The atrioventricular node reentrant tachycardia[AVNRT] is a common type of supraventricular tachycardias. Recently we experienced two cases of AVNRT. One is AVNRT with severe aortic regurgitation[grade IV] and the other is AVNRT with patent ductus arteriosus. Dissection of perinodal tissue has been successfully carried out in the beating heart under the normothermic cardiopulmonary bypass, and aortic valve replacement and ligation of patent ductus arteriosus were also performed, respectively. Postoperatively, permanent atrioventricular block was not occured and AVNRT was not developed during the follow up. We propose that the surgical dissection of perinodal tissue is a simple and effective treatment for the patient with refractory AVNRT.