized while fibrillation is not.
For example, atrial flutter consists of well-organized but over-rapid contractions of the atrium of the heart (usually at a rate of 250-350 contractions per minute). Atrial flutter is a serious and potentially unstable cardiac rhythm.
Quick GuideHeart Disease: Causes of a Heart Attack
Subscribe to MedicineNet's Heart Health Newsletter
Healthy Heart Resources
Last Editorial Review: 6/9/2016