Radiofrequency Transseptal Catheter Electrode Fracture

Transseptal puncture is performed using a long needle advanced from the femoral approach. A radiofrequency catheter has been developed that delivers a short burst of radiofrequency energy and creates a micro puncture in the interatrial septum. We describe a case in which the distal radiofrequency electrode broke and became embedded in the interatrial septum. (PACE 2010; 33:e57–e58)     

Use of an Angioplasty Wire to Perforate the Interatrial Septum for a Difficult Transseptal Puncture

With the expansion in catheter‐based treatments for atrial fibrillation the number of transseptal punctures being performed by cardiac electrophysiologists has increased significantly. Although in general transseptal puncture is successful, in a small percentage of cases it cannot be achieved due to complex intraatrial anatomy. We report the case of a difficult transseptal puncture (TSP), performed where the conventional approach using a Brockenbrough needle sheath was unable to perforate the septum. TSP was only achieved using a novel technique assisted by an angioplasty wire. (PACE 2010; 33:243–245)     

Phased-Array Intracardiac Echocardiography for Guiding Transseptal Catheter Placement: Utility and Learning Curve

JOHNSON, S.B., et al. : Phased-Array Intracardiac Echocardiography for Guiding Transseptal Catheter Placement: Utility and Learning Curve. The utility of a new intracardiac 64-element, phased-array, longitudinal ultrasound imaging system for guiding transseptal catheterization was assessed during 69 crossing attempts in 45 dogs because of the inherent limitations of fluoroscopy and mechanical ultrasound. Multifrequency (7.5–8.5 MHZ) imaging of the membranous fossa ovalis, posterior left atrium, and left atrial appendage was conducted from the right atrium. Contact of the Brockenbrough needle with the interatrial septum as reflected by membranous fossa ovalis "tenting" was uniformly identified. Transseptal crossing and advancement of the dilator and sheath were adequately imaged because of deeper ultrasound tissue penetration. Transseptal catheterization was successfully accomplished in 44 of 45 dogs: on the first attempt in 40 and with additional attempts in 4 and confirmed by direct far-field imaging of nonagitated saline injection via the sheath. Total transseptal catheterization time was  3.0 ± 1.8 minutes  . Unsuccessful first attempts and/or subsequent sheath pullback into the right atrium with catheter manipulation were also readily recognized. Insertion of the transseptal needle beyond the ultrasound imaging plane resulted in perforation of the posterior left atrial wall in three attempts. Accompanying effusions in these animals and three others related to subsequent intracardiac ablation catheter manipulation were readily identified and monitored echocardiographically. In conclusion, phased-array intracardiac imaging provides a highly reliable means of guiding transseptal access to the left atrium. In addition, inadvertent complications such as perforation and pericardial effusion development can be readily recognized.     

Transseptal Left Ventricular Lead Placement Using Snare Technique

Background: Coronary sinus (CS) lead placement for cardiac resynchronization therapy has a failure rate of ～5–10%. Here we describe a way of implanting an endocardial left ventricular (LV) lead via a transseptal puncture (TSP), using a GooseNeck snare and active fixation lead. Methods: Three male patients (67–83 years) with failed or extracted epicardial LV leads implanted via the CS had an endocardial LV lead implanted. TSP was performed via a femoral vein. The active fixation pacing lead was advanced to the right atrium from a subclavian vein. A GooseNeck snare was passed via the TSP sheath and used to grasp the tip of the pacing lead. The sheath, GooseNeck snare, and pacing lead tip were then passed to the left atrium by sliding the system up the TSP guidewire and across the interatrial septum before deflecting the lead to permit implantation in the left ventricle. Results: Successful implantation was performed in all patients with an LV implant time of 25–55 minutes. Conclusion: The use of a GooseNeck snare via a deflectable transseptal sheath represents a reliable alternative method for endocardial LV lead placement in patients with failed CS LV lead implantation. (PACE 2012; 35:1248–1252)     

