The activation of haemostasis during radiofrequency catheter ablation

The aim of the study was to investigate chosen haemostasis activation markers during electrophysiologic study (EPS) with consequent radiofrequency catheter ablation (RFA). Sixty-three patients were studied prospectively. Indications for EPS and RFA were supraventricular tachycardias with the arrhythmogenic substrate located in the right atrium. Blood samples were drawn 24 hours before the procedure (T -1), at the beginning of the procedure (T0), at the end of EPS (T1), 30 minutes after completion of RFA (T2), and 24 hours after the procedure (T3). To study coagulation, fibrinolytic and platelet activation were measured concentrations of thrombin-antithrombin III (TAT), D-dimers (DD), platelet count and parameters, and circulating platelet aggregates (CPAi). During the EPS and RFA, TAT levels increased from the baseline 5.03 +/- 2.53 microg/l (T -1) to 12.90 +/- 12.83 microg/l at T0 (p < 0.001) to 36.07 +/- 15.59 microg/l at T1 (p < 0.001) and decreased to 28.85 +/- 13.14 microg/l at T2 (p < 0.001). Levels of DD increased from 0.30 +/- 0.20 mg/l at T0 to 0.44 +/- 0.25 mg/l at T1 (p < 0.001) and to 0.87 +/- 0.74 mg/l at T2 (p < 0.001). The number of platelets was significantly decreased (-13.7%) before and during the procedure (T -1 vs. T3; p < 0.001). Marked platelet activation (CPAi 0.62 +/- 0.32) was observed before the procedure opposite to the physiological values (CPAi 1.0 +/- 0.1), without changes during the procedure (CPAi at T2 0.69 +/- 0.23). Our results confirmed activation of several haemostasis parameters during EPS and RFA, and support eligibility of the antithrombotic prevention in patients indicated for EPS and RFA.     

射频消融术对凝血系统的影响

目的：探讨射频消融术（RFCA）后外周血管栓塞的发生机制及防治对策。方法：将90例室上性心动过速患者分为3组：A组术前不用抗凝药,B组术前使用阿司匹林,C组术前使用钙通道阻滞剂－氨氯地平。在术前、插管完成心内电生理检测后、RFCA后即刻及术后2d,抽静脉血观察血小板α－颗粒膜糖蛋白（Gmp-140)、血栓烷B2（TXB2）、蛋白C、蛋白S的变化。结果：A组病人,与术前比较,其他3个时段血浆Gmp-140、TXB2含量明显增加,蛋白C及蛋白S血浆含量无明显变化,且发现左右心导管操作对Gmp-140、TXB2变化无明显影响;B、C组病人与A组相比,相同时段的血浆Gmp-140、TXB2含量减小。结论：RFCA可引起血小板的激活,抗凝系统无明显变化,可能致血栓形成,服用阿司匹林及氨氯地平可阻止血小板的激活,有阻止血栓形成的作用。     

心脏导管消融与膈神经损伤

导管消融术已成为治疗各类快速心律失常安全有效的措施,随着心房颤动（房颤）消融术广泛应用于临床”^[1-2],导管消融引起的膈神经损伤（phrenicnerveinjury,PNI）受到临床医生的关注,尤其是近年来心外膜消融技术的开展,消融大头导管的机械刺激以及在膈神经附近放电等都不可避免的会造成PNI。     

射频消融治疗对局部心肌组织损伤的研究

目的　研究射频消融术 (RFCA)患者术前及术后不同时间血清心肌肌钙蛋白T(cTnT) ,肌酸激酶 (CK) ,肌酸肌酶同功酶 (CK MB)及天冬氨酸转氨酶 (AST)浓度变化及与RFCA诸因素的关系。探讨RFCA对心肌组织损伤程度。方法　采用ELISA一步夹心免疫测定法 ,分别测定 40例阵发性室上性心动过速 (PSVT)患者RFCA术前及术后即刻 ,6h ,12h ,2 4h血清cTnT以及上述心肌酶浓度。结果　RFCA患者cTnT ,CK ,CK MB ,AST均于术后即刻升高 ,术后 6h达到峰值 ,12h下降 ,2 4h除CK外 ,其余均恢复正常 (P均 <0 0 5 )。经相关分析表明cTnT活性变化的峰值升高程度与消融时间 ,平均功率及累计能量均无线性关系 (r=0 .33 ,r =0 .2 5 ,r=0 .2 9,P均 >0 0 5 ) ,而与消融靶点个数高度正相关(r=0 .81,P <0 0 0 1) ,与消融次数也有显著关系 (r=0 .5 1,P <0 0 1)。结论　RFCA对心肌组织确有不同程度的损伤 ,但持续时间短 ,损伤轻 ,恢复快。提示RFCA系安全有效的治疗快速心律失常的方法。测定cTnT可作为临床判断RF CA对心肌损伤的监控指标。     

