Catheter ablation of incessant ventricular tachycardia: acute and long-term results

SUBJECTS: Seventeen patients with incessant ventricular tachycardia refractory to anti-arrhythmic therapy underwent catheter ablation between 1987 and 1993. Fifteen patients had coronary heart disease and two had dilated cardiomyopathy. The mean age of the patients was 65 +/- 8 and the mean left ventricular ejection fraction was 31 +/- 9%. METHODS: Ablation sites were selected on the basis of endocardial activation mapping, concealed entrainment or bundle branch mapping. Catheter ablation was performed with direct current in nine patients and with radiofrequency energy in eight patients. Incessant ventricular tachycardia was terminated by catheter ablation in all 17 patients. RESULTS: One patient died after the ablation procedure due to pericardial tamponade. During electrophysiological testing 5-14 days later, 7 of 16 patients (44%) had inducible sustained or non-sustained ventricular tachycardia. Five of them underwent implantation of an automatic cardioverter/defibrillator, and three of these experienced discharges of the device during a mean follow-up of 30 +/- 12 months. another patient underwent implantation of a cardioverter/defibrillator after spontaneous recurrence of ventricular tachycardia. Out of the nine patients without inducible ventricular tachycardia, one died as a result of sudden cardiac death, and another had spontaneous ventricular tachycardia. Thus, ventricular tachycardia recurred clinically in 6 of 16 patients (38%), in whom ventricular tachycardia with the same morphology as that of the ablated ventricular tachycardia could be determined only in one patient. CONCLUSION: Catheter ablation is the method of choice for the emergency treatment of patients with incessant ventricular tachycardia. Due to the high risk of recurrence, additional anti-arrhythmic management, such as the implantation of a cardioverter/defibrillator, has to be considered.     

A perspective on the ESVEM trial and current knowledge: catheter ablation for ventricular tachyarrhythmias

Although an effective and potentially curative technique for treating idiopathic ventricular tachycardia, map-guided transcatheter radiofrequency ablation is far from optimal for ventricular tachyarrhythmias in patients with advanced ischemic or other types of organic heart disease. First, this technique can be applied only to a minority of patients with structural heart disease, who can tolerate relatively long episodes of induced ventricular tachycardia necessary for mapping and successful ablation. Second, the success rate is lower and recurrence higher in patients with organic heart disease. Finally, for patients who lose consciousness during tachycardia or who present with prehospital cardiac arrest, transcatheter radiofrequency ablation is inappropriate as definitive treatment. At best, it is palliative and may be used to suppress relatively slow, frequent, or incessant ventricular tachycardias but does not obviate the need for other therapies such as cardioverter-defibrillator implantation or antiarrhythmic drug therapy.     

Detection of renal artery stenoses by MRI with surface reconstruction. Value in patients with chronic renal failure

BACKGROUND: The so called tachycardia-induced cardiomyopathy may develop as a complication of persistent abnormal high rates. It is especially common in patients who have either a permanent form of junctional reciprocating tachycardia or an ectopic atrial tachycardia. Radiofrequency catheter ablation has become established as an effective and safe treatment to eliminate both arrhythmias. METHODS AND RESULTS: Four children aged from 3 months to 8 years, who had incessant tachyarrhythmias and left ventricular dysfunction (shortening fraction of mean +/- SD, 21.7 +/- 1.2%) underwent radiofrequency catheter ablation. The youngest patient had permanent junctional reciprocating tachycardia caused by a left posteroseptal pathway. She was presented with severe heart failure that did not improve with digoxin and amiodarone. The other patients had palpitations and exercise intolerance. Two of them had an ectopic atrial tachycardia caused by a single atrial focus localized in the left atrial appendage apex and the orifice of the right atrial appendage respectively. The other patient had the permanent form of junctional reciprocating tachycardia caused by a right posteroseptal pathway. All four patients underwent one successful ablation. The average procedure mean time was 3.7 hours with an fluoroscopy time of 44 minutes. There were no complications. Subsequently shortening fraction improved progressively. After a mean follow-up of 21.7 months all patients are asymptomatic without medical treatment. CONCLUSIONS: Radiofrequency catheter ablation is the therapy of choice in children with either the permanent form of junctional reciprocating tachycardia or ectopic atrial tachycardia refractory to medical treatment. The tachycardia-induced cardiomyopathy is reversible after the elimination of the arrhythmia. The presence of tachycardia-induced cardiomyopathy is an indication for radiofrequency ablation even in small infants.     

