Clinical and Laboratory Predictors of Long-Term Outcomes after Catheter Ablation for a Ventricular Electrical Storm.

Background: Ventricular electrical storm (VES) is characterized by the occurrence of multiple episodes of sustained ventricular arrhythmias (VA) over a short period of time. Radiofrequency ablation (RFA) has been reported as an effective treatment in patients with ventricular tachycardia (VT). Objective: The aim of the present study was to indicate the short-term and long-term predictors of recurrent VA after RFA was performed due to VES. Methods: A retrospective, single-centre study included patients, who had undergone RFA due to VT between 2012 and 2021. In terms of the short-term (at the end of RFA) effectiveness of RFA, the following scenarios were distinguished: complete success: inability to induce any VT; partial success: absence of clinical VT; failure: inducible clinical VT. In terms of the long-term (12 months) effectiveness of RFA, the following scenarios were distinguished: effective ablation: no recurrence of any VT; partially successful ablation: VT recurrence; ineffective ablation: VES recurrence. Results: The study included 62 patients. Complete short-term RFA success was obtained in 77.4% of patients. The estimated cumulative VT-free survival and VES-free survival were, respectively, 28% and 33% at the 12-month follow-up. Ischemic cardiomyopathy and complete short-term RFA success were predictors of long-term RFA efficacy. Neutrophil to lymphocyte ratio (NLR) and GFR <60 mL/min/1.73 m2 were associated with VES recurrence. NLR ≥2.95 predicted VT and/or VES recurrence with a sensitivity of 66.7% and specificity of 72.2%. Conclusion: Ischemic cardiomyopathy and short-term complete success of RFA were predictors of no VES recurrence during the 12-month follow-up, while NLR and GFR <60 ml/min/1.73 m2 were associated with VES relapse.

Role of Metoprolol Succinate in the Treatment of Heart Failure and Atrial Fibrillation: A Systematic Review.

BACKGROUND: Beta-blockers are one of the most important classes of cardiovascular agents and have been considered a cornerstone therapy in heart diseases, such as heart failure (HF) and atrial fibrillation (AF). Among different beta-blockers, metoprolol is a selective beta1-adrenergic antagonist, which has been extensively used since the 1970s. AREAS OF UNCERTAINTY: Although current guidelines include recommendations for the use of controlled-release metoprolol succinate in specific HF and AF indications, and despite extensive clinical experience with metoprolol, comparative evidence on the use of metoprolol succinate compared with other beta-blockers in these indications is limited. DATA SOURCES: We systematically reviewed the data from head-to-head studies directly comparing this compound with other beta-blockers in the treatment of HF or AF. Only clinical trials and observational studies were considered; no other limits were applied. The quality and relevance of retrieved articles were reviewed. RESULTS: A total of 18 articles of the 353 articles identified were selected for inclusion; 12 HF articles and 6 for AF. Additional references were identified from the bibliographies of retrieved articles. The studies show that oral prophylaxis with an appropriate dose of metoprolol may reduce new incidents of AF in high-risk patients. Furthermore, metoprolol succinate is associated with significant mortality and morbidity benefits in the treatment of HF. CONCLUSIONS: Despite the introduction of newer beta-blockers with differing clinical characteristics since its introduction, metoprolol succinate remains a useful drug in both HF and AF.

Nutritional therapy complications in children with ultra-short bowel syndrome include growth deficiency but not cholestasis.

AIM: Children with ultra-short bowel syndrome (USBS) have not been extensively studied to date because the condition is rare. The aim of the study was to assess the nutritional status of children with USBS receiving home parenteral nutrition, using citrulline serum concentration and cholestasis. METHODS: We studied 17 patients with USBS, with a median age of 6.6 years and median duration of parenteral nutrition of 6.6 years. The study was carried out at The Children's Memorial Health Institute, Warsaw, from January 2014 to January 2015. RESULTS: The median standard deviation score (SDS) was -1.2 for body mass according to chronological age, -1.72 according to height and -0.59 according to height for age. Patients requiring seven days per week parenteral nutrition had a citrulline concentration below 10 µmol/L. Decreased bone-mineral density was observed in 87% of the patients. Low values of 25-hydroxyvitamin D were found in 53% of the children. None of the patients had elevated conjugated bilirubin levels above 34.2 µmol/L. CONCLUSION: Children with USBS were growth deficient according to their chronological age, with frequent abnormal bone mineralisation and vitamin D deficiency. Children requiring parenteral nutrition seven days a week had citrulline concentrations below 10 µmol/L. Cholestasis was not seen.

Can two-dimensional speckle tracking echocardiography be useful for left ventricular assessment in the early stages of hereditary haemochromatosis?

BACKGROUND: Hereditary haemochromatosis (HH) is a common inherited disease. Abnormally increased intestinal iron absorption and accelerated recycling of iron by macrophages lead to progressive body iron accumulation and the generation of oxidative stress. In the late stages, iron overload can lead to dysfunction of the left ventricle (LV). It is believed that two-dimensional speckle tracking echocardiography (2D STE) can evaluate LV dysfunction more accurately than conventional echocardiography. This accurate evaluation seems to be clinically important in the early stages of HH before substantial damage of the LV. Evaluation of this assessment was the purpose of this paper. METHODS: We prospectively enrolled 24 patients with early diagnosed HH and without any history of cardiovascular diseases; 23 healthy age- and sex-matched volunteers constituted the control group. Standard echocardiographic parameters and LV rotation and strain parameters were assessed and compared between the groups. RESULTS: All echocardiographic parameters were within normal ranges, and there were no differences between the groups. 2D STE revealed significantly worse basal and apical rotation, twist and torsion values in HH patients. The peak systolic longitudinal strain was decreased in HH patients, even though the LV ejection fraction (LVEF) was normal. There were weak correlations between the iron turnover and 2D STE parameters. CONCLUSIONS: 2D STE seems to be more sensitive than traditional echocardiography for detecting LV abnormalities in HH patients who are diagnosed early. The results of this study may be clinically useful, but their relevance and therapeutic implications remain to be confirmed by further studies.

Effectiveness of antazoline versus amiodarone, flecainide and propafenone in restoring sinus rhythm at the emergency department.

PURPOSE: Little is known about the effectiveness of pharmacological cardioversion (PCV) with antazoline in comparison to flecainide. The aim of this study was to compare the effectiveness of antazoline in restoring sinus rhythm (SR) versus amiodarone, flecainide and propafenone in a group of emergency department (ED) patients. MATERIALS/METHODS: This was a single-centre retrospective analysis of patient records from an ED in a large hospital in Poland. We analysed a total of 1878 patient records, divided based on the anti-arrhythmic drug (AAD) administered during PCV: antazoline (n â€‹= â€‹1080), antazoline â€‹+ â€‹ß-blocker (n â€‹= â€‹479), amiodarone (n â€‹= â€‹129), flecainide (n â€‹= â€‹102), propafenone (n â€‹= â€‹88). Of the patients, 63.5 â€‹% were female (median 65 years, [19-100]). RESULTS: The percentage of successful PCV was significantly higher in the antazoline group (84.3 â€‹%) than in the antazoline â€‹+ â€‹ß-blocker (75.8 â€‹%, p â€‹= â€‹0.0001), propafenone (75.6 â€‹%, p â€‹= â€‹0.0364) and amiodarone (68.8 â€‹%, p â€‹< â€‹0.0001) groups. Post-hoc analysis revealed that patients who received PCV with antazoline, antazoline â€‹+ â€‹ß-blocker, flecainide and propafenone had significantly shorter time to SR than those who received amiodarone (p â€‹< â€‹0.0001). Univariate regression analysis revealed that patients who underwent PCV with antazoline were almost twice as likely to return to SR compared to the other groups (p â€‹< â€‹0.0001, OR 1.81, 95 â€‹% CI 1.44-2.27). CONCLUSIONS: This is the first study comparing the effectiveness of antazoline in PCV versus flecainide in addition to the previously studied amiodarone and propafenone. Our results indicate that antazoline is more effective in restoring SR than amiodarone, flecainide and propafenone. In addition, antazoline restored SR significantly faster than amiodarone or propafenone.

Prevention of sudden cardiac death in patients with chronic kidney disease.

Cardiovascular deaths account for about 40% of all deaths of patients with chronic kidney disease (CKD), particularly those on dialysis, while sudden cardiac death (SCD) might be responsible for as many as 60% of SCD in patients undergoing dialysis. Studies have demonstrated a number of factors occurring in hemodialysis (HD) that could lead to cardiac arrhythmias. Patients with CKD undergoing HD are at high risk of ventricular arrhythmia and SCD since changes associated with renal failure and hemodialysis-related disorders overlap. Antiarrhythmic therapy is much more difficult in patients with CKD, but the general principles are similar to those in patients with normal renal function - at first, the cause of arrhythmias should be found and eliminated. Also the choice of therapy is narrowed due to the altered pharmacokinetics of many drugs resulting from renal failure, neurotoxicity of certain drugs and their complex interactions. Cardiac pacing in elderly patients is a common method of treatment. Assessment of patients' prognosis is important when deciding whether to implant complex devices. There are reports concerning greater risk of surgical complications, which depends also on the extent of the surgical site. The decision concerning implantation of a pacing system in patients with CKD should be made on the basis of individual assessment of the patient.

Apple Watch-guided diagnosis of AVNRT in a pregnant woman-A case report and literature review.

Cardiac arrhythmias occurring during pregnancy pose a therapeutic problem as antiarrhythmic drugs can be potentially harmful to the fetus. A 35-years-old woman in the 20th week of pregnancy was admitted to the Department of Cardiology due to the first episode of arrhythmia in her life. During the event, the patient was wearing an Apple Watch Series 6, which records a 30-sec single-channel ECG. The recording showed narrow QRS complex tachycardia of 216 bpm, and short RP interval and atrioventricular nodal reentrant tachycardia (AVNRT) was recognized. Due to the mild nature of the arrhythmia, antiarrhythmic pharmacotherapy was not initiated. The use of mobile health (mHealth) devices such as wearables and health monitoring applications is now a valuable addition to routine cardiac diagnostics for patients of all ages and levels of cardiovascular risk.

Clinical anatomy of the spatial structure of the right ventricular outflow tract.

BACKGROUND: The right ventricular outflow tract (RVOT) is located above the supraventricular crest and reaches the level of the pulmonary valve. Detailed knowledge of the RVOT spatial structure and its morphology is extremely important for cardiac invasive therapeutic procedures. OBJECTIVES: To examine the spatial structure of the RVOT using virtual models of the right ventricle (RV) interior obtained post mortem. MATERIAL AND METHODS: The study was carried out using 40 adult hearts from both sexes fixed in formalin. Donors had a negative history of cardiovascular diseases. Silicone models of the interior of the RV were made and then subjected to a digital modelling procedure using the photogrammetry technique. For each 3D model of the RV, the RVOT was extracted and measurements were performed. RESULTS: Statistical analysis demonstrated that the dimensions of the transverse (p < 0.001) and sagittal (p = 0.002) axis at the level of the upper and lower border of the RVOT differed significantly. There was also a significant difference between the right and left height of the RVOT (p = 0.009). A clear correlation was found between the volume of the RVOT and the volume of the entire RV (r = 0.718, p < 0.001). CONCLUSIONS: The obtained 3D models of the RVOT can help standardize the data related to RVOT architecture. Furthermore, they can extend knowledge about the RVOT in the field of cardiology and improve the procedures in cardiac surgery.

Does the choice of drug in pharmacologic cardioversion correlate with the guidelines? Systematic review.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia, the most common cause of supraventricular tachycardia in the global population and the most common arrhythmia requiring treatment in an emergency department. OBJECTIVES: To systematically review recent literature and quantify the correlation between the choice of pharmacological cardioversion (PCV) drug and the national or international guidelines. MATERIAL AND METHODS: A systematic review was performed in accordance with the PRISMA statement methodology. The PubMed search engine was used to search for articles regardless of type or language and published in the last 6 years (May 2014-May 2020). In addition, we searched for AF guidelines and recommendations published online by cardiology and emergency medicine societies. RESULTS: The search strategy returned a total of 2615 abstracts. A total of 2598 full texts were screened; 2540 full texts were excluded with reasons and 58 articles from 32 countries were included in the analysis. In 17 of the 58 articles (29%), we noted discrepancies with the AF guidelines, specifically regarding the PCV drug used, the patients' comorbidities and the contraindications associated with the PCV drug. The most common clinical situation for the use of a contraindicated drug was when ibutilide was administered to patients with heart failure. The analysis did not reveal any statistically significant correlations, although the correlation between the sample size and guideline adherence was close to statistical significance (p < 0.06). CONCLUSION: Our systematic analysis revealed substantial non-adherence to AF treatment guidelines.

Transferrin isoform analysis from dried blood spots and serum samples by gel isoelectric focusing for screening congenital disorders of glycosylation.

Congenital disorders of glycosylation (CDG) are a growing, heterogeneous group of genetic disorders caused by a defect in the glycoprotein synthesis. The first and still widely used method for routine CDG screening was isoelectric focusing (IEF) of serum transferrin. Dried blood spot (DBS) testing is commonly used in newborn screening procedures to detect inborn errors of metabolism. The aim of this study was to demonstrate the reliability of the IEF method in DBS testing. Dried blood spot testing can help in the postmortem diagnosis of CDG disorders when other material is unavailable. The patterns and concentrations of transferrin isoforms in serum and DBS are comparable, and slight differences do not affect interpretation of results.

Could autonomic nervous system parameters be still helpful in identifying patients with left ventricular systolic dysfunction at the highest risk of all-cause mortality?

BACKGROUND: Autonomic imbalance is associated with poor prognosis of patients with systolic dysfunction. Most of the previous data were written several years ago and constituted to cardiovascular or arrhythmic mortality. The current treatment of these patients has improved substantially over the last decades, and thus, the population at risk of death may have altered as well. Consequently, data on high-risk patients with systolic dysfunction in the modern era are sparse and those from previous trials may no longer be applicable. The aim herein, was to verify whether well-known autonomic indices - baroreflex sensitivity (BRS) and heart rate variability (HRV) - remain accurate predictors of mortality in patients with systolic dysfunction. METHODS: Non-invasively obtained BRS and HRV were analyzed in 205 clinically stable patients with left ventricular ejection fraction (LVEF) ≤ 40%. 28 patients died within 28 ± 9 month follow-up. RESULTS: Baroreflex sensitivity, low-frequency (LF) in normalized units, LF to high-frequency ratio and standard deviation of average R-R intervals were significantly associated with mortality; cut-off values of the highest discriminatory power for abovementioned parameters were ≤ 3.0 ms/mmHg, ≤ 41, ≤ 0.7 and ≤ 25 ms, respectively. In bivariate Cox analyses (adjusted for LVEF, New York Heart Association [NYHA] or absence of implantable cardioverter-defibrillator [ICD]) autonomic indices remain significant predictors of death. CONCLUSIONS: Baroreflex sensitivity and HRV - may still be helpful in identifying patients with left ventricular systolic dysfunction at the highest risk of all-cause mortality, independently of LVEF, NYHA class, and ICD implantation.

Single-site Bachmann's bundle pacing is beneficial while coronary sinus pacing results in echocardiographic right heart pacemaker syndrome in brady-tachycardia patients.

BACKGROUND: It has been proposed that multisite atrial pacing (MSAp) restores atrial electrical activation and prevents atrial fibrillation recurrence; however, single-site Bachmann's bundle pacing (BBp) has also been reported as providing effective atrial resynchronization. Coronary sinus pacing (CSp) leads to reversed impulse propagation within the atria. METHODS AND RESULTS: Acute echocardiographic examination was performed in 15 healthy subjects, and in 25 patients with sinus node dysfunction and recurrent atrial fibrillation during MSAp (atrial leads in the BB area and CS ostium), and single-site BBp and CSp. Regional atrial synchrony was assessed by tissue Doppler echocardiography. Pacing mode had no effect on stroke volume. CSp resulted in right atrial filling diminution, shortened mechanical atrioventricular delay in the right heart and diminished right ventricular inflow. The magnitude of reversion of the physiological right-to-left atrial contraction sequence was most prominent during CSp (15+/-11, 12+/-23, 3+/-21, 42+/-23 ms; control, MSAp, BBp, CSp respectively, P<0.0001). BBp provided the best atrial contraction synchrony, and had a comparable effect on global cardiac function to MSAp. CONCLUSIONS: Single-site BBp provides comparable hemodynamics to MSAp and is sufficient to restore atrial contraction synchrony. Single-site CSp induced echocardiographic pacemaker syndrome in the right heart.

Relationship between cycle length of typical atrial flutter and double potential interval after achievement of complete isthmus block.

BACKGROUND: There is some disagreement concerning the minimal value of the interval between components of double potentials (DPs interval) that allows distinguishing complete and incomplete block in the cavotricuspid isthmus (CTI). OBJECTIVES: To assess clinical utility of the relationship between atrial flutter cycle length (AFL CL) and the DPs interval. METHODS: Ablation of the CTI was performed in 87 patients during AFL (245 ± 40 ms). Subsequently, DPs were recorded during proximal coronary sinus pacing at sites close to a gap in the ablation line and after achievement of complete isthmus block. RESULTS: We noted strong correlation between AFL CL and the DPs interval after achievement of isthmus block (r = 0.73). The mean DPs interval was 95.3 ± 18.3 ms (range 60-136 ms) and 123.3 ± 24.3 ms (range 87-211 ms) during incomplete and complete isthmus block, respectively (P < 0.001). When expressed as a percentage of AFL CL, this interval was 35.7 ± 3.5% AFL CL (range 28-40.2%) and 50.4 ± 6.9% AFL CL (range 39-72%) during incomplete and complete isthmus block, respectively (P < 0.001). A cutoff value of 40% of AFL CL identified CTI block with 96.7% sensitivity and 100% specificity. CONCLUSIONS: The interval between DPs after achievement of block in the CTI correlates with AFL CL. The DPs interval expressed as a percentage of AFL CL allows better distinguishing between complete and incomplete isthmus block compared to standard method based on milliseconds. The DPs interval below 40% of AFL CL indicates sites close to a gap in the ablation line.

Echocardiographic assessment in patients with atrial fibrillation (AF) and normal systolic left ventricular function before and after catheter ablation: If AF begets AF, does pulmonary vein isolation terminate the vicious circle?

BACKGROUND: Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) can be curative. There are conflicting data on whether AF associated atrial and ventricular structural remodeling reverses after ablation. The aim of this study was to evaluate the hemodynamic effect of AF ablation in patients with preserved left ventricular ejection fraction (LVEF). METHODS: Forty three AF patients were studied (aged 56 ± 11 years; 29 male, 23% persistent AF, LVEF ≥ 50%) in whom RFCA was performed. Echocardiographic evaluation of atrial and ventricular diameters, volumes and strain imaging by two-dimensional speckle tracking were performed before and at least 6 months after RFCA. Nine patients had AF during baseline examination. RESULTS: A significant decrease in the left (LA) and right (RA) atrial volume and an increase in the LA strain were observed 15 ± 7 months after RFCA. In the subgroup with baseline sinus rhythm, the increment in LA strain was only borderline significant. An increase in RA, right ventricular (RV) and Biatrial strain was noticed (p < 0.05). LVEF and global longitudinal strain of the left ventricle (LV), however, did not improve substantially. CONCLUSIONS: Radiofrequency catheter ablation of AF in patients with preserved LV systolic function results in significant improvement in RA and RV function with a substantial reduction in LA and RA size. No deleterious impact of AF ablation on LA function was revealed.

Clinical picture and treatment effects in 5 patients with Methylmalonic aciduria related to MMAA mutations.

INTRODUCTION: Methylmalonic Aciduria (MMA) is a heterogeneous group of rare diseases leading to accumulation of methylmalonic acid in body fluids. One of the causes of the disease is the methylmalonic aciduria, cblA type (cblA - type MMA), conditioned by a mutation in the MMAA gene, which is essential for the proper functioning of a cofactor of the methylmalonyl-CoA mutase. The symptoms of the disease, depending on the cause, may manifest themselves at different ages. Most patients are sensitive to high doses of hydroxycobalamin, which is associated with better prognosis. MATERIAL AND METHOD: The purpose of the study was to retrospectively analyze the clinical picture and effects of treatment of patients with methylmalonic aciduria related to mutation in the MMAA gene. RESULTS: Five patients with diagnosed cblA - type MMA were presented. At the time of diagnosis the median of age was 18.8 months, but the symptoms had already appeared since infancy, as recurrent vomiting and delayed psychomotor development. Significant excretion of methylmalonic acid in urine and metabolic acidosis traits with significantly increased anionic gap were observed in all patients. All of them were sensitive to the treatment with vitamin B12. The median of therapy duration and observation is 12.2 years. During the treatment, good metabolic control was achieved in all patients, but their cognitive development is delayed. Three patients have renal failure and pharmacologically treated arterial hypertension. CONCLUSIONS: Patients with a mutation in the MMAA gene are sensitive to treatment with hydroxocobalamine, but the inclusion of appropriate treatment does not protect against neurodevelopmental disorders and chronic kidney disease.

Atrial function during different multisite atrial pacing modalities in patients with bradycardia--tachycardia syndrome.

BACKGROUND: Multisite atrial pacing (MAP) was introduced to improve atrial electrical synchrony and prevent recurrence of atrial fibrillation (AF). METHODS AND RESULTS: In the present study there were 57 patients with sinus node disease, AF recurrence and prolonged P-wave on ECG with 2 MAP modalities. In all patients 1 lead was implanted in the coronary sinus (CS) ostium area. In the right atrial appendage (RAA)+CS group (28 patients) the other atrial lead was in the RAA, and in the BB+CS group (29 patients) in the Bachmann's bundle (BB) region. Tissue Doppler was used to register the electromechanical delay (EMD) in the atrial walls and estimate the atrial contraction synchrony. Cardiac output and myocardial performance index did not differ during the 2 MAP modalities. During BB+CS, in comparison with RAA+CS pacing, the peak of the mitral atrial wave occurred earlier (P<0.01), the usual right-left atrial contraction sequence was reversed more frequently (P<0.004), all atrial EMDs except for the lateral left atrium (LA) were shorter (P<0.05), and LA synchrony was greater (P<0.001). CONCLUSIONS: In patients treated with MAP, implanting 1 of the atrial leads in the BB area instead of the RAA has no influence on global cardiac hemodynamics, but does result in earlier LA contraction, and reversal of the typical right-left atrial contraction sequence, as well as providing greater LA contraction synchrony.

Survival analysis in patients with preserved left ventricular function and standard indications for permanent cardiac pacing randomized to right ventricular apical or septal outflow tract pacing.

BACKGROUND: Optimal right ventricular (RV) pacing site in patients referred for permanent cardiac pacing remains controversial. A prospective randomized trial was done to compare long-term effect of permanent RV apex (RVA) vs RV outflow tract (RVOT) pacing on the all-cause and cardiovascular mortality. METHODS AND RESULTS: A total of 122 consecutive patients (70 men, 69 +/-11 years), with standard pacing indications were randomized to RVA (66 patients) or RVOT (56 patients) ventricular lead placement. After the 10-year follow-up period the mortality data were summarized on the basis of an intention-to-treat analysis. During the long-term follow-up, 31 patients from the RVA group died vs 24 patients in the RVOT group (hazard ratio (HR), 0.96; 95% confidence interval (CI), 0.57-1.65; P=0.89). There were 10 cardiovascular deaths in the RVA and 12 in the RVOT group (HR, 1.04; 95%CI, 0.45-2.41; P=0.93). There were no differences in the all-cause or cardiovascular mortality between the pacing sites after adjustment for age, gender, arterial hypertension, atrial fibrillation, New York Heart Association class and left ventricular end-diastolic diameter. CONCLUSIONS: The RVOT provides no additional benefit in terms of long-term survival over RVA pacing.

The LocaLisa system as the key to shortening the procedure duration and fluoroscopy time during ablation of atrial fibrillation.

BACKGROUND: Ablation of atrial fibrillation (AF) can be difficult and time-consuming. Systems facilitating catheter navigation may be helpful. AIM: To compare the efficacy of the LocaLisa system with the conventional mapping/ablation approach to radiofrequency (RF) ablation of AF. METHODS: Group 1, consisting of 64 patients (48 male; aged 51.5+/-10.6 years), underwent segmental isolation of the pulmonary veins with the Lasso catheter and the LocaLisa system. Group 2, consisting of 64 patients (44 male, aged 51.4+/-11.0 years), had RF ablation guided by means of a conventional fluoroscopy-based approach. Clinical and procedural data were analysed. RESULTS: Nine patients from group 1 and three patients from group 2 had persistent AF. In group 1 the mean number of isolated veins was 3.98+/-0.96, while in group 2 - 4.0+/-0.95 (NS). In group 1 cavotricuspid isthmus lines were created in four patients and lines in the roof of the left atrium in two patients. One patient needed slow pathway ablation. In group 2 six patients had ablation of the cavotricuspid isthmus and a line was created at the roof of the left atrium in one patient. Two patients had ectopic activity ablated in the crista terminalis. Procedure times were 131.6+/-40.3 and 170.0+/-56.5 min (p <0.0001) and fluoroscopy times were 16.93+/-9.7 and 35.66+/-12.7 min (p <0.0001) for groups 1 and 2, respectively. Long-term efficacy of RF ablation was similar in both groups (for example, complete success was achieved in 59% of patients using LocaLisa and 50% without using this system, NS). CONCLUSIONS: The LocaLisa navigation system makes it possible to shorten both the duration of the procedure and the total fluoroscopy time during ablation of AF.