Transesophageal Echocardiographic Guidance of Transseptal Left Heart Catheterization During Radiofrequency Ablation of Left-Sided Accessory Pathways in Humans

Radiofrequency ablation (RFA) of left-sided accessory pathways can be achieved using catheters introduced by a retrograde or transseptal approach. Transesophageal echocardiography (TEE) has previously been demonstrated to be safe and efficacious in guiding transseptal puncture in patients during mitral valvuloplasty (MV). This study was undertaken to assess the feasibility, safety, and clinical utility of TEE during transsepta! puncture and RFA of left-sided accessory pathways. Methods: TEE was performed during transseptal puncture in 30 patients (41 ± 12 years, 19 females), 15 patients during attempted RFA of a left-sided accessory pathway and 15 patients during attempted balloon MV. Results: There was no difference in age, sex distribution, or procedural complications when MV patients were compared to RFA patients. At baseline, left atrial dimension was increased and congestive heart failure was more common when MV patients were compared to RFA patients (P < 0.05) Adequate baseline two-dimensional and Doppler TEE images were obtained in all patients. One patient sustained mild esophageal bleeding during the TEE, Positioning of the transseptal catheter in the fossa ovalis was facilitated and confirmed by TEE in 29 of 30 cases. One case of cardiac perforation occurred and was associated with inadequate TEE localization of the fossa ovalis. Thrombus was detected on the transseptal catheter by TEE in two cases prior to systemic heparinization. In both cases, thrombus was removed without embolic event. Conclusions: TEE safely guides transseptal puncture in patients undergoing RFA of left-sided accessory pathways. TEE markers of the fossa ovalis facilitate puncture and may reduce the risk of cardiac perforation particularly in patients with a normal size left atrium. TEE may be especially valuable for identifying thrombus during transseptal puncture.     

Atrioventricular nodal reentry tachycardia: slow pathway ablation using the transseptal approach

Four hundred twenty consecutive patients with symptomatic slow/fast atrioventricular nodal reentry tachycardia had attempted slow pathway radiofrequency ablation. All patients had successful slow pathway ablation and no inducible tachycardia after ablation using the standard right-sided approach except for three patients. The three unsuccessful patients had inducible slow/fast atrioventricular nodal tachycardia after attempted right-sided posterior and inferoposterior anatomic ablative techniques and with slow pathway potential electrogram guidance. Lesions were also delivered linearly in the triangle of Koch and within the coronary sinus ostium. A transseptal puncture was performed and slow pathway ablation was obtained in each of these patients. Ablation was performed from the septal mitral valve annulus, anterior to the os of the coronary sinus and inferior to the His-bundle catheter with elimination of slow pathway conduction. Prior to the ablation, two of the three patients exhibited initiation of tachycardia with a double fast/slow antegrade response, and all three patients had long AH intervals (mean 378 ms) during slow pathway conduction. These electrophysiological findings may be consistent with a large area of slow pathway conduction that may include the left atrial septum not approachable by conventional right-sided ablative techniques. Slow pathway ablation to eliminate atrioventricular nodal reentry tachycardia at times may require a left atrial/transseptal approach when conventional right-sided techniques are ineffective.     

Left ventricular lead insertion using a modified transseptal catheterization technique: A totally endocardial approach for permanent biventricular pacing in end-stage heart failure

This article describes a new technique of LV lead insertion, using transseptal catheterization performed through the right internal jugular vein, to obtain a totally endocardial biventricular chronic pacing in end-stage heart failure. Three patients with QRS widening (> 180 ms) linked to complete left bundle branch block (n = 2) or right ventricular pacing (n = 1) were included in this preliminary study. Catheterization was performed under fluoroscopy and transesophageal echocardiography guidance. Transseptal catheterization was achieved by puncture of the right internal jugular vein at the base of the neck and by using a Brockenbrough needle, the tip curve of which was more curved than the standard model. A flexible long sheath was advanced in the left atrium through the interatrial septum and then a unipolar electrode was placed easily in the LV. The proximal tip of the LV lead was tunneled from the neck to the subclavian area and connected to the ventricular channel of a dual (n = 1) or simple (n = 2) chamber pacemaker. Efficient acute sensing (V wave amplitude = 13 +/- 3 m V) and pacing (acute pacing threshold = 0. 7 +/- 0.4 V) were obtained in the three patients. Early loss of capture occurred in two patients requiring lead replacement. Functional status dramatically improved in all three patients. At 6-month follow-up, biventricular pacing was maintained in all patients (mean threshold 1.4 V) who were free of clinical embolic event with oral anticoagulation therapy. This modified technique of jugular transseptal catheterization appears promising for the development of left heart pacing.     

Transseptal Catheterization: Considerations and Caveats

Transseptal catheterization is used by interventional cardiologists to gain access in the left atrium. This technique was initially introduced for left‐sided pressure measurements and has been integrated in a variety of procedures including left atrial ablations and percutaneous mitral valvuloplasties. The establishment of catheter ablation of atrial fibrillation as an effective treatment strategy has brought transseptal catheterization back to the limelight. Technique refinements, introduction of adjunctive imaging tools, and enrichment of available technical equipment have simplified the procedure. In the present article we review the technique of transseptal catheterization, presenting tips and caveats that could be of value for safe and successful transseptal punctures. (PACE 2010; 33:231–242)     

Yoked catheter positioning in transseptal endocardial left ventricular lead placement

Background: Transseptal (TS) endocardial left ventricular (LV) lead placement may be needed for cardiac resynchronization therapy, and often requires crossing a preformed puncture in the interatrial septum (IAS) with a lead delivery catheter inserted from an upper body vein (UBV), which can be difficult or impossible to achieve by manipulation from its hub. Consequently, yoked superior approach TS catheterization was developed. Methods: A loop snare housed in a deflectable delivery catheter inserted from an UBV captured the guide wire extending out of a TS sheath inserted from the right femoral vein into the inferior vena cava (IVC). After the IAS had been punctured, the guide wire was left in the left atrium (LA) and the TS sheath withdrawn into the IVC. The delivery catheter was advanced over the snare onto the guide wire, and then pushed by the TS sheath across the IAS puncture into the LA. The snare released the guide wire and was withdrawn. The delivery catheter was manipulated to point toward the LV for lead deployment. If that was not possible, the IAS puncture was dilated with an electrophysiology (EP) catheter housed in a second TS sheath alongside the first one. The EP catheter was captured by the snare and manipulated across the IAS puncture into the LV. The delivery catheter was advanced over the EP catheter directly into the LV. Results: The technique was tried in four patients with challenging anatomy and allowed successful endocardial LV lead placement in all. Conclusions: Yoked catheter positioning facilitates TS endocardial LV lead placement. (PACE 2011; 34:884–893)     

Successful cryoablation of atrial fibrillation from jugular approach in patient with interrupted inferior vena cava and azygos continuation

We herein report successful cryoablation of paroxysmal atrial fibrillation via right jugular vein in a patient with interrupted inferior vena cava. We preferred cryoablation instead of radiofrequency ablation in the treatment of our patient. For stronger support in aiming the Brockenbrough needle toward the septum, we manuallly curved the needle with a 120° angle about 6 cm proximal to the tip. After successful transseptal puncture, we performed balloon dilatation in the septal puncture zone to facilitate passage. Cryoablation has theoretical advantage, particularly in challenging anatomies, in which it eliminates the need for point‐by‐point ablation around the pulmonary vein.     

Electrophysiologic characteristics and radiofrequency catheter ablation in children with Wolff-Parkinson-White syndrome

BACKGROUND: The majority of cardiac arrhythmias in children are supraventricular tachycardia, which is mainly related to an accessory pathway (AP)-mediated reentry mechanism. The investigation for Wolff-Parkinson-White (WPW) syndrome in adults is numerous, but there is only limited information for children. This study was designed to evaluate the specific electrophysiologic characteristics and the outcome of radiofrequency (RF) catheter ablation in children with WPW syndrome. METHODS: From December 1989 to August 2005, a total of 142 children and 1,219 adults with atrioventricular reentrant tachycardia (AVRT) who underwent ablation at our institution were included. We compared the clinical and electrophysiologic characteristics between children and adults with WPW syndrome. RESULTS: The incidence of intermittent WPW syndrome was higher in children (7% vs 3%, P=0.025). There was a higher occurrence of rapid atrial pacing needed to induce tachycardia in children (67% vs 53%, P=0.02). However, atrial fibrillation (AF) occurred more commonly in adult patients (28% vs 16%, P=0.003). The pediatric patients had a higher incidence of multiple pathways (5% vs 1%, P<0.001).Both the onset and duration of symptoms were significantly shorter in the pediatric patients. The antegrade 1:1 AP conduction pacing cycle length (CL) and antegrade AP effective refractory period (ERP) in children were much shorter than those in adults with manifest WPW syndrome. Furthermore, the retrograde 1:1 AP conduction pacing CL and retrograde AP ERP in children were also shorter than those in adults. The antegrade 1:1 atrioventricular (AV) node conduction pacing CL, AV nodal ERP, and the CL of the tachycardia were all shorter in the pediatric patients. CONCLUSION: This study demonstrated the difference in the electrophysiologic characteristics of APs and the AV node between pediatric and adult patients. RF catheter ablation was a safe and effective method to manage children with WPW syndrome.     

Interatrial Septum Thickness and Difficulty with Transseptal Puncture during Redo Catheter Ablation of Atrial Fibrillation

Background: Patients undergoing catheter ablation for atrial fibrillation (AF) frequently require redo procedures, but there are no data reporting interatrial septum thickness (IAS) and difficulty during repeat transseptal puncture (TSP). Methods: Patients undergoing two separate AF ablation procedures had preprocedural fossa ovalis (FO) thickness measured using transesophageal echocardiography (TEE). “Difficult” TSP was defined by two observers as requiring excessive force, or conversion to TEE guidance. Results: The study comprised 42 patients (37 male) with mean ± SD age 55 ± 9 years. Mean FO thickness was significantly greater at the time of redo TSP (2.2 ± 1.6 mm vs 2.6 ± 1.5 mm at redo, P = 0.03); however, this finding was limited to those who underwent initial dual transseptal sheath procedures, FO thickness 2.0 ± 1.5 mm and 2.5 ± 1.4 mm for TEE 1 and 2, respectively (P = 0.048). There was a trend for more frequent difficult redo TSP procedures, 7/42 (17%; 95% confidence interval [CI] 8–31) redo, versus 4/42 (10%; 95% CI 3–23) first TSP. On univariate analysis, FO thickness was not predictive of TSP difficulty; the only predictor of difficult redo TSP was diabetes. Conclusions: IAS thickness at the FO increased following catheter ablation of AF, yet on subgroup analysis this was limited to initial procedures utilizing dual transseptal sheaths. There was a trend toward more frequent difficulty during redo TSP, yet this was not associated with FO thickening. Diabetes may predispose to difficulty during redo TSP; this finding requires confirmation in a larger study population.     

A higher than expected prevalence of AV nodal reentrant tachycardia in patients receiving implantable cardioverter-defibrillators

Background: Epidemiologic studies have indicated that the prevalence of paroxysmal supraventricular tachycardia (SVT) is approximately two to three of 1000 persons, of whom 50–60% have atrioventricular node reentrant tachycardia (AVNRT). Although SVT has been reported to account for a significant portion of inappropriate shocks in patients receiving implantable cardioverter‐defibrillators (ICDs), the incidence of AVNRT is unknown. Objective: To define the incidence of AVNRT in patients with ICDs. Methods and Results: Of 426 patients followed with an ICD, 15 patients with AVNRT were identified (3.5%). AVNRT was noted preimplant in eight patients. One had remote AVNRT and had undergone radiofrequency (RF) ablation several years prior to ICD implantation. Three patients had known episodes and underwent RF ablation prior to ICD implant. Four had AVNRT induced at preimplant electrophysiology study and three had RF ablation prior to ICD implant. Seven patients had clinical episodes of AVNRT after ICD implant and six of seven received inappropriate ICD therapy for AVNRT. All seven patients underwent RF ablation for treatment of AVNRT. No patient who underwent RF ablation had further clinical episodes of SVT, and only one had further inappropriate ICD therapy for sinus tachycardia. Conclusion: The substantially higher prevalence of AVNRT in our followed ICD population (3.5%) compared to the general population may be due to detection bias or electroanatomic changes in the atrioventricular nodal area induced by the accompanying heart disease. In any case, further studies to evaluate the inducibility of AVNRT prior to ICD implant, its prognostic implications, and the role of RF ablation to prevent inappropriate shocks are warranted. (PACE 2011; 34:584–586)     

Clinical Observations and Outcome of Ventricular Tachycardia Ablation in Patients with Left Ventricular Assist Devices

Background: Ablation of ventricular tachycardia (VT) in patients with left ventricular assist devices (LVAD) is challenging and not well documented. This report describes our experience with endocardial VT ablation in six patients with an LVAD. Methods: We retrospectively reviewed the clinical records of LVAD patients who underwent an ablation procedure for refractory VT. Results: A total of eight ablation procedures were performed in six patients who, during the last 2 weeks before the ablation procedure, received a total of 101 appropriate shocks for VT. A closed aortic valve (n = 2) or aortic atheroma (n = 1) required a transseptal catheterization in three of six patients. The apical LVAD cannula served as a VT substrate in two of six patients. VT was eliminated in four patients and markedly reduced in two others. The latter two patients experienced a total of only four implantable cardioverter defibrillator (ICD) shocks during a follow‐up of 130 and 493 days. Intravenous antiarrhythmic medications used in five of six patients before ablation were discontinued in all. The ablation procedures permitted hospital discharge in four of six patients. Five patients died during follow‐up (228 ± 207 days after the procedure). The cause of death was unrelated to cardiac arrhythmias. One patient is still alive 1,205 days after the procedure. Conclusion: Ablation of VT in LVAD patients is feasible and can result in a markedly decreased VT burden with a reduction of ICD shocks. The subsequent discontinuation of intravenous antiarrhythmic medications may facilitate hospital discharge. (PACE 2012; 35:1377–1383)     

Revival of the transseptal approach for catheterization of the left atrium and ventricle

Since 1980, use of the transseptal approach to catheterization of the left side of the heart has increased at our institution. In our experience, the transseptal technique has been used most commonly in adult patients with aortic stenosis, in whom the ease of access and the more reliable hemodynamics make it preferable to the retrograde approach. Several recent innovations in equipment and refinement of the transseptal technique have rendered it a safer procedure than was reported in earlier experiences. Specific precautions, however, should be observed in all patients in whom the procedure is attempted and particularly in those with conditions that distort the usual anatomy of the inferior vena cava or atrial septum. Transseptal catheterization is a versatile and relatively safe procedure when it is done by experienced personnel. Because we have noted fewer complications with prolonged experience, we recommend that the procedure be restricted to high-volume cardiac catheterization laboratories that are equipped with biplane fluoroscopy.     

Generating radiofrequency ablation lesions using magnetically coupled bipolar catheters

Background: Transmural lesions are difficult to produce in myocardial regions with thick walls, such as the left ventricle (LV), using conventional radiofrequency (RF) ablation catheters. This study was performed to evaluate the efficacy of magnetically coupled bipolar catheters and compare the performance with conventional unipolar and bipolar RF ablation catheters. Methods and Results: Neodymium magnets assembled in ablation catheters were used to facilitate tissue contact in a bipolar RF ablation system. In vitro sheets of porcine skeletal muscle, with 10‐mm thickness, were ablated with a 4‐mm‐tip unipolar RF ablation catheter (UA), a bipolar ablation system (BA) using a pair of 4‐mm‐tip catheters, and a magnetically coupled bipolar system (MB). The RF generator setting was 50 W and 90°C. RF energy was delivered for 30 or 60 seconds and five lesions were created in each ablation condition. The bottom side of the skeletal‐muscle sheet was exposed to saline at 37°C and a flow of 5.6 L/min, mimicking the LV endocardial surface. The top side was exposed to air, mimicking the epicardial surface. In the 60‐second ablation cases, the transmuralities were 0%, 0%, and 40% (UA, BA, and MB, respectively). The volumes of the lesions were 61.5 ± 8.5, 224.3 ± 51.8, and 359.3 ± 93.8 mm³ (UA, BA, and MB, respectively). Conclusions: The magnetically coupled bipolar RF ablation system created transmural lesions more efficiently than the conventional ablation system, primarily due to higher RF current density and stronger tissue contact. This prototype method could be applied to the development of novel ablation devices for thick areas of tissue. (PACE 2011; 34:934–938)     

Entrainment to Distinguish Orthodromic Reciprocating Tachycardia from Atrioventricular Nodal Reentry Tachycardia in Children

Background : Studies in adults suggest that after entrainment from the right ventricle, a post‐pacing interval (PPI) minus tachycardia cycle length (TCL), when corrected for atrioventricular node delay (cPPI‐TCL), is useful to distinguish atrioventricular nodal reentry tachycardia (AVNRT) from orthodromic reciprocating tachycardia (ORT), but this has not been evaluated in children. Methods : In 100 children undergoing catheter ablation, entrainment of ORT or AVNRT was performed from the right ventricular apex. The atrial‐His (AH) interval was measured on the return cycle (post‐AH) and during tachycardia just prior to pacing (pre‐AH). The cPPI‐TCL was calculated as (PPI‐TCL) ? (post‐AH ? pre‐AH). In the first 50 children, the best cutoff was identified and then validated in the next 50 children. Results : In the first 50 children, cPPI‐TCL was longer in AVNRT compared with ORT (122 ± 19 ms vs 63 ± 23 ms, P < 0.001). Furthermore, cPPI‐TCL exceeded 95 ms in all AVNRT patients, but was less than < 95 ms in 28 of 29 ORT patients. In the next 50 children, a cPPI‐TCL < 95 ms was 100% specific for ORT; a cPPI‐TCL > 95 ms was 95% specific for AVNRT. There was even greater separation of cPPI‐TCL values comparing AVNRT with ORT utilizing a septal accessory pathway. Conclusions : The cPPI‐TCL is a useful technique to distinguish AVNRT from ORT in children. Our data suggest that in children a cPPI‐TCL < 95 ms excludes AVNRT, while a value > 95 ms is rarely observed in ORT. This technique is particularly useful to distinguish AVNRT from ORT utilizing a septal accessory pathway. (PACE 2010; 469–474)     

Linear Lesion Cryoablation for the Treatment of Atrioventricular Nodal Re‐entry Tachycardia in Pediatrics and Young Adults

Background: Radiofrequency (RF) ablation is a relatively safe and effective method for treatment of atrioventricular nodal re‐entry tachycardia (AVNRT), but carries a 1–2% risk of AV nodal injury. Cryothermal ablation reduces the risk of AV block, but has had decreased procedural success and increased recurrence of tachycardia. We sought to evaluate the technique of linear lesion cryoablation (LLC) for treatment of AVNRT. Methods: Single institution retrospective cohort study. Each patient underwent slow pathway modification using either RF, single lesion cryoablation, or LLC. Procedural success, recurrence, freedom from tachycardia 12 months following ablation and fluoroscopy time were compared between ablation methods. Results: A total of 125 patients, median age 15.5 (4.7–23.1) years, underwent ablation: 32 RF energy, 31 single lesion cryoablation, 62 LLC. Procedural success was obtained in 94% of the LLC group compared to 58% using single lesion cryoablation (P ≤ 0.001). Ninety‐seven percent of the LLC group was free from tachycardia recurrence, significantly higher than with single lesion cryoablation (68%, P = 0.001) and equal to that of RF (97%, P = NS). Fluoroscopy time was reduced in the LLC group compared to both single lesion and RF groups (P = 0.02). There was no permanent AV nodal injury in the cryoablation groups. Conclusion: LLC is an effective means of treatment for AVNRT and is associated with significantly improved procedural success and freedom from recurrence compared to single lesion methods, while at the same time obtaining equivalent efficacy to RF. (PACE 2010; 1304–1311)     

Use of three-dimensional catheter guidance and trans-esophageal echocardiography to eliminate fluoroscopy in catheter ablation of left-sided accessory pathways

Background: Newer technologies such as three-dimensional mapping and echocardiography can decrease x-ray exposure during catheter ablation. Many right-sided tachycardias can now be ablated without fluoroscopy. Left-sided tachycardias, however, have not yet been ablated using a zero fluoroscopy approach.
Objective: This study sought to examine the utility of trans-esophageal echocardiography (TEE) in providing adequate imaging as an alternative to fluoroscopy for transseptal puncture. When combined with NavX guidance (St. Jude Medical, St. Paul, MN, USA), fluoroscopy may not be necessary.
Methods: Ten pediatric patients with supraventricular tachycardia (SVT) had accessory pathways mapped to the left side. Right atrial and coronary sinus geometries were created using NavX. Once a left-sided pathway was confirmed, a transseptal puncture was performed. A guide wire was placed in the SVC and confirmed by TEE. A transseptal sheath and dilator were advanced over the wire and positioned with TEE guidance so that the tip of the dilator was tenting the fossa ovalis. A transseptal needle was advanced across the fossa. Left atrial location of the needle tip was confirmed on TEE by saline contrast injection. The sheath and dilator were advanced over the needle with continuous pressure monitoring and TEE. Once the sheath was appropriately positioned, the ablation was completed using NavX guidance.
Results: All patients had acutely successful ablations and none required the use of fluoroscopy. Number of cryo lesions ranged from five to 19, with a mean of 9. Mean procedure time was 4.4 hours, with a range of 3.2 hours to 7.2 hours. There were no complications. One patient had recurrence.
Conclusions: Three-dimensional mapping combined with TEE shows potential for eliminating fluoroscopy use during catheter ablation.     

Transjugular liver biopsy: modified Ross transseptal needle versus Quick-core biopsy needle

Background: We evaluated the differences in sample adequacy and safety between a transseptal needle and Quick-core biopsy needle for transjugular liver biopsy. Methods: Eighteen consecutive patients who had a bleeding diatheses and/or ascites underwent transjugular liver biopsy using a transseptal needle (11 patients) and Quick-core biopsy needle (seven patients). The length of the specimens was measured before fixation. A pathologist reviewed histologic slides for sample adequacy and pathologic diagnoses. Clinical records were reviewed for complication. Results: In all patients, liver biopsy was successful. A total of 45 specimens were obtained, with an average of 2.5 passes per patient. The length of specimen was significantly longer with the Quick-core biopsy needle than with the transseptal needle (p < 0.05). Biopsied tissue was fragmented in 17 of 25 specimens with the transseptal needle but not fragmented in any specimen with the Quick-core biopsy needle. All specimens were determined to be adequate except one with the transseptal needle. There was no early or delayed complication in any patient. Conclusion: Transjugular liver biopsy is a safe and effective procedure without any significant difference in complication and adequacy when using a transseptal needle or Quick-core biopsy needle. Larger specimens can be obtained without tissue fragmentation with the Quick-core biopsy needle. Received: 30 August 1999/Revision accepted: 26 January 2000