Radiofrequency catheter ablation of sustained monomorphic ventricular tachycardia in hypertrophic cardiomyopathy

INTRODUCTION: Incessant monomorphic ventricular tachycardia (VT) with a right bundle branch block morphology and a northwest axis is a rare arrhythmic complication in a patient with hypertrophic cardiomyopathy and apical left ventricular aneurysm. METHODS AND RESULTS: The origin of this VT was localized using the following criteria: the presence of entrainment without fusion, equal intervals from the stimulus to the beginning of the QRS complex and from the electrogram to the QRS complex during VT, and the first postpacing interval identical to the tachycardia cycle length. Radiofrequency energy applied to the septoapical part of the apical left ventricular aneurysm terminated the tachycardia within 2 seconds. CONCLUSION: Using criteria to guide radiofrequency (RF) ablation of VT in patients with coronary artery disease, an incessant monomorphic VT in a patient with hypertrophic cardiomyopathy was successfully ablated.     

Analysis of the immunoglobulin heavy-chain gene rearrangement providing molecular evidence of second lymphoma in a patient in apparent relapse after autotransplantation

Thirteen consecutive patients with idiopathic ventricular tachycardia underwent radiofrequency catheter ablation. This group included 9 idopathic left ventricular tachycardia (ILVT) and 4 idiopathic right ventricular tachycardia (IRVT). Five ILVT patients with left axis deviation and one with right axis deviation were ablated successfully. By pace mapping, two IRVT patients with ventricular tachycardia originating from right ventricular out-flow tract were ablated. No complications occured. By means of follow-up of 3-22 months one case showed recurrence with successful reablation. It indicates that radiofrequency catheter ablation therapy is an effective and safe procedure in patients with idiopathic ventricular tachycardia.     

Phosphatidylinositol 3-kinase inhibitor wortmannin blocks mitogenic activation of the transferrin receptor gene promoter in late G1

Currently, analysis of sustained ventricular tachycardia postmyocardial infarction in man is limited by the time required for single point activation mapping and the difficulty in obtaining information during hemodynamically unstable arrhythmias. To overcome these limitations, we developed a multielectrode "basket" catheter for endocardial recording and pacing. This report describes the first clinical use of such a catheter to guide successful radiofrequency ablation of incessant sustained ventricular tachycardia postmyocardial infarction. This system may significantly shorten the time required for VT analysis and improve the results of radiofrequency catheter ablation for VT postmyocardial infarction.     

Idiopathic verapamil-responsive left ventricular tachycardia: clinical characteristics and long-term follow-up of 33 patients

Long-term prognosis, pharmacological prophylaxis and transcatheter ablation in a large group of patients with idiopathic verapamil-responsive left ventricular tachycardia (IVRLVT) are reported in this study. Thirty-three patients with a mean age of 27 +/- 16 years at their first IVRLVT episode, were studied retrospectively. Ventricular tachycardia was of the right bundle branch block morphology in all cases, with left axis deviation in 29 and right axis deviation in five (one patient had the two morphologies). Mitral valve prolapse was present in four patients; no heart disease was found in the remaining 29. Ventricular tachycardia could be electrophysiologically induced in 90% of the patients; Holter monitoring showed only sporadic ventricular extrasystoles in 76%; late potentials were found in 33% of the cases. At the end of a follow-up of 5.7 +/- 4.7 years, no patient had died. Thirty-one patients (94%) received a mean of 2.5 +/- 1.2 drugs; beta-blockers were effective in 71% of the cases, verapamil in 25%, class 1 drugs in 22%, class 3 drugs in 18%. Two patients who never received prophylaxis and four in whom it was stopped, were controlled with verapamil in case of recurrence. Six patients underwent catheter ablation; two with DC shock in whom it was successful in one, and four with radiofrequency energy, with a total success rate. The good prognosis of IVRLVT has been confirmed in a long-term follow-up; a new finding is the high efficacy of beta-blockers for prophylaxis. Radiofrequency transcatheter ablation is an effective and safe therapy for patients with symptoms not controlled by drug treatment.     

Verapamil-sensitive left anterior fascicular ventricular tachycardia: results of radiofrequency ablation in six patients

INTRODUCTION: Verapamil-sensitive left ventricular tachycardia (VT) with a right bundle branch block (RBBB) configuration and left-axis deviation has been demonstrated to arise from the left posterior fascicle, and can be cured by catheter ablation guided by Purkinje potentials. Verapamil-sensitive VT with an RBBB configuration and right-axis deviation is rare, and may originate in the left anterior fascicle. METHODS AND RESULTS: Six patients (five men and one woman, mean age 54+/-15 years) with a history of sustained VT with an RBBB configuration and right-axis deviation underwent electrophysiologic study and radiofrequency (RF) ablation. VT was slowed and terminated by intravenous administration of verapamil in all six patients. Left ventricular endocardial mapping during VT identified the earliest ventricular activation in the anterolateral wall of the left ventricle in all patients. RF current delivered to this site suppressed the VT in three patients (ablation at the VT exit). The fused Purkinje potential was recorded at that site, and preceded the QRS complex by 35, 30, and 20 msec, with pace mapping showing an optimal match between the paced rhythm and the clinical VT. In the remaining three patients, RF catheter ablation at the site of the earliest ventricular activation was unsuccessful. In these three patients, Purkinje potential was recorded in the diastolic phase during VT at the mid-anterior left ventricular septum. The Purkinje potential preceded the QRS during VT by 66, 56, and 63 msec, and catheter ablation at these sites was successful (ablation at the zone of slow conduction). During 19 to 46 months of follow-up (mean 32+/-9 months), one patient in the group of ablation at the VT exit had sustained VT with a left bundle branch block configuration and an inferior axis, and one patient in the group of ablation at the zone of slow conduction experienced typical idiopathic VT with an RBBB configuration and left-axis deviation. CONCLUSION: Verapamil-sensitive VT with an RBBB configuration and right-axis deviation originates close to the anterior fascicle. RF catheter ablation can be performed successfully from the VT exit site or the zone of slow conduction where the Purkinje potential was recorded in the diastolic phase.     

Two cases of ventricular parasystole associated with ventricular tachycardia

In two patients, ventricular parasystole (VP) was associated with ventricular tachycardia (VT), and in one patient, catheter ablation was successful. In patient 1, with dilated cardiomyopathy, VP led to VT, which converted to ventricular fibrillation. In patient 2, VP led to symptomatic nonsustained polymorphic VT. The origin of parasystolic focus was determined by endocardial mapping, and a radiofrequency current was delivered to patient 2. Both VP and VT disappeared immediately, and no recurrence has been observed during a follow-up of 8 months. Catheter ablation to the parasystolic focus was effective and a relationship between VP and VT was strongly suggested.     

Radiofrequency current caused slowing of non-reentrant idiopathic right ventricular tachycardia originating from a wide arrhythmogenic area

Radiofrequency catheter ablation was attempted in a patient with non-reentrant idiopathic right ventricular tachycardia (VT). Endocardial mapping indicated that the VT originated in the outflow tract of the right ventricle; however, an electrogram with an almost the identical activation time was recorded from an area extending to 1.0 x 2.0 cm. Each application of radiofrequency current within the area terminated VT, but a progressively slower VT with the same QRS configuration was induced until the area was covered by separate radiofrequency lesions. A progressive prolongation of VT cycle length might be related to a residual arrhythmogenic myocardium. Termination and slowing of the VT rate can be a hallmark of efficacy of each radiofrequency lesion.     

