Efficacy of Catheter Ablation Using the Electroanatomical System without the Use of Fluoroscopy in Patients with Ventricular Extrasystolic Beats.

BACKGROUND: Catheter ablation (CA) has become safe and efficient for the treatment of patients with ventricular extrasystolic beats (VEBs). The three-dimensional electroanatomic mapping (EAM) system allows the elimination of fluoroscopy time during CA procedures. Non-fluoroscopy CA is a challenging procedure requiring intimate knowledge of cardiac anatomy in patients with VEBs. The study aimed to evaluate the efficacy and safety of the non-fluoroscopy CA using the EAM system in patients with VEBs. METHODS: Completely fluoroless CA of VEBs guided by EAM was performed in 86% (94 out of 109) of consecutive patients with VEBs. The remaining 15 patients underwent conventional fluoroscopy-guided CA. Demographic and clinical baseline characteristics, procedure parameters, and following complications were obtained from the medical records. Primary outcomes were the acute procedural success rate, the permanent success rate (6-month follow-up), complications, and procedure time. RESULTS: There were no significant differences between groups regarding baseline characteristics. Acute procedural success was achieved in 85 patients (90%) in the non-fluoroscopy group and in 14 patients (93%) in the fluoroscopy group (ns). A long-term success rate was achieved in 82 patients (87%) in the non-fluoroscopy group and in 14 (82%) patients in the fluoroscopy group (ns). The median procedure time was 85 min in the non-fluoroscopy group and 120 min in the fluoroscopy group (p = 0.029). There was only one major complication in the non-fluoroscopy group (ns). CONCLUSIONS: Completely fluoroless CA of VEBs guided by EAM is a feasible, safe, and efficient procedure.

Sequential changes in cellular properties accompanying amniote somite formation.

Somites are transient structures derived from the pre-somitic mesoderm (PSM), involving mesenchyme-to-epithelial transition (MET) where the cells change their shape and polarize. Using Scanning electron microscopy (SEM), immunocytochemistry and confocal microscopy, we study the progression of these events along the tail-to-head axis of the embryo, which mirrors the progression of somitogenesis (younger cells located more caudally). SEM revealed that PSM epithelialization is a gradual process, which begins much earlier than previously thought, starting with the dorsalmost cells, then the medial ones, and then, simultaneously, the ventral and lateral cells, before a somite fully separates from the PSM. The core (internal) cells of the PSM and somites never epithelialize, which suggests that the core cells could be 'trapped' within the somitocoele after cells at the surfaces of the PSM undergo MET. Three-dimensional imaging of the distribution of the cell polarity markers PKCζ, PAR3, ZO1, the Golgi marker GM130 and the apical marker N-cadherin reveal that the pattern of polarization is distinctive for each marker and for each surface of the PSM, but the order of these events is not the same as the progression of cell elongation. These observations challenge some assumptions underlying existing models of somite formation.

Is Increased Resting Heart Rate after Radiofrequency Pulmonary Vein Isolation a Predictor of Favorable Long-Term Outcome of the Procedure?

Background: Increased resting heart rate (RHR) after pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF) is a common observation, possibly resulting from ganglionated plexus modification during ablation. Previous trials have suggested that an increase in RHR after ablation might be related to higher efficacy of the procedure. The aim of this study was to determine whether or not higher increase in RHR after radiofrequency (RF) PVI might predict better long-term outcome of the procedure in a real-life cohort of patients in whom index ablation for paroxysmal AF was performed. Material and methods: The health records of patients who underwent index point-by-point or drag lesion RF PVI for paroxysmal AF in our department between January 2014 and November 2018 were analyzed. Resting heart rate (RHR) was determined from 12-lead ECG recorded prior to the ablation and before discharge to evaluate changes in RHR after PVI. Only patients in sinus rhythm before the procedure and at discharge were included in the analysis. Telephone follow-up was collected for evaluation of arrhythmia recurrence status. Results: A total of 146 patients who underwent PVI for paroxysmal AF were included. Mean follow-up time was 3.5 years. RHR increased from 64 [58.5−70], prior to procedure, to 72 [64.25−80] bpm at discharge (p < 0.001). Higher increase in RHR was not protective from arrhythmia recurrence in long-term observation in both univariable HR = 1.001 (CI 0.99−1.017, p = 0.857) and multivariable analyses HR = 1.001 (CI 0.99−1.02, p = 0.84). Conclusions: RHR after PVI increased in comparison to baseline in our cohort. However, we did not observe higher increase in RHR to be associated with more favorable long-term effectiveness of the procedure.

