My heart starts pounding occasionally even when I am at rest, what could it be?

My heart starts pounding occasionally even when I am at rest, what could it be?

It could be simply that you are becoming anxious at that time or having a panic attack, both of which are not heart diseases. But sometimes it could also be due to an abnormal rhythm of the heart or cardiac arrhythmia. Many common arrhythmias like ventricular premature beats or premature beats originating from the lower chambers of the heart rather than from the sinus node situated in the right upper chamber of the heart, may not be harmful if they occur occasionally. Some rare forms of abnormal heart rhythms like a ventricular tachycardia, a fast rhythm originating from the lower chambers of the heart could be dangerous. An ECG recorded during the episode will often clarify the correct reason.