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Introduction: In the current study, we present single surgeon experience of a new radiofrequency ablation system, the catheter, and the device. Patients and Methods: The new system, which comprises a generator and an intervally illuminated radiofrequency ablation catheter, was used for the treatment of 272 consecutive patients with chronic venous insufficiency of the great saphenous vein between November 2017 and October 2018. Mean age of the patients was 53.40 ± 11.91 years. Mean saphenous vein diameter was 8.51 ± 2.45 mm. Bilateral great saphenous vein reflux disease was present in 19% (51 cases) of the patients. At the end of the procedure, the closure of the great saphenous vein was confirmed with Doppler ultrasonography. Results: Procedures could be successfully performed in all, except 1 obese (BMI> 30 kg/m2) male patient. At the 3rd month, outpatient clinic follow-up control Doppler USG revealed successful ablation of the treated great saphenous vein in 260 patients (96%), whereas in 12 cases (4%), there was continuing reflux. The diameters of the saphenous veins in these patients ranged between 6.9 mm and 19.5 (mean: 10.68 ± 3.41) mm. Ten patients could be treated successfully with ablation with the same device controlled both at the interventional section as well as on the 3rd month outpatient clinic follow-up. The remaining patients underwent high ligation of the great saphenous vein. Paresthesia occurred in 1 patient and had been permanent. Hematoma occurred in a male patient and resolved spontaneously. Conclusion: Preliminary results of our new radiofrequency ablation device with illumination guidance for the treatment of great saphenous vein reflux disease indicated successful results with enhanced physician utilization, comfort, and reliability.

Objective: The objective of the study is to evaluate the success of re-use by assessing the recanalization rates following radiofrequency ablation (RFA) with Closure Fast® catheter in patients with symptomatic varicose veins. Methods: This retrospective study approved by the institutional review board analyzed the occlusion rates of the great saphenous vein (GSV) in patients who underwent RFA between January 1, 2015, and December 31, 2016. A record of the number of times the RFA catheter was re-used was maintained. The catheter was used for a maximum of five systems. Follow-up was performed postoperatively at 1 week and 6 months with an ultrasound to assess failure by looking for recanalization. Results: In this study, 272 GSV endoablations (RFA) were performed in 238 patients. The mean age was 47.68 (standard deviation ± 13.05). Majority of the patients were male (76.9%). 27.3% (73 GSV) of the venous systems received a first fire with the RFA catheter. At the first follow-up on week 1, 97.7% (266 GSV systems) had complete occlusion, 2.3% (6 GSV systems) had partial recanalization, and none had complete failure. Recanalization rates at 1 week with 1st, 2nd, 3rd, 4th, and 5th re-use were 0%, 2%, 2%. 4.1%, and 3.8%, respectively. At 6-month postoperative follow-up, 96.5% (250) had complete occlusion, 2.7% (7) had partial recanalization, and 0.8% (2) had complete recanalization. Recanalization rates at 6 weeks with 1st, 2nd, 3rd, 4th, and 5th re-use were 1.4%, 2.1%, 2.3%. 6.4%, 5.9% respectively. There was no statistical significance with the recanalization rates at 1st week and at 6 weeks. 4.2% (10) of the patients were lost to follow-up. None of the patients had any complications. Conclusion: The results of GSV occlusion rates are encouraging when the RFA catheter was re-used and cut the cost of treatment substantially, thereby making RFA ablation more affordable to the common human.

Objective: Gastroesophageal reflux disease is easily missed on X-ray or even computer tomography. This study was to evaluate the endoscopic imaging for the radiofrequency ablation (RA) on the diagnosis and management of gastroesophageal reflux disease related extra-esophageal symptoms. Methods: From January 2011, to January 2012, we allocated 51 patients to LTF and 47 to RA procedure. Primary outcome measures, including symptom scores of globus hysterics, chest pain, belching, hiccup, cough and asthma as well as proton pump inhibitors (PPIs) use, were analyzed after 5-year follow-up. Results: There were 90 patients following RA procedure (N = 40) or LTF (N = 50) that completed the designated 5-year follow-up and were included in the final analysis. At the end of 5-year follow-up, the symptom scores were all significantly decreased as compared with the corresponding values before the two procedures in both groups (p < 0.05). Moreover, the improvement in symptom scores between the two groups did not achieve statistical significance. After RA procedure and LTF, 18 (45%) and 32 (64%) patients in each group achieved complete PPIs therapy independence (p = 0.071). Comparing with LTF, however, the RA procedure had a higher risk of reoperation (17.5% vs. 0, p = 0.002). Conclusion: Comparing with LTF in controlling GERD-related extra-esophageal symptoms, RA procedure can offer equivalent relief on symptoms and PPIs independence. However, it has a higher risk of reoperation during the 5 years follow-up.

Objective: Gastroesophagel reflux disease is not readily diagnosed using X-ray or even computer tomography. This study was to evaluate the endoscopic imaging for the radiofrequency ablation (RA) on the diagnosis and management of gastroesophageal reflux disease. Methods: We allocated 85 to mechanical RA and 80 patients to LTF. Primary outcome measures, including symptom scores of heartburn, regurgitation, chest pain, belching, hiccup, cough and asthma as well as proton pump inhibitors (PPIs) use, were analyzed. Results: There were 125 patients following mechanical radiofrequency ablation procedure (N = 60) or LTF (N = 65) included in the final analysis. The symptom scores were all significantly decreased as compared with the corresponding values before the two procedures in both groups (p < 0.05). After mechanical RA procedure and LTF, 30 (50%) and 45 (69.2%) patients in each group achieved complete PPIs therapy independence (p = 0.028). Comparing with LTF, the mechanical RA procedure had less effect on improving typical symptoms of heartburn and chest pain and the rate of reoperation (13% vs. 0, p = 0.003). Conclusions: Comparing with LTF in controlling GERD symptoms, the mechanical radiofrequency ablation procedure can offer equivalent relief on atypical symptoms. However, it has less effect on improving PPIs independence and avoiding reoperation.

Recurrent varices after surgery (REVAS) is a common problem with no established treatment. Ultrasonography is a hard method to identify the source of veins that cause REVAS, especially in obese patients with thick thighs. Here, we report the case of a 64-year-old obese patient who previously underwent endothermal venous ablation for her right great saphenous vein. The patient presented with right leg swelling and venous ulceration due to REVAS. Although the source of REVAS was unclear because the patient had thick thighs on ultrasonography assessment, venography revealed that the source of REVAS was the incompetent perforator vein (IPV). Selective ablation for the IPV with radiofrequency ablation catheter was performed. We could ablate the target veins selectively so as not to ablate within the deep vein. The patient remains asymptomatic for 2 years after the procedure, and there has been no recurrence of her varicose veins. Venography allows better visualization of the source of REVAS than ultrasonography. With selective ablation, it is especially effective procedure in obese patients, in whom it is difficult to identify and access the source of REVAS with ultrasonography.

Aims To examine the effect of renal denervation (RDN) on 24‑h ambulatory blood pressure (ABP) with a standard radiofrequency ablation catheter (RF catheter). Methods Seventy-five patients with resistant hypertension received bilateral RDN with an RF catheter (6 RF applications, 1 minute each, 8–12 watts). Seventy patients fulfilled inclusion criteria with mean systolic ABP ≥140 mmHg (mean 165/89) despite treatment with ≥3 antihypertensive drugs (mean 5.9) including a diuretic, and were further analysed for ABP changes. Follow-up at 1/3/6/12 months comprised biochemical evaluations and ABP measurement. At 6/12 months, duplex sonography of the renal arteries was additionally performed. Results At 1/3/6/12 months we observed a significant reduction in systolic ABP of −15/−17/−18/−15 mmHg (n = 55/53/57/50; non-parametric Friedman test, p 70 %) with subsequent stenting without complications. Logistic regression analysis with systolic ABP reduction ≥10 mmHg at 12 months follow-up as criterion revealed that only the mean baseline systolic ABP was significant, OR = 2.174. Conclusions RDN with a standard RF catheter can be used safely to reduce mean ABP in resistant hypertension as shown in long-term follow-up.

Purpose: Endobiliary radiofrequency ablation (RFA) is a new endoscopic ablative technique. However, the ideal power setting for RFA has not yet been clarified. Therefore, we intended to evaluate th...

Radiofrequency, a common ablation modality, is used clinically to terminate cardiac arrhythmias. With excessive heating, complications sometimes occur when the applied energy generates steam pops, which cause release of energy in the form of tissue and/or air emboli. In this study, we investigated numerous parameters potentially associated with intracardiac steam pops including (1) wattage, (2) catheter tip temperature, (3) catheter irrigation, (4) anatomic site, and (5) repeat ablations at a given site. Using unique Visible Heart® methodologies in reanimated swine hearts, we visualized 539 ablations; steam pops developed in 140 of these ablations. The incidence of steam pops significantly increased for both nonirrigated and irrigated ablations at 40 W (p

INTRODUCTION Although noninferiority of cryoballoon ablation (CBA) and radiofrequency catheter ablation for antral pulmonary vein isolation (APVI) has been reported in patients with paroxysmal atrial fibrillation (PAF), it is not clear whether contact force sensing (CF-RFA) and CBA with the second-generation catheter have similar procedural costs and long-term outcomes. The objective of this study is to compare the long-term efficacy and cost implications of CBA and CF-RFA in patients with PAF. METHODS AND RESULTS A first APVI was performed in 146 consecutive patients (age: 63 ± 10 years, men: 95 [65%], left atrial diameter: 42 ± 6 mm) with PAF using CBA (71) or CF-RFA (75). Clinical outcomes and procedural costs were compared. The mean procedure time was significantly shorter with CBA than with CF-RFA (98 ± 39 vs. 158 ± 47 minutes, P

BACKGROUND Different types of irrigated-tip ablation catheters are available for ablation of atrial flutter (AFL). The aim of this study was to compare an established with a novel dedicated Gold irrigated-tip catheter for ablation of AFL. METHODS AND RESULTS We compared consecutive patients undergoing ablation of AFL using a standard 3.5 mm irrigated-tip platinum-iridium (Pt-Ir) catheter (Thermocool, TC-group) and a 3.5 mm irrigated gold-tip catheter (Gold-group) specifically designed for cavotricuspid isthmus ablation (CTI). The primary endpoint was acute efficacy (net RF time) to achieve block across the CTI. Secondary endpoints included procedure time, fluoroscopy duration, complications, and recurrence of AFL.153 patients (age 68 ± 11 years, 74% male) were included. Net RF time to achieve CTI block was not different between the TC-group (793 ± 503 s) and the Gold-group (706 ± 422 s; p = 0.406). Total procedure time was not significantly different between the TC-group (70 ± 26 min) and the Gold-group (70 ± 27 min; p = 0.769). A significant difference between the groups was identified for the fluoroscopy duration (TC-group: 934 ± 537 s, Gold-group: 596 ± 362 s, p

Background The origin of pulmonary sinus cusp (PSC)-derived ventricular arrhythmia (VA) is a highly specialized anatomical structure; therefore, insertion of the radiofrequency ablation catheter tip to the target site to ensure safe ablation is a major challenge for clinicians. Purpose To summarize ablation methods, and provide valuable experience for the treatment of pulmonary sinus cusp-derived VA with ablation. Methods A retrospective analysis and summary of the clinical data of 15 patients undergoing catheter ablation for pulmonary sinus cusp-derived VA in Cardiac Intervention Therapy Center, The Second Xiangya Hospital of Central South University between January 2013 and July 2015 was conducted. Results For the 15 patients, the pulmonary sinus cusp-derived VA originated from the lower regions of the pulmonary sinuses, leading from the right, left and anterior sinuses of the pulmonary sinus cusp in 4, 6 and 5 patients, respectively. Nine patients with pulmonary sinus cusp-derived VAs originating from the right and anterior sinuses underwent successful reversed U-curve catheter ablation, while the other 6 cases with arrhythmias originating from the left sinus underwent successful ablation with the conventional method (non-reversed U-curve catheter ablation). All the patients were followed-up for 6–31 months, and no cases of recurrence or complications occurred. Conclusions Reversed U-curve catheter ablation is suitable for VAs originating from the right and anterior pulmonary sinus cusps, while conventional ablation can also be used for those originating from the left PSCs. This article is protected by copyright. All rights reserved

WOS: 000393203900005, PubMed: 27373341, Purpose: The purpose of this study was to determine the occlusion rate of incompetent great saphenous veins (GSVs) and small saphenous veins (SSVs) treated with radiofrequency ablation (RFA) and individualize variables associated with recanalization. Materials and methods: A retrospective review of 311 veins (256 GSVs and 55 SSVs) in 211 patients [177 women, 34 men; mean age, 45 years +/- 12 (SD) (range: 18-75 years)] with incompetent GSVs and/or SSVs who were treated using new-generation RFA catheters was performed. The clinical results, occlusion rates, and variables associated with recanalization for the incompetent GSVs and SSVs were analyzed. Results: No major complications were observed in the study population. Ten months after RFA, the occlusion rate was 89% (227/256) for GSVs and 91% (50/55) for SSVs. An increased pre-procedure diameter of the incompetent GSVs was associated with a higher rate of recanalization (OR: 0.825; 95% CI: 0.715-0.952) (P < 0.05). No significant differences in age, gender, and side of treated veins were found between patients with recanalization of treated veins and those without recanalization. Conclusion: Our results show that pre-procedure diameter of the GSV is the single risk factor for recanalization after RFA. (C) 2016 Editions francaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

PVI with nMARQ™ Background Simultaneous multipolar ablation catheters have been proposed to simplify pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF). Recently, a new multipolar irrigated radiofrequency (RF) ablation catheter (nMARQ™, Biosense Webster Inc., Diamond Bar, CA, USA) combining both 3-dimensional electroanatomic mapping and multipolar open-irrigated ablation capability has been developed. Aim of our study was to assess feasibility, acute and short-term success and safety of PVI by the use of this new technology with particular regard to the incidence of postablation silent cerebral ischemia (SCI). Methods and Results Twenty-five patients (76% males; age 57 ± 13 years) with paroxysmal AF underwent PVI using the nMARQ™ catheter. PVI, confirmed by Lasso catheter mapping, was achieved in 100 out of 102 pulmonary veins (98%) identified, and final PVI was obtained in 24 out of 25 (96%) patients. The overall concordance between Lasso and nMARQ™ signals in demonstrating PVI was 78%. No major procedural complications occurred and no patient suffered SCI, on the basis of cerebral magnetic resonance imaging performed before and after the procedure. Following a 6-month follow-up, 17/25 (68%) patients remained free from AF without antiarrhythmic drugs. Conclusions In our preliminary experience, PVI with nMARQ™ catheter appears to be feasible and safe, without incidence of SCI. Long-term clinical efficacy has to be evaluated in further studies.

In recent years, new ablation catheters have been developed to facilitate atrial fibrillation (AF) ablation procedures, including the multi-electrode pulmonary vein ablation catheter (PVAC), capable of using different proportions of unipolar and bipolar energy. The purpose of this study was to evaluate the acute efficacy, as well as safety, when using the two different energy settings for the PVAC catheter.

The Closure Fast™ Endovenous Radiofrequency Ablation Catheter is the latest version of a minimally invasive system for the treatment of patients with superficial venous disease. The Closure Fast™ catheter heats the vein wall to 120°C, causing denaturation of the collagen of the vein wall and contraction of the vessel such that no blood can flow through it. Nearly one million systems have been sold since the product was launched. Many, if not all, patients can be treated under local anesthesia with the Closure Fast™ catheter. Duplex ultrasound reports occlusion rates for the treated vein of 94%–98% at 1 year and 85%–93% at 3 years. The system produces average postoperative pain scores of less than 2 out of 10 on a visual analog score. In the first postoperative week, 76% of patients do not require analgesia. Some 45% of patients return to normal activity on the first postoperative day. Serious complications appear to be rare following the Closure Fast™ procedure. Transient paresthesia occurs in 0.2% of cases, thrombophlebitis in 1%–10%, and thromboembolic events in up to 1.4%, mainly heat-induced thrombosis. Closure Fast™ adds significant costs to treating superficial venous disease but studies have shown it to be cost-effective when used in an office setting.

Visualizing Steam Pops Introduction Steam pops are a risk of irrigated RF ablation even when limiting power delivery. There is currently no way to predict gas formation during ablation. It would be useful to visualize intramyocardial gas formation prior to a steam pop occurring using near-field ultrasound integrated into a RF ablation catheter. Methods and Results In an in vivo open-chest ovine model (n = 9), 86 lesions were delivered to the epicardial surface of the ventricles. Energy was delivered for 15–60 seconds, to achieve lesions with and without steam pops, based on modeling data. The ultrasound image was compared to a digital audio recording from within the pericardium by a blinded observer. Of 86 lesions, 28 resulted in an audible steam pop. For lesions that resulted in a steam pop compared to those that did not (n = 58), the mean power delivered was 8.0 ± 1.8 W versus 6.7 ± 2.0 W, P = 0.006. A change in US contrast due to gas formation in the tissue occurred in all lesions that resulted in a steam pop. In 4 ablations, a similar change in US contrast was observed in the tissue and RF delivery was stopped; in these cases, no pop occurred. The mean depth of gas formation was 0.9 ± 0.8 mm, which correlated with maximal temperature predicted by modeling. Changes in US contrast occurred 7.6 ± 7.2 seconds before the impedance rise and 7.9 ± 6.2 seconds (0.1–17.0) before an audible pop. Conclusion Integrated US in an RF ablation catheter is able to visualize gas formation intramyocardially several seconds prior to a steam pop occurring. This technology may help prevent complications arising from steam pops.

Background— A common strategy for ablation of scar-based ventricular tachycardia is delivering multiple lesions in a linear pattern. Methods and Results— We tested the efficacy of a novel linear irrigated multipolar ablation catheter capable of creating linear lesions with a single application. Healthy swine underwent endocardial and epicardial linear ablation using a novel linear irrigated ablation catheter; control animals underwent focal lesions in a linear pattern over 3.5 cm with an irrigated radiofrequency catheter. The linear catheter contained 7 irrigated electrodes spaced over 3.5 cm and could deliver ≤25 W to each electrode. Linear ablation required significantly less radiofrequency time than focal ablation (56±11 versus 497±110 seconds; P P 3 ; P =0.002). There was no difference between linear (n=22) and focal (n=7) endocardial line length or volume. Gaps (length 2.8±0.9 mm) were present in 53% of focal lines and 0% of linear ablation lines. No perforations, steam pops, or thrombus were noted. Conclusions— Compared with sequential focal radiofrequency ablation in a linear pattern, an irrigated multipolar linear ablation catheter safely delivers contiguous endocardial or epicardial lesions without gaps in a single ablation. This catheter shows promise for decreasing ventricular tachycardia ablation procedure time and improving outcome.

Large-tip (10 mm) catheters (LTCs) and open-irrigation-tip catheters (OITCs), both capable of creating large lesions, are more effective than conventional catheters for cavotricuspid isthmus (CTI) ablation. However, it is not clear whether complete CTI block can be achieved more efficiently using an LTC or an OITC. The purpose of this study was to compare the efficiency of radiofrequency catheter ablation (RFA) of the CTI using LTC versus OITC to eliminate atrial flutter (AFL).Sixty consecutive patients (age = 62 ± 10 years) with typical AFL were randomized to undergo RFA of CTI using an LTC (10 mm) or an OITC. If complete CTI block was not achieved by ≤30 minutes of RFA, patients were allowed to cross over to ablation with the other catheter. A 3-dimensional electroanatomical mapping system was used for catheter navigation only with the OITC. The mean duration of RFA to achieve CTI block in 50% of the patients was 6.8 ± 2.2 minutes with an LTC and 11.7 ± 2.7 minutes with an OITC (P = 0.001). After 30 minutes of RFA, CTI block was achieved in 26/30 (87%) and 25/30 patients (83%) using an LTC and an OITC, respectively (P = 1.0). After crossover, CTI block was achieved in 4/5 (80%) and in 4/4 patients (100%) with an LTC and OITC, respectively (P = 1.0). LTC was associated with a lower volume of intravenous fluid administration (388 ± 365 mL versus 865 ± 451 mL, P = 0.0001) and a trend for shorter procedure duration (95 ± 31 minutes versus 114 ± 50 minutes, P = 0.09) than the OITC. At 6 ± 3 months, 30/30 patients (100%) in the LTC and 27/30 patients (90%) in the OITC groups remained free from AFL, respectively (P = 0.24). Except for one inconsequential steam-pop during RFA with the OITC, there were no complications.Complete CTI block is achieved more rapidly using an LTC than an OITC, and with a similar clinical efficacy.

Outflow tract tachycardias (OTT) originating from the right or left ventricular outflow tract are thought to be benign. However, symptoms can be disabling and deterioration of left ventricular function may occur with a high arrhythmia burden. Catheter ablation has a high acute success rate of up to 90 %, but recurrences are not uncommon [1, 2]. Novel catheter designs, and mapping and ablation technologies aim to improve procedural outcome, lower the complication rate, and increase the long-term success rate [3]. The TactiCath (R) catheter (TactiCath (R), Endosense, SA Meyrin/Geneva, Switzerland, distributed by Biotronik, Berlin, Germany) is a contact force (CF) sensing radiofrequency ablation catheter that provides real-time assessment of tip-to-tissue CF during ablation [4]. Until now, it has only been used in ablation of supraventricular tachycardias, mainly atrial fibrillation. In this report, we describe the case of a patient who underwent successful ablation of right ventricular OTT and ventricular premature beats (VPBs) using CF guidance. To the best of our knowledge, this is the first case ever described of OTT ablation using CF with the TactiCath (R) catheter.

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 (p0.001); 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 (p0.001); 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; p0.001), 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.

Ahmed et al. ([1][1]) clearly define the 3-fold purpose of their paper: 1) new therapeutic approach for renal denervation; 2) description of their irrigated radiofrequency ablation catheter technique; and 3) the indication for the use of this procedure (i.e., management of drug-resistant

Renal denervation has been proven to be beneficial in treating resistant hypertension in patients with normal renal function. There are a significant number of end stage renal disease (ESRD) patients who have resistant hypertension despite being on multiple drugs and the benefits of RDN in such

catheter was inserted (Simplicity Flex) inside the renal artery, allowing the delivery of radiofrequency energy to the renal artery innervation. Radiofrequency applications were performed within the main stem of the renal arteries, bilaterally, with a series of 6 applications, 60 s duration each. At the end of the procedure, renal arteriography was performed for evaluation of vascular integrity. Results: Data were obtained at baseline and monthly until 180th day of follow-up. Baseline values of blood pressure were 196/122 mmHg in the office, and 164/109 mmHg by 24h ABPM. The decreased of ABPM data was 47/38mmHg, achieving values of 117/71mmHg with 14 days after procedure (figure 1), with the same average at 180th day, reducing from 7 to 3 antihypertensive drugs in 6 months. The procedure was performed without complications. Conclusions: Renal sympathetic denervation using the irrigated radiofrequency ablation catheter was effective in a patient with resistant hypertension.

Microcatheters were initially developed for the purpose of electrophysiological mapping within the right coronary arterial system to locate right-sided accessory pathways. These included 2.2-French bipolar catheter manufactured by Viggo-Spectramed from Oxnard, California, and a 3-French fixed-wire design catheter with ten bipolar electrode pairs manufactured by Cardima, Inc. from Fremont, California. Both Elecath, Inc. and Mansfield/Boston Scientific, Inc. also had microcatheters applying a different design; they used an over-the-guide-wire system similar to the angioplasty approach, using 0.014-inch high-torque floppy angioplasty guide wire.1 Unfortunately, for various reasons this application failed to gain popularity and none of these microcatheters received approval from the U.S. Food and Drug Administration (FDA).