Irrigated Ablation Research Articles

Cardiac mapping and pulmonary vein isolation using a novel ablation catheter with tip minielectrodes.

Pulmonary vein isolation (PVI) is a standard treatment for atrial fibrillation (AF). Identification of gaps in the ablation line is difficult. Tip-ring electrograms from ablation catheters represent relative large areas of myocardial tissue. Recently, an ablation catheter with three minielectrodes (ME) on the catheter tip with closer interelectrode spacing was introduced. The aim of our study was to evaluate the novel electrodes during PVI. PVI was performed with an irrigated ablation catheter equipped with conventional electrodes and three additional radial tip electrodes. Detection of pulmonary vein potentials (PVPs), local signal amplitude, amplitude reduction during ablation, and loss of capture after ablation were compared between the ME and the conventional tip-ring electrodes. Thirty-one patients (mean age 67.8 ± 10.3 years, 45.2 % men) were included. A total of 306 mapping/lesion points were analyzed. A PVP was significantly more often obtained with the ME compared to the conventional tip-ring electrodes (99.2%vs 83.5%, P<0.001). Local amplitude was significantly higher on the ME (0.8 ± 0.6mV vs 0.67 ± 0.46mV, P=0.003). Amplitude reduction during 1 RF pulse was significantly greater on the ME (82.9 ± 19.5%vs. 61.8 ± 26.9%, P<0.001). During pace mapping, loss of capture after 1 RF pulse was observed significantly more often on ME (98.3%vs 63.3%, P<0.001). Signal amplitude is higher and sensitivity during PVP mapping and ablation is increased when ME are used. ME may facilitate catheter ablation of AF in the future.

Temperature-Controlled Radiofrequency Ablation for Pulmonary Vein Isolation in Patients With Atrial Fibrillation

BackgroundSaline irrigation improved the safety of radiofrequency (RF) ablation, but the thermal feedback for energy titration is absent. ObjectivesTo allow temperature-controlled irrigated ablation, a novel irrigated RF catheter was designed with a diamond-embedded tip (for rapid cooling) and 6 surface thermocouples to reflect tissue temperature. High-resolution electrograms (EGMs) from the split-tip electrode allowed rapid lesion assessment. The authors evaluated the preclinical and clinical performance of this catheter for pulmonary vein (PV) isolation. MethodsUsing the DiamondTemp (DT) catheter, pigs (n = 6) underwent discrete atrial ablation in a temperature control mode (60°C/50 W) until there was ∼80% EGM amplitude reduction. In a single-center clinical feasibility study, 35 patients underwent PV isolation with the DT catheter (study group); patients were planned for PV remapping after 3 months, regardless of symptomatology. A control group included 35 patients who underwent PV isolation with a standard force-sensing catheter. ResultsPorcine lesion histology revealed transmurality in 51 of 55 lesions (92.7%). In patients, all PVs were successfully isolated; no char or thrombus formation was observed. Compared with the control group, the study cohort had shorter mean RF application duration (26.3 ± 5.2 min vs. 89.2 ± 27.2 min; p < 0.001), shorter mean fluoroscopic time (11.2 ± 8.5 min vs. 19.5 ± 6.8 min; p < 0.001), and lower acute dormant PV reconduction (0 of 35 vs. 5 of 35; p = 0.024). At 3 months, 23 patients underwent remapping: 39 of 46 PV pairs (84.8%) remained durably isolated in 17 of these patients (73.9%). ConclusionsThis first-in-human series demonstrated that temperature-controlled irrigated ablation produced rapid, efficient, and durable PV isolation. (ACT DiamondTemp Temperature-Controlled and Contact Sensing RF Ablation Clinical Trial for Atrial Fibrillation [TRAC-AF]; NCT02821351)

P857Comparison of pulmonary vein isolation using a laser balloon and using an open irrigated mapping and ablation catheter (nMARQ)

P857Comparison of pulmonary vein isolation using a laser balloon and using an open irrigated mapping and ablation catheter (nMARQ)

P856Acute safety and efficacy outcome of pulmonary vein isolation with different generations of a multipolar irrigated circular ablation catheter

P856Acute safety and efficacy outcome of pulmonary vein isolation with different generations of a multipolar irrigated circular ablation catheter

Radiofrequency Catheter Ablation Targeting the Vein of Marshall in Difficult Mitral Isthmus Ablation or Pulmonary Vein Isolation.

The ligament of Marshall may hinder the creation of mitral isthmus (MI) block or pulmonary vein (PV) isolation (PVI) in radiofrequency (RF) catheter ablation of atrial fibrillation (AF). We aimed to assess the benefit of RF ablation targeting the vein of Marshall (VOM) in failed cases of MI block or PVI. We reviewed the medical records of patients who underwent RF ablation targeting the VOM after failed MI ablation or left PVI using the conventional method, which included circumferential point-by-point ablation around the PV antrum and carina for PVI, and endocardial MI and epicardial distal coronary sinus (CS) ablation for MI block. The VOM was identified by using selective VOM venography with an external irrigation RF ablation catheter. RF ablation targeting the VOM was performed with RF application at the ostium of the VOM inside the CS or at the endocardial region facing the VOM course. During the set period, CS venography was performed in 42 patients after failure of left PVI (n = 5) or MI block (n = 37). Under CS venography, the VOM was visualized in 22 of 42 patients (MI = 19 and PVI = 3). During selective venography of the VOM, no procedure-related complication was observed. RF application targeting the VOM successfully achieved MI block in 13 patients (68.4%) and PVI in 2 patients (66.7%). Selective VOM venography using an irrigated ablation catheter is feasible and safe. RF ablation targeting the VOM may provide additional benefit in failed cases of MI block or PVI.

Peri-procedural Corticosteroid Use in Improving Outcomes Following Atrial Fibrillation Ablation: Back to Square One?

Bilateral pulmonary vein (PV) isolation by catheter ablation has become an established therapy for highly symptomatic, drug refractory, paroxysmal atrial fibrillation (AF) (1, 2). The efficacy of pulmonary vein isolation has improved over the years through refinement of procedural technique as well as improved ablation technology involving irrigated ablation, contact force sensing, and “single shot” ablation techniques such as cryo, laser, and multielectrode ablation catheters(1, 3-5). However, durable pulmonary vein isolation has remained a significant challenge with increasing rates of pulmonary vein reconnection noted during long-term follow-up (6, 7). Similarly, acute reconnections as well as early recurrences during the blanking period have been associated with reduced freedom from AF during follow-up(8). With radiofrequency (RF) ablation, acute inflammation from the ablation lesions itself have been thought to have a major role in AF recurrences during the immediate peri-procedural period (9).

Abstract 13166: Externally Irrigated Radiofrequency Ablation With Low Osmolarity Irrigant for the Treatment of Cardiac Arrhythmias

Introduction: Certain cardiac arrhythmias arise from deep or thick myocardium and may be refractory to standard external irrigated ablation. Externally irrigated ablation (EIA) is generally performed with normal saline (NS) as the infusing irrigant. Recent data suggest that larger ablation lesions can be created by decreasing the irrigant osmolarity. Hypothesis: We sought to evaluate the use of half normal saline (HNS) as the irrigant in externally irrigated ablation under ex vivo and in vivo conditions. Methods: Bovine myocardium was placed in a circulating saline bath in an ex vivo model. Two externally irrigated ablation catheters were oriented across from each other, with myocardium in between. Sequential unipolar ablations with HNS were performed at 50 Watts for 60 seconds, and ablation lesions were compared to using NS or HNS irrigation. In addition, a retrospective analysis was performed of all ablations using HNS completed at the University of Colorado from 2015-2016. Results: In vivo porcine ablations with HNS irrigation generated larger lesions, compared to control ablations using standard NS irrigation, and there was no increased incidence of steam pops (Figure 1). Clinically, 7 cases were identified that utilized HNS as the irrigant in EIA for refractory arrhythmias (1 atrial tachycardia, 6 VT/PVC cases). Acute success was achieved in 7/7 of procedures, with no recurrences at a mean follow up of 109 days. There were no complications (Figure 2). Conclusions: By decreasing irrigant osmolarity and charge density in EIA through the use of HNS, larger ablation lesions can be created to target deep arrhythmia circuits refractory to standard ablation.

Acute and Mid-Term Results after Pulmonary Veins Isolation Using a Novel Circular Irrigated Multielectrode Mapping and Ablation Catheter (nMARQ)

Background: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation in both paroxysmal and persistent AF. However, this procedure is still challenging and time consuming. Objective: The aim of this study was to present our approach for PVI using a novel circular irrigated multielectrode mapping and ablation catheter (nMARQTM) and to present acute and mid-term results. Methods: The study included 31 consecutive patients with symptomatic AF (4 had persistent and 27 had paroxysmal AF) who underwent PVI using the nMARQTM catheter. Circular ablation was guided by CT image integrated into fast anatomical map and by intra cardiac echo. Isolation of pulmonary veins was identified using the nMARQTM catheter if it was possible to advance it into the veins, otherwise Lasso catheter was used. Patients were followed up to 20 months. Results: PVI was achieved in 119 (98%) out of 121 pulmonary veins identified, and final PVI was obtained in 30 (97%) out of 31 patients. Lasso catheter was needed for PVI confirmation in 16 (52%) patients. Touch up ablation using standard catheter guided by Lasso catheter was needed in 4 (13%) patients. Pericardial tamponade occurred in 1 patient who was treated with pericardiocentesis. No other major complications were detected. During follow-up (mean 15.9 ± 3.6 months, range 9 - 20 months), 4 (13%) patients had recurrence of atrial tachyarrhythmia. Conclusion: PVI using the novel nMARQTM catheter is safe with good acute and mid-term efficacy. Long term follow up trials are needed.

Renal Sympathetic Denervation in Mild to Moderate Chronic Kidney Disease Patients with Chronic Heart Failure Refractory to Cardiac Resynchronization Therapy: A Safety Evaluation Study

Background: Heart failure (HF) is a challenging disease to control. Chronic overactivation of the sympathetic nervous system occurs early in HF and chronic kidney disease (CKD). The aim of this study was to evaluate the safety and effects of renal sympathetic denervation (RSD) in reducing lesions on the heart and kidneys in patients with CKD and HF refractory to cardiac resynchronization therapy (CRT). Methods and results: Twenty-one patients were included and treated with a standard irrigated cardiac ablation catheter. RSD was performed by a unique operator. All the patients included in the study had HF in functional New York Health Association (NYHA) class III, were refractory to CRT, and had mild-to-moderate CKD. Data were obtained at baseline, and at 6 and 12 months of follow-up. RSD was safe and feasible to perform in this population. No changes in blood pressure were observed during this period. At baseline, patients walked 172.4 ± 26.4 m during a 6-minute walk test, increasing to 209.4 ± 29.1 m at 12 months post RSD (p<0.001). All echocardiographic parameters evaluated improved at 6 (p<0.001) and 12 months (p<0.001) after RSD. Estimated glomerular filtration rate improved from 67.4 ± 20.5 mL/min/1.73 m2 at baseline to 87.8 ± 17.9 mL/min/1.73 m2 at 12 months post procedure (p<0.001). At 12 months after RSD, 42% of patients were in functional NYHA class I, 50% were in functional class II, and 8% remained in functional NYHA class III. Conclusions: RSD seemed to be safe, feasible, and effective, resulting in an improvement in echocardiographic parameters, 6-minute walk test distance, renal function, and functional NYHA class in mild-to-moderate CKD patients with HF refractory to CRT.

Reduction of Fluoroscopic Exposure Using a New Fluoroscopy Integrating Technology in a 3D-Mapping System During Pulmonary Vein Isolation With a Circular Multipolar Irrigated Catheter.

Pulmonary vein isolation (PVI) is a cornerstone therapy in patients with atrial fibrillation (AF). With increasing numbers of PVI procedures, demand arises to reduce the cumulative fluoroscopic radiation exposure for both the physician and the patient. New technologies are emerging to address this issue. Here, we report our first experiences with a new fluoroscopy integrating technology in addition to a current 3D-mapping system. The new fluoroscopy integrating system (FIS) with 3D-mapping was used prospectively in 15 patients with AF. Control PVI cases (n = 37) were collected retrospectively as a complete series. Total procedure time (skin to skin), fluoroscopic time, and dose-area-product (DAP) data were analyzed. All PVI procedures were performed by one experienced physician using a commercially available circular multipolar irrigated ablation catheter. All PVI procedures were successfully undertaken without major complications. Baseline characteristics of the two groups showed no significant differences. In the group using the FIS, the fluoroscopic time and DAP were significantly reduced from 571 ± 187 seconds versus 1011 ± 527 seconds (P = 0.0029) and 4342 ± 2073 cGycm(2) versus 6208 ± 3314 cGycm(2) (P = 0.049), respectively. Mean procedure time was not significantly affected and was 114 ± 31 minutes versus 104 ± 24 minutes (P = 0.23) by the FIS.The use of the new FIS with the current 3D-mapping system enables a significant reduction of the total fluoroscopy time and DAP compared to the previous combination of 3D-mapping system plus normal fluoroscopy during PVI utilizing a circular multipolar irrigated ablation catheter. However, the concomitant total procedure time is not affected. Thus, the new system reduces the radiation exposure for both the physicians and patients.

Abstract 16285: Routine Use of 3D Mapping and Irrigated Ablation Improves Outcomes of Pulmonary Vein Antral Isolation Among Patients With Persistent AF

Bckground: Pulmonary Vein Antrum Isolation (PVAI) is a widely accepted treatment option in Atrial Fibrillation (AF). However, despite procedural advancements, post-PVAI AF recurrences remain a common challenge. We thought to investigate whether the addition of routine 3D electroanatomical mapping and routine use of irrigated ablation catheters (IC) vs 8 mm tip catheters made an impact on the outcomes of PVAI guided by intracardiac echocardiography (ICE) and a decapolar circular mapping catheter (CMC) alone. Methods: Patient and procedural data were collected for 884 AF consecutive patients undergoing PVI at a single Canadian center during 2004 - 2014 (469 patients in 2004-2009, Group 1vs. 415 patients in 2010-2014, Group 2). Group 1 patients received PVAI guided by ICE and CMC. All Group 2 patients had PVAI guided by ICE, CMC and 3D mapping with the use of irrigated tip ablation catheters. Mean ages for Groups 1 and 2 were = 58.6 ± 10.0 and 61.0 ± 10.7 years respectively (p= 0.001). Mean follow up time was 17.1 ± 18.8 months for Group 1 and 14.1± 9.7 months for Group 2 (p=0.003). ECG and ambulatory monitoring was performed at 1, 3, 6, and 12 months. Recurrences ≤ 3 months post-PVI were considered Early (ER), while recurrences after 3 months post-PVI were considered Late (LR). Using survival analysis, rates of LR stratified by AF type [Paroxysmal AF (PAF) vs. Non-PAF (NPAF)] were compared between the two cohorts Results: ER rate was lower in Group 2 vs. Group 1 (36.8% vs. 44.7%, P=0.05) in patients with PAF and for those with NPAF (54.8% vs. 66.9%, P=0.03). LR rates did not differ between the Groups among PAF patients (62.5% in Group 1 vs. 57.3% in Group 2, P=0.16), but improved significantly for the NPAF patients (55.6% in Group 1 vs. 37.9% in Group 2 , P=0.002). Conclusion: Late recurrence of AF post-PVI has dramatically improved since 2010 for patients with persistent AF following routine addition of 3D mapping to ICE and CMC, while substituting an irrigated for an 8mm ablation catheter.

Irrigated Needle Ablation Creates Larger and More Transmural Ventricular Lesions Compared With Standard Unipolar Ablation in an Ovine Model

Ventricular tachycardia recurrence can occur after ventricular tachycardia ablation because of incomplete and nontransmural ventricular lesion formation. We sought to compare the lesions made by a novel irrigated needle catheter to conventional radiofrequency lesions. Thirteen female sheep (4.6±0.7 years, 54±8 kg) were studied. In 7 sheep, 60-s radiofrequency applications were performed using an irrigated needle catheter. In 6 sheep, conventional lesions were made using a 4-mm irrigated catheter. 1.5T in vivo and high-density magnetic resonance imaging (9.4T) were performed on explanted hearts from animals receiving needle radiofrequency. Conventional lesion volume was calculated as (1/6)×π×(A×B(2)+C×D(2)/2). Needle lesion volume was measured as Σ(π×r(2))/2 with a slice thickness of 1 mm. The dimensions of all lesions were also measured on gross pathology. Additional histological analysis of the needle lesions was performed. One hundred twenty endocardial left ventricular ablation lesions (conventional, n=60; needle, n=60) were created. At necropsy, more lesions were found using needle versus conventional radiofrequency (90% versus 75%; P<0.05). Comparing needle versus conventional radiofrequency: lesion volume was larger (1030±362 versus 488±384 mm(3); P<0.001), lesion depth was increased (9.9±2.7 versus 5±2.4 mm; P<0.001), and more transmural lesions were created (62.5% versus 17%; P<0.01). Pericardial contrast injection was observed in 4 apical attempts using needle radiofrequency, however, with no adverse effects. Steam pops occurred in 3 attempts using conventional radiofrequency. Irrigated needle ablation is associated with more frequent, larger, deeper, and more often transmural lesions compared with conventional irrigated ablation. This technology might be of value to treat intramural or epicardial ventricular tachycardia substrates resistant to conventional ablation.

Usefulness of intracardiac echocardiography during pulmonary vein isolation with the novel multipolar irrigated ablation catheter (nMARQ™).

Previous studies reported the usefulness of an irrigated circular radiofrequency ablation catheter (nMARQ(TM), Biosense Webster) for pulmonary vein isolation (PVI). We evaluated the role of intracardiac echocardiography (ICE) to optimize the manipulation of nMARQ(TM) catheter. Thirty-seven patients (pts), (mean age 55 ± 12 years; 28 males) were enrolled to perform PVI. All pts underwent PVI with the nMARQ(TM) catheter. In 20 pts (group 1), we utilized ICE to guide nMARQ(TM) catheter positioning at the PV ostia; in the other 17 pts (group 2), nMARQ(TM) catheter was positioned at the PV ostia guided by fluoroscopy and TissueConnect(TM) technology. Radiofrequency (RF) applications were significantly lower in group 1 compared to group 2 [left PVs: 6 (range 3 to 12) in group 1 and 12 (range 5 to 16) in group 2 (p < 0.001); right PVs: 7 (range 4 to 14) in group 1 and 10 (range 5 to 16) in group 2 (p = 0.04)]; similarly regarding the time of RF delivery [left PVs: 318 ± 194 s in group 1 vs. 542 ± 104 s in group 2 (p < 0.001); right PVs: 410 ± 270 s in group 1 vs. 550 ± 156 s in group 2 (p = 0.05)]. Fluoroscopy time (23 ± 9 min vs. 28 ± 5 min; p = 0.05), procedural time (83 ± 23 min vs. 160 ± 42 min; p < 0.001), and radiation dose (109 ± 20 Gy/cm(2) vs. 127 ± 29 Gy/cm(2); p = 0.04) were significantly lower in group 1 compared to group 2. ICE might be a useful tool to guide nMARQ(TM) catheter position in the left atrium during atrial fibrillation (AF) ablation procedures.

Efficacy evaluation of renal denervation with a standard irrigated cardiac ablation catheter in a 44 years old male with refractory hypertension: a case report

Background: Central hemodynamics and arterial stiffness evaluations are important for cardiovascular risk. The behavior of central blood pressure (CBP), and pulse wave velocity (PWV) during 24 hours is not well known. Objective: To investigate CBP and PWV in relation to brachial BP in 24 hours, awake and sleep periods in normotensive and untreated hypertensive individuals from 18 to 50 years old. Methods: A total of 104 subjects (60 females (57.7%) and 44 males (42.3%)), 48 (46.2%) individuals between 18 and 35 years old and 56 (53.8%) individuals between 36 and 50 years old were included. Exclusion criteria were: use of antihypertensive drugs, body mass index 35 kg/m, eGFR <60 ml/min, diabetes and smoking. All were submitted to clinical and laboratory evaluation; office BP was measured using a oscillometric sphygmomanometer OMRON, model HEM-705CP, and 24h monitoring brachial BP, CBP, Augmentation Index (AIx) and PWV were obtained with the Mobil-O-Graph equipment (DINA MAP cardios ESI GmbH, Stolberg, Germany). Results: The study population showed a mean age of 36.99 8:53 years, BMI 25.80 3.82kg/m, and prevalence of hypertension 32.7%. Office BP means were: systolic BP (SBP) 130.45 17.28mmHg and diastolic BP (DBP) 80.11 10.39mmHg. Awake brachial was lower than office BP (p<0.001, difference between office SBP and awake SBP 1⁄4 11.17 14.21mmHg, and of office DBP and awake DBP 1⁄4 1.76 7.88mmHg). Systolic CBP was lower than brachial SBP in 24h, and awake and sleep periods (p<0.001, differences were 8.49 2.72mmHg, 9.35 3.42mmHg and 5.68 2.96mmHg between brachial SBP and systolic CBP in 24h, awake and sleep periods, respectively). Conversely, diastolic CBP was slightly higher than brachial DBP in 24h, awake and sleep periods (p<0.001, differences were 0.91 1.59mmHg, 1.55 1.78mmHg and 0.82 1.53mmHg between brachial SBP and diastolic CBP in 24h, awake and sleep periods, respectively). There were significant reductions between awake and sleep periods for systolic and diastolic CBP, for AIx and for PWV (p<0.001, differences were 5.62 7.13mmHg, 10.14 7.01mmHg, 3.85 9.07mmHg and 0.19 0.25mmHg for systolic CBP, diastolic CBP, AIx, and PWV, respectively). Conclusion: In normotensive and untreated hypertensive young adults, awake brachial BP was lower than office BP and systolic CBP means were lower than brachial BP, but diastolic CBP means were higher than brachial DBP. Reductions between awake and sleep periods were observed in the CBP, AIx and PWV means, similarly to what is observed with brachial BP, but with lower averages.

Ablation of atrial fibrillation and esophageal injury: Role of bipolar and unipolar energy using a novel multipolar irrigated ablation catheter.

The circular nMARQ ablation catheter is a useful tool for pulmonary vein isolation (PVI). Some studies reported a high incidence of esophageal lesions by using this catheter. The primary aim of this study was to compare the effects on the esophageal wall of bipolar and unipolar energy applied by the nMARQ ablation catheter during AF ablation. Forty patients (mean age 53 ± 8 years; 26 [65%] men) were enrolled to perform PVI for symptomatic atrial fibrillation. Thirty patients underwent PVI with the nMARQ catheter (group 1) and 10 patients with the ThermoCool Surround Flow catheter (group 2). The procedures were performed with the CARTO3 system. All patients received an esophageal temperature probe. In group 1, we delivered unipolar energy on the left posterior wall with power between 15 and 18 W or bipolar energy with power at 15 W. In group 2, unipolar energy was delivered on the posterior atrial wall at 20-25 W power. All patients underwent esophagoscopy the day after the procedure. No patients had procedural complications. In group 1, bipolar energy was associated with a lower esophageal temperature increase as compared with unipolar energy (0.6°C [range 0-2.2°C] vs 2.1°C [range 0.8-2.9°C]; P < .001). Unipolar energy was associated with a similar temperature increase in the 2 groups (1.9°C [range 0.8-2.9°C] in group 1 vs 1.7°C [range 0.7-2.9°C] in group 2; P = .49). No patient had esophageal injury. The use of the nMARQ catheter for PVI is feasible and safe. The use of 15 W for bipolar energy or 15-18 W for unipolar energy is an optimal strategy to avoid esophageal injury with this new catheter.

Safety and efficacy of renal denervation as a novel treatment of ventricular tachycardia storm in patients with cardiomyopathy

Modulation of the autonomic nervous system has been used to treat refractory ventricular tachycardia (VT). Renal artery denervation (RDN) is under investigation for the treatment of sympathetic-driven cardiovascular diseases. The purpose of this study was to report the largest case series to date using RDN as adjunctive therapy for refractory VT in patients with underlying cardiomyopathy. Four patients with cardiomyopathy (2 nonischemic, 2 ischemic) with recurrent VT despite maximized antiarrhythmic therapy and prior endocardial (n = 2) or endocardial/epicardial (n = 2) ablation underwent RDN ± repeat VT ablation. RDN was performed spirally along each main renal artery with either a nonirrigated (6 W at 50°C for 60 seconds) or an open irrigated ablation catheter (10-12 W for 30-60 seconds). Renal arteriography was performed before and after RDN. RDN was well tolerated acutely and demonstrated no clinically significant complications during follow-up of 8.8 ± 2.6 months (range 5.0-11.0 months). No hemodynamic deterioration or worsening of renal function was observed. The number of VT episodes was decreased from 11.0 ± 4.2 (5.0-14.0) during the month before ablation to 0.3 ± 0.1 (0.2-0.4) per month after ablation. All VT episodes occurred in the first 4 months after ablation (2.6 ± 1.5 months). The responses to RDN were similar for ischemic and nonischemic patients. This case series provides promising preliminary data on the safety and effectiveness of RDN as an adjunctive therapy in the treatment of patients with cardiomyopathy and VT resistant to standard interventions.

Ablation of right ventricular outflow tract tachycardia using a novel multipolar irrigated ablation catheter (nMARQ)

A 54-year-old man with a history of hypertension presented with sudden onset of palpitation, chest pain, and dizziness. Frequent runs of nonsustained broad complex tachycardia were captured on ambulance 3-lead electrocardiogram with an inferior axis, suggestive of outflow tract ventricular tachycardia (VT). VT resolved spontaneously on admission at the coronary care unit. Subsequent echocardiography revealed normal biventricular function with normal sized left and right ventricles and no significant valvular abnormality.

Enhanced efficiency of a novel porous irrigated RF ablation catheter for pulmonary vein isolation

Enhanced efficiency of a novel porous irrigated RF ablation catheter for pulmonary vein isolation

Fluid overload and re-hospitalization following catheter ablation of long standing persistent atrial fibrillation: results from randomized study using a new irrigated catheter

