Yes. But there is usually a cause for this happening. It depends on what age you are if it is really serious or just needs watching. My heart started doing this when I was a 7-8 years old, it progressively became worse as I aged. It has several causes, mine was inherited, another cause is being too athelic, and others, It is commonly referred to as Sudden Cardiac Death. I am now 64 and had a pacemaker-defibrillator implanted 16 days ago. you should have a Cardiologist check it out. It may be nothing to worry about, but yet it may be serious