Efficacy and Safety of Zero-Fluoroscopy Approach during Catheter Ablation of Accessory Pathway.

BACKGROUND: Catheter ablation (CA) is a safe and efficient treatment in patients with an atrioventricular accessory pathway (AP). Electroanatomical mapping (EAM) systems are useful during CA of AP, especially for reducing fluoroscopy. There are limited data about the feasibility of CA procedures performed with the use of the EAM system entirely without fluoroscopy in adults with AP. The aim of the study is to assess the feasibility, efficacy and safety of CA with the use of EAM without fluoroscopy, compared to CA with EAM and fluoroscopy in patients with AP. METHODS: The study included 83 consecutive patients (age 38.25 ± 15.8 years), who were subjected to CA for AP. In 40 patients CA was performed with the use of EAM without fluoroscopy (EAM group), and in 43 patients CA was performed with EAM and fluoroscopy (control group). Baseline characteristics, procedure parameters and complications were obtained from the medical records. Data on permanent success rate was obtained after the mean follow-up time of 1 year. Primary outcomes were acute procedural success rate, long term success rate at 1-year follow-up and complications. Secondary outcomes were the procedure time and number of applications. RESULTS: There were no statistically significant differences in baseline characteristics between the groups, except for the AP locations. Right-sided AP was more common in the EAM group, while left-sided AP was more common in the control group (p = 0.007 and p = 0.004, respectively). Acute procedural success was achieved in 38 patients (95.0%) in the EAM group and in 39 patients (90.7%) in the control group (p = 0.449). Long term success rate was achieved in 36 patients (90.0%) in the EAM group and in 36 (83.7%) patients in the control group (p = 0.399). There was one minor complication in the form of RBBB in the EAM group (p = 0.138). The mean procedure time was shorter in the EAM group compared to the control group (93.0 ± 58.3 min vs. 127.6 ± 57.5 min; p = 0.009). CONCLUSIONS: CA of both right-sided and left-sided AP completely guided by EAM without the use of fluoroscopy is feasible, safe and effective.

An assessment of heart rate and blood pressure asymmetry in the diagnosis of vasovagal syncope in females.

Introduction: Heart Rate Asymmetry (HRA) describes a phenomenon of differences between accelerations and decelerations in human heart rate. Methods used for HRA assessment can be further implemented in the evaluation of asymmetry in blood pressure variations (Blood Pressure Asymmetry-BPA). Methods: We have analyzed retrospectively the series of heartbeat intervals extracted from ECG and beat-to-beat blood pressure signals from 16 vasovagal patients (age: 32.1 ± 13.3; BMI: 21.6 ± 3.8; all female) and 19 healthy subjects (age: 34.6 ± 7.6; BMI: 22.1 ± 3.4; all female) who have undergone tilt test (70°). Asymmetry was evaluated with Poincaré plot-based methods for 5 min recordings from supine and tilt stages of the test. The analyzed biosignals were heart rate (RR), diastolic (dBP) and systolic Blood Pressure (sBP) and Pulse Pressure (PP). In the paper we explored the differences between healthy and vasovagal women. Results: The changes of HRA indicators between supine and tilt were observed only in the control group (Porta Index p = 0.026 and Guzik Index p = 0.005). No significant differences in beat-to-beat variability (i.e. spread of points across the line of identity in Poincaré plot-SD1) of dBP was noted between supine and tilt in the vasovagal group (p = 0.433 in comparison to p = 0.014 in healthy females). Moreover, in vasovagal patients the PP was significantly different (supine: 41.47; tilt: 39.27 mmHg) comparing to healthy subjects (supine: 35.87; tilt: 33.50 mmHg) in supine (p = 0.019) and in tilt (p = 0.014). Discussion: Analysis of HRA and BPA represents a promising method for the evaluation of cardiovascular response to orthostatic stressors, however currently it is difficult to determine a subject's underlying health condition based only on these parameters.

Cellular aspects of somite formation in vertebrates.

Vertebrate segmentation, the process that generates a regular arrangement of somites and thereby establishes the pattern of the adult body and of the musculoskeletal and peripheral nervous systems, was noticed many centuries ago. In the last few decades, there has been renewed interest in the process and especially in the molecular mechanisms that might account for its regularity and other spatial-temporal properties. Several models have been proposed but surprisingly, most of these do not provide clear links between the molecular mechanisms and the cell behaviours that generate the segmental pattern. Here we present a short survey of our current knowledge about the cellular aspects of vertebrate segmentation and the similarities and differences between different vertebrate groups in how they achieve their metameric pattern. Taking these variations into account should help to assess each of the models more appropriately.

