| BackgroudAtrial fibrillation (AF) is the most commom clinical arrhythmia. Hu dayi found that the total prevalence of atrial fibrillation in our country is0.77%(Standard rate is0.61%) from the cluster sampling survey in13provinces in2002, and age cohorts show that prevalence tends to increase with age, the morbidity of atrial fibrillation in man is higher than in women (0.9%vs0.7%, p=0.013).Because of valve open/close function disorder, hemodynamics and atrial or ventricular compensatory to expand, the incidence of atrial fibrillation in patients with heart valve disease is higher. Atrial fibrillation is serious atrial electrical disorder,normal electrical activity is replaced by atrial fibrillation wave. the main harm of atrial fibrillatio is:1. irregular heart rhythm, may cause heart palpitations, discomfort and anxiety;2.because of atrial invalid fibrillation and loss of active systolic function and irregular rhythm of the heart, cardiac output than normal drop10-20%,the result is the decrease of heart function;3.cause atrial thrombosis, increase the incidence of thromboembolism. So the persistence of atrial fibrillation is not only affects the quality of survival, to increase the patient’s pain, but also at the same time aggravating illness change, even life threatening. Because of the dangers of atrial fibrillation, for decades, many scholars had a lot of research on the mechanism of atrial fibrillation, proposed all sorts of hypotheses to show the corresponding required conditions of AF.The.multipke waveket hypothesis proposed by Moe and increased self-discipline of local ectopic foci hypothesis proposed by Schorf were accepted. Moe put forward multipke waveket hypothesis,it is the reason that excited wave transmission in heart is not evenly,excitation wave divide into many turn-back impulses lead to AF. Current research suggests that multipke waveket hypothesis is the maintaining mechanism of AF. The increased self-discipline of local ectopic foci hypothesis suggested that rapid excitment originated from the focal atrial could lead to AF.These ectopic excitment and inhomogenous refractory period of different parts of the atrial tissue determine that the ventricular rate is absolute arrhythmia. The current research thinks that the hypothesis is the induced mechanism of atrial fibrillation. In recent years, along with the development of molecular genetics and molecular biology technology research, atrial fibrillation mechanism of molecular genetics and molecular biology has been revealed, at the same time there is evidence showing that inflammation is associated with atrial fibrillation. There are many atrial fibrillation classification method, now usually adopts "3p" classification. Atrial fibrillation is divided into paroxysmal AF and persistent AF and persistent AF:1. paroxysmal AF:when patients have two or more than two episodes of atrial fibrillation (namely repeated paroxysmal atrial fibrillation), but every time can terminate by itself. These patients onset of atrial fibrillation tend to be short, generally within7days, in most cases not more than24h.;2. persistent AF:atrial fibrillation recurrent usually lasts more than1week, and cannot be terminated by itself,must with drug therapy or non-drug therapy;3. persistent AF:AF lasts for a long time, usually more than1year, the effecet of drug therapy or non-drug therapy is poor,so generally do not need cardioversion, because it is hard to maintain sinus rhythm. To identify the type of atrial fibrillation correctly and clarify the pathogenesis deeply can help to formulate appropriate clinical treatment, AF treatment involves three aspects:thromboembolism prevention, ventricular rate control, sinus rhythm conversion and maintain, include drug therapy and non-drug therapy, paroxysmal AF,if no special illness, may not be processed, if AF recurrent, appropriate medication may be used.Persistent AF, need drug therapy,if the effect is poor,the drug therapy and non-drug therapy should be combined.The treatment for permanent AF is ventricular rate control and thrombosis prevention,because the treatment of sinus rhythm conversion and maintain is always invalid. Surgical treatment of AF belongs to sinus rhythm conversion treatment in above three aspects, can completely cure atrial fibrillation. Surgical treatment is mainly Cox maze procedure,this procedure insulates the right or left ear, inferior vena cava, pulmonary vein, coronary sinus openings of atrial muscle by cutting and stitching into multiple electric insulation areajust like a maze, so it is called the maze procedure. success rate reached90%,maze surgery is the gold standard for surgical treatment for AF. But the complex procedure, long operation time, the high risk, limit its application. With the further study of atrial fibrillation and the development of new technology, improved operation gradually replaced the classic. Radiofrequency ablation, frozen ablation, microwave ablation, laser ablation, ultrasound ablation were applied for treating AF. Because of long clinical time, simple and convenient operation, low cost, little damage to the heart and high postoperative sinus converting rate, radiofrequency ablation widely used in numerous improved new technology,and its application prospect is much well.ObjectiveTo evaluate the near and medium-term clinical curative effect of surgical treatment of atrial fibrillation with maze procedure by radiofrequency ablation during valve replacement or placement procedure and analyse the multiple factors assosiated with sinus converting rate.Clinical dataIn Guangzhou military general hospital cardiac surgery center,from April2007to May2013,76cases with heart vavle diseases and atrial