Fig. 2
Improvement in cardiac function after extensive septal myectomy. The numbers of patients in NYHA Class I-II and NYHA Class III-IV were calculated before surgery, 2.5 years and 5 years after surgery, respectively. χ2 test was performed to analyze the differences among groups. There was significant difference in preoperative and postoperative cardiac function (P < 0.05). There was no difference in cardiac functions between 2.5 years after surgery and 5 years after surgery (P > 0.05). n = 59 for NYHA Class I-II and n = 80 for NYHA Class III-IV before surgery; n = 110 for NYHA Class I-II and n = 25 for NYHA Class III-IV at 2.5 years after surgery; n = 117 for NYHA Class I-II and n = 15 for NYHA Class III-IVat 5 years after surgery