心房颤动导管消融的地位和进展

心房颤动(房颤)是临床常见的心律失常之一,最大风险是血栓栓塞,常见是脑卒中。随着人口的老龄化,房颤人数持续增加,治疗问题也逐渐成为人们关注重点。房颤导管消融是其重要治疗方法之一,可明显改善房颤患者预后。且随着技术发展,消融方法也日趋成熟,故导管消融术治疗房颤地位正在逐步提升。但消融方法尚无固定术式,发生机制尚未完全明确,尤其对于持续房颤。因此房颤消融术仍存在一些问题有待进一步探索。     

Tissue temperatures and lesion size during irrigated tip catheter radiofrequency ablation: an in vitro comparison of temperature-controlled irrigated tip ablation, power-controlled irrigated tip ablation, and standard temperature-controlled ablation

The limited success rate of radiofrequency catheter ablation in patients with ventricular tachycardias related to structural heart disease may be increased by enlarging the lesion size. Irrigated tip catheter ablation is a new method for enlarging the size of the lesion. It was introduced in the power-controlled mode with high power and high infusion rate, and is associated with an increased risk of crater formation, which is related to high tissue temperatures. The present study explored the tissue temperatures during temperature-controlled irrigated tip ablation, comparing it with standard temperature-controlled ablation and power-controlled irrigated tip ablation. In vitro strips of porcine left ventricular myocardium were ablated. Temperature-controlled irrigated tip ablation at target temperatures 60 degrees C, 70 degrees C, and 80 degrees C with infusion of 1 mL saline/min were compared with standard temperature-controlled ablation at 70 degrees C and power-controlled irrigated tip ablation at 40 W, and infusion of 20 mL/min. Lesion size and tissue temperatures were significantly higher during all modes of irrigated tip ablation compared with standard temperature-controlled ablation (P < 0.05). Lesion volume correlated positively with tissue temperature (r = 0.87). The maximum recorded tissue temperature was always 1 mm from the ablation electrode and was 67 +/- 4 degrees C for standard ablation and 93 +/- 6 degrees C, 99 +/- 6 degrees C, and 115 +/- 13 degrees C for temperature-controlled irrigated tip ablation at 60 degrees C, 70 degrees C, and 80 degrees C, respectively, and 112 +/- 12 degrees C for power-controlled irrigated tip ablation, which for irrigated tip ablation was significantly higher than tip temperature (P < 0.0001). Crater formation only occurred at tissue temperatures > 100 degrees C. We conclude that irrigated tip catheter ablation increases lesion size and tissue temperatures compared with standard ablation in the temperature-controlled mode at the same or higher target temperatures and in the power-controlled mode. Furthermore, tissue temperature and delivered power are the best indicators of lesion volume during temperature-controlled ablation.     

Left atrial flutter after segmental ostial radiofrequency catheter ablation for pulmonary vein isolation

Segmental ostial ablation to electrically isolate pulmonary veins has been performed for atrial fibrillation. Left atrial flutter that utilized a critical isthmus adjacent to the ostium of the left superior pulmonary vein was diagnosed and successfully ablated in a patient 3 months after a successful pulmonary vein isolation procedure. Documenting the cause of symptoms after pulmonary vein isolation in patients with atrial fibrillation is critical in guiding therapy.     

Early recurrence of atrial tachyarrhythmias following radiofrequency catheter ablation of atrial fibrillation

The use of blanking periods, the immediate period postablation during which transient tachyarrhythmia episodes are not considered recurrences, has been predicated on the assumption that not all early recurrences of atrial tachyarrhythmias (ERAT) will lead to later recurrences and, as such, does not necessarily represent treatment failure. While ERAT can be expected to occur in approximately 38% of patients within the first 3 months of atrial fibrillation (AF) ablation, only half of these patients will manifest later recurrences. Clinical features related to the patient's history of AF, the index ablation procedure, and particularities of the ERAT can help identify patients at higher risk of later recurrence in whom aggressive attempts to control rhythm, including early cardioversion and reintervention, may be justified.     

