During these episodes patients may feel abrupt onset heart fluttering or palpitations, where their heart beats at rates up to 120-250 times per minute. This kind of an arrhythmia can be serious if it arises in the ventricles of the heart. Fortunately, this site of origin is relatively uncommon and usually occurs in patients who have had a previous heart attack or other heart damage.
Many more patients have a rapid arrhythmia arising in the upper portion or atria of the heart.
In these individuals, the rhythm abnormality is usually benign, although it can be accompanied by symptoms such as palpitations, shortness of breath, chest tightness, fatigue, or even lightheadedness. Less commonly, a patient may actually pass out because of this kind of rhythm abnormality. Atrial flutter usually occurs because of changes in the atrial muscle, such as slowing of the conduction of electrical impulses through the atrium. This does not necessarily mean, however, that the patient has some other serious form of heart muscle disease. In atrial flutter, the abnormal heart rhythm originates completely within the atria.