RESUMO
Normokalemic periodic paralysis is an autosomal dominant disorder involving the abnormal function of skeletal muscle's voltage-gated alpha-subunits. It is characterized by paralysis attack of varying severity with concomitant normal serum potassium concentration. Although normokalemic periodic is well established in the literature, but its cardiac manifestations are very rare. We present 21 years old age male, which referred to Imam Ali hospital with severe palpitation, atypical angina and flaccid quadric paralysis. Electrocardiographic manifestation was first-degree AV block. Bijeminated ventricular extrasystole and severe ST-T change in pericardial leads. Initial potassium level was 4 meq/l, CPK and aldolase level was normal. Echocardiography and exercise test were normal. After four days administration of acetazolamide, his weakness was disappeared and ECG became normal. He discharged from hospital with normal neurological examination and effective treatment outcome