A mechanical model of early somite segmentation.

Somitogenesis is often described using the clock-and-wavefront (CW) model, which does not explain how molecular signaling rearranges the pre-somitic mesoderm (PSM) cells into somites. Our scanning electron microscopy analysis of chicken embryos reveals a caudally-progressing epithelialization front in the dorsal PSM that precedes somite formation. Signs of apical constriction and tissue segmentation appear in this layer 3-4 somite lengths caudal to the last-formed somite. We propose a mechanical instability model in which a steady increase of apical contractility leads to periodic failure of adhesion junctions within the dorsal PSM and positions the future inter-somite boundaries. This model produces spatially periodic segments whose size depends on the speed of the activation front of contraction (F), and the buildup rate of contractility (Λ). The Λ/F ratio determines whether this mechanism produces spatially and temporally regular or irregular segments, and whether segment size increases with the front speed.

Direct results of a prospective randomized study comparing ablation with the nMARQ catheter and the PVAC catheter used with and without a 3D system (MAPER 3D Study).

INTRODUCTION: Our aim was to compare in a prospective randomized study the safety, direct results and periprocedural data of ablation using an nMARQ catheter, a PVAC catheter used with the EnSite system, or a PVAC catheter only under fluoroscopy control. MATERIAL AND METHODS: One hundred two patients (70 male, 57 ±11 years) with atrial fibrillation (AF) were prospectively randomized to: group 1 - ablation performed with an nMARQ catheter and the CARTO 3 system; group 2 - a PVAC catheter used with the EnSite system; group 3 - ablation with a PVAC catheter without a 3D system. RESULTS: Complete isolation of 400/402 pulmonary veins (PV) (99.5%). Linear ablation was performed in 23 patients in group 1 (small distance between lines isolating PV), in 3 patients in group 2, in 1 patient in group 3. The superior vena cava was isolated in 1 patient, 9 patients, and 9 patients respectively. Duration of fluoroscopy and dose area product were significantly smaller in group 1 (6.5 ±2.9 min/808.8 ±393.9 cGy/cm2 vs. 13.6 ±5.6 min/1662.6 ±677.8 cGy/cm2 and 18.8 ±7.6 min/2327.9 ±975.5 cGy/cm2; p < 0.001). Procedure duration was shorter in group 1 (82.9 ±18.8 min vs. 101.2 ±19.6 min, p < 0.001 and 99.8 ±20.8 min, NS). Contrast injection was necessary in 2 patients in group 1, in 8 patients in group 2 and in all patients in group 3. Because nMARQ is a thermocool catheter, the volume of fluid injection was significantly greater (2348.5 ±543.5 ml vs. 1077.9 ±280.5 ml and 1076.5 ±375.6 ml, p < 0.001). There were no periprocedural deaths. We observed no cardiac tamponade, neurological complications and no atrioesophageal fistula during follow-up. CONCLUSIONS: The lowest radiological exposure was observed during ablation performed with an nMARQ catheter. 3D systems reduced fluoroscopy duration and the necessity of contrast injection. The nMARQ catheter requires injection of a large volume of fluid.

Transfer Information Assessment in Diagnosis of Vasovagal Syncope Using Transfer Entropy.

The paper presents an application of Transfer Entropy (TE) to the analysis of information transfer between biosignals (heart rate expressed as R-R intervals (RRI), blood pressure (sBP, dBP) and stroke volume (SV)) measured during head up tilt testing (HUTT) in patients with suspected vasovagal syndrome. The study group comprised of 80 patients who were divided into two groups: the HUTT(+) group consisting of 57 patients who developed syncope during the passive phase of the test and HUTT(-) group consisting of 23 patients who had a negative result of the passive phase and experienced syncope after provocation with nitroglycerin. In both groups the information transfer depends on the phase of the tilt test. In supine position the highest transfer occurred between driver RRI and other components. In upright position it is the driver sBP that plays the crucial role. The pre-syncope phase features the highest information transfer from driver SV to blood pressure components. In each group the comparisons of TE between different phases of HUT test showed significant differences for RRI and SV as drivers.

Effectiveness comparison of various atrial fibrillation ablation methods in patients with common venous trunk.

BACKGROUND: Atrial fibrillation (AF) is a common clinical problem. The left atrium anatomy makes up a factor that may significantly affect the effectiveness of the AF ablation. OBJECTIVES: The aim of the study was to evaluate a long-term effectiveness ablation in patients with common pulmonary vein trunk (CPVT) and AF. MATERIAL AND METHODS: The outcomes of 129 procedures in 95 patients with CPVT out of 1,475 procedures carried out in 1,150 patients with AF treated with ablation, were analyzed. Ablation with CARTO 3 system (Johnson & Johnson, New Brunswick, USA), cryoballoon, and the circular multipolar duty-cycled radiofrequency-based pulmonary vein ablation producer with catheter (PVAC) were considered as advanced methods. The following data was recorded for every patient: age, gender, AF duration and type, previous antiarrhythmic drugs, weight, height, any prior cardioversion, and comorbidities, including hypertension, diabetes, hypothyreosis, thyrotoxicosis, heart failure, and stroke/transient ischemic attack. The following anatomical factors were assessed: the presence of patent foramen ovale (PFO) and localization of the CPVT on the basis of venography or computed tomography (CT). In the 1st year after ablation, 24-h Holter monitoring was performed 3-5 times, and the patients were encouraged to visit their doctor or an emergency department if a cardiac arrhythmia occurred. Long-term ablation effectiveness was assessed based on a telephone interview and patients' answers to the questionnaires including 12-lead electrocardiography (ECG). RESULTS: Sinus rhythm was maintained in 44 patients (43.6 %) after a median of 42 months (range 12-120). A lower number of clinical factors (odds ratio [OR] range 0.09; 95% confidence interval [CI] 0.02-0.56; p < 0.01), and advanced ablation methods (OR 3.1; 95% CI 1.4-7.1; p < 0.01) were related to a better longterm effectiveness. CONCLUSIONS: The long-term effectiveness of pulmonary vein (PV) isolation in patients with AF and CPVT is higher when advanced ablation techniques are used. Accumulation of clinical factors was found to be the most tremendous predictor of AF recurrence.

The complexity of hemodynamic response to the tilt test with and without nitroglycerine provocation in patients with vasovagal syncope.

The paper presents a comparison of vasovagal syndrome occurrence in a head up tilt table test between patients with a positive result of passive tilt test and those with a positive result after pharmacological provocation. The study group consisted of 80 patients: 57 patients who experienced syncope in the passive phase of the test (43 women (aged: 35.6 ± 16.2) and 14 men (aged: 41.7 ± 15.6) and 23 patients who experienced syncope after pharmacological provocation (17 women (age: 32.3 ± 12) and 6 men (age: 43 ± 15). The main investigation was based on the assessment of monitored signals complexity: heart rate, blood pressure and stroke volume. The analysis of complexity in chosen measurement phases was performed with Sample Entropy. The investigation showed that the reactions of autonomic nervous system during tilt test and before syncope are similar for positive result of passive tilt test and positive result of tilt test with provocation. The differences in supine position occurred only in analysis based on impedance measurement (SV: p = 0.01). Significant differences were denoted for all signals just before the syncope (RRI, sBP, dBP: p = 0,00001 and SV: p = 0.01). In analysis of signals complexity the significant differences occurred just before the syncope for Sample Entropy of blood pressure (SampEn (sBP): p = 0.0008, SampEn (dBP): p = 0,0001).

Entropy Measures in Analysis of Head up Tilt Test Outcome for Diagnosing Vasovagal Syncope.

The paper presents possible applications of entropy measures in analysis of biosignals recorded during head up tilt testing (HUTT) in patients with suspected vasovagal syndrome. The study group comprised 80 patients who developed syncope during HUTT (57 in the passive phase of the test (HUTT(+) group) and 23 who had negative result of passive phase and developed syncope after provocation with nitroglycerine (HUTT(-) group)). The paper focuses on assessment of monitored signals' complexity (heart rate expressed as R-R intervals (RRI), blood pressure (sBP, dBP) and stroke volume (SV)) using various types of entropy measures (Sample Entropy (SE), Fuzzy Entropy (FE), Shannon Entropy (Sh), Conditional Entropy (CE), Permutation Entropy (PE)). Assessment of the complexity of signals in supine position indicated presence of significant differences between HUTT(+) versus HUTT(-) patients only for Conditional Entropy (CE(RRI)). Values of CE(RRI) higher than 0.7 indicate likelihood of a positive result of HUTT already at the passive phase. During tilting, in the pre-syncope phase, significant differences were found for: (SE(sBP), SE(dBP), FE(RRI), FE(sBP), FE(dBP), FE(SV), Sh(sBP), Sh(SV), CE(sBP), CE(dBP)). HUTT(+) patients demonstrated significant changes in signals' complexity more frequently than HUTT(-) patients. When comparing entropy measurements done in the supine position with those during tilting, SV assessed in HUTT(+) patients was the only parameter for which all tested measures of entropy (SE(SV), FE(SV), Sh(SV), CE(SV), PE(SV)) showed significant differences.

Safety and efficacy of cryoablation without the use of fluoroscopy.

BACKGROUND: Development of electroanatomical systems make it possible to perform ablations without the use of fluoroscopy. The aim of this study was to evaluate the efficacy and safety of cryoablation pro-cedures without the use of fluoroscopy. METHODS: The study group consisted of 45 patients (14 female; age 36 ± 15 years) treated with cry-oablation using the EnSite electroanatomical system: 10 with ventricular extrasystoly from the right ventricle, 6 with the arrhythmogenic site near the left coronary artery, 17 patients with Wolff-Parkinson- -White syndrome (WPW), 2 patients with atrioventricular nodal reentrant tachycardia (AVNRT) type 2, 7 patients with AVNRT type 1, 3 patients with atrial tachycardia. RESULTS: In 38 of the 45 patients (84%) cryoablation procedure was performed without the use of fluoroscopy. Cryoablation efficacy was 78.9%. In 5 patients unsuccessful cryoablation was fallowed by radiofrequency applications. Finally, efficacy reached 92.1%. There were no deaths. In 1 patient a small adverse event - right bundle branch block was observed after ablation of para-Hisian accessory path-way. No other adverse events were observed. In the long term follow-up efficacy was 89.5%. CONCLUSIONS: Cryoablation using electroanatomical system without the use of fluoroscopy is a safe and efficient procedure and it is a possible alternative in most patients qualified for cryoablation.

Catheter ablation of cardiac arrhythmias in pregnancy without fluoroscopy: A case control retrospective study.

BACKGROUND: Cardiac arrhythmias are common in pregnant women. In most cases, they do not require treatment other than rest, electrolyte supplementation and avoidance of strong coffee and tea. Persistent arrhythmia or the ventricular rate running at a high frequency may cause hemodynamic deterioration in the fetus or in both the fetus and the mother. OBJECTIVES: The aim of this study was to assess the prevalence and characteristics of arrhythmias in pregnant women who qualified for ablation as well as the feasibility and specific features of these interventions. MATERIAL AND METHODS: The study group consisted of 11 pregnant women (16-32 Hbd) aged 31 + 6. The control group consisted of 111 women aged 15-50 years (34 + 10), scheduled for ablation in 2012. The medical records of the selected study and control groups were analyzed and the following data was retrieved: age, the reason the ablation procedure was performed, the ablation duration, the number of radiofrequency applications, the total duration of radiofrequency applications, gravity, and comorbidities. RESULTS: In the study group, accessory pathway related arrhythmias or atrial tachycardia (AT) accounted for 62% of cases, whereas in the control group for 32% (p = 0.042). All the procedures in the study group were performed with an electroanatomical system without fluoroscopy. All of the patients, but one, had no recurrence of arrhythmia. There were no complications and no overt effects were noted in the fetus. CONCLUSIONS: Ablation of arrhythmias during pregnancy is rare. An experienced surgeon using electroanatomical system is usually able to ablate arrhythmic substrate without the use of X-ray fluoroscopy. The most prevalent causes of arrhythmias in pregnant women requiring ablation are accessory pathway and AT focus.

The 4q25, 1q21, and 16q22 polymorphisms and recurrence of atrial fibrillation after pulmonary vein isolation.

INTRODUCTION: The efficacy of pulmonary vein isolation (PVI) in atrial fibrillation (AF) is well documented. Several single nucleotide polymorphisms (SNPs) are associated with AF, mainly in the 4q25 locus, but also in 16q22 and 1q21. The aim of our study was to test the association between those SNPs and short- and long-term results of PVI. MATERIAL AND METHODS: Patients with AF who underwent PVI between 2006 and 2009 were included in the study. Pulmonary vein isolation was performed using a 4-mm non-irrigated ablation catheter, circular mapping catheter, and the LocaLisa system. All patients were genotyped for the 4q25, 16q22, and 1q21 SNPs. RESULTS: Two-hundred and thirty-eight patients were included. The median follow-up was 45 months. Six-month efficacy was 59.7%. None of the polymorphisms was linked with the risk of AF recurrence after 6 months in univariate analysis. In multivariate analysis rs2200733 in the recessive model was linked significantly with AF recurrence (odds ratio 1.87, p = 0.008). None of the polymorphisms predicted AF recurrence in long-term follow-up. CONCLUSIONS: There is a trend in the relationship between TT genotype of the rs2200733 polymorphism and increased rate of AF recurrence after PVI in short-term (6 months) follow-up. None of the tested SNPs 4q25, 16q22, and 1q21 correlated with the results of a single AF ablation in long-term follow-up.

Multiple roles of timing in somite formation.

During development, vertebrate embryos produce serially repeated elements, the somites, on each side of the midline. These generate the vertebral column, skeletal musculature and dermis. They form sequentially, one pair at a time, from mesenchymal tissue near the tail. Somite development is a complex process. The embryo must control the number, size, and timing of somite formation, their subdivision into functional regions along three axes, regional identity such that somites develop in a region-specific way, and interactions with neighbouring tissues that coordinate them with nearby structures. Here we discuss many timing-related mechanisms that contribute to set up the spatial pattern.

Antazoline for termination of atrial fibrillation during the procedure of pulmonary veins isolation.

PURPOSE: Pulmonary vein isolation is a well established method of definite treatment of atrial fibrillation (AF). Periprocedural onset of AF usually terminates spontaneously within minutes, but not in all cases. Antazoline is an antihistaminic agent with antiarrhythmic properties. The aim of our retrospective study was to evaluate the efficacy of antazoline in termination of AF in patients undergoing pulmonary vein isolation. MATERIALS AND METHODS: Consecutive 141 patients who received antazoline to terminate AF during pulmonary vein isolation were analyzed. The antazoline was administered at the rate of 30-50mg/min (max. 500mg) after the circumferential ablation in the ostia of pulmonary veins and before confirmation of isolation. Success was defined as restoration of sinus rhythm within 20min after antazoline infusion. RESULTS: The efficacy of antazoline was 83.6% in paroxysmal and 31.1% in persistent AF patients. Clinical variables that were independently predictive of antazoline ineffectiveness were female (odds ratio [OR]: 4.35; 95% confidence interval [CI]: 1.26-14.3; p=0.018) and AF at the beginning of procedure (OR 28.4; 95% CI 3.89-208.0; p=0.001). Due to antazoline related side effects infusion was discontinued in 7 patients (5%). CONCLUSIONS: Antazoline seems to be safe agent in termination of AF in patients undergoing pulmonary vein isolation. We also observed satisfying efficacy, which needs to be proved in a randomized clinical trial.

Members of the emergency medical team may have difficulty diagnosing rapid atrial fibrillation in Wolff-Parkinson-White syndrome.

BACKGROUND: Atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome is potentially life-threatening as it may deteriorate into ventricular fibrillation. The aim of this study was to assess whether the emergency medical team members are able to diagnose AF with a rapid ventricular response due to the presence of atrioventricular bypass tract in WPW syndrome. METHODS: The study group consisted of 316 participants attending a national congress of emergency medicine. A total of 196 questionnaires regarding recognition and management of cardiac arrhythmias were distributed. The assessed part presented a clinical scenario with a young hemodynamically stable man who had a 12-lead electrocardiogram performed in the past with signs of pre-excitation, and who presented to the emergency team with an irregular broad QRS-complex tachycardia. RESULTS: A total of 71 questionnaires were filled in. Only one responder recognized AF due to WPW syndrome, while 5 other responders recognized WPW syndrome and paroxysmal supraventricular tachycardia or broad QRS-complex tachycardia. About 20% of participants did not select any diagnosis, pointing out a method of treatment only. The most common diagnosis found in the survey was ventricular tachycardia/broad QRS-complex tachycardia marked by approximately a half of the participants. Nearly 18% of participants recognized WPW syndrome, whereas AF was recognized by less than 10% of participants. CONCLUSIONS: Members of emergency medical teams have limited skills for recognizing WPW syndrome with rapid AF, and ventricular tachycardia is the most frequent incorrect diagnosis.