患者男性，２４岁。发现阵发性心悸１０余年，发作呈突发突止，心动过速时ＥＫＧ示ＱＲＳ波宽大畸形，每次发作数分钟至数小时。近几年患者发作频繁且伴有晕厥症状，长期服用抗心律失常药。体格检查：心浊音界扩大，胸骨左缘３～４肋间可闻及ＳＭⅡ～Ⅲ级杂音，Ｐ２音亢进，胸 Male patient, 24 years old. Found that more than 10 years of paroxysmal palpitations, sudden onset of sudden onset, tachycardia QRS wave EKG showed large deformity, each attack a few minutes to several hours. In recent years, patients with seizures frequently accompanied by symptoms of syncope, long-term use of anti-arrhythmic drugs. Physical examination: the expansion of the heart dullness, the left sternal border intercostal 3 ~ 4 can be heard and SM Ⅱ ~ Ⅲ level murmurs, P2 tone hyperthyroidism, chest