Organization of atrial fibrillation using a pure sodium channel blocker: Implications of rotor ablation therapy.

Background: Rotors are the source of atrial fibrillation (AF). However, the ablation of rotors for persistent AF is challenging. The purpose of this study was to identify the dominant rotor by accelerating the organization of AF using a sodium channel blocker and detecting the rotor's preferential area that governs AF. Methods: Overall, 30 consecutive patients with persistent AF who underwent pulmonary vein isolation and still sustained AF were enrolled. Pilsicainide 50 mg was administered. An online real-time phase mapping system (ExTRa Mapping™) was used to identify the meandering rotors and multiple wavelets in 11 left atrial segments. The time ratio of non-passive activation (%NP) was evaluated as the frequency of rotor activity in each segment. Results: Conduction velocity became slower-from 0.46 ± 0.14 to 0.35 ± 0.14 mm/ms (p = .004)-and the rotational period of the rotor was significantly prolonged-156 ± 21 to 193 ± 28 ms/cycle (p < .001). AF cycle length was prolonged from 169 ± 19 to 223 ± 29 ms (p < .001). A decrease in %NP was observed in seven segments. Additionally, 14 patients had at least one complete passive activation area. Of them, the use of high %NP area ablation resulted in atrial tachycardia and sinus rhythm in two patients each. Conclusions: A sodium channel blocker organized persistent AF. In selective patients with a wide organized area, high %NP area ablation could convert AF into atrial tachycardia or terminate AF.

Japan ablation registry: cryoablation in atrioventricular nodal reentrant tachycardia ("JARCANRET study"): results from large multicenter retrospective investigation.

PURPOSE: Cryoenergy has been demonstrated to be a safe alternative to radiofrequency ablation for catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). This study aimed to evaluate the safety and efficacy of cryoablation in patients with AVNRT. METHODS: A multicenter retrospective study was performed. Two hundred eighty-three consecutive patients with AVNRT underwent cryoablation. Cryomapping at - 30 °C and - 80 °C was performed to predict cryoablation outcome and ascertain antegrade conduction. Cryoenergy was delivered subsequently at the same spot (cryoablation at - 80 °C) for 240 s. RESULTS: Ablation procedure was acutely successful in 281 out of 283 patients (99.3%). Of note, 22 patients (10.1%) had transient AV block during the cryoablation, but no injurious effects on AV conduction were provoked during cryomapping. During a follow-up period of 367 ± 35 days, the recurrence rate was 3.9% (11 out of 281). There were no significant differences among the patients with a complete elimination of slow pathway conduction, AH jump without an echo beat, and AH jump with a single echo beat, in terms of the long-term recurrence of AVNRT. CONCLUSIONS: Cryoablation of AVNRT appears to be effective both acutely and during the long-term with a minimal risk of unwanted injuries to the conduction system. It seems to be important to monitor the antegrade conduction during cryoenergy applications, even when cryomapping demonstrates a safe location for cryoablation. The recurrence rate of AVNRT did not differ according to the properties of the residual slow pathway conduction.

Important factors in left atrial posterior wall isolation using 28-mm cryoballoon ablation for persistent atrial fibrillation-Block line or isolation area?

INTRODUCTION: Left atrial (LA) roof ablation using the cryoballoon technique, combined with pulmonary vein isolation (PVI), has been reported to be beneficial for ablation therapy in patients with persistent atrial fibrillation (AF). Left posterior wall ablation also results in improved patient outcomes. However, the contribution of these techniques to the success of cryoballoon ablation (CBA) treatment of AF is not known. The present study examined the influence of the roofline block and isolation area on outcomes after CBA. METHODS AND RESULTS: We enrolled 78 patients with persistent AF. LA roof ablation was performed using a 28-mm cryoballoon with a single freezing of 3 minutes at each region (median number of freezes: 4) after PVI. After CBA, bipolar voltage amplitude mapping was performed during sinus rhythm using the NavX mapping system. Patients were divided into two subgroups according to the voltage and activation map: the roof-conduction (n = 46) and roofline-block groups (n = 32). Atrial tachyarrhythmia recurred in 20 patients of the conduction group and 4 patients of the roofline-block group. The rate of 12-month freedom from tachyarrhythmia after a single ablation procedure was 78% (95% confidence interval [CI], 60%-89%) in the roofline-block group and 45% (95% CI, 30%-60%) in the conduction group (P = .048). Cox proportional hazard analysis revealed that the isolated area was not a significant predictor of recurrence (hazard ratio, 0.94; 95% CI, 0.86-1.02; P = .15). CONCLUSION: Creating a complete roofline block is the major factor predicting the maintenance of sinus rhythm in patients with persistent AF.

Successful catheter cryoablation for premature ventricular contractions originating from the para-Hisian region.

We achieved successful catheter cryoablation in a patient with para-Hisian premature ventricular contractions (PVCs) without conduction disturbance using the freeze-thaw-freeze method while observing the atrial-His bundle interval. Cryoablation could be considered an alternative to radiofrequency ablation for patients with para-Hisian PVCs.

Novel use of a 3-dimensional mapping system in cryoablation of right-sided and septal accessory pathways: playback ablation.

PURPOSE: Despite recent advances in the treatment of eliminating accessory pathways (APs), catheter-induced mechanical block (bump) of APs has been reported to result in a less favorable outcome with high primary failure and recurrence rates. The real bump site cannot always be precisely reapproached under fluoroscopy so physicians can perform ablation to a location different from where the mechanical block was encountered. In this paper, we describe this novel use of a 3-dimensional (3D) mapping system (playback ablation) with a case series. METHODS: The EnSite Velocity system (St. Jude Medical, St. Paul, MN, USA), a 3D mapping system, has a unique function that records the positional information of catheters in a 3D geometric map and the local potential of catheters continuously. This function enables physicians to specify the bump site in a 3D geometric map and apply ablation to the bump site even if the catheter moves away from the bump site. RESULTS: This technique helped us eliminate APs in two patients with bump of APs, and they have been free of preexcitation and arrhythmias without the use of anti-arrhythmic drugs for more than 3 months. CONCLUSIONS: This technique may contribute to improving long-term success in patients with mechanical block of APs.

A relation between ablation area and outcome of ablation using 28-mm cryoballon ablation: Importance of carina region.

INTRODUCTION: Pulmonary vein isolation (PVI) with wide antral ablation leads to better outcomes in atrial fibrillation ablation therapy, but the ablation area is relatively small during cryoballoon ablation (CBA). The present study tested the hypothesis that wide ablation can lead to better outcomes in CBA. METHODS AND RESULTS: Ninety-six patients with atrial fibrillation were enrolled (paroxysmal 76%, 64.1 ± 11.7 years). All patients underwent preprocedural computed tomography and the PV diameter at left atrial PV junction was measured. PV isolation was performed using a 28-mm CB for 3 minutes with single freezing. Sinus rhythm bipolar voltage amplitude maps with the NavX mapping system were generated after ablation. According to the voltage map, patients were divided into 3 subgroups (68 in the extensive isolation group, 17 in the individual isolation group, and 10 in the incomplete isolation group). Atrial tachyarrhythmias recurred in 9 patients of the extensive isolation group and 6 in the individual isolation group. The rate of 12-month freedom from tachyarrhythmia after a single ablation procedure was 84% (95% confidence interval [C.I.], 72%-91%) in the extensive group and 57% (95% C.I., 28%-78%) in the individual group (P = 0.048). Multiple logistic regression analyses revealed that maximal PV diameter was the only predictor to achieve extensive PVI (odds ratio, 1.57; 95% C.I. 1.08-2.29 P = 0.018). CONCLUSION: Extensive isolation is superior to individual isolation for achieving freedom from atrial arrhythmia in long term follow-up by CBA. Evaluating PV diameter at the left atrial PV junction is essential for applying CBA.

[One-stage resection of intravenous leiomyomatosis extending into the right atrium].

Intravenous leiomyomatosis (IVL) is a benign tumor that originates from a uterine myoma and rarely extends to the heart through the inferior vena cava (IVC). Echocardiography revealed an abnormal mass in the right atrium in a 63-year-old asymptomatic woman. Preoperative examination revealed a tumor extending from a myoma through the right internal iliac vein to the right atrium, and the patient was diagnosed with IVL. She underwent sternotomy combined with laparotomy, and the intravenous and intracardiac tumor was removed under normothermic cardiopulmonary bypass without cardiac arrest. Hysterectomy and bilateral adnexectomy were also performed. No additional therapy was required after surgery.