Predictors of zero X ray procedures in supraventricular arrhythmias ablation.

To evaluate predictors of zero-X ray procedures for supraventricular arrhythmias (SVT) using minimally fluoroscopic approach (MFA). Patients referred for RF catheter ablation of SVT were admitted for a MFA with an electro-anatomical navigation system or a conventional fluoroscopic approach (ConvA). Exclusion criterion was the need to perform a transseptal puncture. 206 patients (98 men, age 53 ± 19 years) underwent an EP study, 93 (45%) with an MFA and 113 (55%) with a ConvA. Fifty-five had no inducible arrhythmias (EPS). Fifty-four had AV nodal reentrant tachycardia (AVNRT), 49 patients had typical atrial flutter (AFL), 37 had AV reciprocating tachycardia (AVRT/WPW), 11 had focal atrial tachycardia (AT), and underwent a RF ablation. X-ray was not used at all in 51/93 (58%) procedures (zero X ray). MFA was associated with a significant reduction in total fluoroscopy time (5.5 ± 10 vs 13 ± 18 min, P = 0.01) and operator radiation dose (0.8 ± 2.5 vs 3 ± 8.2 mSV, P < 0.05). The greatest absolute dose reduction was observed in AVNRT (0.1 ± 0.3 vs 5.1 ± 10 mSV, P = 0.01, 98% relative dose reduction) and in AFL (1.3 ± 3.6 vs 11 ± 16 mSV, P = 0.003, 88% relative dose reduction) groups. Both AVNRT or AFL resulted the only statistically significant predictors of zero x ray at multivariate analysis (OR 4.5, 95% CI 1.5-13 and OR 5, 95% CI 1.7-15, P < 0.001, respectively). Success and complication rate was comparable between groups (P = NS). Using MFA for SVT ablation, radiological exposure is significantly reduced. Type of arrhythmia is the strongest predictor of zero X ray procedure.

The relationship between the P wave and local atrial electrogram in predicting conduction block during catheter ablation of cavo-tricuspid isthmus-dependent atrial flutter.

PURPOSE: The endpoint for radiofrequency catheter ablation (RFA) of cavo-tricuspid isthmus (CTI)-dependent atrial flutter (AFL) is complete conduction block along the CTI. The purpose of this study is to evaluate the utility of the temporal relationship between the P wave and the local atrial electrograms in determining complete CTI block. METHODS: RFA of CTI was performed in 125 patients (age 63 ± 11 years). During pacing from the coronary sinus (CS), the intervals from the peak of the P wave (Ppeak) in lead V1 to the second component of the local atrial electrogram (A2) along the ablation line (Ppeak-A2) and from the end of the P wave (Pend) to A2 (Pend-A2) were investigated before and after complete block in the first 100 patients (training set). In the next 25 patients (validation set), Ppeak-A2 and Pend-A2 intervals were prospectively assessed to determine CTI block. RESULTS: The mean Ppeak-A2 and Pend-A2 immediately before complete block were - 15±24 and - 39±23 ms compared to 49 ± 17 and 21 ± 16 ms after CTI block (P < 0.0001). Ppeak-A2 ≥ 20 ms and Pend-A2 ≥ 0 ms predicted CTI block with 98% sensitivity and 95% specificity and 96% sensitivity and 100% specificity, respectively. In the validation set, the positive and negative predictive values of Ppeak-A2 ≥ 20 ms or Pend-A2 ≥ 0 ms were 100 and 96%, respectively. The diagnostic accuracy was 98%. CONCLUSIONS: During pacing from the CS, the temporal relationship between the P wave in lead V1 and A2 is a simple and reliable indicator of complete block during RFA of CTI-AFL.

Arrhythmia-specific settings for automated high-density mapping: A multicenter experience.

BACKGROUND: Advancements in electrophysiology 3-D mapping systems facilitate the broadening scope of electrophysiology study and catheter ablation to treat complex arrhythmias. While electroanatomical mapping systems have default settings available for a variety of mapping parameters, significant operator customization driven by arrhythmia type and experience can occur. However, multicenter comprehensive reporting of customized mapping settings is lacking. METHODS: In this prospective, multicenter observational registry, subjects with cardiac arrhythmias underwent electrophysiology study and ablation procedure using the EnSite Precision™ electroanatomical mapping system per standard of care, and associated automated mapping thresholds and procedural characteristics were observed. RESULTS: Cardiac mapping and ablation was performed in 503 patients (64.4% male, 59.6 ± 13.2 years) for a variety of indications including atrial fibrillation (N = 277), atrial flutter (N = 67), other supraventricular tachycardias (N = 96), and ventricular tachycardia (N = 56). Automated electroanatomical mapping was used to generate 88.2% of all maps, and arrhythmia-specific adjustments of mapping thresholds were utilized to collect electrophysiologically relevant data. The most commonly used thresholds for mapping in AF were Distance (average 2.7 ± 3.5 mm) and Signal-to-Noise Ratio (5.2 ± 1.1), while mapping in VT commonly used Score (88.5 ± 6.5%) and Distance (0.6 ± 0.5 mm). Automated mapping collected and utilized 8.8 times more data than manual mapping without increasing mapping time. CONCLUSIONS: This registry revealed arrhythmia-specific automated mapping settings used to generate electroanatomical maps of multiple cardiac rhythms with higher point density than manual mapping without increasing mapping time. Commonly used mapping threshold settings could serve as an important reference for new automated electroanatomical mapping users or those expanding their usage to new indications and arrhythmias.

Electroanatomic characteristics of the mitral isthmus associated with successful mitral isthmus ablation.

AIMS: The success of mitral isthmus (MI) ablation has been related to CT scan defined MI anatomy. We sought to correlate electroanatomical MI characteristics with MI ablation success in patients with perimitral flutter (PMF). METHODS AND RESULTS: In 53 consecutive patients (46 males, 61 ± 10 years) with PMF, MI was ablated with endocardial ± coronary sinus (CS) linear radiofrequency (RF) ablation lesion. Acute (termination of PMF during ablation) and long-term procedural success were studied. Mitral isthmus characteristics (thickness--minimal endocardial to CS distance, length, maximal MI bipolar voltage), as well as MI ablation line length and width, RF duration, and delivered energy were analysed. In 43 of the 53 patients (81%), acute success was observed. This was more frequently achieved in patients with thinner MI (2.4 ± 3.1 vs. 7 ± 3.2 mm; P = 0.0009). Mitral isthmus thickness predicted ablation failure with a ROC area of 0.84. The best threshold to predict MI ablation failure was 8.3 mm with a sensitivity of 67% and a specificity of 97%. Left atrial size was of greater importance in failed cases (2D echo surface: 24.1 ± 2.5 vs. 32.5 ± 6.9 cm2, P = 0.005; electroanatomic volume: 124 ± 32 vs. 165 ± 23 mL, P = 0.02). None of the other electroanatomical characteristics were associated with outcome. After a mean follow-up of 28 ± 15 months, 21 patients (39%) had atrial fibrillation (AF) or atypical flutter (PMF recurrence in four). CONCLUSION: Smaller MI thickness is associated with acute success in PMF ablation. Mitral isthmus electroanatomical characteristics might be used for decision-making on strategy during persistent AF ablation and for selecting the best location for interrupting PMF.

Real-time magnetic resonance-guided ablation of typical right atrial flutter using a combination of active catheter tracking and passive catheter visualization in man: initial results from a consecutive patient series.

AIMS: Recently cardiac magnetic resonance (CMR) imaging has been found feasible for the visualization of the underlying substrate for cardiac arrhythmias as well as for the visualization of cardiac catheters for diagnostic and ablation procedures. Real-time CMR-guided cavotricuspid isthmus ablation was performed in a series of six patients using a combination of active catheter tracking and catheter visualization using real-time MR imaging. METHODS AND RESULTS: Cardiac magnetic resonance utilizing a 1.5 T system was performed in patients under deep propofol sedation. A three-dimensional-whole-heart sequence with navigator technique and a fast automated segmentation algorithm was used for online segmentation of all cardiac chambers, which were thereafter displayed on a dedicated image guidance platform. In three out of six patients complete isthmus block could be achieved in the MR scanner, two of these patients did not need any additional fluoroscopy. In the first patient technical issues called for a completion of the procedure in a conventional laboratory, in another two patients the isthmus was partially blocked by magnetic resonance imaging (MRI)-guided ablation. The mean procedural time for the MR procedure was 109 ± 58 min. The intubation of the CS was performed within a mean time of 2.75 ± 2.21 min. Total fluoroscopy time for completion of the isthmus block ranged from 0 to 7.5 min. CONCLUSION: The combination of active catheter tracking and passive real-time visualization in CMR-guided electrophysiologic (EP) studies using advanced interventional hardware and software was safe and enabled efficient navigation, mapping, and ablation. These cases demonstrate significant progress in the development of MR-guided EP procedures.

Assessing the atrial electromechanical coupling during atrial focal tachycardia, flutter, and fibrillation using electromechanical wave imaging in humans.

Minimally-invasive treatments of cardiac arrhythmias such as radio-frequency ablation are gradually gaining importance in clinical practice but still lack a noninvasive imaging modality which provides insight into the source or focus of an arrhythmia. Cardiac deformations imaged at high temporal and spatial resolution can be used to elucidate the electrical activation sequence in normal and paced human subjects non-invasively and could potentially aid to better plan and monitor ablation-based arrhythmia treatments. In this study, a novel ultrasound-based method is presented that can be used to quantitatively characterize focal and reentrant arrhythmias. Spatio-temporal maps of the full-view of the atrial and ventricular mechanics were obtained in a single heartbeat, revealing with otherwise unobtainable detail the electromechanical patterns of atrial flutter, fibrillation, and tachycardia in humans. During focal arrhythmias such as premature ventricular complex and focal atrial tachycardia, the previously developed electromechanical wave imaging methodology is hereby shown capable of identifying the location of the focal zone and the subsequent propagation of cardiac activation. During reentrant arrhythmias such as atrial flutter and fibrillation, Fourier analysis of the strains revealed highly correlated mechanical and electrical cycle lengths and propagation patterns. High frame rate ultrasound imaging of the heart can be used non-invasively and in real time, to characterize the lesser-known mechanical aspects of atrial and ventricular arrhythmias, also potentially assisting treatment planning for intraoperative and longitudinal monitoring of arrhythmias.

Crista Terminalis as the Anterior Pathway of Typical Atrial Flutter: Insights from Entrainment Map with 3D Intracardiac Ultrasound.

BACKGROUND: The precise location of truly active reentry circuits of typical atrial flutter (AFL) has not been well identified. The purpose of this study was to verify our hypothesis that the posterior block line is located along the posteromedial right atrium (PMRA) and the crista terminalis (CT) is the anterior pathway of AFL, with real-time intracardiac echo (ICE). METHODS: The entire right atrium (RA) three-dimensional activation and entrainment mapping were evaluated during AFL in 18 patients using CARTO sound. RESULTS: The CT was clearly visualized by ICE and the local electrograms along the CT were single potentials in all the patients. The CT was recognized as the truly active anterior pathway based on entrainment mapping in all patients. Double potentials were recorded along the PMRA. Entire RA entrainment mapping could be performed in 16 patients. The reentry circuits were separated into three passages. The first was around the tricuspid annulus (TA), the second the anterior superior vena cava (SVC; AFL waves passed between the anterior SVC and RA appendage), and the last the posterior SVC (between the posterior SVC and upper limit of the PMRA). All three of these passages were active in four, around the TA and anterior SVC in eight, around the TA and posterior SVC in three, and around only the anterior SVC in one patient. CONCLUSIONS: The CT functions as the anterior pathway of typical AFL, and the posterior block line was located along the PMRA. Dual or triple circuits were recognized in the majority of AFL patients.

Two-dimensional echocardiographic features of the inferior right atrial isthmus: the role of vestibular thickness in catheter ablation of atrial flutter.

OBJECTIVES: The aim of this study was to examine the feasibility of transthoracic two-dimensional (2D)-echocardiography in defining the cavo-tricuspid isthmus (CTI) anatomy and its value concerning the ease of catheter ablation of isthmic atrial flutter (AF). METHODS: CTI analysis was accomplished in 39 cases: 16 necropsy specimens and 23 patients. Sixteen were patients with isthmus-dependent AF and seven controls with other supraventricular re-entrant tachycardias. Two-dimensional transthoracic echocardiography and a right atrium angiogram were performed before radiofrequency catheter ablation (RFCA). RESULTS: The measurements of the CTI with angiography were compared with those taken with echocardiography and correlation was excellent (r= 0.91; P < 0.0001). In normal patients, the dimension of the vestibular thickness was successfully compared and validated with the histological examination of the necropsy specimens: histology median 6.8 mm, range 4.4-10.5 vs. echo median 6.2 mm, range 5.4-8.7; P: NS. Vestibular thickness was greater in complex than in simple RFCA (13.6 ± 1.9 mm vs. 10.0 ± 2.3 mm; P = 0.01). When vestibular thickness ≥11.5 mm, the ablation prone to be complex (sensitivity 83.3%, specificity 80%, positive predictive value 71.4%, and negative predictive value 88.9%). CONCLUSIONS: Two-dimensional transthoracic echocardiography clearly depicts the inferior isthmus and, displaying the thickness of the tricuspid vestibule, it was related with complexity of the ablation procedure in isthmus-dependent AF.

Variable procedural strategies adapted to anatomical characteristics in catheter ablation of the cavotricuspid isthmus using a preoperative multidetector computed tomography analysis.

OBJECTIVES: This study aimed to investigate the anatomical characteristics complicating cavotricuspid isthmus (CTI) ablation and the effectiveness of various procedural strategies. METHODS AND RESULTS: This study included 446 consecutive patients (362 males; mean age 60.5 ± 10.4 years) in whom CTI ablation was performed. A total of 80 consecutive patients were evaluated in a preliminary study. The anatomy of the CTI was evaluated by multidetector row-computed tomography (MDCT) prior to the procedure. A multivariate logistic regression analysis revealed that the angle and mean wall thickness of the CTI, a concave CTI morphology, and a prominent Eustachian ridge, were associated with a difficult CTI ablation (P < 0.01). In the main study, 366 consecutive patients were divided into 2 groups: a modulation group (catheter inversion technique for a concave aspect, prominent Eustachian ridge, and steep angle of the CTI or increased output for a thicker CTI) and nonmodulation group (conventional strategy). The duration and total amount of radiofrequency energy delivered were significantly shorter and smaller in the modulation group than those in the nonmodulation group (162.2 ± 153.5 vs 222.7 ± 191.9 seconds, P < 0.01, and 16,962.4 ± 11,545.6 vs 24,908.5 ± 22,804.2 J, P < 0.01, respectively). The recurrence rate of type 1 atrial flutter after the CTI ablation in the nonmodulation group was significantly higher than that in the modulation group (6.3 vs 1.7%, P = 0.02). CONCLUSION: Changing the procedural strategies by adaptating them to the anatomical characteristics improved the outcomes of the CTI ablation.

Frequency of atrial flutter after adult lung transplantation.

Lung transplantation, which involves an anastomosis of the graft to the native left atrium, may increase the risk of left-side atrial flutter (AFL). Our aim was to evaluate the incidence, predisposing conditions, and course of AFL after lung transplantation in adults. Two hundred sixty-nine consecutive patients who underwent lung transplantation were studied retrospectively. All patients received a preoperative echocardiogram and postoperative electrocardiographic monitoring. All 12-lead electrocardiograms were reviewed. Typical or atypical AFL was diagnosed by 2 independent reviewers based on accepted criteria. Predictors of AFL were investigated separately using univariate and multivariate logistic regression analyses. AFL occurred in 35 of 269 patients (13%) over a mean of 12 days after transplantation. All patients who developed AFL had no previous atrial arrhythmia. Of these 35 patients, 24 (68.6%) had atypical AFL by electrocardiographic criteria. In multivariate logistic regression analysis, patients with idiopathic pulmonary fibrosis (IPF) were 2.9 times more likely to have AFL than those patients with lung transplant without IPF (p = 0.009). Other independent risk factors for AFL were advanced age and preoperative left atrial enlargement. Only 3 of 35 patients (8.6%) with AFL had persistent atrial arrhythmia and needed electrophysiologic study and ablation. In conclusion, AFL is common soon after lung transplantation. Those with IPF, advanced age, or left atrial enlargement are at increased risk. In most cases, AFL is a self-limited arrhythmia that resolves spontaneously with no need for ablation.

Intracardiac echocardiography in complex cardiac catheter ablation procedures.

With the availability of catheter ablation for the elimination of complex cardiac arrhythmias, new imaging tools have enhanced the safety and efficacy of procedures performed in the electrophysiology laboratory. We review the use of intracardiac ultrasound (ICE) as the modality that allows real-time monitoring and reconstruction of cardiac anatomy. Practical technical information related to the use of ICE in ablation procedures in general and particular aspects related to ablation of atrial fibrillation, atrial flutter, ventricular tachycardia, and arrhythmias in adults with congenital heart disease are discussed in this manuscript.

Prospective randomized comparison of a steerable versus a non-steerable sheath for typical atrial flutter ablation.

AIMS: Although cavotricuspid isthmus (CTI) ablation can cure typical atrial flutter (AFL), it might be difficult to achieve a bidirectional conduction block in the isthmus in some patients. We investigated the usefulness of a steerable sheath for CTI ablation in patients with typical AFL or atrial fibrillation. METHODS AND RESULTS: A total of 40 consecutive patients (36 males; mean age 55.2 +/- 10.0 years) undergoing CTI ablation were randomized to one of the following two groups: group S (using a steerable long sheath) or group NS (using a non-steerable long sheath). Ablation was performed using an 8 mm tip catheter. The anatomy of the CTI was evaluated by a dual-source computed tomography scan prior to the procedure. The procedural endpoint was the achievement of a bidirectional isthmus conduction block. Bidirectional block in the CTI was achieved in all patients with 485.3 +/- 416.4 s of radiofrequency (RF) application. The CTI anatomy, including the length, depth, and morphology, was similar between the two groups. The duration and total amount of RF energy delivery were significantly shorter and smaller in group S than in group NS (310 +/- 193 vs. 661 +/- 504 s, P = 0.006, and 12,197 +/- 7306 vs. 26,906 +/- 21,238 J, P = 0.006, respectively). CONCLUSION: The use of a steerable sheath reduced the time and amount of energy needed to achieve a bidirectional conduction block in the CTI. For patients in whom the establishment of a conduction block is difficult, a steerable sheath should be considered as a therapeutic option for typical AFL ablation.

Radiofrequency catheter selection based on cavotricuspid angiography compared with a control group with an externally cooled-tip catheter: a randomized pilot study.

BACKGROUND: Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) can be performed using either externally cooled-tip RFA catheters or large-tip (8 mm) catheters. However, experimental and clinical studies suggest that the efficacy of both catheters may vary with CTI anatomy and catheters orientation. OBJECTIVES: The aim of this prospective study was to evaluate: a RFA catheter selection based on CTI angiography compared with a control group with an externally cooled-tip catheter together with the risk of an expensive crossover catheter in both groups. METHOD: Over a period of 16 months, 119 patients were included and randomized. RESULTS: When comparing the angiographic group (n = 56) and the externally cooled-tip RFA catheter group (n = 63), the duration of application time with a median of 7 min (interquartile range 4.5-11) versus a median of 10 min (interquartile range 6-20; P = 0.008) and the duration of X-ray exposure with a median of 7 min (interquartile range 4-10) versus a median of 10 min (interquartile range 5-15; P = 0.025) were significantly lower in the angiographic group versus externally cooled-tip catheter group. Furthermore, the number of catheters crossover was significantly higher in the angiographic group versus externally cooled-tip catheter group I (27% vs 7%; P = 0.007). CONCLUSIONS: This study shows that a strategy with a catheter selection based on a CTI angiographic evaluation is superior to an empirical use of an externally cooled-tip catheter during CTI RFA. Thus, angiographic isthmus evaluation predicts the effectiveness of a RFA catheter and the risk of an expensive catheter crossover.

The electroanatomic characteristics of the cavotricuspid isthmus: implications for the catheter ablation of atrial flutter.

INTRODUCTION: Radiofrequency ablation (RFA) of typical AFL is sometimes difficult because of the poor electroanatomic approach to the cavotricuspid isthmus (CTI). The aim of this study was to correlate the anatomy of the CTI between contact mapping (NavX) and right atrial angiography (RAG), and to investigate the impact of the electroanatomic characteristics of the CTI on the RFA of typical atrial flutter (AFL). METHODS: One hundred patients with typical AFL undergoing RFA were studied. The image-guided group consisted of 50 consecutive patients with the guidance of NavX. NavX geometry and RAG were performed to investigate the morphology of the CTI. The bipolar voltages of the CTI were collected during sinus rhythm by a NavX. The control group consisted of 50 consecutive patients with the guidance of conventional fluoroscopy. RESULTS: There was a good correlation between the angiography and NavX for the anatomy of the CTI. The pouch type had a longer length of CTI than the flat type (33.4 +/- 5.0 vs 22.6 +/- 8.4 mm, P < 0.0001) and deeper depth than the concave type (6.5 +/- 2.2 vs 3.7 +/- 0.8 mm, P < 0.0001) on the angiography. The pouch-type CTI had a longer ablation time and larger pulses of RFA than the other two types. The control group had a longer ablation time, fluoroscopy time, and larger pulses of RFA than image-guided group. CONCLUSIONS: The 3-D mapping system provided a good reconstruction of CTI, which may help in the RFA in patients with a complex anatomy of the CTI.

Relationship between anatomic location of the crista terminalis and double potentials recorded during atrial flutter: intracardiac echocardiographic analysis.

INTRODUCTION: The activation sequence in typical atrial flutter (AFL) around the tricuspid annulus is well described. However, activation of the remainder of the right atrium (RA) is not well defined. Previous studies have shown a linear block at the crista terminalis (CT) during AFL. The aim of this study was to evaluate the relationship between the location of the CT and the line of block by intracardiac echocardiography (ICE). METHODS AND RESULTS: Twenty-one patients with typical AFL were included in the study. The ICE imaging catheter (9-French with 9-MHz ultrasound transducer) was advanced to the RA. Under ICE guidance, a 20-pole roving catheter was used to map double potentials (DPs) during AFL, and three-dimensional images of the RA were reconstructed. During counterclockwise (CCW), clockwise (CW) AFL, or both, a line of conduction block manifested by DPs was identified at a septal site adjacent to the CT in 12 patients and in the posteroseptal RA in 9 patients. CONCLUSION: The functional line of block in CCW and CW AFL is localized not at the CT but at the septal edge of the CT or in the posteroseptal RA.

Comparison of coronary sinus morphology in patients with and without atrioventricular nodal reentrant tachycardia by intracardiac echocardiography.

INTRODUCTION: Dual AV nodal physiology is the electrophysiologic substrate for AV nodal reentrant tachycardia (AVNRT), but the anatomic basis for this arrhythmia remains to be elucidated. Atrial flutter (AFL) has been shown to be more frequently inducible in patients with AVNRT. METHODS AND RESULTS: A 3.2-French, 20-MHz intracardiac ultrasound (ICUS) catheter was introduced into the coronary sinus (CS), and two-dimensional ICUS images were recorded during transducer pullback in 21 patients with AVNRT and 18 control patients. Three-dimensional reconstruction of the CS was created using the TomTec Imaging system. The area of the CS lumen at 15 mm within the CS ostium (os) was not significantly different in patients with and without AVNRT (54.4 +/- 34.7 mm2 vs 39.1 +/- 28.5 mm2). However, the area of the CS os was significantly larger in patients with AVNRT than in those without (112.1 +/- 60.9 mm2 vs 71.7 +/- 44.4 mm2, P < 0.05). Three-dimensional morphology of the CS os revealed flaring in patients with AVNRT, giving it a "windsock" appearance. Sustained AFL was induced in 10 of 21 patients with AVNRT, but in none of 18 control patients (P < 0.005). CONCLUSION: The CS os was significantly wider in patients with AVNRT than in those without. These findings may have important implications for arrhythmia pathogenesis in AVNRT as well as AFL.

Ablation of typical atrial flutter using a three-dimensional ultrasound mapping system.

AIMS: The aim of the study was to test the feasibility of the new Realtime Position Management mapping system for ablation of typical atrial flutter. METHODS AND RESULTS: The ultrasound multi-transducer catheters of the RPM Mapping System are placed in the coronary sinus and at the right ventricular apex. Position and movement of the ablation catheter can be depicted on the monitor at any time. Several guiding marks are set in the right atria and thus, define the subsequent lesion lines. A total of 15 patients were treated. In 13 patients complete bi-directional block was established after the ablation. In two patients only significant conduction delay was measured after the end of the procedure. A total of 10.2 +/- 6.3 cooled RF-applications were needed to reach the end-point of the procedure. The total energy was 18.76 +/- 13.23 J. The fluoroscopy time for ablation was 22.2 +/- 8.34 min. During a mean follow-up of 8.4 +/- 3.2 months no recurrence of atrial flutter occurred. One patient developed atypical flutter and another patient had atrial fibrillation. Both patients were treated with antiarrhythmic drugs. There was one ablation related complication, a pericardial effusion. CONCLUSION: The Realtime Position Management system is easy to manage and control. The precision of anatomical linear lesions is improved and fluoroscopic exposure time considerably reduced after learning curve.