射频消融治疗特发性室性心动过速的临床观察

目的观察射频消融(RFCA)治疗9例特发性室性心动过速(IVT)方法和结果。方法分别行激动顺序标测法和起搏标测法,对左室特发性室速(ILVT)7例,右室特发性室速2例,行射频消融治疗。结果6例ILVT射频消融治疗成功,均起源于左室间隔面,有效消融靶点处P电位较体表心电图QRS起始点提前(34.6±8.9)m s(25~58 m s),2例IRVT射频消融成功,有效消融靶点处与心动过速时的12导联心电图QRS波形完全相同。无一例出现并发症。结论射频消融是治疗特发性室性心动过速的有效方法。     

导管射频消融治疗右室流出道室性早搏的护理

目的探讨导管射频消融治疗右室流出道室性早搏的护理方法。方法对52例右室流出道室性早搏患者,采用射频消融治疗,并给予心理护理和基础护理。结果52例均完成了射频消融治疗。随访2~60个月,根治率92.3%(48/52),有效率98.1%(51/52)。结论合理、细致的护理可消除患者的恐惧心理,提高手术耐受性,且能及早发现和防治并发症,增加手术的安全性。     

Comparison of the point-by-point versus catheter dragging technique for curative radiofrequency ablation of atrial fibrillation

Background: The relationship between the applied techniques and clinical outcomes after radiofrequency (RF) ablation of atrial fibrillation (AF) remains unclear. We compared the results of ablation by RF delivered via a point‐by‐point versus catheter dragging technique for the treatment of AF. Methods: This study included 66 patients with drug‐refractory AF who underwent circumferential pulmonary vein (PV) ablation. A point‐by‐point technique was used in 35 (53%) patients (Group I), and catheter dragging technique in the remaining 31 (47%) patients (Group II). If AF persisted or remained inducible after the PV isolation, additional ablation of complex fractionated atrial electrograms and linear ablation were performed. Results: Significantly, fewer RF applications were delivered in Group II than in Group I. The total RF energy duration delivered was comparable between the two groups (P = 0.55). However, the total energy of RF deliveries was significantly greater in Group II than in Group I (P = 0.02). Despite a longer fluoroscopic exposure time (P = 0.01), the total procedural duration was significantly shorter in Group II than in Group I (P = 0.005). Within 3 months after a single ablation procedure, 24 patients (69%) in Group I versus 13 patients (42%) in Group II had ≥1 recurrence(s) of atrial tachyarrhythmias (P = 0.03). A multivariate analysis showed that a point‐by‐point ablation was the only independent predictor of early atrial tachyarrhythmia recurrences. Conclusions: The catheter dragging technique for ablation of AF was associated with a lower early recurrence rate of atrial tachyarrhythmias than the point‐by‐point technique. (PACE 2011; 15–22)     

Swallowing-induced atrial tachyarrhythmias: prevalence, characteristics, and the results of the radiofrequency catheter ablation

BACKGROUND: Detailed information on swallowing-induced tachyarrhythmias has been lacking. METHODS: The prevalence, characteristics, and results of the radiofrequency catheter ablation (RFCA) of swallowing-induced tachyarrhythmias were examined in 544 patients with symptomatic premature atrial contractions (PACs), paroxysmal atrial tachycardia (AT), and/or paroxysmal atrial fibrillation (AF). We also conducted a search of the medical literature on swallowing-induced tachyarrhythmias. Further, we presented an in-depth review of the literature and investigated the published data on swallowing-induced tachyarrhythmias. RESULTS: The prevalence of swallowing-induced tachyarrhythmias was 0.6% (three patients). An analysis of the published literature and our three cases demonstrated that (1) males predominated 9:1 over females, (2) most cases occurred over 35 years of age, (3) tachyarrhythmias occurred consistently and reproducibly shortly after each swallow, (4) 90% of the patients had PACs and/or AT as the manifesting arrhythmia, (5) the PACs provoked by swallowing usually had the same P-wave morphology as the first beat of the AT and AF, and (6) RFCA procedures performed in five cases resulted in success with no recurrence or complications. CONCLUSIONS: Swallowing-induced tachyarrhythmias are rare, but have several distinct characteristics. RFCA should be considered in appropriately selected patients with reliable inducibility because such an ablation may offer a permanent cure.     

Time course of adenosine-induced pulmonary vein reconnection after isolation: implications for mechanism of dormant conduction