射频消融对血小板活化的影响

目的 :探讨射频消融 （RFCA）损伤血小板活化的关系。方法 :对 30例连续接受 RFCA治疗的患者在插管前、电生理标测后、放电后及术后 40～ 48h,血小板 GMP- 140表达情况进行检测。结果 :在标测后、放电后及术后 48h,血小板活化率依次明显增高 ,与插管前基线值比较 ,均 P<0 .0 1。结论 :射频消融可激活血小板而使血凝状态发生改变 ,射频损伤具有血栓源性。     

阵发性室上性心动过速心率和射频导管消融的性别差异观察

目的探讨经射频导管消融治疗阵发性室上性心动过速患者性别差异的临床意义。方法回顾性分析434例阵发性室上性心动过速患者发作时心率和射频导管消融的相关参数。结果心动过速发作时女性心率(176.5±28.2次/min)比男性快(170.3±25.4次/min ),放电消融次数女性(3.0±1.2次)比男性(3.7±1.8次)少,差异均有非常显著性意义(P均<0.01)。房室结折返性和房室折返性心动过速组男女性年龄、消融成功率性别差异则无显著性意义(P>0.05)。结论阵发性室上性心动过速发作时心率女性较男性快,消融放电次数女性较男性少。     

射频消融术的射频电流对心肌损伤的临床研究

目的：研究射频消融术(RFCA)患术后不同时间血清心肌酶浓度变化及肌酸激酶同功酶(CK—MB)与RFCA诸因素的关系。探讨RFCA对心肌的损伤程度。方法：采用酶连续检测法，分别测定40例阵发性室上性心动过速(PSV丁)患RFCA术前及术后即刻，6、12、24小时血清肌酸激酶(CK)，肌酸激酶同功酶(CK—MB)及天冬氨酸氨基转氨酶(AS丁)的浓度。结果：RFCA患CK，CK—MB，AS丁均于术后即刻升高，术后6小时达到峰值．12小时下降，24小时除CK外，均恢复正常(P均＜0．05)。经相关分析表明CK。MB活性变化的峰值升高程度与消融时间，平均功率及累计能量均无线性关系(r＝0．14，r＝0．19，r＝0．27，P均＞0．05)，而与消融靶点个数高度正相关(r＝0．84，P＜0．001)，与消融次数也有显关系(r＝0．52，P＜0．01)。结论：RFCA对心肌组织确有不同程度的损伤，但持续时间短，损伤轻，恢复快。这提示RFCA系安全有效的治疗快速心律失常的方法。     

Microbubbles during radiofrequency catheter ablation: Composition and formation

OBJECTIVES: The purpose of this study was to measure tissue temperatures associated with microbubble formation during radiofrequency (RF) ablation. BACKGROUND: Microbubble formation visualized by echocardiography has been used to indicate excessive tissue heating during RF pulmonary vein isolation. However, little is known about the tissue temperatures associated with microbubble formation. METHODS: Optical fluorometric thermometry probes were used to record tissue temperatures in isolated porcine atrium overlying either lung or esophageal tissue in a saline bath. RF energy was delivered through an irrigated ablation electrode during echocardiographic monitoring for microbubble formation. RESULTS: The maximal recorded tissue temperatures were 81.0 +/- 5.0 degrees C and 88.3 +/- 8.1 degrees C at the time of intermittent (type 1) microbubble formation for lung and esophageal preparations, respectively. During continuous (type 2) microbubble formation, the temperatures were 91.4 +/- 8.2 degrees C and 99.2 +/- 7.8 degrees C, respectively (both P < .001 vs type 1). Tissue temperatures averaged >100 degrees C at the time of "pops." The maximal recorded temperature occurred up to 4 mm deep in the tissues and frequently occurred external to the atrial tissue. The total RF lesion volumes for lung and esophageal preparations were related to the pattern of microbubble formation but not to total power delivered. After generation of type 1 bubbles, up to 60% reductions in RF energy were needed to restore target tissue temperatures of 65 degrees C. Gas chromatographic analysis of the microbubbles was consistent with steam formation. CONCLUSIONS: Microbubble formation during RF ablation represents excessive tissue heating to the point of steam formation. Maximal tissue heating may occur in the adjacent lung and esophagus during cooled ablation.     

Delayed injury of autonomic nerve induced by radiofrequency catheter ablation

Objective

Radiofrequency catheter ablation (RFCA) is the curative treatment of choice for many cardiac arrhythmias and may cause myocardial injury and inappropriate sinus tachycardia. This study aimed to determine the delayed injury of autonomic nerve after RFCA.

Methods

Spectral analysis of heart rate variation on 24-hour Holter electrocardiogram recordings was carried out in 86 cases (39 women, 47 men; mean age, 42 years; range, 17-67 years) with paroxysmal supraventricular tachycardia 1 hour before and 1 year after successful RFCA (WPW type A = 31; Wolf-Pakinson-White Syndrome type B = 9; atrioventricular [AV] nodal tachycardia = 46; group A: septal accessory pathway + AV nodal tachycardia [n = 52], group B: free wall accessory pathway [n = 34]).

Results

Heart rate variation data (time domain and frequency domain) in group A 1 year after RFCA; including very low frequency; low frequency (LF); high frequency (HF); R-R interval; root mean squared successive difference interval; the percentage of sinus cycles differing from preceding cycle by more than 50 milliseconds (PNN50); and δ very low frequency, δ LF, δ HF, δ root mean squared successive difference interval and δ PNN50 significantly decreased, compared with that before the procedure. LF/HF, SD of all normal-to-normal intervals, and SD of 5-minute average normal-to-normal intervals were not significantly changed after RFCA. Heart rate variation data in group B 1 year after RFCA was not significantly changed, compared with that before the procedure.

Conclusion

Radiofrequency catheter ablation operation in site of septal accessory pathway and AV node slow pathway can cause delayed injury of autonomic nerves. Heart rate variation decrement 1 year after RFCA and persistent inappropriate sinus tachycardia post RFCA resulted from delayed injury of cardiac vagus nerve by radiofrequency current.     

射频导管消融术致心脏压塞一例

患者男性 ,66岁。因反复发作心悸 10年 ,加重 3个月入院。近 3个月来 ,几乎每天发作 1次。院外心电图提示阵发性室上性心动过速。既往无出血史。入院体格检查 ,血压12 0 /70mmHg(1mmHg =0 13 3kPa) ,全身皮肤黏膜未见出血点 ,心率 80次 /min ,心律齐 ,无杂音。诊断为阵发性室上性心动过速。术前常规检查血小板 3 9× 10 9/L ,3d后 (即消融术当天 ) ,复查血小板为 44× 10 9/L。术前心电图、X线胸片、超声心动图无异常。于 2 0 0 2年 10月 14日行心内电生理检查和射频导管消融术。按常规置入冠状静脉窦 (CS)、高位右心房、希氏束和右心…     

Comparison of hemostatic activation created by right- and left-heart radiofrequency catheter ablation

BACKGROUND: Thromboembolic complications commonly occur in radiofrequency (RF) ablation procedures (0.6-1.3% of cases). Comparison of hemostatic activation between left and right RF ablation is limited. HYPOTHESIS: The purpose of this study was to evaluate platelet and hemostatic activation before, immediately after, and 48 h following left and right myocardial RF ablation procedures. METHODS: The subjects were two groups of patients who underwent right-heart (24 patients) and left-heart (20 patients) RF ablation. Blood samples taken before, immediately after, and 48 h after the procedure were tested for changes in platelet and hemostatic activation. RESULTS: No indication of clinically symptomatic thromboembolism and no major differences in baseline characteristics and procedure were apparent in either group, except for a higher temperature mode setting (p < 0.001) in the left-heart group. The hemostatic evaluation levels increased significantly by the end of the procedure in both groups and the platelet activation level remained elevated for 48 h after the procedure. The platelet activation level increased insignificantly at the end and 48 h after the procedure. Of the other changes in levels of platelet and hemostatic activation, only an increase in one of the hemostatic levels in the right-heart group at 48 h after procedure was significant (p = 0.01). CONCLUSIONS: Our findings suggest that similar hemostatic activation occurred during and immediately after RF ablation in both groups. Sustained elevation of the hemostatic marker after the ablation procedure in the right-heart group was observed as of significant therapeutic and prognostic implications.     

Disseminated intravascular coagulation as a complication of radiofrequency catheter ablation of atrial fibrillation

Since Haissaguerre and his colleagues demonstrated the importance of the pulmonary veins in the generation of atrial fibrillation (AF) in 1998, a variety of different ablative interventions have been performed to eliminate AF. Various complications related to catheterization, ablation itself including pulmonary vein stenosis, pericardial effusion, stroke, and atrioesophageal fistula have been reported. Disseminated intravascular coagulation (DIC) is a systemic syndrome characterized by enhanced activation of coagulation with some intravascular fibrin formation and deposition. This is the first report, to our knowledge, of a patient whose condition was complicated by DIC after segmental ostial isolation of pulmonary veins for persistent AF. The patient has completely recovered from the DIC by hemodialysis, administration of blood constituents for 15 days.     

Temperature monitoring during radiofrequency catheter ablation of accessory pathways.

BACKGROUND. Animal studies have suggested that the temperature of the electrode-tissue interface during radiofrequency catheter ablation accurately predicts lesion size. The purpose of the current study was to evaluate the utility of continuous temperature monitoring during radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome. METHODS AND RESULTS. Twenty patients with manifest preexcitation were included in the study. The ablation catheter was positioned on the ventricular side of the mitral annulus for left-sided accessory pathways and on the atrial side of the tricuspid annulus for right-sided and septal accessory pathways. A thermistor imbedded in the distal electrode of the ablation catheter allowed continuous temperature monitoring during each energy application. To define the relation between power and temperature, radiofrequency current was applied several times at each site using outputs of 20, 30, 40, and 50 W. The accessory pathways were successfully ablated in each of the 20 patients. Because of marked variability in the efficiency of heating between sites, power output did not predict temperature. However, at any given site, there was a positive dose-response relation between power and temperature. Radiofrequency energy applications on the atrial side of the tricuspid annulus produced lower temperatures than did applications on the ventricular side of the mitral annulus (49 +/- 7 versus 60 +/- 16 degrees C, p = 0.0001). Transient block in the accessory pathways occurred at a mean of 50 +/- 8 degrees C, whereas permanent block was seen at a mean of 62 +/- 15 degrees C (p = 0.0001). Less than half of the applications at outputs < or = 40 W produced temperatures adequate to interrupt accessory pathway conduction. An abrupt rise in impedance caused by coagulum formation occurred only at temperatures between 95 and 100 degrees C. CONCLUSIONS. Temperature monitoring may facilitate radiofrequency catheter ablation of accessory pathways. By adjusting power output to ensure that adequate but not excessive temperatures have been achieved, a rise in impedance can be avoided and the total number of energy applications and procedure duration may be reduced.     

射频消融术对儿童局部心肌损伤的随访研究

目的　探讨儿童射频消融术 (radiofrequencycatheterablation ,RFCA)对局部心肌损伤及其影响。方法　 (1)对 2 5 0例接受RFCA术的患儿进行手术前、后心电图 ,超声心动图和 2 4小时动态心电图长期随访 ;(2 )对其中 30例接受RFCA术患儿的手术前、后心肌肌钙蛋白I(cardiactroponinI,cTnI)浓度进行 3个月动态观察。结果　 (1)RFCA术后 1dcTnI浓度最高 ,随后逐渐下降 ,术后 3个月降至正常水平 ;(2 )RFCA术中对心肌组织损伤程度为IVT >AVRT(LP) >AVRT(RP) >AVNRT ;(3)没有出现因靶点的瘢痕组织导致的新的心律失常。结论　儿童RFCA术是安全的 ,从急性损伤到形成瘢痕组织所需的时间约 3个月 ,靶点处瘢痕组织不会导致新的心律失常。     

Radiation exposure during radiofrequency catheter ablation of accessory atrioventricular connections

BACKGROUND. Catheter ablation of accessory atrioventricular (AV) connections has been demonstrated to be effective in more than 85% of patients. One of the risks of this procedure is radiation exposure during the fluoroscopic imaging necessary to guide catheter manipulation. The objective of the present study was to measure the radiation received by patients and physicians during radiofrequency catheter ablation and to estimate the resultant somatic and genetic risks. METHODS AND RESULTS. Radiation exposure to patients and physicians was measured during attempts at radiofrequency catheter ablation of accessory AV connections in 31 consecutive patients. Radiation exposure was measured using thermoluminescent sensors placed on the patient and on the physician. Somatic and genetic risks were estimated based on the radiation levels recorded using these sensors. The durations of fluoroscopy and of the catheter ablation procedure were recorded for each patient. Catheter ablation was successful in 28 of 31 patients (90%). Mean +/- SD duration of fluoroscopy was 44 +/- 40 minutes. The largest patient radiation dose was measured over the ninth vertebral body posteriorly (median, 7.26 rem [roentgen equivalents man]; range, 0.31-135.7 rem). Median radiation dose to the thyroid was 0.46 rem (range, 0.06-7.26 rem), and median radiation dose to the posterior iliac crest was 2.43 rem (range, 0.01-8.3 rem). The greatest radiation dose to the operator was recorded at the left hand (99 mrem). Mean radiation dose to the operator's eyes was 28 mrem. CONCLUSIONS. Radiofrequency catheter ablation of accessory AV connections may result in significant radiation exposure to the patient and to the physician. Each hour of fluoroscopic imaging is associated with a lifetime risk of developing a fatal malignancy of 0.1% and a risk of a genetic defect of 20 per 1 million births. Although these risks must be recognized, they are relatively small compared with the risks associated with alternate approaches to management, including no therapy, antiarrhythmic drug therapy, and surgery.     

射频导管消融术并发急性心脏压塞一例

本文报告我院1例阵发性心房颤动(房颤)病人在Carto标测系统引导下，应用Pappone法消融后并发急性心脏压塞。