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.
Startled? If you wake up to an alarm clock, the noise may send stress chemicals in your body such as adrenaline. This could lead to palpitations right when you wake up. It would be helpful to have your doctor listen to your heart and possibly use a heart monitor to see what the heart is doing when you wake up. In the meantime, avoid caffeine, sleep deprivation and alcohol which can worsen palpitations. Read more...