Successful radiofrequency ablation of idiopathic left ventricular tachycardia at a site away from the tachycardia exit

OBJECTIVES: This study sought to assess the possibility of ablating verapamil-responsive idiopathic left ventricular tachycardia at a site distant from the tachycardia exit and thus to define the tachycardia circuit. BACKGROUND: The nature of the reentry circuit in idiopathic left ventricular tachycardia is unclear. If the circuit is of considerable size, then it should be possible to ablate the tachycardia at a site distant from the exit site. METHODS: Electrophysiologic studies and radiofrequency ablation were performed in 27 consecutive patients with verapamil-responsive idiopathic left ventricular tachycardia. In all 27 patients, the tachycardia exit site was defined as the site where the earliest Purkinje potential was recorded > or = 25 ms before the onset of the QRS complex during the tachycardia and where the pace map QRS complex resembled that during the tachycardia. A potential ablation site other than the exit site was then sought around the midseptum, proximal to the exit site. At such sites the tachycardia could be terminated transiently by pressure applied to the catheter tip, without induction of ventricular ectopic beats. RESULTS: The potential ablation site, other than the tachycardia exit site, was identified in seven male patients (mean [+/-SD] age 31 +/- 12 years, range 13 to 52). Application of the radiofrequency current at this site resulted in termination of the tachycardia within 1 to 5 s (mean 2.9 +/- 1.6), and successful ablation of the tachycardia was achieved in all seven patients (success rate 100%, 95% exact confidence interval 0.5898 to 1). The mean distance between the ablation site and the tachycardia exit site was 3.1 +/- 0.7 cm (range 2.0 to 4.0). A presystolic Purkinje spike was recorded 14 +/- 5 ms (range 8 to 20) before the onset of the QRS complex during the tachycardia. During the follow-up period of 24 +/- 11 months (range 12 to 39), there was no recurrence of tachycardia in these seven patients. CONCLUSIONS: Successful ablation of idiopathic left ventricular tachycardia can be achieved at sites away from the tachycardia exit site in some patients. This finding suggests that the reentry circuit is likely to be of considerable size, encompassing the middle, inferior and lower aspects of the left interventricular septum.     

Radiofrequency catheter ablation in monomorphic ventricular tachycardia

Twenty patients with symptomatic monomorphic ventricular tachycardia (VT) underwent radiofrequency (RF) energy catheter ablation. Four patients (20%) had underlying heart disease (1 prolapse mitral valve, 1 dilated cardiomyopathy and 2 myocarditis). Five patients (25%) had left sided VT and right sided VT in the remainder (75%). Radiofrequency catheter ablation was initially successful in all patients without major complication. Recurrence occurred in three patients (15%). In conclusion, RF ablation is an effective treatment for symptomatic monomorphic right and left sided VT especially in patients who do not want long term antiarrhythmic agents.     

Right ventricular radiofrequency ablation of ventricular tachycardia after myocardial infarction

Radiofrequency transcatheter ablation of ventricular tachycardia in the setting of a prior myocardial infarction is typically performed with application of energy to the left ventricular endocardium. In this article, two cases are described in which successful radiofrequency transcatheter ablation of ventricular tachycardia occurred with energy delivery to the right ventricular septum after failed ablation attempts from the left ventricle. Both patients had tachycardias with a left bundle branch block morphology and markedly presystolic activity recorded from the right ventricular septum. Right ventricular septal activation mapping during ventricular tachycardia should be performed in patients with left bundle branch block tachycardia morphology and coronary artery disease to maximize efficacy of the catheter ablation procedure.     

Retrograde Purkinje potential activation during sinus rhythm following catheter ablation of idiopathic left ventricular tachycardia

We describe two patients with idiopathic left ventricular tachycardia that were cured by radiofrequency catheter ablation. Tachycardia was inducible by ventricular stimulation and was verapamil sensitive. Two distinct presystolic potentials (P1 and P2) were recorded during tachycardia in the mid-septal or inferoapical area, but only one potential (P2) was recorded during sinus rhythm. After catheter ablation at this site, the P1 potential was noted after the QRS complex during sinus rhythm, while the P2 was still observed before the QRS complex. The P1 potential showed a decremental property during atrial or ventricular pacing. These data suggest that Purkinje tissue with decremental properties was responsible for the tachycardia mechanism, and that the reentry circuit involving this tissue is likely to be of considerable size.     

Radiofrequency catheter ablation of an incessant supraventricular tachycardia initiated by a Hisian parasystole

The coexistence of a parasystolic focus, tachycardia dependent right bundle branch aberrancy, and an AV accessory pathway is reported here. This condition was present in a 40-year-old man, which led to an incessant AV reciprocating tachycardia. Further electrophysiological study revealed that the parasystolic focus was located somewhere in the His bundle; endocardial mapping disclosed a right posterior accessory pathway. Radiofrequency current was delivered at the atrial level of the right posterolateral AV groove and successfully ablated the accessory pathway, leading to a dramatic improvement in cardiac function. In conclusion, the recognition of the electrophysiological mechanism of incessant supraventricular tachycardia was of crucial importance for the therapy decision. A definitive intervention using radiofrequency catheter ablation should be considered early and not postponed in patients with tachycardia-induced cardiomyopathy.     

Age-related changes in the compressive strength of cancellous bone. The relative importance of changes in density and trabecular architecture

Ectopic atrial tachycardia (EAT) is a rare but reversible cause of dilated cardiomyopathy (DCMP). The diagnosis and the definite control of the arrhythmia are essential for the regression of DCMP. Unfortunately, conventional antiarrhythmic drugs usually fail to control the arrhythmia, and the results of surgery or direct current ablation are suboptimal. Recently, radiofrequency (RF) catheter ablation has been evolving as a safe and effective therapy for EAT. This report describes the RF ablation treatment of a 14-year-old boy with DCMP secondary to chronic EAT. Activation mapping was used for the purpose of identifying the focus origin located just anterior to the coronary sinus os. RF energy applied at this focus successfully terminated the tachycardia. No complications related to the procedure were observed. RF ablation not only caused elimination of the EAT but also led to improvement in left ventricular function as early as two weeks after the procedure, and complete resolution of DCMP in three months.     

Radiofrequency treatment of tachyarrhythmias in children and adolescents

INTRODUCTION: Radiofrequency ablation has been extensively used in adults to treat supraventricular and ventricular tachycardia. In children and adolescents few data are available on its safety and efficacy. METHODS: 28 patients (mean age 12.8) with symptomatic tachyarrhythmias underwent catheter ablation; 21 children had atrioventricular accessory pathways (11 right connections, 9 lef connections and one midseptal pathway), 3 had intranodal tachycardia, 2 had ventricular tachycardia and 2 had atrial tachycardia. Only four patients had associated structural anomalies. RESULTS: Success rate was 71.4% (20 patients). The success per cents in each group were: in intranodal tachycardias 100%; we failed in the two patients with ventricular tachycardias; in accessory pathways 76.1% and 50% in atrial tachycardia. There were no recurrences of arrhythmia in a mean chase period of 24 months (12-46). Major complications were only observed in one patient who developed a Wallenberg syndrome after ablation. CONCLUSIONS: Radiofrequency catheter ablation appears to be a safe and effective method to treat arrhythmias in children and adolescents, which in most cases can supersede surgery. Alow incidence of complications is reported, although long term damage on endocardial structures remains yet to be determined.     

Non-pharmacologic prevention of sudden cardiac death

Non-pharmacologic therapy has revolutionized the management of arrhythmias and prevention of sudden cardiac death (SCD). Of particular importance is the introduction of radiofrequent catheter ablation (RFCA) and implantable cardioverter-defibrillator (ICD). RFCA is effective and useful in the treatment and prevention of SCD, especially in supraventricular tachyarrhythmias related to dual or accessory atrioventricular pathways. There are some limitations in using this method in the prevention of SCD in ventricular tachyarrhythmias. RFCA is very successful, particularly in the treatment of bundle branch reentrant ventricular tachycardia and ventricular tachycardia in patients without structural heart disease. RFCA can be used as a palliative treatment of incessant or frequent VT before and after ICD implantation. Antibradycardia pacing decreases SCD not only by the removal of serious bradyarrhythmias but also by prevention of the occurrence of malignant ventricular tachyarrhythmias induced by bradyarrhythmia. Antitachycardia pacing is used in the prevention of SCD only as a part of ICD device. Implantation of an antitachycardia pacemaker as an isolated permanent treatment of tachycardias is currently almost not used. This method was replaced by RFCA in supraventricular tachyarrhythmias and by ICD in ventricular tachyarrhythmias. ICD is a very perspective non-pharmacologic approach to SCD prevention, particularly as transvenous leads were introduced and device construction was simplified. ICD is indicated especially in patients with spontaneous sustained hemodynamically significant ventricular tachycardia/ventricular fibrillation and when antiarrhythmic drug treatment, RFCA or antitachycardia surgery are ineffective, intolerated, contraindicated or cannot be performed. ICD as the treatment of first choice instead of antiarrhythmic drugs as well as prophylactic ICD implantation in asymptomatic patients at high risk is a subject of discussion. ICD decreases the incidence of SCD significantly. However, the decrease in overall mortality was not verified. Antitachycardia surgery is less frequently used after RFCA, and ICD have been introduced. At present, this therapy is reserved only for the cases of failure of RFCA or the impossibility to use RFCA and ICD. Surgical therapy can be combined also with concommitant surgical correction of associated structural heart disease. Sympathectomy is used in prevention of malignant ventricular tachyarrhythmias and SCD in patients with congenital long Q-T syndrome. Selective left cardiac sympathetic denervation significantly reduces the risk of SCD in these patients but does not remove it completely. Heart transplantation is the last alternative of non-pharmacologic prevention of SCD. It is indicated in cases when all pharmacologic and non-pharmacologic approaches have been exhausted. Heart transplantation is the only effective modality for the improvement of long-term prognosis in patients with malignant ventricular tachyarrhythmias and advanced chronic heart failure.     

Unusual features of right and left idiopathic ventricular tachycardia abolished by radiofrequency catheter ablation

Two unusual cases are presented with idiopathic right and left ventricular tachycardia (IVT) with intriguing clinical and electrophysiological characteristics. The first patient with a sustained IVT of right ventricular outflow tract origin, and an electrophysiological mechanism suggesting reentry, had been resuscitated from cardiac arrest. The second patient had an IVT with a left bundle branch block morphology, which originated from the basal-septal region of the left ventricle (left ventricular outflow tract tachycardia). Both patients were cured with radiofrequency catheter ablation, guided by endocardial activation sequence and pace mapping.     

Radiofrequency ablation of accessory pathways in the presence of atrial fibrillation

Radiofrequency catheter ablation was performed in 595 consecutive patients with Wolff-Parkinson-White syndrome. We attempted ablation of right and left accessory pathways, during sustained atrial fibrillation with rapid anterograde conduction over the accessory pathway in three patients. In other patient, who had an accessory pathway with anterograde decremental conduction properties, referred to as Mahaim atriofascicular fiber, originating from the right posterolateral atrium, who also had sustained atrial fibrillation during the electrophysiological study to assess accessory pathway conduction properties, was also submitted to ablation of the accessory pathway. At the successful ablation sites, a ventricular electrogram was consistently recorded preceding the onset of preexcitation, in the surface electrogram by 20 ms, during atrial fibrillation. All patients were successfully ablated with a single radiofrequency impulse. After successful ablation direct current cardioversion with 200 joules terminated the atrial fibrillation. In conclusion, radiofrequency catheter ablation of accessory pathways during sustained atrial fibrillation is feasible with a high success rate.