Frequent ventricular ectopic beats are a very common phenomenon and utterly benign. They are, however, a source of great concern to many, many people who worry needlessly about it. Also, fleeting, severe, sharp twinges in the chest are very common and nothing to worry about either.
If this is what you are suffering from, then relax. Go and see a good doctor with a sensitive manner who can put your mind at rest.
David