How to Achieve Complete and Permanent Pulmonary Vein Isolation without Complications

The efficacy and safety of catheter ablation for the management of atrial fibrillation (AF) has been improved in recent years. Radiofrequency (RF) catheter ablation for maintaining sinus rhythm is superior to the current antiarrhythmic drug therapy in selected patients. Pulmonary vein isolation (PVI) is the cornerstone of various catheter ablation strategies. It is well recognized that pulmonary vein (PV) antrum contributes to the AF initiation and/or perpetuation. Since PV stenosis is a complication of ablation within a PV, the ablation site for PVI has shifted to the junction between the left atrium and the PV rather than the ostium of the PV. However, PV reconnection after ablation is the major cause of recurrence of AF. The recovery of PV conduction could be caused by anatomical variations such as the failure to produce complete transmural lesion or gaps at the ablation line due to the transient electrophysiologic effects from the RF ablation. In this review, we discussed several factors to be considered for the achievement of the best PVI, including clinical aspects and technical aspects.

Irreversible Electroporation of a Hepatocellular Carcinoma Lesion Adjacent to a Transjugular Intrahepatic Portosystemic Shunt Stent Graft

We report in a 65-year-old man hepatocellular carcinoma adjacent to a transjugular intrahepatic portosystemic shunt stent-graft which was successfully treated with irreversible electroporation (IRE). IRE is a new non-thermal tissue ablation technique which uses electrical pulses to induce cell necrosis by irreversible membrane poration. IRE proved to be more advantageous in the ablation of perivascular tumor with little injury to the surrounding structures.

Taquicardiomiopatía, causa reversible de insuficiencia cardiaca: caso clínico / Tachycardiomyopathy as a reversible cause of heart failure: Report of one case

Tachycardiomyopathy is a potentially reversible cause of heart failure. It can be induced by supraventricular or ventricular arrhythmias. When these are treated, systolic function improves or normalizes. We report a 20year-old male with deterioration of left ventricular function and dilated cardiomyopathy secondary to an incessant atrial tachycardia that was treated with radiofrequency catheter ablation. After the procedure, the patient experienced a significant improvement of his ventricular function.

Ablación de fibrilación auricular en un paciente con miocardiopatía dilatada / Ablation of Atrial Fibrillation in a Patient with Dilated Cardiomyopathy

El tratamiento invasivo de la fibrilación auricular en pacientes con miocardiopatía dilatada con sospecha de taquicardiomiopatía representa una decisión difícil y controversial. En esta presentación se describe el caso de un paciente de 57 años, internado por insuficiencia cardíaca congestiva progresiva. En el electrocardiograma se evidenció fibrilación auricular de alta respuesta ventricular y en el ecocardiograma, miocardiopatía dilatada con deterioro grave de la función del ventrículo izquierdo e insuficiencia mitral grave sin compromiso orgánico valvular. Se descartó enfermedad coronaria. Se planteó la ablación por radiofrecuencia como la mejor alternativa para su cuadro. El paciente recuperó ritmo sinusal, con el cual permanece desde hace 2 años, con evolución asintomática y mejoría de todos los parámetros ecocardiográficos.

Invasive treatment of atrial fibrillation in patients with dilated cardiomyopathy and suspicion of tachycardia induced cardiomyopathy is a difficult and controversial decision. We describe the case of a 57 year-old patient who was hospitalized due to progressive congestive heart failure. The electrocardiogram showed atrial fibrillation with high ventricular response and the echocardiogram revealed the presence of dilated cardiomyopathy with severe left ventricular dysfunction and severe mitral regurgitation with no evidence of organic compromise of the mitral valve. Coronary artery disease was ruled out. Radiofrequency ablation of atrial fibrillation was the best option to treat the arrhythmia. Sinus rhythm was restored and the patient remains without arrhythmia 2 years after the procedure. He is asymptomatic and presents improvement of the echocardiographic parameters.

Effects of percutaneous radiofrequency ablation and repeat hepatectomy for the treatment of solitary recurrent hepatocellular carcinoma with the diameter no more than 3 cm / 中华消化外科杂志

Objective To compare the efficacy of percutaneous radiofrequency ablation (PRFA) and repeat hepatectomy for solitary recurrent hepatocellular carcinoma (HCC) with the diameter≤3 cm. Methods The clinical data of 151 patients with recurrent HCC (diameter≤3 cm) who were admitted to the Cancer Center of Sun Yat-Sen University from January 1999 to December 2009 were retrospectively analyzed. Of all the patients, 79received PRFA (PRFA group) and 72 received repeat hepatectomy (repeat hepatectomy group). The survival rate, morbidity and recurrence of the tumor between the two groups were compared. All data were analyzed using t test, chi-square test or Log-rank test, and the survival of the patients were analyzed using the Kaplan-Meier method. Results The mobidities of the PRFA group and repeat hepatectomy group were 13% (10/79) and 36%(26/72), respectively, with a significant difference between the two groups (x2=11.411, P＜0.05). The cumulative 1-, 2-, 3-, 4-, 5-year survival rates were 89.7%, 75.2%, 67.1%, 61.5%, 56.6% in the PRFA group, and 86.0%, 67.6%, 53.6%, 44.1%, 40.2% in the repeat hepatectomy group, with no significant difference between the two groups (x2=1.610, P＞0.05). The cumulative 4-, 5-year survival rates of the PRFA group were significant higher than those in the repeat hepatectomy group (x2=4.682, 4. 196, P ＜ 0.05). The local tumor recurrence rate of the PRFA group was 5% (4/79), and the incisal margin recurrence rate was 3% (2/72) in the repeat hepatectomy group, with no significant difference between the two groups (x2=0.565, P＞0.05). Conclusion As a less invasive treatment method, PRFA is superior to repeat hepatectomy for solitary recurrent HCC with the diameter≤3 cm.

Preparation of EUS-guided radiofrequency probe and test of its functions / 中华消化内镜杂志

Objective To prepare a radiofrequency (RF) ablation probe guided by endoscopic ultrasonography (EUS) and to evaluate its efficacy and safety. Methods A modified 19-gauge needle ( Olympus) was used, which was electrically insulated with shrink tubing, with the tip of lcm naked. The insulation was tested, and the current signal was stable. Three rabbits were anesthetized with 8% chloral hydrate ( 3 ml/kg) intraperitoneally, fixed on the dissecting table. A standard neutral pad was applied to the thigh of the rabbit to complete the electrical circuit, both the pad and the needle electrode connected with RF generator. After anesthesia was ready, the needle was advanced through the gastric wall into the liver. Ablations were performed three times in the same zone. Extent and tissue lesion were measured after ablation. Results Ablation could be successfully performed by the needle electrode, with brown lesions surrounded by normal hepatic tissue. The mean diameter of the ablated zone in the liver was 1.0 cm× 1.2 cm. After ablation,specimens along the passage were subjected to NADH staining, and no lesions were found. HE and NADH staining showed no viable cells in the central ablation area. Conclusion With the advance of the technology and selection of materials, an EUS-guided needle electrode can be made. This preliminary animal trial demonstrates that radiofrequency ablation can be performed effectively and safely by using this EUS-guided needle electrode.

Efficacy evaluation of laparoscopic surgery in the treatment of 128 patients with liver cancer / 中华消化外科杂志

Objective To investigate the value of laparoscopy in the treatment of liver cancer.Methods The clinical data of 128 liver cancer patients who received laparoscopic surgery at Southwest Hospital from March 2007 to October 2009 were retrospectively analyzed.Of all patients,116 were with primary liver cancer,and 12 with metastatic liver cancer.There were 107 patients who received laparoscopie bepatectomy,15 received laparoscopic radiofrequency ablation(RFA)and 6 received laparoscopic ligation of the right branch of portal vein.Results Of the 107 patients who received laparoscopic bepatectomy,7 were converted to open surgery,and 5 were converted to hand-assisted laparoscopic hepatectomy.Anatomical hepatectomy was performed on 88 patients,including left lateral lobectomy on 21,left hemihepatectomy on 15,extended left hemihepatectomy on 2,medial lobectomy on 1,right hemihepatectomy on 11,right posterior lobeetomy on 9 and hepatic segmentectomy on 29.Combined hepatic resection was performed on 4 patients,and nonanatomical hepatectomy on 15.The mean oporatire time and blood loss were(228±92)minutes and(393±213)ml,with no operative mortality.The mean postoperative hospital stay was(8±4)days,and the incidence of complications was 15%(16/107).A total of 126 patients were followed up for 1-42 months,12 patients with laparoscopic hepatectomy died within 16 months,with the mean survival time of(118±7)weeks and the mean tumor free survival time of(105±7)weeks;2 patients with laparoscopic RFA died within 11 months:2 patients with laparoseopie ligation of the right branch of portal vein received two-stage radical resection.Conclusion Laparoscopic surgery is safe and feasible with the advantages of minimal operative trauma and quick recovery of patients when it is applied to the treatment of liver cancer.

Hypertonic saline enhanced radiofrequency ablation in the treatment of liver cancer / 中华消化外科杂志

Objective To investigate the efficacy and safety of hypertonie saline enhanced radiofrequency ablation (RFA) in the treatment of liver cancer. Methods The clinical data of 42 patients with primary liver cancer (n = 28) or metastatic liver eancer (n = 14) who had been admitted to First Affiliated Hospital of Nanjing Medical University from September 2001 to December 2007 were collected. Forty-eight lesions were detected with a diameter ranging from 1.2 cm to 7.5 cm. RFA electrode and 20G needle were pricked into the target lesion under the guidance of B ultrasound or computed tomography (CT) through percutaneoas puncture or open approaches. An amount of 5-10 ml hypertonie saline was infused through the needle at regular intervals during RFA. All patients were followed up for 3-79 months. Contrast-enhanced ultrasound and CT scanning were performed postoperatively to determine the efficacy of RFA. The levels of alpha-fetoprotein (AFP) before and after treatment were compared using t test, and the survival of the patients were analyzed using a Kaplan-Meier survival curve. Results The AFP expression changed to negative in 14 out of the 18 AFP-positive patients, with statistical difference (t =7.703, P <0.05). The complete necrosis rate of tumors was 94% (45/48), and the necrosis rate of tumors with diameter of ≤4.0 cm reached 100% (35/35). The incidence of complication was 5% (2/42). No perioperative mortality occurred. The 1-, 2-, 3-year survival rates were 91%, 85% and 70%, respectively. Conclusions Hypertonic saline enhanced RFA in the treatment of liver cancer was proved to be safe and effective.

Comparison of 2 radiofrequency ablation methods in idiopathic left posterior fasci-cular ventricular tachycardia / 第三军医大学学报

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.

DISCRETE RADIOFREQUENCY CATHETER ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION IN A DOG MODEL / 解放军医学杂志

To investigate an approach of treatment for atrial fibrillation with discrete ablation lesion, 12 dogs with experimental atrial fibrillation underwent radiofrequency catheter ablation. Atrial lesion was made at the most vulnerable site. The results showed that in 10 of 12 dogs persistent fibrillation could be ablated. There was no significant change in sinus heart rate, P wave duration, and corrected sinoatrial node recovery time (cSNRT). The results suggested that paroxysmal atrial fibrillation could be eliminated by point ablation of the lesion, and that trigger activity might be involved in the mechanism of atrial fibrillation.

Cellular electrophysiology of fast pathway ablation of rabbit atrioventricular node

Discrete radiofrequency lesion at the atrial insertion site of the tendon of Todaro in the perfused rabbit preparation lengthens A-H interval, mimicking fast pathway input ablation. This study attempts to define the cellular electrophysiology of the ablation region prior to and after the elimination of fast AV node conduction. In six superfused rabbit AV node preparations, the cellular electrophysiology around the region of the atrial insertion to the tendon of Todaro was recorded using standard microelectrode technique prior to and after ablation. Before ablation, the action potentials recorded in the area of proposed lesion were exclusively from atrial or AN cells. At postablation, the superior margin of the lesion was populated with atrial or AN cells. AN, N, or NH cells bordered the lower part of the lesion. Electrophysiology of surviving cells at the edges of the lesion showed no significant changes in their Vmax, APD50 or APD90 and MDP from preablation values. Fast AV node pathway input ablation in the rabbit heart can be accomplished with a singular lesion around the atrial insertion site of the tendon of Todaro, involving atrial or AN cells. The results of the studies imply that inputs to the compact node may act as a substrate for successful ablation of AV node reentry tachycardia.

The methodological study of segmental isolation of pulmonary veins during atrial fibrillation / 中国介入心脏病学杂志

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

New cognition of mapping,ablation and mechanism of typical atrial flutter using non-contact mapping / 中国介入心脏病学杂志

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.

Evaluating the method of segmental isolation of pulmonary veins in patients with paroxysmal atrial fibrillation / 中国介入心脏病学杂志

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.

Radiofrequency catheter ablation of verapamil-sensitive idiopathic left ventricular tachycardia / 中国介入心脏病学杂志

Objective To study the effect of RF catheter ablation of verapamil-sensitive idiopathic left ventricular tachycardia according to the re-entrant route mapped during electrophysiologic test. Methods 6 patients (4 male & 2 female) suffered from the ioliopathic left venticulan tachycondia (ILVT). After placing the catheter in the right ventricular apex and the coronary sinus, a radiofrequency (RF) catheter and a octapolar catheter (mapping catheter) with an interval of 2-8-2 min were introduced through the right and left femoral arteries. The mapping catheter recorded the His potential (HP), the left bundle potential (LBP), the left posterior fascicle Purkinje potential (PP) and V electrogram sequentially, PP was the first potential to be detected with the RF catheter during TV, we searched for the earliest PP recording site near the couple of electrodes of the mapping catheter recording PP and ablated it. Results In the first 3 cases, ablation didn′t have effect at sites recording the earliest V electrogram without PP and it was finally successful at the sites recording the earliest PP. Since the fourth case all patients needed only one application because ablation was carried out only at the site recorded the earliest PP. Patients have been followed for 6-20 months without antiarrhythmic drugs, and none of them has had a recurrence of VT. Conclusion The mapping on the left ventricular septum is not only important to study the reentrant route in ILVT, but also helpful for clinical treatment of ILVT. It shortens the operation time and minimizes injury of cardiac muscle due to noneffective ablation.