室上性心动过速的射频消融治疗

应用射频导管消融术治疗室上性心动过速204例。其中房室折返性心动过速175例;房室结折返性心动过速28例;房性心动过速1例。成功 189例,成功率为92.7％。有5例出现并发症,占2.45％。随访 1～36个月,有8例复发,5例再次消融成功。我们认为射频消融术是一种安全和有效的根治室上性心动过速主要方法。     

Catheter Cryoablation of Supraventricular Arrhythmias:

LOWE, M.D., et al .: Catheter Cryoablation of Supraventricular Arrhythmias: A Painless Alternative to Radiofrequency Energy. Cryothermy has potential advantages over RF energy for catheter ablation, including reversibility of lesion formation, catheter stability, and less procedural discomfort. Cryoablation procedures were performed in 14 patients with atrioventricular reentrant tachycardias (AVNRTs), 13 patients with accessory pathway (AP)-mediated tachycardias, and 5 patients with atrial fibrillation. The numbers of energy applications, pain scores, procedural times, and outcomes were recorded and compared with age- and sex-matched patients undergoing similar RF procedures. Cryoablation was successful in 26 of 32 patients (11/14 AVNRT, 10/13 AP, 5/5 AF) compared with 30 of 32 undergoing RF procedures, with similar numbers of energy applications and procedural times. Cryothermy was painless in all patients, and the overall procedural discomfort was significantly less than in patients treated with RF   (1.3 ± 2.2 vs 6.1 ± 3.5)   . In patients with anteroseptal pathways, cryomapping successfully identified safe sites to target the delivery of energy. Cryothermy is a painless and safe alternative to RF. It may be particularly useful for catheter ablation of patients with pathways close to the atrioventricular node. (PACE 2003; 26[Pt. II]:500–503)     

Radiofrequency Catheter Ablation of Concealed Atrio-His Bypass Tract Involved in Paroxysmal Supraventricular Tachycardia

In a patient with paroxysmal supraventricular tachycardia and without any evidence for preexcitation syndrome or dual atrioventricular (AV) nodal pathways, the tachycardia reentry circuit consisted of the AV node as an antegrade limb of the circuit and a concealed atrio-His bypass tract located in the posterior septum as a retrograde limb. During the tachycardia, the atrial potentials in the septal region and coronary sinus were inscribed in the QRS complex, and the earliest atrial activation site was located in the posterior septum. Ventricular extrastimulation at critically short intervals reproducibly demonstrated a ventriculo-His-atrial activation sequence with the same earliest retrograde atrial activation site as that during the tachycardia. Radiofrequency energy (20 W) was applied to this earliest activation site during ventricular pacing, which resulted in complete ventriculo-atrial block within 2 seconds after energy application. The antegrade AV conduction property was not affected and the tachycardia was no longer induced. The patient has been free from tachycardia attack for a follow-up period of 8 months. Therefore, radiofrequency catheter ablation for an atrio-His bypass tract is feasible without inducing any AV conduction disturbance.     

经导管射频消融治疗阵发性室上性心动过速78例

目的:探讨经导管射频消融治疗阵发性室上性心动过速的临床疗效.方法:78例阵发性室上性心动过速患者均行心内电生理检查和经导管射频消融治疗.结果:消融成功率为97.4%(76/78),复发率为3.8%(3/78),并发症发生率为2.56%(2/78).结论:经导管射频消融是治疗阵发性室上性心动过速的一种有效方法.     

Palpitations Occur Frequently Following Radiofrequency Catheter Ablation for Supraventricular Tachycardia, But Do Not Predict Pathway Recurrence

Radiofrequency ablation of extranodal pathways is an effective treatment for supraventricular tachycardia, but late recurrences of pathway conduction do occur. To determine if recurrence of palpitations following ablation predicts pathway recurrence, we interviewed 77 patients who were at Jeast 4 weeks status-post successful ablation of an accessory pathway (43 overt, 11 concealed)or a slow pathway (23)for AV nodal reentrant tachycardia. Palpitations were reported by 45 (58%)patients postablation, and 28 (36%)patients reported palpitations lasting ≥10 seconds and/or felt their symptoms represented recurrent tachycardia (major palpitations). Repeat electrophysiological testing was performed 3 months postablation in 53 patients, including 34 patients with palpitations (22 with major symptoms). Eight (10%)patients had recurrent pathway conduction demonstrated on repeat testing: two had no symptoms prior to restudy and six had major symptoms. One patient had major symptoms, but was found to have inducible atrial tachycardia and not pathway recurrence on restudy. Thus, 15 (68%)of 22 patients with major symptoms who were restud-ied had no pathway recurrence or inducible arrhythmia to explain their symptoms. Of the 24 patients not restudied, none has had documented recurrent tachycardia or overt pathway conduction by electrocardiogram over a mean follow-up of 335 ± 138 (range 132–616)days. Thus, palpitations, including palpitations reminiscent of preablation symptoms, are common following radiofrequency ablation and often do not predict pathway recurrence. Repeat electrophysiological testing is frequently required to document long-term success of radiofrequency ablation for supraventricular tachycardia in patients with recurrence of major symptoms.     

Studies on the Prevalence of Complicated Atrial Arrhythmias, Flutter, and Fibrillation in Patients with Reciprocating Supraventricular Tachycardia Before and After Successful Catheter Ablation

Atrial flutter and AF are complications in approximately 30% of cases of paroxysmal supraventricular tachycardia (PSVT)-indicated catheter ablation, and it is of interest to determine if therapeutic modification for PSVT would eliminate combined atrial tachyarrhythmia like atrial flutter and AF. The aim of this study was to determine the incidence and the risk of atrial tachyarrhythmias after catheter ablation of PSVT. A total of 152 patients (age range 12-74, mean 41 +/- 17 years) with accessory pathway (n = 106) and/or dual atrioventricular nodal conduction (n = 46) were enrolled in a 2-year follow-up program after successful catheter ablation. Possible risks on clinical background (age, sex, PSVT duration, hemodynamic instability during attacks), premature atrial contraction (PACs) on Holter monitoring, echocardiographic left atrial size, and electrophysiological property (insertion site, conduction type, effective refractory period) were evaluated. Atrial flutter and AF were complications in 53 (35%) of the subjects, who were elderly and had a longer PSVT history with a larger left atrial dimension and frequent PACs; however, the electrophysiological properties were similar. After a 2-year follow-up period 36 (24%) of the patients still exhibited PAC runs, including 13 (9%) with atrial flutter and AF, each one of whom were complicated with nonlethal cerebral thromboembolism and congestive heart failure. Multiplelogistic-regression analysis revealed that advanced age (> or = 41 years, P = 0.0152) and frequent PACs (> or = 1% of total daily QRS counts, P = 0.0426) on Holter monitoring are the risk factors of PAC runs and/or atrial flutter and AF. In conclusion, successful ablation for PSVT is thought to be beneficial for preventing atrial flutter and AF. However, careful follow-up to monitor for the recurrence and atrial flutter and AF related complications, especially in patients of solitary atrial flutter and AF without reciprocating tachycardia and with frequent PAC.     

Control of Refractory Supraventricular Arrhythmias After Unsuccessful Closed-Chest His Bundle Ablation

Six patients underwent attempted catheter ablation of the His bundle for control of refractory supraventricular tachyarrhythmias. Permanent complete heart block was achieved in only three patients. All six patients have remained asymptomatic without antiarrhythmic medications over a follow-up period of six to 17 months (mean 10 months). There were no complications of the procedure apart from mild elevation of creatine kinase levels in three patients. In this series, resumption of atrioventricular (AV) conduction following attempted His bundle ablation was not associated with recurrence of symptomatic arrhythmias. Preservation of AV conduction may also obviate the need for permanent ventricular pacing.     

儿童阵发性室上性心动过速的射频消融治疗

目的观察射频消融治疗儿童阵发性室上性心动过速(SVT)的有效性和安全性.方法38例患儿,男22例,女16例;年龄8～14岁,平均(12.5±2.2)岁,有反复阵发性心悸1～144个月,平均(36.4±32.0)个月.全部患儿均接受心内电生理检查及射频消融治疗.左旁道经主动脉逆行法或经房间隔法,右旁道和双径路经股静脉法.结果左旁路22例、右旁路9例、双径路7例.双径路成功率100%、左旁路100%、右旁路88.9%.术中有Ⅰ°AVB1例,一过性Ⅱ°AVB1例,未发现其它严重并发症.操作时间(91±27)min,X线透视时间(30±12)min.随访10～87个月,1例双径路2周后再发,再次消融获得成功,1例右旁路不成功.结论射频消融治疗儿童SVT是一种有效而安全的方法,但应根据儿童特点严格掌握适应症.     

临床护理路径在射频消融术治疗室上性心动过速健康教育中的应用

目的比较临床护理路径进行健康教育与传统方法进行健康教育的护理效果差别。方法将89例室上性心动过速行射频消融术患者,按病例单双号分成2组,观察组采用临床护理路径进行健康教育,对照组采用传统方法进行健康教育,并对两组的护理效果进行比较。结果两组患者的心理状态、健康知识掌握情况、行为改变、住院日、满意度差异均有统计学意义（P〈0．01）,观察组术后不良反应发生率少于对照组（P〈0．05或P〈0．01）。结论应用临床护理路径对射频消融术患者实施健康教育,能促进患者更好地掌握健康教育知识,降低术后不良反应、住院日及医疗费用,提高满意度。     

The Effects of Radiofrequency Ablation Versus Medical Therapy on the Quality-of-Life and Exercise Capacity in Patients with Accessory Pathway-Mediated Supraventricular Tachycardia: A Treatment Comparison Study

This study aims to evaluate the impact of transcatheter radiofrequency ablation on quality-of-life (QOL) and exercise capacity in patients with paroxysmal Supraventricular tachycardia (SVT) on stable medical therapy and the extent of symptomatic benefits of this treatment in patients with SVT of different clinical severity. A total of 55 patients with SVT on stable medications for 3 months were randomly selected for either radiofrequency ablation treatment (46 patients) or continuation of medical therapy (medical control group, 9 patients). Severity of SVT was classified based on the frequency and duration of SVT episodes, hemodynamic disturbance, and the presence of preexcited atrial fibrillation during an episode. Treadmill exercise capacity (Bruce protocol) and QOL (questionnaire study and interview) were assessed before and at 3-month intervals for 1 year after the radiofrequency procedure and at 3 months in the medical control group. Thirty-six of 46 patients were successfully ablated in one session, and a QOL measure before and at 3 months after ablation in these patients showed an improvement in total scores for “General Health Questionnaire” (20.3 ± 6.2 vs 16.9 ± 5.3, P < 0.01), “Somatic Symptoms Inventory” (73. 0 ± 6.0 vs 76.1 ± 4.1, P < 0.02), and “Sickness Impact Profile” (12.6 ±1.7 vs 4.9 ± 3.9, P < 0.01). This improvement in QOL was progressive and sustained over a 1-year period. Major arrhythmia limitations, such as apprehension of strenuous activities and long distance travel, were alleviated after a successful procedure. The extent of improvement in QOL was significant for patients considered to have “mild” or “severe” arrhythmia. Maximum exercise capacity during treadmill exercise increased from 13.1 ± 5.5 to l4.9 ± 4.5 minutes at 3 months after successful ablation (P < 0.002), which was mainly due to suppression of exercise induced SVT. There was no change in QOL or exercise capacity in the medical control group and in patients with an initially unsuccessful radiofrequency ablation. Thus, transcatheter radiofrequency ablation is superior to medical therapy in improving QOL and exercise capacity of patients with SVT of different clinical severity.     

Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia in Children

Radiofrequency (RF) catheter ablation has been widely used in the treatment of cardiac arrhythmias. In atrioventricular nodal reentrant tachycardia (AVNRT), the experience has been predominantly in adults. The cardiac electrophysiological records of 18 consecutive children undergoing RF catheter AV node modification for AVNRT were reviewed. The patients (10 females, 8 males) were 8.2–17.9 years of age (mean 13.6 ± 3.0), weight 15.2–88.1 kg (mean 52.2 ± 20.8), and height 103–190 cm (mean 157.1 ± 21.7). Thirteen were on antiarrhythmic medications (1–3, average 1.5 drugs/day). All drugs were discontinued 48 hours prior to the ablations. The procedures were performed under sedation and local anesthesia. Pre- and post-AV node modification electrophysiological studies were performed in all procedures. The 18 patients underwent a total of 25 procedures (1.39 ± 0.61 per patient): the anterior approach aimed at the antegrade fast pathway in the first four patients and the posterior approach aimed at the slow pathway in the remainder. Thenumber of energy applications was 8–54 (19.8 ± 10.7) per procedure. The maximum energy used in each procedure was 30–50 watts (33.8 ± 8.4). The average energy was 24–50 watts (33.0 ± 6.8). The fluoroscopy time was 7.1–73.4 minutes (29.9 ± 20.0) per procedure, for a total catheterization time of 228–480 minutes (300.3 ± 59.1). Preablation spontaneous or induced AVNRT (cycle length 310.4 ± 55.0 msec) was seen in all except one who had the arrhythmia (cycle length 270 msec) on surface ECG. In 22 of 25 studies, the AH interval measured 67.4 ± 13.2 msec pre- and 98.7 ± 58.4 msec post-AV node modification (P < 0.02). Procedures were initially successful in 16 (89%) of 18 patients. One patient developed complete AV block requiring DDD pacemaker and has since recovered normal AV conduction. Transient third- or second-degree block was seen in four. Other complications included airway obstruction in one and excessive emesis in another. In follow-up of 2–26 months (13.0 ± 7.3), one patient underwent surgical ablation for failed initial RF catheter ablation, and two underwent successful RF procedures for recurrences. RF catheter AV node modification for AVNRT in children is a useful technique. Under ideal circumstances, it is safe and efficacious. Follow-up to determine the potential long-term complications is necessary.     

Curative Radiofrequency Catheter Ablation for Permanent Junctional Reciprocating Tachycardia

Two patients with the permanent form of junctional reciprocating tachycardia successfully treated with the radiofrequency catheter ablation technique are described. In both patients a reentrant tachycardia utilizing a conceoled slow conducting posterior septal accessory pathway for retrograde conduction was demonstrated. Radiofrequency current was delivered below the coronary sinus orifice. The procedure resulted in ablation of the accessory pathway conduction in both patients. During the follow-up, both patients remained free from tachycardia on no medication. This report demonstrates that the arrhythmogenic substrate of the permanent junctional reciprocating tachycardio can be easily suppressed by means of the radiofrequency catheter technique.     

Radiofrequency Catheter Ablation of AV Nodal Reentrant Tachycardia in Situs Inversus Totalis

A 41‐year‐old male with situs inversus totalis had paroxysmal supraventricular tachycardia. On electrophysiology study, the mechanism of the tachycardia was determined as slow/fast atrioventricular nodal reentrant tachycardia and slow pathway was successfully performed under fluoroscopic guidance.     

The Evolution of Platelet Aggregability in Patients Undergoing Catheter Ablation for Supraventricular Tachycardia with Radiofrequency Energy: The Role of Antiplatelet Therapy

