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An isoproterenol infusion was administered during an electrophysiologic study (EPS) in a patient with a history of near syncope, left bundle branch block, and no documented atrioventricular (AV) block. Isoproterenol precipitated classic 2:1 Infra-Hisian AV block most probably proximal to the site of recording a His-Purkinje potential consistent with right bundle branch activity. Paroxysmal AV block also occurred during isoproterenol washout at a different site located distal to the presumed right bundle branch potential. Isoproterenol may be valuable diagnostically in an occasional patient suspected of AV block in whom an EPS is unrevealing and a drug challenge is negative.

Background Atrial electrical conduction properties have been implicated in atrial fibrillation (AF) pathogenesis. Objective The purpose of this study was to prospectively assess the potential association of interatrial conduction time (IACT) with incident AF. Methods The study included persons referred for invasive electrophysiologic study (EPS), aged ≥50 years, without AF history or valvular disease. IACT was defined as the interval between the high right atrium electrogram and the distal coronary sinus atrial electrogram. Results Six hundred twelve subjects were included (median follow-up 43 months, interquartile range 40–47). AF incidence was 21.7 cases per 1000 person-years. IACT was a significant predictor of AF with a c -statistic of 0.770 (95% confidence interval 0.702–0.838). In time-dependent analysis, IACT was a significant stratifier of AF risk (log-rank 28.0, P Conclusion IACT is independently associated with incident AF. The invasive nature of the measurement is a limitation for its use as a clinical risk stratifier (although it could be used in patients referred for EPS), but these results are of interest in themselves because they suggest a strong pathophysiologic connection between atrial conduction times and substrate alterations ultimately leading to AF.

International audience; The aim of study was to report different and unusual patterns of preexcitation syndrome (PS) noted in patients referred for studied for poorly-tolerated arrhythmias and their frequency. Electrophysiologic study (EPS) is an easy means to identify a patient with PS at risk of serious events. However the main basis for this diagnosis is the ECG which associates short PR interval and widening of QRS complex with a delta wave.METHODS:ECGs of 861 patients in whom PS related to an atrioventricular accessory pathway (AP) was identified at electrophysiological study (EPS), were studied.RESULTS:The most frequent unusual presentation (9.6%) was the PS presenting with a normal or near normal ECG, noted preferentially for left lateral AP and rarely for posteroseptal or right lateral location. More exceptional (0.1%) was the presence of a long PR interval, which did not exclude a rapid conduction over AP. The association of a complete AV block with symptomatic tachycardias was exceptional (0.3%) and was shown related to a rapid conduction over AP after isoproterenol. Most of the presented patients were at high-risk at EPS.CONCLUSION:The diagnosis of PS is not always evident and symptoms should draw attention to minor abnormalities and lead to enlarge indications of EPS, only means to confirm or not PS.

Objective Unexplained syncope is a challenge facing electrophysiologists. The prognosis varies widely depending on underlying causes, specially, cardiac ones. We sought to determine the abnormal electrophysiolgic (EP) study results as predictors of prognosis in syncope patients with suspected cardiac cause and risk factors associated with mortality. Methods A total of 227 consecutive patients with unexplained syncope were prospectively enrolled in this study. EP study was performed in 177 patients in base of inclusion criteria. These patients, in whom a cardiac cause of syncope was suspected, underwent EP study and if negative, head-up tilts test (HUTT). Complete follow-up was obtained for 132 patients for 20.0±10.8 months. Results A cardiac cause of syncope was established in 35%, a neurally mediated syncope in 35.6%, and in the rest 29.4% the cause of syncope remained unexplained despite a throughout neurologic and cardiologic evaluation. Logistic analysis revealed that the significant predictors of a cardiac cause of syncope were the absence of prodromal symptoms, left bundle branch block (LBBB), sever left ventricle (LV) dysfunction and male gender. At logistic analysis, the presence of LBBB (OR=6.63; 95% CI: 1.09-40) was significantly associated with outcome of death. Conclusion The present study provides evidence that presence of LBBB, abnormal EP study result and structural heart disease (SHD) have prognostic value in patients with suspected cardiac cause of syncope. The patients with SHD and unexplained syncope who had a negative EP study have a good long-term prognosis even in the presence of LV dysfunction.

