目的 探讨1例行双肺移植同期冠状动脉旁路移植术患者的麻醉管理方法.方法 1例特发性肺纤维化合并冠心病患者,男,55岁,于体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)辅助下采用全静脉麻醉行双肺移植同期冠状动脉旁路移植术.术中采用小潮气量保护性肺通气策略联合ECMO维持心肌氧供,应用经食管超声和Swan-Ganz导管监测心脏收缩功能、血流动力学参数和容量状态,指导血管活性药物使用.记录麻醉诱导后10 min(To)、置入Swan-Ganz导管后5 min(T1)、ECMO运转10 min(T2)、单肺通气30 min(T3)、吻合左前降支(T4)、搭桥完成后10 min(T5)、左肺动脉阻断后10 min(Te)、左肺动脉开放后10 min(T7)、右肺动脉阻断后10 min(T8)、右肺动脉开放后10 min(T9)、双肺通气10 min(T10)、出手术室(T11)时心率、动脉血压、中心静脉压、血氧饱和度和肺动脉压.记录患者麻醉诱导前、T3、T4、T7、T9时pa(O2)和pa(CO2),肺移植前后双侧肺静脉流速.结果 术中动脉血压、中心静脉压在T8时均降低,其他各时间点均维持正常范围;随着ECMO运行及肺移植手术的进行,T2～T11时肺动脉压逐渐下降维持稳定但均高于正常值,双肺移植后(T9～T11)肺动脉压降至术中最低(28/19 mm Hg);患者术中氧合状态良好,血氧饱和度、pa(O2)均维持在正常范围;ECMO运行后,T3、T4、T7、T9时pa(CO2)逐渐降至正常范围;肺移植前左、右肺静脉流速分别为60、56 cm/s,双肺移植后分别升高至92、100 cm/s.术后16 h撤除ECMO,术后第1天出现低心排血量综合征,术后第2天出现中度原发性移植肺失功,经对症治疗后心功能、肺功能逐渐改善.术后第6天为便于气道管理行气管切开.术后第13天患者心功能恢复良好,血流动力学平稳,可下床活动,间断撤离呼吸机.目前继续康复治疗中.结论 双肺移植同期冠状动脉旁路移植术中麻醉管理采用小潮气量保护性肺通气策略联合应用ECMO可改善患者术中氧合状态、纠正高碳酸血症、降低肺动脉压力、维持心肌氧供需平衡;术中应用经食管超声和Swan-Ganz导管指导血管活性药物使用和限制性液体治疗,可维持术中血流动力学平稳,减轻术后心功能衰竭.

目的 探讨终末期支气管扩张症患者行肺移植术治疗的效果.方法 回顾性分析7例行肺移植术的终末期支气管扩张症患者的临床资料.7例术前均行胸部CT、痰培养、6 min步行试验;术中术后采用保护性通气策略、早期液体负平衡管理、抗感染、抗排异、早期肺康复运动训练等治疗措施.记录肺移植术式、围术期情况;比较肺移植术前及术后动脉血气达稳定期时pa(CO2)、肺动脉收缩压.随访至2022年11月30日,记录患者生存情况.结果 (1)6例术前胸部CT影像表现为双肺弥漫性支气管扩张,1例左肺弥漫性支气管扩张、右上肺叶未见明显支气管扩张;7例痰培养均检出铜绿假单胞菌,其中3例检出多种病原菌;7例6 min步行试验均未完成.(2)4例行双肺移植术,1例行双侧肺叶移植术,1例行右肺移植+左侧肺叶移植术,1例行左肺移植+右肺中下叶切除术,手术时间270～510(373±85)min,住院时间29(16,45)d.单肺移植或双肺移植者第一侧供肺冷缺血时间330～510(429±66)min,双肺移植者第二侧肺冷缺血时间450～750(590±110)min.5例术前先建立体外膜肺氧合者中4例术后13.5(11.0,17.0)h顺利撤机,1例因围术期原发性移植物失功、脓毒血症、凝血功能异常死亡.5例术中输注红细胞6(2,26)u.5例术后20(14,40)h顺利拔出气管插管,2例脱机后pa(CO2)升高,再次气管插管后好转.6例患者病情好转出院.(3)7例术后动脉血气达稳定期时pa(CO2)[42(40,50)mm Hg]、肺动脉收缩压[(25±6)mm Hg]均明显低于术前[60(42,80),(46±20)mm Hg](Z=2.371,P=0.018;t=2.690,P=0.036).(4)随访至2022年11月30日,1例术后3个月死于肺部多重耐药菌感染,1例术后24个月死于耶氏肺孢子菌感染和闭塞性细支气管炎,余4例生存状况良好.结论 终末期支气管扩张症患者常合并铜绿假单胞菌感染,加强肺移植术中气道开放、支气管吻合期间无菌保护、围术期管理,可延长生存时间,改善预后.

目的:分析肝肺联合移植手术的麻醉处理.方法:采用全静脉麻醉诱导和维持,在体外膜肺氧合辅助下施术.根据血流动力学监测和食管超声检查指导输血、输液和血管活性药物的使用.对血流动力学、通气模式、容量管理、凝血功能等方面实施个体化的调控.结果:术中循环稳定、氧合良好,术后第 3 天撤除体外膜肺氧合,第 4天撤除呼吸机.术后第10 天出现顽固性低氧血症,经呼吸机辅助呼吸和肺动脉球囊扩张治疗效果不佳.术后第32 天在等待再次移植中因感染性休克、心搏骤停死亡.结论:肝肺联合移植术的麻醉不仅要求血流动力学和内环境稳定,而且在容量管理、通气策略、凝血功能等方面应个体化管理.

自1968年施行世界首例心肺联合移植( heart-lung transplant,HLT)以来,HLT经历了曲折的发展.目前,HLT已成为公认治疗终末期心肺疾病的有效方法[1].近几十年来,随着技术的不断提高和改进,尽管绝大多数终末期心肺疾病能通过单纯的肺移植或心脏移植治疗,但HLT仍是某些特殊心肺原发病患者的唯一治疗方式.

目的 分析1例特发性肺纤维化合并酒精性肝硬化失代偿期行肝肺联合移植术患者的临床资料,探讨其临床治疗效果.方法 患者于体外膜肺氧合辅助下先行左肺移植术,后行肝移植术.肺移植吻合顺序为左主支气管、左肺动脉、左侧左房袖;肝移植吻合顺序为肝上下腔静脉、肝下下腔静脉、门静脉、肝动脉、胆总管-胆总管端端吻合.肺动脉开放前予以巴利昔单抗、甲泼尼龙琥珀酸钠诱导免疫;术后鼻饲他克莫司、吗替麦考酚酯,静脉注射甲泼尼龙琥珀酸钠.结果 患者术后64 h撤离体外膜肺氧合;术后第4天撤离呼吸机并下床活动;术后第10天出现不明原因的顽固性低氧血症,行气管切开、呼吸机辅助呼吸及肺动脉球囊扩张,低氧血症仍存在,拟行右肺移植术;术后第21天肺泡灌洗液培养出大肠埃希氏菌、嗜麦芽窄食单胞菌、烟曲霉;术后第32天因感染性休克、心脏骤停死亡.结论 终末期肝脏、肺部疾病患者可行肝肺联合移植术;严格选择供体、进一步优化手术流程、尽可能双肺移植是该病例带来的经验教训;应用体外肺灌注技术改善供体质量、延长器官保存时间,是未来发展的方向.

目的 观察心脏杂交手术联合肺移植术治疗1例艾森曼格综合征的临床效果。方法 1例室间隔缺损合并动脉导管未闭导致重度肺动脉高压、艾森曼格综合征患者，女，30岁，行心脏杂交手术联合肺移植术治疗。先行体外膜肺氧合下经皮动脉导管未闭封堵术，再行右侧开胸体外循环下室间隔缺损修补术，后行左侧开胸左肺移植术。观察患者术中及术后临床资料。结果 手术时间13 h,术中体外循环支持时间130 min,出血量3 000 mL,手术过程顺利，术后患者发绀较术前减轻，心脏未闻及明显杂音。术后42 h撤除体外膜肺氧合；术后第3天X线胸片提示左肺膨胀可，与胸腔大小匹配，心脏超声心动图显示肺动脉压由术前107 mm Hg降为术后48 mm Hg,术后左室射血分数62%（术前65%）;术后第4天撤离呼吸机，撤机后吸氧4 L/min下，pa（O 2 ）由术前50.8 mm Hg升高至147 mm Hg;术后第6天胸部CT示双侧胸腔少量积液，封堵器位置良好；术后第7天谷丙转氨酶36 u/L,谷草转氨酶26 u/L,血肌酐51μmol/L,白蛋白34.2 g/L;术后患者出现阵发性室上性心动过速，给予普罗帕酮90 mg静脉注射后转律恢复窦性心律。术后第7天生命体征平稳（体温36.9℃,呼吸频率20次/min,心率96次/min,血压110/51 mm Hg,血氧饱和度98%）,目前仍在院康复中。结论 对部分简单性先天性心脏病（如房间隔缺损、室间隔缺损、动脉导管未闭等）合并艾森曼格综合征患者，行心脏杂交手术联合肺移植术治疗早期效果良好，远期疗效有待进一步观察。

目前,肺移植是公认的治疗多种终末期肺疾病的唯一有效方法[1].然而,供肺资源短缺严重制约了肺移植的发展,为解决这一难题,已提出并临床实践的对应策略有:边缘供肺肺移植、心死亡供体肺移植、体外肺灌注( EVLP)体外肺修复肺移植、解剖和非解剖性肺减容肺移植、肺叶移植[2-3].对于身材矮小或者有限制性肺疾病的小胸腔患者来说,肺叶移植已成为扩大其供肺来源的重要方式之一[2-8].现对郑州大学第一附属医院完成的华中地区首例双侧肺叶移植治疗成人支气管扩张并感染的资料进行总结,并结合相关文献复习,报道如下.

Objective To improve the management strategy for the infants with low weight and decreased pulmonary artery blood flow undergoing cardiopulmonary bypass(CPB). Methods The clinical data of 38 infants including age,body weight,operation type and CPB conditions including equipment,composition of priming liquids,duration of CPB and clamping time of ascending aorta were retrospectively ana-lyzed,who were less than 5 kg in body weight and underwent CHD operations. The infants aged 20 days to 8 months,weighed 2. 6 ~ 5. 0 kg. All cases used mild hypothermia and moderate hypothermia,Modified ultrafiltration(MUF)and Balanced ultrafiltration(BUF)was used in all pa-tients. Results After cross clamping release,heart beat recovered spontaneously in 34 patients without severe arrhythmia. 38 cases were suc-cessfully weaned from CPB without severe complications. Conclusion Appropriate infant bypass,low prime volume,keeping high HCT and col-loidal pressure adapted perfusion flow rate matching temperature,myocardial preservation and pulmonary protection during CPB,MUF and BUF can lead to good results.

Objective To investigate the supporting effect of extracorporeal membrane oxygenation (ECMO) for respiratory and circulatory instability donors before organ transplantation.Methods During September 2013 to August 2014,4 cases of donation after braindeath (DBD) patients were treated in our hospital.All of 4 cases were treated emergently with ECMO supporting for 9.5-78.0 h,and liver and kidney were removed after liver and kidney functions were improved to some extent and medical procedures completed.Results Four cases were supported for 78.0,32.0,9.5 and 14.0 h,respectively.Internal environment of body was stable.The liver and kidney functions were improved to varying degrees.Four livers and 6 kidneys obtained were successfully transplanted,andf 2 kidneys were abandoned for consolidation.After surgery 2 cases had delayed renal graft function.Ten recipients recovered.Conclusion Donor can be improved by ECMO,which can provide effective support of the respiration and circulation,and improve the function of organs.

目的：探讨体外循环（CPB）辅助技术在腔静脉肿瘤手术治疗中的应用及效果。方法回顾性分析8例腔静脉肿瘤在 CPB 辅助下行手术治疗的相关资料，其中3例为原发或继发下腔静脉平滑肌瘤（其中1例蔓延至右心房），1例为原发性平滑肌肉瘤，1例为肝癌下腔静脉内转移，2例为肾癌下腔静脉转移，1例为胸腺瘤累及上腔静脉及右心房。通过右房原主动脉插管或右心房回输管建立 CPB 行辅助循环。结果8例患者均成功将腔静脉肿瘤完整切除，顺利出院。术后随访显示，1例术后2个月出现肝衰竭死亡，2例分别于术后4、6个月复发再次手术，其余5例随访1 a 无复发。结论 CPB 辅助技术在腔静脉肿瘤手术治疗中的应用，扩大了手术适应证，有效维持血流动力学稳定，同时通过充分暴露术野，保证了肿瘤的彻底切除。

Objective To explore the clinical application and significance of retrograde autologous priming (RAP) combined with modified ultrafiltration (MUF) in infant cardiac surgery.Methods Sixty pediatric patients with cardiac surgery were selected and randomly divided into the control (n =33) and experimental groups (n =27).The experimental group was given RAP and MUF,while the control group was only subjected to the conventional method.The situations of hematocrit (Hct,T1,T2,T3,T4) and lactate (Lac) at different perioperative time points,the filtrate volume of MUF,mechanical ventilation time,hospital stay,intraoperative and postoperative 2-h blood transfusion were observed and compared between the two groups.Results The number of patients receiving perioperative blood transfusion in the experimental group (9) was less than that in the control group (31) (P ＜ 0.05).Intraoperative Hct in the experimental group was lower than in the control group [T2:(25.08 ± 0.50) ％ vs.(26.81 ± 0.52) ％,P ＜ 0.05;T3:(26.04 ± 0.36) ％ vs.(27.79 ± 0.51) ％,P ＜ 0.05].Other indicators showed no significant difference (P ＞ 0.05).Conclusion RAP combined with MUF could effectively reduce hemodilution in pediatric patients,satisfy intraoperative perfusion conditions,and reduce perioperative blood transfusion volume.

目的：探讨磷酸肌酸钠联合乌司他丁在体外循环下心脏瓣膜置换术中的心肌保护效果。方法筛选该院心外科2012年3月至2013年3月体外循环下行心脏瓣膜置换术患者80例，随机分配进入磷酸肌酸钠组（C组）、乌司他丁组（U组）、磷酸肌酸钠加乌司他丁复合组（C U组）和对照组（M组），每组20例。观察各组术中心脏复跳情况、体外循环时间、后并行时间、主动脉阻断时间、术后大剂量正性肌力药物使用例数、IC U 时间、并发症发生和住院死亡情况；同时检测不同时间血浆肌钙蛋白 I （cTnI）、肌酸激酶同工酶（CK-MB）浓度。结果4组患者术中体外循环时间、升主动脉阻闭时间、术后住院死亡、并发症的发生和ICU时间方面比较差异无统计学意义（P＞0．05）。C组、U组、CU组术中体外循环后并行时间低于M组（P＜0．05），并且CU组后并行时间低于C组和U组（P＜0．05）；与M组比较，术后血浆中CK-MB、cTnI浓度均比其他组低（P＜0．05），但CU组降低更明显。结论 CP联合UTI的应用对体外循环下心脏瓣膜置换手术具有良好的心肌保护作用，减轻体外循环下瓣膜置换术的心肌损害，有利于患者术后恢复。

目的 比较非体外循环下冠状动脉搭桥术(OPCABG)和药物洗脱支架(DES)植入术治疗冠心病多支病变再次血运重建率.方法 回顾性分析210例冠心病多支冠状动脉病变患者,其中108例行DES置入术,92例行非体外循环下冠状动脉搭桥术.比较随访3～5年不良心血管事件(全因死亡、再发非致死性心肌梗死、再次血管重建)的发生情况.结果 两组患者一般资料比较差异无统计学意义,OPCABG组与DES组全因病死率(5.88％ VS4.63％,P=0.613)比较差异无统计学意义,再发非致死性心肌梗死率(5.88％ VS12.04％,P=0.007)、再次血管重建率(7.84％ VS 16.67％,P=0.004)心脏主要不良事件(19.61％ VS33.33％,P=0.023)比较差异均有统计学意义.结论 对于多支冠状动脉病变患者OPCABG组远期疗效优于DES组。

目的探讨动脉导管未闭合并慢性肺动脉血栓栓塞的外科治疗疗效。方法回顾性总结2010年1月至2013年6月间9例动脉导管未闭合并慢性肺动脉血栓栓塞患者的诊治过程和临床经验。患者均在深低温低流量或停循环下行动脉导管缝闭或动脉导管结扎术,肺动脉切开取栓术或内膜剥脱术,术中持续泵入前列地尔。结果术后1例因急性灌注肺死亡,其余8例均存活顺利康复出院,肺动脉压下降31 4 5 mm Hg(1 mm Hg=0.133 kPa);术后随访2个月 3 年,临床症状均有减轻、无明显并发症,活动能力均有明显提高,未见复发病例。结论动脉导管未闭合并慢性肺动脉血栓栓塞的外科治疗能有效的降低肺动脉高压,缓解临床症状;围术期处理好肺再灌注损伤、肺水肿等并发症是确保疗效的关键。

Objective To investigate the effect of alprostadil on the cardio-pulmonary function of the patients after coronary artery bypass graft (CABG) by using Liposome prostaglandin.Methods Sixty cases of CAD were evenly divided into two groups:observation group and control group.Both groups were given the basic treatments such as anti-inflammation,mechanical ventilation,etc.Liposome prostaglandin was intravenously injected after surgery in control group,10 μg,thrice every day for 2 days.The changes of PaO2,and PaO2/FiO2 were examined at 0.5,6.0,and 12.0 h after surgery.The changes in RVEF and PVRI at 48.0 h after surgery were measured by using the right cardiac catheterization techniques.Results Before alprostadil administration and at 0.5 h after surgery,the PaO2 value was (82.3 ± 8.4) mmHg (1 mmHg=0.133 kPa) in observation group and (83.1 ±8.5) mmHg in control group,and the PaO2/FiO2 value was (212.8 ± 10.4) mmHg in observation group and (214.3 ± 10.7) mmHg in control group (P ＞0.05).After alprostadil administration and at 6.0 and 12.0 h after surgery,the PaO2 value was (96.0±9.8) and (108.0 ± 10.6) mmHg in observation group and (84.3 ±6.1) and (86.7 ±7.3) mmHgin control group,and the PaO2/FiO2 value was (248.6 ± 18.9) and (280.9 ±34.8) mmHg in observation group and (220.5 ± 16.1) and (245.9 ±28.2) mmHg in control group,respectively (P ＜0.01).At 48.0 h after surgery,RVEF in observation and control groups was (0.53 ±0.05) and (0.46 ± 0.04),and PVRI was (203 ±28) and (235 ± 33) mL,respectively (P ＜0.05).Conclusion Patients after CABG that were given liposome prostaglandin can get improvement in PaO2,PaO2/FiO2,RVEF and PVRI.Liposome prostaglandin administration also contributes to the recovery of postoperative cardiopulmonary function.

2008年1月至2013年3月,我们收治9例妊娠合并感染性心内膜炎(infective endocarditis,IE)患者,现总结手术时机的选择、手术方法和围手术期处理的经验,报道如下.资料和方法 本组年龄23～ 35岁,初产妇7例,经产妇2例,孕10～35周,其中妊娠早期1例,中期6例,晚期2例.术前患者心功能均为Ⅲ～Ⅳ级.所有患者术前均行超声心动图,发现心内赘生物8例.术前均行血培养检查,阳性6例,其中金黄色葡萄球菌2例、溶血性链球菌2例、草绿色链球菌1例、粪肠球菌1例.所有患者基于临床、超声心动图和微生物学等结果,按改良Duke标准诊断为IE.B超检查示胎儿均为单胎,活动良好,羊水正常.所有患者均常规给予敏感抗生素或三代头孢+万古霉素静脉输液抗感染治疗,同时考虑对胎儿的影响.其中2例患者出现进行性心力衰竭;4例出现大于7天的持续性发热患者中3例复查超声心动图示:赘生物直径进行性增大.所有患者均具有外科手术指征。

OBJECTIVE:To explore the clinical application and experience of cardiopulmonary bypass (CPB) diluted autologous transfusion so as to provide clinical rationales for blood conservation.METHODS:At Department of Cardiothoracic Surgery, First Affiliated Hospital, Zhengzhou University, the clinical data were reviewed for 5000 CPB surgical patients without banked blood from September 1996 to March 2012 to analyze the clinical application of autologous blood transfusion and summarize the experience of depth hemodilution. No significant changes occurred in blood pressure, central venous pressure or heart rate after blood collection. The values of blood gases stayed within the normal perioperative range. The collected blood and all the remaining blood in CPB machine were reinfused to bring the postoperative level of Hb to over 90 g/L. Only 129 cases on a second thoracotomy for hemostasis required banked blood transfusion because of hemogloblin (Hb) under 70 g/L.RESULTS:Hb, hematocrit (Hct), pH, base excess (BE), lactate (Lac), cerebral oxygen saturation (rSO2) and arterial oxygen saturation (SaO2) indicated a statistically significant during CPB compared with pre-anesthetic (P < 0.05). The remaining indicators stayed within the normal perioperative range except for Hb and Hct. There were 146 cases of deaths. And the causes were postoperative low cardiac output (n = 34), cerebrovascular accident (n = 48), malignant arrhythmias (n = 28) and lung infection and multiple organ dysfunction (n = 36). The case fatality rate was merely 2.92%. All survivors recovered well and no heart, brain, kidney or other complications occurred.CONCLUSION:Hct 15%-19% depth of hemodilution with proper cooling and anesthetic management during cardiopulmonary bypass is both safe and feasible. And neutralization heparinemia in stored blood before CPB by protamine is one of the effective methods of blood conservation.

对于合并巨大左心房与慢性心房颤动(AF)的二尖瓣病变患者,我们尝试在行二尖瓣置换术与射频消融术同时加行左心房折叠术(LAP),现总结报道如下.资料和方法 2008年1月至2010年7月,48例风湿性二尖瓣病变合并巨大左心房和慢性AF的患者,按是否处理巨大左心房分为二尖瓣置换术与冲洗式射频消融术同时加行左房折叠术(LAP)组23例和二尖瓣置换术与冲洗式射频消融术(对照)组25例.患者一般资料详见表1.所有手术均由同一组医师完成.

Objective:To study the role of ginsenoside Rb1 in inhibiting the autologous vein graft proliferating cell nuclear antigen(PCNA) expression and autologous vein graft intimal hyperplasia. Method:Fourty-five New Zealand rabbits were randomly divided equally into experimental group,model group and control group.Endoscopic surgery was utilized to excise their external jugular veins,and then establish an animal model for transplanted vein bridges by anastomosing every unilateral jugular vein end-to-end with the common carotid artery.After 4 weeks,the morphology and thickness of the vein graft intimas were observed under HE staining;the PCNA mRNA expression was examined by RT-PCR. Result:The HE-stained sections under light microscopy showed that at 4 weeks after transplantation the thickness of vein graft intimas in experimental group,model group and control group were(41.57±2.43)μm,(73.76±7.83)μm,(11.38±0.71)μm,with significant differences(P0.05);The intimal/medial thickness ratios of the 3 groups were(1.21±0.09),(1.44±0.12) and(0.28±0.07),and there were significantly differences(P0.05).The relative expression coefficients of PCNA mRNA in experimental group,model group and and control group were(0.942±0.004),(0.756±0.003) and(0.574±0.002),and there were significantly differences(P0.05). Conclusion:Ginsenoside Rb1 inhibits the overexpression of PCNA mRNA in vein grafts,which effectively reduces the risk of restenosis caused by intimal hyperplasia,and extends the lifespan of vein grafts.

Objective To evaluate the benefits of radiofrequency ablation modified maze procedure and left atrial placation (LAP) during mitral valvular replacement in patients with chronic atrial fibrillation and giant left atrium associated with mitral valve disease. Methods Forty-six patients with chronic atrial fibrillation and giant left atrium (left atrial diameter or 1eft atrial volume index over 55 mL/m2)associated with mitral valve disease were treated by radi-ofrequency ablation modified maze procedure and mitral valvular replacement.Among them,23 patients underwent LAP at the same time(LAP group). The patient′s changes of heart electricity activity and NYHA were observed by Electrocardiogram, Echocardiogram and the follow-up study was made for 12 months. Results The rate of restoration to sinus rhythm was higher in LAP group than that in the control group (82.6% vs. 56.5%,P<0.01).The improvement of the NYHA classes was greater in LAP group than that in the control group (1.71±0.65,0.78±0.63,P<O.01).The Left atrial volume index (LAVI)was smaller in LAP group than that in the control group (39.88±11.02 vs. 51.86±13.09,P<0.01).The 1eft ventricular ejection fraction was higher in LAP group than that in the control group[(64.04±6.81)% vs. (55.69±5.32)%,P<0.01]. Conclusions For the patients with chronic atrial fibrillation and giant left atrium associated with mitral valve disease,LAP combined radiofrequency ablation modified maze procedure during mitral valvular replacement is the effective treatment in treating chronic atrial fibrillation,maintaining sinus rhythm and improving atrial and ventricular contraction functions