A 36 year old female recurrent chest pain and palpitation varying in duration and severity and 6-7 ectopics per minute (Possibly supraventrigation is) not related to exertion. Her BP is 86 mm Hg and pulse rate is 86/min. The ideal investigation is
Echocardiography
Electrophysiological studies
Thallium study
Technetium pyrophosphate