ABSTRACT
La taquicardia reentrante nodal aurículo ventricular es la forma más común de taquicardia sostenida, regular con QRS angostos. Fisiopatológicamente está determinada por una anatomía y fisiología nodal aurículo ventricular dual, con una vía rápida y otra lenta que forman el sustrato de la reentrada. El estudio electrofisiológico determina el diagnóstico de certeza si es inducida, aunque en algunos casos no es posible. Presentamos nuestra casuística donde la aplicación de radiofrecuencia indujo taquicardia reentrante nodal aurículo ventricular cuando el estudio electrofisiológico no pudo hacerlo, y explicamos su mecanismo electrofisiológico.
Atrioventricular nodal reentrant tachycardia is the most common form of sustained regular narrow QRS complex tachycardia. It is caused by the presence of a dual atrioventricular nodal anatomy and physiology, with a fast and a slow pathway forming a substrate for re-entry. Electrophysiology study confirms the diagnosis when the tachycardia is induced, although in some cases this is not possible. Casuistry is here presented where the application of radiofrequency induced atrioventricular nodal reentrant tachycardia, when the electrophysiological study could not do it; we explain here its electrophysiological mechanism.
Subject(s)
Humans , Female , Adult , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Catheter Ablation , Electrocardiography , ElectrophysiologyABSTRACT
Objective By comparing the efficacy and complication rates of the 8-mm-tip cryoablation catheter with the normal electrode ablation catheter in the treatment of atrioventricular nodal reentrant tachycardia,this study investigated the efficacy and feasibility of ablation with the 8-mm-tip cryoablation catheter.Methods This is a retrospective case-control study including 122 patients with AVNRT treated with CRYO (n =56) using an 8-mm-tip cryoablation catheter or RF ablation (n =66) from June 2014 to May 2016.The procedure success rate,the recurrence rate,atrioventricular block incidence,procedure time and the difference between the X-ray fluoroscopy dose were compared between the 2 groups.Results The procedure success rate was comparable between the 2 groups(100％ for CRYO vs.98.5％ for RF,P ＞0.999)and no AVB was found in both groups.The CRYO group needed shorter procedural time [(66.29±4.72)min vs.(70.00 ± 7.50) min,P =0.001] and less X-ray exposure [(674.14 ± 126.12) mSv vs.(837.52 ± 138.38) mSv,P ＞ 0.001] than the RF group.Conclusions 8-mm-tip cryoablation catheter cryoablation for atrioventricular nodal reentrant tachycardia is as safe and effective as compared to conventional radiofrequency ablation with potential advantages.
ABSTRACT
La complejidad anatómica y la variabilidad en el sistema de conducción en la transposición congénita corregida de los grandes vasos plantean intervenciones con el uso de recursos tecnológicos que faciliten un desenlace favorable. Describimos un caso de ablación de taquicardia por reentrada intranodal en donde el mapeo no fluoroscópico facilitó una intervención compleja.
The anatomy in congenital corrected transposition of the great arteries is complex and the conduction system may experience large degrees of variation. Invasive procedures should be done with the use of the highest possible technological sources to warrant success. We describe here, a patient with recurrent atrioventricular node reentry tachycardia where non-fluoroscopic navigation system helped in a complex ablation.
Subject(s)
Female , Humans , Middle Aged , Cardiac Imaging Techniques , Catheter Ablation , Imaging, Three-Dimensional , Tachycardia, Atrioventricular Nodal Reentry/surgery , Fluoroscopy , Recurrence , Transposition of Great Vessels/surgeryABSTRACT
Objective:To compare the efficacy and safety between cryoablation(Cryo)and radiofrequency (RF)ablation in patients with atrioventricular nodal reentrant tachycardia(AVNRT). Methods: A total of 83 patients with AVNRT underwent electrophysiological treatment in our hospital from October 2006 to March 2009 were studied. Patients were divided into two groups according to their own choices. Cryo group (n=41) and RF group (n=42). The clinical characteristics,success rate,procedural time and ablative time were compared between two groups. Results:The procedural time and ablative time in Cryo group was significantly longer than those in RF group (119.14±40.16 min vs.85.86±28.24 min,P=0.001; 1118.91±620.62 s vs.370.97±279.23 s,P<0.001). The acute success rate was achieved in 40/41(97.6%)patients in Cryo group,and 42/42(100.0%) in RF group. Transient AV-block was encountered in 6 (15%) patients in the Cryo group and 5 (11.9%) in RF group (P=0.681). There was no complete atrial-ventricular(AV)conduction block at the end of procedures. There was no recurrence of AVNRT in either Cryo group nor in RF group during 11.6±5.5 months of follow up period.Conclusion:Cryoablation was as effective and safe as RF ablation for AVNRT. Cryo-energy was one kind of alternative ablation energy for AVNRT.
ABSTRACT
Introduction: Atrioventricular nodal reentrant tachycardia is quite common in clinical. The use of radiofrequency for this condition is more common. However, there are few studies on the impact of slow pathway ablation on AV conduction.Objectives: To investigate the impact of slow pathway ablation on AV conduction in atrioventricular nodal reentrant tachycardia. Subjects and method: Between Jul 2003 to Jul 2006, 27 patients with typical atrioventricular nodal reentrant tachycardia underwent the slow pathway eradication using radiofrequency. Some AV conduction measurements before and after ablation were compared. Results: There is a significant difference in sinus interval before and after ablation (745.81 +/- 136.63ms vs. 634.61+/-148.82ms, p<0.05). The differences in PA interval (32.03+/-8.71ms vs. 34.15+/-9.36ms), AH interval (67.72+/-18.66ms vs. 69.31+/-25.92ms), Wenckebach AV nodal block (316.32+/-52.13ms vs. 338.16+/-65.52ms), 2:1 AV block (245.95+/-78.46ms vs. 251.62+/-65.31ms) were all not significant. . The fast pathway refractory periods before and after ablation was 358.31+/-68.67ms and 362.48+/-92.11ms, respectively. Conclusion: The slow pathway eradication by radiofrequency for atrioventricular nodal reentrant tachycardia has no impact on the AV conduction.
Subject(s)
Tachycardia, Atrioventricular Nodal ReentryABSTRACT
Objective: To analyze the elcctrophysiological and clinical features of 68 common and 9 refractory atrioventricular nodal reentrant tachycardia(AVNRT) cases,thereby to seek safe and effective strategies for the treatment of refractory AVNRT with radiofrequency catheter ablation(RFCA). Methods: Ablation at lower zone is customarily applied in AVNRT,if noneffective,ablation electrode can be gradually moved upward,and radiofrequency energy can be delivered at a midpoint or upper position of His Bundle even with small H waves.The movement of the ablation electrode must be carefully monitored lest His bundle be eroded mistakenly.For those both atrioventricular nodal dual pathways(AVNDP) and atrioventricular accessory pathways(AVAP) are present,we always ablate AVAP first. Results: All 68 common AVNRT cases are simple slow-fast type.Among the 9 cases of refractory AVNRT,2 cases were combined with concealed left postseptal AVAP and concealed right AVAP respectively,while 1 case with atrioventricular nodal three pathways. Conclusion: X-ray anatomical position and intraventricular local mapping should be analyzed for the use of RFCA in refractory AVNRT.Safe and effective mapping should be: small A wave and big V wave,shattered A wave with width≥68 ms,A/V= 0.1-0.25,no H or H≤(0.02?0.03) mV.If lower position and middle position method are noneffective,linear ablation at mid-level of Koch's triangle seems to be a satisfactory alternative,which could avoid complications of atrioventricular block in the upper position ablation.
ABSTRACT
La taquicardia por reentrada nodal atrioventricular, es una de las causas más frecuentes de taquicardia supraventricular. Es generalmente una arritmia benigna y usualmente no está asociado a cardiopatía estructural, se presenta más frecuentemente en mujeres de media edad, pero no es infrecuente encontrarlo en personas jóvenes y en ancianos. El desarrollo de la ablación con radiofrecuencia a través de un catéter facilita la cura definitiva de la arritmia y permite una mejor compresión del sustrato anatómico electrofisiológico.
Atrioventricular nodal reentrant tachycardia is the most frequent regular supraventricular tachycardia. It is generally a benign arrhythmia and usually it is no associated with heart disease. It is more often seen in middle-aged women but it is no infrequent in younger and older patients. The development of radiofrequency with catheter ablation has provided the possibility to definitely cure the arrhythmia and moreover permit a better comprehension of the underlying electrophysiologic and anatomic substrate. (Arch Cardiol Mex 2003; 73:143-154).
Subject(s)
Humans , Catheter Ablation/methods , Tachycardia, Atrioventricular Nodal Reentry/surgery , Electrocardiography , Electrophysiologic Techniques, CardiacABSTRACT
Objective:Atrioventricular nodal reentrant tachycardia(AVNRT) is a common type of arrhythmia,for which radiofrequency ablation(RFCA) is the first therapeutic option.This study is to investigate the causes of 16 cases of temporary atrioventricular block(AVB) during RFCA and 2 cases of permanent AVB after RFCA in common and refractory AVNRT.Methods: We performed RFCA for 77 AVNRT patients by gradually increasing the ablation time,energy and frequency.Generally we chose the lower zone as the first position of ablation and,if invalid,moved the catheter gradually up to the middle or upper zone.Then we analyzed the correlation of AVB with A/V and H-wave in different positions.Results: The AVB risk was increased with the upward movement of the ablation zone and increase of A/V or H-wave(P 0.05). Conclusion: The method of gradually increasing the ablation time,energy and frequency can prevent temporary from permanent AVB.In the common AVNRT group,the middle and lower zone ablation,the multiple-peak A wave,small A wave and big V wave(A/V ≤ 0.45?0.37) with no H wave or H≤0.003?0.01 mV could significantly decrease the risk of RFCA related AVB,but the risk of AVB remains among the refractory AVNRT patients with CSO abnormality or expansion,even if with ablation in the lower zone.
ABSTRACT
BACKGROUND AND OBJECTIVES: Ablation of the slow pathway in patients with atrioventricular nodal reentrant tachycardia (AVNRT) can be performed by using a specific intracardiac electrogram findings predicting a successful radiofrequency catheter ablation. The purpose of the present study is to recognize a specific intracardiac electrogram findings predicting a successful sites of radiofrequency catheter ablation in patients with AVNRT. MATERIALS AND METHODS: The study population consisted of the 18 patients (7 males, mean age:46 yr) to undergo successful catheter ablation using radiofrequency current in order to eliminate AVNRT from January 1993 to september 1994. We have analyzed local intracardiac electrogram at successful and unsuccessful sites of radiofrequency catheter ablation before the radiofrequency application: Atrial electrogram amplitude, duration, number of peaks in atrial electrogram, atrial/ventricular (A/V) electrogram amplitude ratio, and presence of His potential and/or slow potential. RESULTS: Of 18 patients, 16 patients underwent a slow pathway ablation, the other 2 patients a fast pathway ablation. The mean A/V electrogram amplitude ratio at successful and unsuccessful sites was 0.69+/-0.91 and 1.86+/-2.03, respectively. The mean atrial electrogram duration and number of peaks at successful and unsuccessful sites was 57+/-16 msec vs 69+/-16 msec and 1.7+/-0.5 vs 2.2+/-0.7, respectively. His bundle electrogram was seen in one slow pathway ablated and one fast pathway ablated patient. No slow potential could be identified in any of these 18 patients. CONCLUSION: We think that A/V electrocardiogram amplitude ratio below 0.5 at posterior interatrial septum along tricuspid annulus is important marker indicating a successful ablation sites.
Subject(s)
Humans , Male , Catheter Ablation , Electrocardiography , Electrophysiologic Techniques, Cardiac , Tachycardia, Atrioventricular Nodal ReentryABSTRACT
Métodos - No período de março de 1987 a março de 1990, 20 portadores de TRN foram submetidos a tratamento cirúrgico, 14 do sexo feminino, com idades variando entre 12 e 70 (média 42,8 ± 17,1) anos. Apresentavam crises recorrentes de TRN de 6 meses a 60 anos (média de 18,4 15,9 anos ). Dez apresentaram síncopes ou présíncopes durante as crises e dois foram ressuscitados durante tentativa de reversão com drogas antiarrítmicas. Fizeram uso de 1 a 6 (média de 3,75 ± 1,45) drogas antiarrítmicas, sem sucesso. Todos foram submetidos a estudo eletrofisiológico que caracterizou a forma comum de TRN. O procedimento cirúrgico foi semelhante em todos os casos, com dissecção profunda da região perinodal posterior. Seis pacientes submeteram-se a procedimentos cirúrgicos associados. Dezoito pacientes foram submetidos a estimulação atrial programada antes da alta hospitalar. A avaliação tardia resultou de observação clínica ambulatorial e de EEF e Holter quando necessários. Resultados - A estimulação atrial programada realizada em 18 pacientes não reproduziu a TRN, mesmo após administração de atropina IV. A média do intervalo PR variou de 153 ± 50,36 ms no pré, para 152 ± 38 ms no pós-operatório (p>0,05). Nenhum paciente apresentou recorrência da TRN no seguimento de 26,3 ± 10 m. Dois pacientes evoluíram para FA crônica após 24 meses da cirurgia. Conclusão - A técnica de dissecção perinodal empregada foi eficaz e segura a longo prazo, preservando a condução AV
Purpose - To analyze the long term results of surgical treatment of atrioventricular nodal reentrant tachycardia (AVNT). Methods - From March 1987 to March 1990, 20 patients with AVNT were submitted to surgical therapy, 14 female, aged 12 to 70 (42.8 ± 17) years. All presented crisis of AVNT from 6 months to 60 (18.4 ± 15.9) years. Ten of them had syncope or near syncope and two with cardiac arrest during reversion of AVNT with antiarrythmic drugs. They used 1 to 6 (3.75 ± 1.45) antiarrythmic drays before surgery. The electrophysiologic study (EPS) showed the commom form of AVNT in all cases. The surgical procedure was anatomically directed to the posterior area of the AV node. Programmed atrial stimulation (PAS) were applied on 18 patients after surgery. The longterm results were analysed by clinical evaluation, EPS andHolter when they were necessary. Results - The pos-operative PAS was done in 18 patients and did not induce any AVNT, even after atropine IV. The PR interval was 153 ± 50 ms before and 152 ± 38 ms after surgery (p > 0.05). During follow up (26 ± 10 m) there were not AVNT reccurence. Two patients developed chronic atrial fibrillation after 24 months of surgery. Conclusion - The perinodal dissection technique used was safe and successful to treat AVNT, preserving AV nodal conduction
Subject(s)
Humans , Male , Female , Tachycardia, Atrioventricular Nodal Reentry/surgery , Middle Aged , Adolescent , Adult , Aged , Brazil/epidemiology , Electrophysiology , English Abstract , Follow-Up Studies , Heart/physiopathology , Recurrence , Tachycardia, Atrioventricular Nodal Reentry/diagnosis , Tachycardia, Atrioventricular Nodal Reentry/epidemiologyABSTRACT
Transcatheter atrioventricular (AV) junction ablation with radiofrequency energy was performed in five patients with AV nodal reentrant tachycardia. Disappearance of ventriculoa-trial condcution in all patients was showed and no dual pathway was observed in four patients, in whom three patients occurred first degree AV block after ablation. No tachycardia was showed in all patients in the electrophysiology test and in follow-up of 1. 5-12. 5 months. The results sug-gested that the application of radiofrequency energy may be a suitable and safe therapeutic mothed for modification of AV nodal conduction in patients with AV nodal reentrant tachycardia.