Introduction: Fluid overload and/or pulmonary congestion with and without hospitalization may occur following catheter ablation of long standing persistent (LSP) atrial fibrillation (AF) with open irrigated catheters. We compared the clinical outcomes of two different open irrigated ablation catheters after catheter ablation of LSP AF. Methods: 138 patients (pts) undergoing ablation for longstanding persistent AF, were randomized to ablation with a standard 3.5 open irrigated catheter (group 1, n=46) and discharged with 40 mg bid of furosemide, or ablation with a standard 3.5 open irrigated catheter (group 2, n=46) and discharged with 80 mg bid of furosemide, and ablation with a new irrigated catheter (SF= surround flow) and discharged with 40 mg bid of furosemide (group 3 n=46). At the end of the procedure all pts were given 40 mg of i.v. furosemide. Clinical data on fluid administration, pulmonary congestion, weight increase, and re-hospitalization due to fluid overload were collected and analyzed. Results: Baseline characteristic had no statistical significant difference between groups. No differences in RF time and procedural time were observed between groups. At the end of the procedures a total of 4.4±0.9 liters of fluid were given in group 1and 2 compared to 1.7±0.7 liters in group 3 (p< 0.005). The weight of the pts the day after the procedure increased by an average of 8±2 pounds in groups 1and 2 while increased of 2±0.4 pounds in group (3) (P<0,005). One hour following the procedure, one patient in group 1 had pulmonary congestion requiring re-intubation. No acute complications were observed in groups 2 and 3. Three days after discharge only 1 pts in group 3 showed 2 pounds increase in weight. However, 27 pts in group 1 and 2 (29%) still had a mean weight increase of 4±0.4 pounds and feeling of shortness of breath. Ten patients in group 1 (22%) and 5 patient (11%) in group 2 required re-hospitalization due to fluid overload, while no patient in group 3 did. Conclusion: This prospective randomized study demonstrates that the use of the "new" open irrigated SF catheter, significantly reduce weight gain and re-hospitalization due to peri-procedural fluid overload

Electroanatomic mapping and catheter ablation of atrial tachycardia originating from the tricuspid annulus

We read with great interest with a recent case report from Cay et al. [1] published in International Journal of Cardiology. They reported an interesting case of successful radiofrequency ablation of idiopathic ventricular arrhythmia originating from the anterolateral free wall of tricuspid annulus (TA). We recently encountered a patient presenting with atrial tachycardia (AT) originating from the anterolateral free wall of the tricuspid annulus, who was successfully ablated using 3dimensional electroanatomic mapping system. A 62-year-old male patient was referred to our department for catheter ablation for symptomatic atrial tachycardia, which was resistant to metoprolol, propafenone, and amiodarone. He had a history of hypertension for 10 years. No underlying structural heart disease was detected by echocardiogram. P-wave morphology during tachycardia (Fig. 1) was “W” shape in the inferior leads, iso in lead I, and predominantly negative in lead V1, all suggesting the AT originating from the lateral free wall of the tricuspid annulus. During electrophysiologic study guided by the noncontact Ensite Array (EA) mapping system (St. Jude Medical, St. Paul, MN, USA), the tachycardia could be induced by atrial burst pacing. The cycle length of the tachycardia was 560 ms. The earliest atrial activation site during the arrhythmia was found near the anterolateral free wall of the TA (Movie). Activation mapping also showed the AT origin and its propagation to the other sites of the right atrium. Radiofrequency ablation using irrigated ablation catheter (Cool Path Ablation Catheter, St. Jude Medical) with average power of 30 W and maximum temperature of 43 °C at this site (Fig. 2) successfully terminated the tachycardia (Fig. 3), and AT was no longer inducible with and without isoproterenol infusion. The patient remained free from any atrial arrhythmias without anti-arrhythmic drugs during a follow-up period of one year. The focal atrial tachycardia originating from the TA is not commonly seen, and has been reported in separate cases [2–4] and case series [5,6] with an incidence of 9–10% of right atrial tachycardia. Furthermore, AT arising from the anterolateral free wall of the TA is relatively rare. Conventionally, intracardiac mapping of focal AT using 1 or 2 roving catheters was utilized to find the origin of AT. Noncontact mapping systems provide an accurate guidance for mapping and ablation of focal AT [7,8]. Supplementary data to this article can be found online at http:// dx.doi.org/10.1016/j.ijcard.2013.06.084. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology.