摘要:

The first experiences of nonpharmacological treatment of ectopic atrial tachycardia (EAT), common atrial flutter (AFI), and atrial fibrillation (AF) were performed by surgical techniques. Many studies reported a very high success rate on the use of catheter ablation with radiofrequency current for the treatment of supraventricular arrhythmias; and recently, various preliminary reports are dedicated to the treatment of EAT, AFI, and AF with that source of energy. To our knowledge 108 cases of EAT treated by catheter ablation of the ectopic focus are reported in the literature with a success rate superior to 90%. On the basis of our personal experience regarding 11 cases (4 of right atrium EAT and 7 of left) we discuss here the essential role of unipolar leads derived from the mapping catheter to select the target for radiofrequency applications. Two hundred and one cases of AFI tested by catheter ablation were previously reported. The majority of them (>80%) were successfully treated with radiofrequency. Some working groups performed the procedure as the basis of electrophysiological findings, while others preferred an anatomical approach applying radiofrequency energy at the isthmus lying between the coronary sinus ostium and the tricuspid ring, near the vena cava orifice. On the basis of these assumptions, we obtained 83% of final success in 12 cases of AFI treated by radiofrequency. Finally, we discuss the problem related to the modulation of atrioventricular (AV) nodal conduction during AF. In our laboratory, five cases with chronic AF and very fast ventricular response were treated with radiofrequency with a posterior septal approach. In all patients, we obtained very encouraging results with a constant decrease of ventricular rate (from 137 ± 33 to 69 ± 14 beats per minute). All cases treated by modulation of AV nodal conduction demonstrated an appropriate chronotropic response to the variations of the functional state that persists during the follow‐up. More experience with longer follow‐up and accurate pre‐ and postprocedure evaluations are needed to finalize the most appropriate technique of radiofrequency applications in thes

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00933.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Background: In the past few years, there has been a relative explosion of activity in the realm of interventional cardiology. The high rate of success of radiofrequency energy ablation have transformed catheter ablation from an investigational procedure into the first‐line therapy for symptomatic Wolff‐Parkinson‐White syndrome. Radiofrequency catheter ablation for preexcitation syndrome is commonly based on a ventricular approach. Such an approach might he associated with the risk of prolonged arterial catheter manipulation, retrograde left ventricular catheterization, and production of multiple, potentially arrhythmogenic, ventricular lesions created during ablation. Potential risks can be avoided using atrial insertion ablation procedures. The transseptal procedure that was developed in the 1950s and 1960s as a diagnostic procedure and then shelved in the 1970s and early 1980s has now come back into prominence as a therapeutic technique in the treatment of valvular heart disease, and then in the ablation of the left accessory atrioventricular connections.Methods: Atrial aspect of mitral annulus is a relatively smooth, nonobstructed surface that simplifies catheter movement, thereby permitting rapid and accurate accessory pathway location. Although primary use of earliest endocardial retrograde atrial activation as a marker of accessory pathway atrial insertion is sufficiently accurate to permit successful ablation, direct recording of an accessory pathway potential is an important predictor of successful ablation site. Moreover, the analysis of the unipolar atrial electrogram, recorded during sinus rhythm from the tip of the ablation catheter, provides further information for localizing the atrial insertion of the accessory pathways. Shortest atrial‐accessory pathway and negative delta‐accessory pathway intervals have been found to be the best predictors of the successful site.Results: A 90.5% success of the transseptal approach on an overall population of 328 patients, higher for overt than for concealed pathways, is comparable with the results of the retrograde. Complications are 0.5%. Conclusion: In conclusion, the transseptal approach for ablation at the atrial site is very safe and highly effective, and avoids prolonged arterial cannulation and catheter manipulation in the ascending aorta and left

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00934.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00935.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

After more than 30 years since the first magnetocardiographic (MCG) recording was carried out with induction coils, MCG is now approaching the threshold of clinical use. During the last 5 years, in fact, there has been a growing interest of clinicians in this new method which provides an unrivalled accuracy for noninvasive, three‐dimensional localization of intracardiac source. An increasing number of laboratories are reporting data validating the use of MCG as an effective method for preoperative localization of arrhythmogenic substrates and for planning the best catheter ablation approach for different arrhythmogenic substrates. In this article, available data from literature have been reviewed. We consider the clinical use of MCG to localize arrhythmogenic substrates in patients with Wolff‐Parkinson‐White syndrome and in patients with ventricular tachycardia in order to assess the state‐of‐the‐art of the method on a large number of patients. This article also addresses some suggestions for industrial development of more compact, medically oriented MCG equipments at reas

