What causes the heart to flutter?

Many causes: The feeling of heart fluttering (palpitations) actually may not be related to the heart at all. Palpitations that are related to the heart are usually due to aberrant electrical activity in the heart otherwise known as arrhythmias. There are multiple kinds of arrhythmias, the more common ones are not life-threatening, but need to be evaluated. A heart monitor (holter) is used for this purpose.

arrhythmias: Generally speaking, the heart fluttering sensation is a response to heartbeats occurring at a rate or time when the body is not expecting them. There are a number of explanations for this ranging from isolated extra heartbeats (pacs or pvcs) to sustained rhythms we call supraventricular tachycardias. A cardiologist or electrophysiologist can help you better evaluate this complaint.

Any arrhythimia: The heart can flutter with premature ventricular contractions ( pvc), premature atrial contractions (pac ), atrial fibrillatrion etc. Fluttering also known as palpitations is basically a symptom and further work up is needed.

Here are few: Hypertension, heart attacks, cardiomyopathy with chf, mitral valve disease, hypertrophic cardiac disease, hyperthyroidism, pulmonary embolus, severe copd/emphysema with pulmonary hypertension, Cocaine and amphetamine addiction, alcoholism, anorexia, congenital heart disease like wpw.