Background: Adenosine (ADO) has been proposed to reconnect isolated pulmonary veins (PVs) postablation through hyperpolarization of damaged myocytes in an animal model. However, PV reconnection can occur via ADO‐mediated sympathetic activation. We sought to determine the mechanism of ADO‐induced PV reconnection in the clinical setting by characterizing its time course and location in patients undergoing PV isolation. Methods: Seventy‐four patients (61 male; age 61 ± 10 years) undergoing PV isolation for atrial fibrillation (54 [73%] paroxysmal and 19 [27%] persistent) were studied. After each PV was isolated, a 12‐mg intravenous bolus of ADO was administered and onset, offset, and location of ADO‐induced PV reconnection and onset and offset of bradycardia were analyzed. Results: In 22 (30%) patients, ADO‐induced PV reconnection occurred in 34 of 270 (13%) PVs. In 24 (71%) PVs, the duration of ADO‐induced reconnection exceeded that of bradycardia. The onset of ADO‐induced reconnection occurred before the onset of bradycardia in 10 (30%) PVs and during bradycardia in 23 (70%) PVs. No PVs exhibited onset of reconnection after resolution of bradycardia. Common sites of PV reconnection included the carinal region (41% of right PVs and 29% of left PVs) and left PV‐atrial appendageal ridge region (35% of left PVs). Conclusions: ADO‐induced PV reconnection occurs during the bradycardic phase of the ADO bolus response and not during the late tachycardic phase. ADO‐induced PV dormant conduction is closely associated with the negative dromotropic effects of ADO and suggests that hyperpolarization of the resting membrane is the unifying mechanism. (PACE 2012;XX:1–8)     

经导管射频消融治疗右室流出道室性期前收缩

目的　评价经导管射频消融治疗单形性右室流出道室性期前收缩的有效性和安全性。方法　采用射频导管消融术对 4 2例症状严重的正常心脏单形性右室流出道室性期前收缩进行治疗 ,男 2 8例 ,女 14例 ,年龄 (42 .2±7.8)岁。将消融电极送至右室流出道区域 ,采用起搏标测和激动顺序标测 ,前者以起搏时与室性期前收缩QRS波形态完全相同为消融靶点 ,后者以室性期前收缩时最早心室激动点为消融靶点。 4 2例室性期前收缩全部起源于右室流出道 ,呈左束支阻滞图形 ,其中 36例起源于右室流出道间隔部 ,6例起源于右室流出道游离壁。以室性期前收缩在放电后 10秒内消失 ,并维持窦性心律 30～ 6 0min为即刻成功标准。结果　消融即刻成功率为 90 .5 % (38/ 4 2 ) ,其中右室流出道间隔部 94 .4 % (34/ 36 ) ,游离壁 6 6 .7% (4/ 6 )。 2 0例患者 2 4小时动态心电图记录消融前后室性期前收缩数分别为 (2 0 80 0± 10 4 0 )次 / 2 4h和 (110± 12 0 )次 / 2 4h(P <0 .0 0 1)。 1例患者消融术中出现室颤经电复律恢复窦性心律 ,其余无任何并发症。随访 4～ 16个月症状缓解率为 89.5 % (34/ 38) ,复发率为 5 .3% (2 / 38) ,均为右室流出道游离壁室性期前收缩。随访期间亦无并发症。结论　经导管射频消融可有效地治疗症状重、药     

Comparison of the efficacy of cooled-tip and 8-mm-tip catheters for radiofrequency catheter ablation of the cavotricuspid isthmus: a meta-analysis

BACKGROUND: Cooled-tip RFA (cRFA) and conventional 8-mm-tip catheters were found to be more effective and as safe as conventional 4-mm-tip catheters for atrial flutter (AFL) radiofrequency ablation (RFA), facilitating the rapid achievement of bi-directional isthmus block (BIB), but studies comparing cRFA and 8-mm-tip catheters are not randomized or results are discussed. Thus, we performed a meta-analysis of available randomized trials to evaluate the effectiveness in terms of primary success and procedure parameters. METHODS: Reports of trials were identified through a Medline, Embase, Current Contents, Cardline, and an extensive bibliography search. Trials that met the following criteria were included: (1) prospective, randomized, controlled, and open trials; (2) patients assigned to an 8-mm-tip or a cRFA catheter for AFL RFA; (3) endpoints events related to primary success rate (BIB achievement), and procedure parameters (number of RF applications, x-ray exposure and ablation duration). RESULTS: Seven trials met the inclusion criteria. They included 603 patients with established AFL randomized to an 8-mm-tip or cRFA catheter group. Comparing 8-mm groups with cRFA groups, the meta-analysis showed similar BIB achievement relative risk (RR) 0.96, 95% confidence interval (CI): 0.92 to 1.01, (P = 0.13); total RF application time weighted mean difference (WMD) 0.88, 95% CI: -0.36 to 2.12, (P = 0.16); duration of x-ray exposure (min) (WMD = 1.07, 95% CI: -0.81 to 0.295, (P = 0.26); ablation procedure duration (min) (WMD = 0.68, 95% CI: -3.37 to 4.73; P = 0.74). CONCLUSION: The present meta-analysis confirms that cooled-tip and large-tip catheters are equally efficient for cavotricuspid isthmus ablation with both similar primary success rates and procedure parameters.     

Successful radiofrequency catheter ablation of ventricular tachycardia originating from underneath the mechanical prosthetic aortic valve

A 67-year-old man who developed sustained ventricular tachycardia (VT) 4 years after a prosthetic aortic valve replacement, underwent electrophysiologic testing and catheter ablation. The mechanism of the VT was suggested to be triggered activity because the VT could be induced by programmed ventricular stimulation, and burst ventricular pacing demonstrated overdrive suppression without a transient entrainment. Successful catheter ablation using a transseptal approach was achieved underneath the mechanical prosthetic aortic valve on the blind side for that approach. This case demonstrated that catheter mapping and ablation of the entire LV using a transseptal approach might be possible.     

The 1998 NASPE prospective catheter ablation registry

The results of the NASPE Prospective Voluntary Registry are reported. A total of 3,357 patients were entered. For those undergoing atrioventricular (AV) junctional ablation (646 patients), the success rate was 97.4% and significant complications occurred in 5 patients. A total of 1,197 patients underwent AV nodal modification for AV nodal reentrant tachycardia, which was successful in 96.1% and the only significant complication was development of AV block (1%). Accessory pathway ablation was performed in 654 patients and was successful in 94%. Major complications included cardiac tamponade (7 patients), acute myocardial infarction (1 patient), femoral artery pseudoaneurysm (1 patient), AV block (1 patient), pneumothorax (1 patient), and pericarditis (2 patients). A total of 447 patients underwent atrial flutter ablation and acute success was achieved in 86% of patients. Significant complications included inadvertent AV block (3 patients), significant tricuspid regurgitation (1 patient), cardiac tamponade (1 patient), and pneumothorax (1 patient). Atrial tachycardia was attempted for 216 patients and the success rate was higher for those with right atrial (80%) or left atrial (72%) compared to those with septal foci (52%). A total of 201 patients underwent ablation for ventricular tachycardia. The success rate was higher for those with idiopathic ventricular tachycardia compared to those with ventricular tachycardia due to ischemic heart disease or cardiomyopathy. While the number of AV junction ablation were higher for those > 60 years of age, there was no significant difference in the success rate or incidence of complication comparing patients > or = 60 to those < 60 years of age. In addition, we found no differences in incidence of success or complications comparing large volume centers (> 100 ablation/year) with lower volume centers or between teaching and non-teaching hospitals.     

缓慢心室率心房扑动患者射频消融术后发生房室传导阻滞分析

目的探讨心房扑动射频消融术后出现房室传导阻滞的原因及对策。方法回顾性分析35例心房扑动患者,存在房室传导比率≥5:1,均采用消融下腔静脉至三尖瓣峡部,终点达到双向阻滞。29例于房扑下消融,6例是转窦性心律后消融,分析术后发生房室传导阻滞的原因。结果 9例患者术后发生I°至高度房室传导阻滞,其中4例患者恢复,5例患者未恢复。结论心房扑动行射频消融术有造成房室传导阻滞可能,但发生率低。缓慢心室率的心房扑动术前可能合并房室传导阻滞,转窦性心律后消融对增加手术安全性及是否存在并发症的判定有帮助。     

左室流出道室性心律失常的射频消融治疗

目的 探讨起源于左室流出道少见部位的室性心动过速和/或频发室性早搏的心电图特点和射频消融治疗.方法 3例左室流出道室速和/或室早患者,术中进行激动和起搏标测,同时结合冠状动脉造影或三维电解剖标测系统(CARTO)定位.结果 3例患者中2例体表心电图特点类似右室流出道间隔部室速及室早,经腔内电生理证实起源于主动脉根部右冠窦内.1例起源于主动脉瓣-二尖瓣连接区(AMC),该部位室速及室早特有的典型心电图表现为II、III、aVF及所有胸前导联QRS波均呈R形.3例患者消融后观察2~24个月,均无复发.结论 右冠窦和AMC是左室流出道室速和/或室早的少见特殊起源部位,根据体表心电图形态,结合多种腔内标测技术及冠脉造影,能进行准确定位及成功消融.     

射频消融术后尿潴留患者的护理

分析86例射频消融术后患者出现尿潴留的不同原因，包括不习惯床上排尿、精神因素、疼痛等。护理对策包括：减少卧床时间，心理护理，变换体位，物理诱导，术后多饮水等，结果81例患者排尿成功，只有5例(5．8％)男性前列腺肥大患者需要导尿。