fibrillation diagnosed by UCG and ECG consist of males24and females52,age ranged from25to65years old,mean age was (52.66±9.55)years old.History of atrial fibrillation was from3to120months, mean was (45.23±19.76) months.Weight was from36to75kg, mean was (50.14±7.28) kg.The main symptoms were physical strength drops, fatigue, shortness of breath, chest tightness, cough, palpitation after activity,nocturnal paroxysmal dyspnea, double leg edema, etc. To perfect chest radiograph, cardiac ultrasound and electrocardiogram and laboratory tests, those who were more than50years old would accept coronary angiography examination, screening other system disease, surgery taboo and complete preoperative inform. Heart functions (NYHA) were as following:class Ⅱ in8cases,classⅢ in60cases,IVin8cases. The EF value which measured by UCG pre-operation ranged from34%to85%,mean value was62.77±8.92%. Classification of diseases:aortic and mitral valve diseases in12cases, pure mitral valve disease in62cases, mitral valve disease and coronary heart disease (CHD) in2cases; After the operation, we collect the cardiac ultrasound and electrocardiogram examination when before discharge, postoperative1or3months,6months and every yeatr,then compare with preoperative date.Surgical methodAll cases adopt whole body compound anesthesia,midline sternum incision to uncover heart. Intubate in ascending aorta after heparinization, then intubate upper and inferior vena cava to establish extracorporeal circulation. Block the inferior vena cava respectively, free the right pulmonary vein to complete pulmonary vein orifice bipolar radiofrequency ablation(If there is left atrial thrombosis,this procedure is did after cardiac arrest). when body temperature down to about30℃, block the ascending aorta,cold blood is filled to stop the heart(If the aortic is regurgitation, make a transverse incision on ascending aorta, perfuse from the left and right coronary artery directly), cut the right atrium, make heart temperature cool down by ice outside the heart to protect myocardial, from the upper right pulmonary artery and left atrial border incision place suction tube into left atrium.Cut interatrial septum along its middle, show internal left atrial, explore presence of thrombus,if thrombosis, remove it firstly, then have a radiofrequency ablation maze operationg by using bipolar radiofrequency ablation device, route, scope and degree must be mastered precisely and strictly. Specific route:right up and down pulmonary veins-left up and down pulmonary vein-remove of LAA-connection between LAA and left up and down pulmonary vein mouth-the left atrium back wall-connection between left pulmonary vein and right pulmonary vein-connection between LAA and right down pulmonary veins and and the mitral valve ring-the right atial crista terminalis-inferior vena cava mouth-connection between coronary sinus and tricuspid vavle.Requirement:route, scope and degree must be mastered precisely and strictly and to avoid damage to the left atrial.Then according to the exploration, decide to adopt valve replacement or placement. Valve replacement adopt mattress suture, replacement of3cases were biological valve,66were mechanical valve,Mitral placement was in7cases,adopt flap resection, chordae tendineae shorten, valve disc shrink technology. If left atrium enlarge significantly, left atrial folding operation will be adopted by4-0proline line sutured. Suture heart incision, exhaust gas,when heart beating then recovery temperature, stop extracorporeal circulation, hemostatic,conventionally seam2epicardial temporary pacemaker wires. Postoperative treatment Back to the ICU,monitor heart rate, rhythm, blood pressure, central venous pressure, consciousness, urine volume per hour, Do auxiliary breath12to72hours by breathing machine regularly.Intravenous pump dopamine,dobutamine(3-8ug/kg.min), adrenaline hydrochloride(0.03-0.08ug/kg.min), isopropyl adrenaline(0.03-0.1ug/kg.min), nitroglycerin drugs to improve cardiac function. Monitor arterial blood gas analysis, to maintain electrolyte balance and internal environment stable. Open temporary cardiac pacemaker When heart rate is lower than80times/min,to maintain the heart rate from90to110times/min. Anticoagulant therapy by low molecular heparin, transition to oral warfarin2days later, to prevent valve thrombosis. Intravenous pump amiodarone from20to30mg/h to be awake, after pull out the endotracheal intubation, oral instead,200mg,3times/d,1week later reduce to200mg,2times/d,1week later reduce to200mg,ltime/d, According to the rhythm and rate of hearts last for3to6months,after discharge,oral strong heart and diuresie,rtc for short time.Statistical methodsUsing SPSS11.0statistical software package for analysis, the count data of said frequency,to compare the groups of count date utilize testing X2, Measurement data as mean±standard deviation(x±s), two groups samples were compared used the number of t test or approximate t test.Standard test a=0.05.Result1.In76patients,12were mitral valve replacement and aortic valve replacement,55were only mitral valve replacement,7were mitral valve placement,2were CABG and mitral valve replacement. All were recovered out of the hospital, no perioperative death, cardiopulmonary bypass time was90-175min, aortic resistance closed time was50-120min, radiofrequency ablation time was20-30min.When out of hospital56people were sinus heart rhythm, sinus converting rate was 73.68%(56/76).From June24,2013to August26th2013,we did telephone follow-up to these patients,and collect reexamination ECG and UCG information, the follow visit time was3-62months, mean was24.98±21.32months.Effective follow-up number was73,3people were lost,61people were sinus heart rhythm,12people were AF, sinus maintain rate was83.56%(61/73). Heart palpitations, shortness of breath and other symptoms of cardiac insufficiency were improved in all patiens.Heart functions after operation:class Ⅰ in18cases,class Ⅱin55cases,.2.The preoperative left atrium diameter of sinus converting group(56cases) was54.88±14.00mm,the AF group (20cases) was67.15±12.93mm when out of hospital, there was significant statistical difference (p<0.05).Divide all the patients to two groups,left atrial diameter≥60mm in one grop (32cases)and diameter<60mm in the other one(44cases), there was significant statistical difference in sinus converting rate (p<0.05).The preoperative left atrium diameter of sinus converting group(61cases) was55.43±13.95mm,the AF group (12cases) was72.17±13.16mm when follow visit, there was significant statistical difference (p<0.05). Divide all the patients to two groups,left atrial diameter≥60mm in one grop (30cases)and diameter<60mm in the other one(43cases),there was significant statistical difference in sinus converting rate (p<0.05). The preoperative left atrium diameter of sinus converting group(61cases) was55.43±13.95mm, when follow visit, the left diameter was47.03±0.65mm, there was significant statistical difference (p<0.05). The preoperative left atrium diameter of AF group(12cases) was72.17±13.16mm, when follow visit, the left diameter was69.19±12.54mm, there was no significant statistical difference (p>0.05).3.Age of sinus converting group(56cases) was50.77±9.08years old, the AF group(20cases) was57.95±7.01years old when out of hospital,there was significant statistical difference (p<0.05). Divide all the patients to two groups,age≥55years old in one grop(40cases) and age<55years old in the other one(36cases), there was significant statistical difference in sinus converting rate (p<0.05).Age of sinus converting group(61cases) was51.75±8.53years old, the AF group (12cases) was58.42±6.88years old when follow vsitl,there was significant statistical difference (p<0.05). Divide all the patients to two groups,age>55years old in one grop(40cases) and age<55years old in the other one(33cases), there was significant statistical difference in sinus converting rate (p<0.05).The sinus converting rate of operation time≥24months group(35cases) was94.29%(33/35) and the operation time<24months group(38cases) was73.86%(28/38), there was significant statistical difference (p<0.05).4.The sinus converting rate of cardiac function grade Ⅱ group was100%(8/8), grade Ⅲ group was76.67%(46/60),grade Ⅳ group was25%(2/8),there was significantly statistical difference between grade II group and grade IV group,grade Ⅲ group and grade Ⅳ group (p<0.05). The sinus converting rate of preoperative EF value≥50%group (66cases) was78.79%(52/66) and preoperative EF value<50%group (10cases) was40%(4/10), there was significant statistical difference (p<0.05).5.The sinus converting rate of aortic and mitral valve replacement group was75.00%(9/12), mitral valve replacement group was73.68%(32/47), mitral valve placement group was71.43%(5/7), there was no statistical significant difference among groups (p>0.05). The sinus converting rate of man group(24cases) was66.67%(16/24), woman group(52cases) was76.92%(40/52), there was no statistical significant difference(p>0.05).6.There were39cases under anti-arrhythmic drugs treatment when out of hospital,34cases were not under anti-arrhythmic drugs treatment,the sinus converting rate of drugs treatment goup was92.31%(36/39),the other group was73.53%(25/34), there was statistical significant difference (p<0.05).conclusion1. The bipolar radiofrequency ablation can cure AF when on valve replacement or valve placement or CABG operation simultaneously in patients with heart valve disease and AF,sinus converting rate is high, long-term sinus maintaining rate is high, it is only safe, convenient, effective, but also could improve heart function, improve the patient’s life quality2. Left atrial size is closely related to the effect of radiofrequency ablation operation, the greater the left atrial is, the worse the effect is. The postoperative sinus conveting rate and forward sinus maintain rate in patients whose preoperative left atrial diameter is less than60mm are higher than those greater than60mm,and after radiofrequency ablation, the expansive left atrial can bereduced significantly.3Age is closely related to the effect of radiofrequency ablation operation, the older the age is, the higher the AF recurrence rate is. The postoperative sinus conveting rate and forward sinus maintain rate in patients whose age is less than55years old are higher than those greater than55years old.Compare with patiens whose postoperative time is longer than24months,the effect of operation in those shorter than24mongths is worse.4. Preoperative heart function is closely related to effect of radiofrequency ablation operation,the effect of grade Ⅱ and grade Ⅲ patiens are better than grade IV,and compare with patiens whose EF value is smaller than50percents,the effect of operation in those bigger than50percents is better. The maintainence of sinus rhythm could improve heart function.5.It is the key step that the radiofrequency ablation lines, scope and degree are precise to guarantee the postoperative curative effect. Improving the postoperative cardiac function treatment and anti-arrhythmic drugs treatment are important link to guarantee the postoperative curative effect.6. The multicenter,large data cases and long-term follow-up (older than10years) are needed to confirm the multiple factors influencing the sinus converting rate of radiofrequency ablation operation. |
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