Forty-two consecutive patients were checked for profiles of platelet aggregability before, during, and 10 and 30 minutes after catheter ablation. They were randomized into Group A (n = 20) who accepted intravenous aspirin (in 0.015 g/kg body weight) and Group P (n = 22) who accepted only placebo treatment. Blood samples were drawn from ascending aorta (Ao) and main pulmonary artery (MPA) simultaneously at each time period. In Group P, the EC₅₀ of substrate induced platelet aggregability decreases significantly during (for ADP, from 1.72 to 0.78/mol/L for samples from Ao, P ± 0.0001; and from 1.68 to 0.69 μmol/ Lfor MPA, P ± 0.0001; for collagen, from 2.26 to 1.34 μg/mLfor Ao, P ± 0.005, and from 2.40 to 1.64 μg/mL, P ± 0.0001) and 10 minutes after successful ablation (for ADP, to 0.70 μmol/L for Ao, P ± 0.000, and to 0.61 μmol/L for MPA, P ± 0.0001; for collagen, to 1.54 μg/mL for Ao, P ± 0.01, and to 1.63 μg/ mL, P ± 0.0001), and then returned to baseline levels 30 minutes later (all P = NS) compared with comparative baseline levels. The levels of thromboxane B2 (TXB2) had the similar evolution. The evolution of platelet aggregability profiles was not associated with total energy dose, duration of energy application, duration of procedure, impedance, and ablation site. However, there were moderate positive correlations between the TXB2 levels and tip temperatures (r = 0.56, P ± 0.05 for Ao and r = 0.65, P ± 0.01 for MPA). These results suggest that increased platelet aggregability can occur during and 10 minutes after radiofrequency current ablation and antiplatelet therapy can maintain "flat" response of platelet aggregability to radiofrequency energy, which may provide possible benefits in preventing the occurrence of the complication.     

Mapping Guided Laser Catheter Ablation of the Atrioventricular Conduction in Dogs

Safety and efficacy of mapping guided laser catheter ablation of the AV junction was tested in a canine model. A total of 43 laser pulses (continuous wave, Nd:YAG, 1,064 nm, 30 W, irradiated spot diameter 2.0–2.5 mm) were delivered in 15 dogs (2–5 per dog) via a novel laser catheter system. Pulses were selectively aimed at: (1) the AV node: (2) the His bundle; and (3) the bundle branches. Laser pulses of 9.7 ± 1.1 seconds (n = 31) produced reversible conduction disturbances in the targeted segment of the AV conduction system, while pulses of 28.6 ± 7.9 seconds (n = 9) resulted in chronic block. The dogs survived the procedure without complications. Follow-up was 6.5–10.5 months. Histopathologically, lesions showed clear-cut oval-shaped areas of fibrosis of 0.5–18.0 mm in diameter and 0.5–3.5 mm (transmural) in depth, depending on the irradiation time. Pervenous mapping guided laser catheter irradiation of the AV junction can produce AV block consistently and selectively in the targeted segment of the right ventricular conduction system in dogs. The method is safe and can be performed in a controllable manner by using the catheter system presented.     

Atrioventricular Nodal Supraventricular Tachycardia with 2:1 Block above the Bundle of His

A patient with narrow complex supraventricular tachycardia underwent electrophysiological study at which time a tachycardia was initiated which had 2:1 AV conduction, with block occurring above the His bundle. The modes of tachycardia initiation, as well as the responses to atrial and ventricular premature depolarizations during tachycardia, made a diagnosis of atrioventricular nodal reentry as the tachycardia mechanism. The unusual finding of 2:1 supra-His block suggests the presence of tissue situated between the tachycardia circuit and His bundle, and effectively excludes the possibility of a His-atrial bypass tract as the retrograde limb of the tachycardia circuit.     

Nonreentrant Supraventricular Tachycardia Due to Simultaneous Conduction Over Fast and Slow AV Node Pathways: Successful Treatment with Radiofrequency Ablation

A 55-year-old woman with frequent problematic supraventricular tachycardia is presented. The tachycardia was irregular with predominately normal QRS morphology and was refractory to multiple antiarrhythmic drugs. At electrophysiology study, the tachycardia was inducible with atrial or ventricular extrastimuli and dual pathways were observed. In contrast to the situation usually seen with dual atrioventricular node physiology, the slow pathway had a longer effective refractory period than the fast pathway and reentrant tachycardia was not induced. Simultaneous conduction over the fast and slow pathways during sinus rhythm was shown to be the mechanism for clinical tachycardia. The tachycardia was successfully treated using radiofrequency ablation of the slow pathway.