β-受体阻滞剂对主动脉瓣置换术后心室内压力阶差的影响

Effects of β-receptor Blocker on Intraventricular Pressure Gradient after Aortic Valve Replacement

目的探讨β-受体阻滞剂对主动脉瓣重度狭窄行主动脉瓣置换术患者心室内压力阶差及其左心室重塑的影响。方法选取郑州大学第一附属医院2008年1月至2010年1月因单纯主动脉瓣重度狭窄行主动脉瓣置换术患者56例,将术后得到随访的32例患者在相同基础临床特征下分为两组,试验组：12例,常规口服β-受体阻滞剂（倍他乐克6.25-25.00 mg/次,2次/天）;对照组：20例,未服用β-受体阻滞剂。在术后早期（1周内）、晚期（6-24个月）复查超声心动图,对两组患者随访的超声心动图指标进行比较。结果两组患者术后晚期随访无死亡,胸闷、气促等症状均明显改善。两组患者术后晚期左心室收缩期末内径（LVESD）、左心室流出道内径（LVOTD）较术后早期均有增加,仅试验组LVOTD与术后早期比较差异有统计学意义（t=-47.937,P=0.001）;两组患者术后晚期室间隔厚度（IVS）、左心室后壁厚度（LVPWT）、左心室流出道射流速度（V）、心室压力阶差（G）、左心室心肌重量指数（LVMI）均较术后早期有所减小,以上指标试验组术后晚期与术后早期结果比较差异均有统计学意义（t=7.781,P=0.001;t=5.749,P=0.001;t=2.637,P=0.023;t=7.167,P=0.001;t=100.061,P=0.001）,而对照组仅V、G和LVMI差异有统计学意义（t=4.051,P=0.001;t=4.759,P=0.001;t=-0.166,P=0.001）;试验组EF值术后晚期与术后早期比较差异有统计学意义（t=-6.621,P=0.001）。组间比较：两组术后晚期EF值差异无统计学意义（t=-0.354,P=0.726）,但术后晚期左心室舒张期末内径（LVEDD）、IVS、G和LVMI两组间比较差异均有统计学意义（t=-2.494,P=0.018;t=-3.434,P=0.002;t=-2.171,P=0.038;t=-2.316,P=0.028）。结论重度主动脉瓣狭窄患者行主动脉瓣置换术后常规应用β-受体阻滞剂是安全、可靠的,可显著降低其残存的心室内压力阶差,并可加速改善左心室的重塑。

Objective To investigate the effects of β-receptor blocker on intraventricular pressure gradient and left ventricle remodeling after valve replacement for critical aortic stenosis. Methods Fifty-six patients with critical aortic stenosis underwent aortic valve replacement surgery from January 2008 to January 2010 in the First Affiliated Hospital of Zhengzhou University.Thirty-two of them who were followed up were selected to be enrolled in this study.The patients were divided into two groups under the same basis of clinical features.Twelve patients in the experimental group received oral β-receptor blocker（Metoprolol,6.25-25.00 mg once,twice daily）.The rest 20 patients in the control group had no β-receptor blocker.The various indicators of ultrasound cardiogram（UCG） shortly after operation（within a week） and long after operation（6-24 months） were compared between the two groups. Results No death occurred in both groups,and chest distress,shortness of breath and other symptoms were obviously alleviated.Although left ventricular end-systolic dimension（LVESD） and left ventricular outflow tract dimension（LVOTD） of both groups increased 6-24 months after operation,compared with the early postoperative period,only the increase of LVOTD in the experimental group showed statistical difference（t=-47.937,P=0.001）.In both groups,interventricular septum thickness（IVST）,left ventricular posterior wall thickness（LVPWT）,filament band velocity of left ventricular outflow tract（V）,intraventricular pressure gradient（G） and left ventricular mass index（LVMI） of the later period after operation were significantly lower than those of the early postoperative period.All these indicators in the experimental group showed significant differences（t=7.781,P=0.001;t=5.749,P=0.001;t=2.637,P=0.023;t=7.167,P=0.001;t=100.061,P=0.001）,while only V,G,and LVMI showed statistical differences in the control group（t=4.051,P=0.001;t= 4.759,P= 0.001;t=-0.166,P=0.001）.EF in the experimental group also indicated significant difference compared with early period after aortic valve replacement（t=-6.621,P=0.001）.EF between two groups indicated no significant difference（t=-0.354,P=0.726）.But differences between the two groups in LVEDD,IVS,G,and LVMI were all statistically significant in the later period after surgery（t=-2.494,P=0.018;t=-3.434,P=0.002;t=-2.171,P=0.038;t=-2.316,P=0.028）. Conclusion β-receptor blocker is a safe and reliable drug for those patients who have undergone aortic valve replacement surgery for critical aortic stenosis,and can decrease significantly the residual intraventricular pressure gradient and accelerate left ventricular cardiac remodeling.