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00936.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Some supraventricular tachyarrhythmias (SVT), particularly if paroxysmal and/or related to Wolff‐Parkinson‐White syndrome (WPW), may in some cases endanger an athlete's professional career due to hemodynamic consequences during athletic activity, which in some instances may be life‐threatening. One must also take into account that in Italy the law makes antiarrhythmic drug treatment (AAD) incompatible with sport eligibility. For these reasons, the utilization of radiofrequency ablation (RFA) in athletes has different indications as opposed to the normal population, since the primary goal is“the eligibility of the athlete.” In our study, we discuss the criteria for indication of RFA in athletes with SVT on the basis of the data obtained from our population of athletes, studied over a 20‐year period, from 1974 to the 31st of December 1993. These athletes were evaluated for arrhythmic events, utilizing a standardized cardioatrhythmological protocol: 1,325 athletes (1,125 men, 200 women, mean age 20.7 years). One subgroup included 380 athletes with WPW (28.7%), 22 athletes with aborted sudden death (1.6%), 6 of whom had WPW, 13 athletes with sudden death (0.98%), and 2 of whom had WPW. Another subgroup was formed by 116 top level elite professional athletes (TLA) (mean age 22.9 years), of which 10 of 116 (8.6%) had WPW and 12 of 116 (10.3%) had paroxysmal SVT. The most important indications for RFA in athletes are represented by: WPW asymptomatic at risk, symptomatic during athletic activity, andlor requiring AAD treatment: paroxysmal junctional reentrant tachycardia; when this condition is disabling and related to exercise and therefore compromising an athlete's performance and sports career. Paroxysmal junctional reentrant tachycardia is easily reproduced via transesophageal atrial pacing (TAP) during exercise (bicycle ergometer), common in athletes but normally the recurrences are concentrated only during the period in which the athlete is engaged in sport. Rare indications for RFA are focal or reentry, permanent SVT, and particularly junctional reentrant tachycardia. For each individual athlete, we have to consider the possible side‐effects of RFA, the possible recurrences with psychobiological traumatic consequences, the effective recovery period, and the natural history of the tachyarrhythmias, which frequently disappear after interruption of the

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00937.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00938.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Catheter ablation has evolved into the dominant therapeutic modality in the treatment of a variety of arrhythmias, particularly supraventricular arrhythmias with the mechanisms of atrioventricular (AV) nodal reentry and AV reciprocating tachycardia via an accessory pathway. The mode of catheter ablation used in the great majority of cases is radiofrequency (RF) catheter ablation. This technology is well‐suited for the above arrhythmias because the targets and the RF lesions are both small and discrete. Using temperature monitoring may improve the outcome of these procedures by decreasing procedure time and incidence of coagulum formation on the catheter after a sudden rise in electrical impedance. New RF catheter designs and new modalities of creating catheter‐induced focal myocardial injury will allow operators to have improved success with the ablation of less approachable arrhythmias, including atrial flutter and reentrant ventricular tachycardia. Studies are currently underway to create a catheter based “maze” procedure for the treatment of atrial fibrillation. As techniques and technologies evolve, a greater proportion of patients with symptomatic or threatening arrhythmias may be approached with catheter ablation as a curative or palliative pr

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00939.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Curative treatment of both supraventricular and ventricular tachyarrhythmias started with the introduction of surgical therapy. Surgical treatment modalities were often very successful and associated with low mortality and morbidity, especially in patients with various supraventricular tachyarrhythmias. However, results were acceptable in patients with ventricular tachyarrhythmias, with often a very complex and extended arrhythmogenic area associated with structural heart disease. Because of the development and proven effectiveness of catheter ablation and defibrillator implantation, the role of surgical therapy became limited. In the treatment of supraventricular arrhythmias, surgical therapy is an option after failure of catheter ablation. Since His‐bundle catheter ablation is only a palliative treatment for atrial fibrillation, the potentially curative Maze operation may be an acceptable alternative. However, its potential against formation of intracavitary thrombi has not yet been proven. In the treatment of ventricular tachyarrhythmias, ischemia related polymorphic ventricular tachycardia and ventricular fibrillation can be treated very effectively by revascularization. Map‐guided surgery is an appropriate treatment modality for patients with monomorphic ventricular tachycardia and an extended arrhythmogenic area. However, patients with very poor left ventricular function may have an unacceptable perioperative risk. In patients with congenital long QT syndrome who are refractory to beta blocking agents, left‐sided sympathectomy is the most appropriate c

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00940.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Atrioventricular nodal reentrant tachycardia has been recognized for many years as a very common cause of supraventricular tachycardia. First curable by surgery, this tachycardia is now successfully approached by selective radiofrequency current application to the slow pathway of the reentrant circuit. Importantly, these curative treatments brought evidence that the reentrant circuit of this arrhythmia was not confined to the compact atrioventricular (AV) node. These findings stimulate anatomists and basic and clinical electrophysiologists to fundamentally reconsider the atrioventricular junction in order to better understand the mysteries of atrioventricular junctional reentrant tachycardia, as we still do not know exactly what we are doing in AV node region procedures. This article will focus on the different hypotheses regarding the effect of selective slow AV pathway ablation in AV junctional reentrant tachycardia.

ISSN:0896-4327    

DOI:10.1111/j.1540-8183.1995.tb00941.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY