ABSTRACT
Objective To investigate whether taking diastolic potential(DP)and earliest Purkinje potential(PP)as ablation targets together is superior to taking earliest PP alone in patients with left posterior fascicular ventricular tachycardia(VT).MethodsTotally 18 patients who were admitted in our department from May 2006 to May 2009 were enrolled,and the results of their electrophysiological examination were analyzed.According to radiofrequency(RF)ablation targets,patients were classified into 2 groups:DP+PP group(DP and PP as ablation targets together)and PP group(PP as the target alone).Successful RF ablation was established when the ventricular tachycardia was no longer inducible.The acute success rate,recurrent rate,number of ablation application,procedure time,X-ray exposure and complications were compared between DP+PP and PP groups.ResultsThere was 1 case receiving no ablation because of not being induced to clinical VT.Seventeen cases were induced to clinical VT and displayed right bundle branch block(RBBB)and left axis morphology(DP+PP group 7 cases,and PP group 10 cases).All cases were successfully ablated,their DP-Q interval and PP-Q interval were 60.17?8.16 and 30.64?7.19 ms,respectively.There was no significant difference between the 2 groups in the age,ventricular tachycardial cycle,procedure time and recurrent rate.Compared to the PP group,the number of RF application in DP+PP group was fewer(4.55?2.07 vs 7.50?1.64,P=0.04),and X-ray exposure time was a little longer(18.33?1.51 min vs 15.37?2.77 min,P=0.03).There was neither left posterior fascicular block nor other complications seen in the 2 groups.The follow-up period was 14.29?10.05 months,and during this there was 1 case recurrence in DP group(2 months after procedure)and 1 case in PP group(1 month after procedure)respectively.ConclusionThe 2 methods are effective and safe for successful ablation of left posterior fascicular VT.Compared to ablation of earliest PP site alone,ablation of DP+PP might need fewer times of RF application but longer X-ray exposure time.
ABSTRACT
Objective To investigate the efficacy and safety of segmental electrical isolation of pulmonary veins (PVs) during atrial fibrillation (AF) Methods Nine patients were included, of whom 4 had recently persistent AF (3～4 months) and 5 suffored from paroxysmal AF occurred AF frequently We adopted one transseptal procedure Lasso mapping catheter and ablation catheter were positioned into target pulmonary vein ostium through the same site of atrial septum RF ablation was applied at the pulmonary vein potential (PVP) breakthrough using thermo control RF catheter during AF Results Twenty nine PVs were targeted for segmental RF ablation and isolated completely PVPs in target PVs were in higher spike and more frequent than left atrial potentials There were no complications associated with the procedure Seven patients were converted to sinus rhythm during the procedure Two patients restored sinus rhythm by cardioversion Conclusion It is suggested that the method of segmental PV isolation during AF is safe and has higher success rate It is not necessary to stop antiarrhymic drugs before RF ablation This study provides a reliable method for segmental electrical isolation of pulmonary veins in patients with persistent AF
ABSTRACT
Objective To describe the new cognition of mapping, ablation and mechanism of typical atrial flutter using non-contact mapping system. Methods In 9 patients with typital AFL, the bi-directional conduction properties of isthmus, atrial activation sequence and reentrant circuit of AFL were mapped using the non-contact mapping system. Linear isthmus radiofrequency ablation was guided by navigation system without fluoroscopy, and isthmus bi-directional block was verified. Results A clockwise moving reentrant activation wavefront in 1 of the 9 patients was observed and a counter-clockwise rotating wavefront in 7 of the 9 patients, respectively. AFL was not inducible in one patient. The mean cycle length of AFL was (215?36) ms. The whole reentrant way and its relation with anatomical structure of right atrium (RA) were displayed by non-contact mapping. In each mapped AFL, the wavefront conducted through the crista terminalis (CT) and propagated slowly, which that indicated the smooth part of RA was involved in the reentrant circuit. In patients with recurrences, the gap in the line of block in the isthmus was identified and ablated, which was navigated by the system. Complete isthmus bi-directional conduction block was achieved at the end of the procedure except in two patients. No recurrences of AFL occurred during the follow-up of 12-36 months. Conclusion The whole activation circuit and its relation with RA anatomical structure of typical AFL can be directly visualized and its reentry mechanism was verified by non-contact mapping system. In recurred cases ,the gap of isthmus block was identified and ablated accurately. CT, which was previously supposed to be a complete posterior conduction barrier, was now proved to be of transverse slow conduction by non-contact mapping.
ABSTRACT
Objective To investigate the efficacy and safety of the segmental electrical isolation of pulmonary veins (PVs) in patients with paroxysmal atrial fibrillation (PAF). Methods Thirty-nine patients (28 males, 11 females) with recurrent documented symptomatic PAF were included. In order to avoid the risk of cardiac tamponand, we adopted one transseptal procedure and obtained unselective angiography of all PVs and left atrial appendage using pigtail catheter. Lasso mapping catheter and ablation catheter were put into target pulmonary vein ostium through the same site of atrial septum. We routinely mapped the right inferior PV lest any pulmonary vein potential (PVP) that triggered PAF should be omitted. RF ablation was applied at the PVP breakthrough and slightly right and left by moving the RF catheter. Results Eighty-five PVs were targeted for segmental RF ablation. Eight-one were isolated completely. Immediate successful rate was 95%. There was not any complication associated with the procedure. Conclusion It is suggested that the method of segmental PV isolation has a higher cure rate and a shorter procedure time compared with other traditional methods. It can minimize the lesion of pulmonary veins and avoid PV stenosis.
ABSTRACT
Objective To evaluate the effect of radiofrequency catheter ablation treament of supraventricular tachyarrhythmias on spontaneous attack of atrial fibrillation (AF) and to further discuss the electrophysiological mechanisms of AF. Methods Thirty-one patients (20 men, 11 women; mean age 54?12 years, age range 24-69 years) with supraventricular tachyarrhythmias coexisting with AF were included in the study. The mean history of the study group was 9?5 (range 1-19) years and the mean number of AF attack was 6?5 times (range 2-18). Of the 31 cases, 5 supraventricular tachyarrhythmias were electrophysiologically proven to be typical atrial flutter (AFL), 17 atrioventricular reentrant tachycardia (AVRT), 9 atrioventricular nodal reentrant tachycardia (AVNRT). Linear lesions to make bi-directional block were done in cavo-tricuspid isthmus in AFL patients, slow pathway modification in AVNRT and accessory pathway ablation in AVRT. Results After mean follow-up of 39?19 months (range 12-72), of the 31 patients, 23 had no occurrence of AF. In 3 of the 5 AFL patients, no AF occurred after ablation, but 2 still had AF occurrence, of whom one had frequent atrial premature contractions (APCs) and short runs of AF. In 26 patients with supraventricular tachycardia, 20 had no occurrence of AF after ablation. In the remaining 6, 2 had less frequent occurrence, and 4 remained the same, of whom one had hypertention with enlarged left atrium, and another had frequent APCs and short runs of atrial tachycardia. Conclusion AFL may share the same substrate with AF or may be the trigger factor of AF, and AVNRT and AVRT are only trigger factors of AF. So after successful ablation treatment of these tachycardias, no AF occurs. But in some cases, AF substrate still exists, and AF can be triggered by other trigger factors besides tachycardias mentioned above.