In order to evaluate the possibilities of MRI in detection of proarrhytmogenic areas of myocardium we did compare directly and quantitatively the local myocardial uptake of paramagnetics to the results of electrophysiologic study of myocardium in twenty-two patients with recent transmural myocardial infarction and frequent ventricular extrasystoles verified by ECG studies.Topic quantitative study of myocardial electric potential has been carried out using Carto XP system (by Biosense Webster).By analysis of the images the measurement of Index of transmurality (IT) for the contrast uptake was calculated as ratio of thickness of paramagnetic uptake to overall thickness of myocardium in a specific segment.The the electrophysiologic and MRI data were analyzed topically as segment vs segment and the significant tendency was revealed with simultaneous grow of pro-arrhythmogenic activity and value of IT. In other words, as bigger the IT increases, as arrhythmogenic the lectrical activity becomes. The best border value of IT that provided separation of electrically normal segments from proarrhythmogenic ones was the IT = 0.3.Therefore we conclude the contrast-enhanced MRI of myocardium deliver additional information on risk of arrhythmias, not only the detection of myocardial damage itself.

Introduction: We investigated electrophysiological properties of the entire right ventricular (RV) endocardium of provoked ventricular tachycardia/ventricular fibrillation (VT/VF) in 2 patients with Brugada syndrome (BS). Methods: N/A. Results: Case 1. Type 3 Brugada type ECG which changed to type 1 ECG by class Ic antiarrhythmic drug, pilsicainide. Electrophysiologic study (EPS): Double ventricular premature stimuli from RVOT (600/260/200 ms) induced VF. The multielectrode array (Ensite, St. Jude Medical) was placed at the right ventricular outflow tract (RVO) and VF was induced again from RVOT (600/224/180 ms). Non-contact mapping during organized rapid VT before degenerating into VF showed that provoked VT arose from RVOT. Case 2: Type 1 Brugada type ECG. EPS: Triple ventricular premature stimuli from RV apex (600/250/220/200 ms) reproducibly induced VF. Non-contact mapping during organized rapid VT showed that provoked VT arose from RV free wall. Conclusion: RVOT and RV free wall appears to be crucial in the initiation and maintenance of VT with degeneration into VF in BS.

Syncope in the setting of infra-hisian block (HVB) is an indication for permanent pacemaker (PPM). However, not all HVB uncovered during electrophysiologic study (EPS) requires a PPM. A 39 year old woman presented with non-prodromal loss of consciousness while driving resulting in an accident.

ObjectiveThe objective of this study was to evaluate the efficacy of a novel approach for endocardectomy during coronary artery bypass graft with surgical ventricular restoration in patients with postinfarction left ventricular aneurysm.MethodsOne hundred sixty-eight patients underwent coronary artery bypass graft with surgical ventricular restoration from 2005 to 2011. Endocardectomy was performed as an integral part of surgical ventricular restoration for the prevention of ventricular tachycardia. The experimental group (surgical ventricular restoration–endocardectomy group; n = 74) underwent preoperative electrophysiologic study with electroanatomic left ventricular mapping. Radiofrequency ablation-induced markings were placed and were used later as guides for performing endocardectomy during coronary artery bypass graft with surgical ventricular restoration. The control group (surgical ventricular restoration group; n = 94) underwent surgical ventricular restoration without endocardectomy.ResultsThe 1-year mortality rates in the surgical ventricular restoration–endocardectomy and surgical ventricular restoration (control) groups were 5% and 13%, respectively. During the postoperative period, 3% of patients in the surgical ventricular restoration–endocardectomy group and 38% of patients in the surgical ventricular restoration group experienced ventricular tachycardia events (P

Propriospinal myoclonus is a rare movement disorder that is hypothesized to arise from a spinal generator that transmits activity up and down the spinal cord via long propriospinal pathways. Polymyography is mandatory for the diagnosis, but the typical electrophysiological pattern described for propriospinal myoclonus has been also found in patients with psychogenic axial jerks, supported by the presence of a Bereitschaftspotential (BP; from German, "readiness potential," also called the premotor potential). We evaluated polymyographic findings in 65 patients referred to us with a clinical diagnosis of propriospinal myoclonus and also looked for the presence of the BP, as detected by jerk-locked back-averaging. At clinical reassessment by a movement disorder specialist, nearly one-half of the patients had clinical clues suggestive of a psychogenic cause of the jerks. Electrophysiological studies were carried out on all 65 patients. Polymyography findings revealed an incongruent electromyographic pattern for propriospinal myoclonus in 84.6% of patients and the presence of the BP in 86.1% of the entire cohort. When taking into account either the presence of BP and/or incongruence of polymyographic features, all patients, including the approximately 50% clinically diagnosed as organic propriospinal myoclonus by a movement disorder expert, had strong neurophysiological evidence for a psychogenic origin of their jerks. The clinical distinction of propriospinal myoclonus from psychogenic axial jerks is unreliable. This is the largest cohort of patients with axial jerks reported so far and we suggest that most of the patients with a clinical picture that clinically resembles propriospinal myoclonus are likely to be psychogenic.

Background and Objectives Ventricular fibrillation (VF) can inadvertently occur during electrophysiologic study (EPS) or catheter ablation. We investigated the incidence, cause, and progress of inadvertently developed VF during EPS and catheter ablation. Subjects and Methods We reviewed patients who had developed inadvertent VF during EPS or catheter ablation. Patients who developed VF during programmed ventricular stimulation to induce ventricular tachycardia or VF were excluded. Results Inadvertent VF developed in 11 patients (46.7±9.3 years old) among 2624 patients (0.42%); during catheter ablation for atrial fibrillation (AF) in nine patients, frequent ventricular premature beats (VPBs) in one, and Wolff-Parkinson-White (WPW) syndrome were observed in one. VF was induced after internal cardioversion in six AF patients due to incorrect R-wave synchronization of a direct current shock. Two AF patients showed spontaneous VF induction during isoproterenol infusion while looking for AF triggering foci. The remaining AF patient developed VF after rapid atrial pacing to induce AF, but the catheter was accidentally moved to the right ventricular (RV) apex. A patient with VPB ablation spontaneously developed VF during isoproterenol infusion. The focus of VPB was in the RV outflow tract and successfully ablated. A patient with WPW syndrome developed VF after rapid RV pacing with a cycle length of 240 ms. Single high energy (biphasic 150-200 J) external defibrillation was successful in all patients, except in two, who spontaneously terminated VF. The procedure was uneventfully completed in all patients. At a mean follow-up period of 17.4±15.5 months, no patient presented with ventricular arrhythmia. Conclusion Although rare, inadvertent VF can develop during EPS or catheter ablation. Special caution is required to avoid incidental VF during internal cardioversion, especially under isoproterenol infusion.

Objective The aim was to evaluate the effects of a new folkloric medicinal plant extract on peripheral nerve function compared with oxidized regenerated cellulose (OC) and bovine collagen (BC). Study Design Under ketamine anesthesia a total of 40 male Sprague-Dawley rat right sciatic nerves were identified. Animals were randomly divided into 5 groups: OC, BC, ankaferd blood stopper (ABS), and negative and positive control groups. The recordings of nerve potentials were carried out using an electrophysiologic data acquisition system. After the application of substances, the nerve conduction velocity (NCV) was recorded for immediate (30 min), early (120 min), and delayed (3 wk) effects on nerve function. Results Statistically, differences were not found among the hemostatic agents (OC, BC, and ABS) at baseline and all tested periods (early, immediate, and delayed; P > .05). The positive control group exhibited lower NCV values compared with the other solutions at the 30-minute period ( P P > .05). OC exhibited NCV values closer to the positive control group at 120 minutes ( P > .05). Conclusions Folkloric medicinal hemostatic agent could be considered as an acceptable hemostatic material without resulting in any serious peripheral nerve function alterations. The possible desirable effects of bovine collagen and undesirable effects of oxidized cellulose on peripheral nerve function should not be overlooked.

Background Non-documented palpitations, or phantom tachycardias, are palpitations deemed to be of unknown origin after evaluation with conventional diagnostic tools, such as 12-lead electrocardiogram and Holter recordings. Our aim was to determine the diagnostic value of an electrophysiologic study (EPS) and its role in the management of patients presenting with non-documented palpitations. Methods We performed EPS in 78 consecutive patients with repeatable, poorly tolerated symptoms of paroxysmal, non-documented tachycardia, the absence of structural heart disease and at least one 24-h Holter recording. The duration and frequency of palpitations was registered in each patient. Results Long-lasting palpitations (>1 hour) were present in 15.4% of patients. Half of patients reported symptoms less often than once per week. Only 13/78 patients (16.6%) had normal EPS findings, while dual pathways at the AV node ± echo beats were identified in another 13 patients without inducible tachycardia. At least one tachycardia event was induced in 52 patients (66.6%). AVNRT was provoked in 32 patients (41.2%). Ablation was performed in 14/52 patients with inducible tachycardia (26.9%). Slow pathway ablation was also performed in three patients with dual AV pathways and atrial echo-beats but without provoked tachycardia. Follow-up data were available in 52 patients, and 84.6% had fewer or no clinical recurrences. Conclusions EPS is safe and of enhanced diagnostic value in patients with unexplained palpitations because only 1/6 had negative results. EPS also provided an explanation about the mechanism of arrhythmia and successfully guided the management of these patients, as well as enhanced improvement in the quality of life.

The purpose of this study was to evaluate electrophysiologic study (EPS) in risk stratification of relative indications for pacemaker implantation (PMI) after transcatheter aortic valve implantation (TAVI).We reviewed files of all patients who had a left bundle branch block (LBBB) and underwent EPS after TAVI between 3/2009 and 5/2015. The indications for EPS were new-onset LBBB and the presence of an old or a new-onset LBBB associated with either PR prolongation after TAVI (∆PR20 ms) or with "slow" atrial fibrillation (100/min). Pacemakers were implanted when significant infranodal disease was demonstrated. The control group comprised of 55 consecutive patients who underwent TAVI and had an indication for an EPS per our definitions. These patients were discharged without further intervention. All patients were followed during 1 year for the composite endpoint of mortality or PMI after hospital discharge.Indications for EPS were new LBBB (n = 8, 30.8%), new LBBB + ∆PR20 ms (n = 9, 34.6%), baseline LBBB + ∆PR20 ms (n = 7, 26.9%) and new LBBB + slow AF100 bpm (n = 2, 7.7%). Multilevel conduction disturbances involving the AV node (n = 19, 73.1%), the His (n = 3, 11.5%), and the infra-His system (n = 4, 15.4%) were found. Post discharge, there were 5 (9%) deaths and 3 (5.5%) PMI in the control group compared to none in the EPS group corresponding to event-free survival of 85 and 100%, respectively (p = 0.04).Patients with LBBB with or without ∆PR20 ms are at a higher risk of mortality and late PMI at 1-year follow-up. EPS can be used to safely identify patients in whom a PMI is needed.

International audience; Background: With ablation, the follow-up of preexcitation syndrome now is difficult to assess. The purpose was to collect data of children with a preexcitation syndrome studied on two separate occasions within a minimal interval of 1 year.Methods: This is a retrospective chart review of 47 children initially aged 12 ± 4 years, who underwent two or more invasive electrophysiological studies (EPS) within 1-25 years of one another (6.3 ± 4.8) for occurrence of symptoms or new evaluation.Results: Among initially symptomatic children (n = 25), four (19%) became asymptomatic and one presented life-threatening arrhythmia. Among asymptomatic children (n = 22), five became symptomatic (22.7%). Anterograde conduction disappeared in seven of 23 children with initially long accessory pathway-effective refractory period, but four of six had still induced atrioventricular reentrant tachycardia (AVRT). AVRT was induced at second EPS in three of 13 asymptomatic preexcitation syndrome with negative initial EPS. There were no spontaneous adverse events in the five children with criteria of malignancy at initial EPS; signs of malignancy disappeared in two. At multivariate analysis, AVRT at initial EPS was the only independent factor of symptomatic AVRT during follow-up. Absence of induced AVRT at initial EPS was the only factor of absence of symptoms and a negative study at the second EPS.Conclusions: There were no significant changes of data in children after 6.3 ± 4.8 years of follow-up. Most children with spontaneous/inducible AVRTs at initial EPS had still inducible AVRT at second EPS. Induced AF conducted with high rate has a relatively low prognostic value for the prediction of adverse events.

This article discusses the merits of electrophysiology study (EPS) and/or ablation for asymptomatic preexcitation Wolff-Parkinson-White (WPW) ECG pattern. Sudden deaths in asymptomatic patients are too few to merit broad screening and aggressive intervention. It also discusses the risks of ablation and the low predictive accuracy of EPS. When WPW is an incidental finding, the decision to proceed with investigation and ablation can be made considering patients' situations and preferences. An invasive strategy is targeted at patients concerned about the low risk of life-threatening arrhythmia as a first presentation after a discussion of the risks and benefits.

Electrocardiographic tracings of an English Bulldog referred for cardiogenic shock due to an orthodromic atrioventricular reciprocating tachycardia conducted with intraventricular conduction disturbance and mimicking ventricular tachycardia (VT) are presented. At admission the surface ECG showed a wide QRS complex tachycardia (WCT) that was converted to sinus rhythm using manual cardioversion (chest thump). This change revealed pre-existing right bundle branch block, and a final diagnosis of supraventricular tachycardia (SVT) with intraventricular conduction disturbance was made. Electrophysiologic study defined the SVT mechanism as an atrioventricular macroreentrant tachycardia mediated by a single mid-septal accessory pathway. The differentiation between various types of WCT is essential when antiarrhythmic therapy is considered. The surface ECG should be systematically evaluated in order to recognize the characteristic features of SVT and VT. Moreover chest thump procedure can be very helpful in the attempt to convert the rhythm to sinus rhythm and to correctly recognize the underlying arrhythmia. © 2012 Elsevier Ltd. All rights reserved.

Background and Objective Among patients with Brugada syndrome (BS) and aborted cardiac arrest, syncope, or inducible ventricular fibrillation at electrophysiologic study (EPS), the only currently recommended therapy is an implantable cardioverter-defibrillator (ICD), but these are not without complications. We assessed the total number of shocks (appropriate and inappropriate) and complications related to ICD in patients with BS. Methods and Results Twenty-five patients implanted with ICD for BS in 6 Gulf centers between January 1, 2002, and December 31, 2010, were reviewed. Implantable cardioverter-defibrillator indication was based on aborted cardiac arrest (24%), syncope (56%), or in asymptomatic patients with positive EPS (20%). During a follow-up of 41.2 ± 17.6 months, 3 patients (all with prior cardiac arrest) had appropriate device therapy. Four patients developed complications; 3 of them had inappropriate shocks. Conclusion In our cohort, appropriate device therapy was limited to cardiac arrest survivors, whereas none of those with syncope and/or positive EPS had arrhythmias. Overall complication rate was relatively high, including inappropriate ICD shocks.

Cardiac arrhythmias are prevalent among humans across all age ranges and may occur in the setting of underlying heart disease as well as in structurally normal hearts. While arrhythmias are widely varied in their clinical presentations, they possess shared electrophysiologic properties at the cellular level. The 3 main mechanisms responsible for cardiac arrhythmias are automaticity, triggered activity, and reentry. Although identifying the specific mechanism may at times be challenging for the clinician and require invasive electrophysiologic study, differentiating and understanding the underlying mechanism may be critical to the development of an appropriate diagnosis and treatment strategy.

A B S T R A C T Cardiac arrhythmias are prevalent among humans across all age ranges and may occur in the setting of underlying heart disease as well as in structurally normal hearts. While arrhythmias are widely varied in their clinical presentations, they possess shared electrophysiologic properties at the cellular level. The 3 main mechanisms responsible for cardiac arrhythmias are automaticity, triggered activity, and reentry. Although identifying the specific mechanism may at times be challenging for the clinician and require invasive electrophysiologic study, differentiating and understanding the underlying mechanism may be critical to the development of an appropriate diagnosis and treatment strategy.

More than 50% of patients with heart failure die from sudden cardiac death as a result of malignant arrhythmia. T wave alternans (TWA) is a convenient, noninvasive, and inexpensive testing modality, with a higher sensitivity and specificity for sudden cardiac death. Its prediction value for malignant arrhythmia may even exceed electrophysiologic study. Generally, the algorithms of TWA can be divided into frequency-domain and time-domain methods, and the latter has a stronger anti-interference ability. So far, a unified measuring formula and diagnostic criteria about TWA measurements have been created. Large clinical studies in recent years strongly suggest that TWA can predict sudden cardiac death, which can be used as a guide for the implanting of implantable cardioverter-defibrillator. This article reviews the current literature on recording techniques and clinical implications of TWA.

VA Intervals to Distinguish PSVT. Introduction: Usefulness of the interval between the last pacing stimulus and the last entrained atrial electrogram (SA) minus the tachycardia ventriculoatrial (VA) interval in the differential diagnosis of supraventricular tachycardias with long (>100 ms) VA intervals has not been prospectively studied in a large series of patients. Our objective was to assess the usefulness of the difference SA–VA in diagnosing the mechanism of those tachycardias in patients without preexcitation. The results were compared with those obtained using the corrected return cycle (postpacing interval—tachycardia cycle length—atrioventricular [AV] nodal delay). Methods and Results: We included 314 consecutive patients with inducible sustained supraventricular tachycardias with VA intervals >100 ms undergoing an electrophysiologic study. Atrial tachycardias were excluded. Tachycardia entrainment was attempted through pacing trains from right ventricular apex. The SA–VA difference and the corrected return cycle were calculated for every patient. Electrophysiologic study revealed 82 atypical AV nodal reentrant tachycardias (AVNRT) and 237 AV reentrant tachycardias (AVRT) using septal (n = 91) or free-wall (n = 146) accessory pathways (APs). A SA–VA difference >110 ms identified an atypical AVNRT with sensitivity, specificity, positive and negative predictive values of 99%, 98%, 95%, and 99.5%, respectively. Similarly, these values were 88%, 83%, 77%, and 92% for SA–VA difference

RésuméHormis avant l’ablation qu’elle précède systématiquement, l’exploration électrophysiologique semble avoir partiellement perdu de son intérêt et il n’existe pas de recommandations spécifiques récentes la concernant. Elle reste cependant toujours d’actualité à titre diagnostique dans nombre de tachycardies et de bradycardies, mais aussi plus rarement à titre pronostique. Cet article passe en revue et discute les diverses indications actuellement retenues.SummaryBeside just before a catheter ablation of arrhythmia, the electrophysiological study seems to have lost part of its interest, and there are no recent specific guidelines dealing with this particular topic. Yet its interest remains for diagnostic purposes of various bradycardia and tachycardia, but also, though less frequently, as a prognostic tool. This article reviews and discuss its current indications.

Background: In this study we evaluate wide QRS complexes observed during pharmacologic termination of supraventricular tachycardias. Methods: Patients with supraventricular tachycardia, undergoing electrophysiologic study were enrolled. 12 mg of adenosine or 10 mg of verapamil were administered during tachycardia, under continuous monitoring of intaracardiac and surface electrocardiograms. Electrocardiographic features of ventricular ectopy were noted. Results: Seventy-four patients were enrolled. 48 patients were randomized to adenosine and 26 to verapamil. Five different appearance patterns of ventricular ectopy were observed during termination of tachycardias. All wide QRS complexes were of ventricular origin and all of them were observed during the termination of tachycardia. Adenosine more frequently resulted in appearance of ventricular beats (15.4% vs 41.7%, P = 0.003), and this was more frequently observed in patients with atrioventricular nodal reentrant tachycardia. Patients with ventricular beats were younger than those without, in both, verapamil (47.5 ± 15.6 vs 65.0 ± 8.8 years, P = 0.04) and adenosine (40.9 ± 13.8 vs 49.7 ± 16.8, P = 0.03) groups. Left bundle branch block (LBBB)/superior axis morphology was most frequent morphology in adenosine group (55%). Two of 4 patients in verapamil group displayed LBBB/inferior axis QRS morphology and another 2 patients displayed LBBB/superior axis morphology. Conclusions: Noncatheter induced, five different appearance patterns and four distinct morphologies of ventricular origin were observed. Most of them do not directly terminate tachycardia, but are associated with its termination and are not observed in ongoing tachycardia.

Resume Introduction Le but de cette etude a ete de determiner et de rechercher des facteurs susceptibles d’expliquer la survenue d’une syncope chez des sujets qui avaient des tachycardies jonctionnelles paroxystiques (TJP) et un ECG intercritique normal. Methodes Quatre cent dix-neuf patients âges de dix a 88 ans (47 ± 19) avec un ECG intercritique normal, ont ete recrutes consecutivement pour des TJP. Soixante-dix-huit patients avaient presente au moins un episode de syncope. Ils ont eu une etude electrophysiologique systematique pratiquee par voie transœsophagienne, un echocardiogramme, des manœuvres vagales et un tilt-test dans 25 cas. Resultats L’âge, le sexe, la methode d’induction, le mecanisme de la tachycardie, la frequence moyenne en tachycardie ont ete similaires chez les sujets avec et sans syncope. La syncope a ete attribuee a une reaction vagale a l’arret de la TJP (n = 31), une frequence cardiaque rapide en crise (n = 15), une dysfonction sinusale (n = 6), une ischemie coronaire (n = 5), une crise de tetanie (n = 3), un âge tres avance (n = 3), des causes multiples (n = 3) et chez huit sujets est restee inconnue. Le traitement de la TJP par ablation dans 28 cas a supprime la syncope chez 26 sujets. Conclusion En conclusion, une syncope peut survenir chez 18 % des sujets qui ont une histoire de TJP. Plusieurs mecanismes sont possibles. Les plus frequents sont une ischemie coronaire ou une dysfonction sinusale chez les sujets âges, une reaction vagale ou une frequence cardiaque rapide ou une crise de tetanie chez les patients de tous les âges.

Noncontact Mapping of the Heart. The noncontact mapping system is a new tool for electrophysiologic study and radiofrequency ablation. The mode of operation includes single beat, three-dimensional, high-density mapping. Careful analysis of unipolar electrograms and isopotential maps are essential to understand the mechanism of the arrhythmia. Radiofrequency catheter ablation guided by this system is effective in curing patients of their tachycardias.

We present a 72-year-old man with interruption of inferior vena cava (IVC) with azygos continuation, who underwent radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). We recorded a His bundle electrogram with an electrode catheter positioned in the aortic root. We also introduced an electrode catheter through the right femoral vein, advanced it via an enlarged azygos vein and the superior vena cava and positioned it at the right ventricular apex (RVA). AVNRT was induced by programmed pacing from a coronary sinus catheter introduced through the left subclavian vein. It was successfully ablated with an ablation catheter introduced through the right internal jugular vein. In a patient with interruption of IVC, it is impossible to access the right side of the heart directly via femoral vein and IVC. In this case, however, alternative routes to the His bundle, RVA and ablation site enabled us to perform an electrophysiologic study and a successful catheter ablation.

Introduction: The aim of our study was to assess the effectiveness of the nonlinear analysis (NLA) of ECG in predicting the results of invasive electrophysiologic study (EPS) in patients with ventricular arrhythmias. Methods: We evaluated 25 patients with history of cardiac arrest, syncope, sustained, or nonsustained ventricular tachycardia (VT). All patients underwent electrophysiologic study (EPS) and nonlinear analysis (NLA) of ECG. The study group was compared with a control group of 25 healthy subjects, in order to define the normal range of NLA. ECG was processed in order to obtain numerical values, which were analyzed by nonlinear mathematical functions. Patients were classified through the application of a clustering procedure to the whole set of functions, and the correlation between the results of nonlinear analysis of ECG and EPS was tested. Results: NLA assigned all patients with negative EPS to the same class of healthy subjects, whereas the patients in whom VT was inducible had been correctly and clearly isolated into a separate cluster. In our study, the result of NLA with application of the clustering technique was significantly correlated to that of EPS (P < 0.001), and was able to predict the result of EPS, with a negative predictive value of 100% and a positive predictive value of 100%. Conclusions: NLA can predict the results of EPS with good negative and positive predictive value. However, further studies are needed in order to verify the usefulness of this noninvasive tool for sudden death risk stratification in patients with ventricular arrhythmias. Ann Noninvasive Electrocardiol 2008;13(3):219‐227 ventricular arrhythmias; ECG; nonlinear analysis; electrophysiologic study

Background Approximately 30% of all accessory pathways (APs) are located in the septal area, and understanding the electrocardiographic and electrophysiologic of these APs is crucial for safe and effective ablation of these pathways. Objective In this study, the electrocardiographic and electrophysiologic characteristics of anteroseptal, midseptal, and posteroseptal APs were investigated in detail to elucidate unique electrical properties of APs in each location. Methods From April 2002 to October 2006, a total of 120 patients with a septal AP-mediated tachycardia were enrolled in the study. A detailed examination including electrocardiographic analysis and electrophysiologic study was performed in all patients. Results A total of 120 patients, including 98 patients with posteroseptal APs, 14 patients with anteroseptal APs, and 8 patients with midseptal APs, were studied. The anteroseptal APs could be differentiated from the midseptal APs by the 2 or more positive delta waves in inferior leads, whereas there is significant overlap in electrocardiographic features of midseptal and posteroseptal APs. The mean tachycardia cycle length was significantly shorter in patients with midseptal AP compared with those with anteroseptal and posteroseptal APs (284 ± 49 ms vs 342 ± 46 ms vs 350 ± 68 ms, P = .03). The AH interval during tachycardia was also shorter in patients with midseptal APs (149 ± 16 ms vs 200 ± 51 ms vs 168 ± 48 ms, P = .04). The patients with posteroseptal AP had a significantly higher incidence of atrial fibrillation (35%) than those with either midseptal (12%) or anteroseptal (14%) APs ( P = .04). The patients with posteroseptal APs also had a significantly shorter antegrade effective refractory period of the AP (276 ± 54 ms) than those with either midseptal (313 ± 71 ms) or anteroseptal (325 ± 61) APs ( P = .036). Conclusion Electrocardiographic analysis is a reliable method for differentiation of the anteroseptal from the midseptal APs, whereas the same is not true for the midseptal and posteroseptal APs. Midseptal APs were characterized by faster orthodromic tachycardia, whereas posteroseptal APs had a higher inducibility of atrial fibrillation.

Objective Transverse myelitis (TM) is a rare complication in patients with systemic lupus erithematosus (SLE). We reviewed a series of our SLE patients to determine the prevalence of TM, and evaluate the clinical characteristics, medical tests, evolution, and response to the treatment. Patients and method Six patients with TM were identified and underwent a neurological evaluation, MRI, electrophysiologic study, and were all subjected to the same treatment. A descriptive statistical study was conducted. Results We observed a prevalence of 0.92% in our patients with SLE. Eighty-three point three per cent had antiphospholipid antibodies and/or lupus anticoagulant. The MRI confirmed the diagnosis in 5 cases. Of the 5 patients with antiphospholypid antibodies, 3 were anticoagulated or took aspirin with a good neurological outcome, leaving 2 of them without posterior complications. Conclusions We found a prevalence similar to that observed in other series, around 1%. The high prevalence of antiphospholypid antibodies in these patients, with good outcome in those anticoagulated or treated with antiplatelet agents suggests an important pathogenic role in the development of TM, and emphasized the possibility of adding to the standard treatment, antiplatelet agents, or anticoagulation.

Background: Ventricular tachyarrhythmia is one of the most important factors determining the prognosis of patients with heart failure and sudden death can be observed even during stable therapy controlling clinical heart failure. In this study, the usefulness of electrophysiologic study (EPS) for the prediction of a future arrhythmic event was evaluated in patients with heart failure. Methods and Results: The patient population consisted of 474 patients with a history of clinical heart failure but without an episode of spontaneous sustained ventricular tachycardia or fibrillation (VT/VF). A Holter ECG was performed in all patients, and 177 of the 474 patients underwent EPS because of a recording of nonsustained VT (NSVT, > 5 beats). When sustained VT/VF was inducible in EPS, the patient was assigned to implantation of a defibrillation device. The patients were divided into 3 groups, ie, 1) no NSVT (n = 297), 2) NSVT + no inducible VT/VF (n = 134), and 3) NSVT + inducible VT/VF (n = 43), and were followed-up for > 12 months. All patients were followed-up under standard therapy for heart failure. There were no significant differences in basic clinical characteristics and therapies among the 3 groups. During the follow-up period of 32 ± 18 months, 56/474 patients suffered a VT/VF episode, ie, 21/297 in no NSVT, 14/134 in NSVT + no inducible VT/VF, and 21/43 in NSVT + inducible VT/VF patients (P = 0.032). All patients were rescued from sudden death among patients with an implanted defibrillator, but 11 patients without a defibrillator died. Conclusion: In patients with heart failure, future arrhythmic events could be predicted by EPS and Holter ECG. EPS-guided risk stratification seems to be useful in managing patients with heart failure.

Background: Clinical independent predictors of inducible sustained ventricular tachycardia (VT) during electrophysiologic study (EPS) are not known in patients with chronic Chagas' heart disease. The purpose of this investigation was to fill this gap. Methods: The medical charts of 47 patients with a positive serology for Chagas' disease who had undergone EPS between September 2006 and July 2012 at our institution were reviewed. Reasons for the EPS were the presence of unexplained syncope, non-sustained ventricular tachycardia (NSVT) on either resting ECG or 24 h-Holter monitoring as well as a LVEF 35% at echocardiography. A stepwise logistic regression analysis was performed to identify noninvasive predictors of inducible sustained VT/ventricular fibrillation during EPS. Results: On univariate analysis, syncopal episodes (p = 0.04), amiodarone therapy (p

Sudden cardiac death threats ischaemic and dilated cardiomyopathy patients. Anti- arrhythmic protection may be provided to these patients with implanted cardiac defibrillators (ICD), after an efficient risk stratification approach. The proposed risk stratifier of an impaired left ventricular ejection fraction has limited sensitivity meaning that a significant number of victims will remain undetectable by this risk stratification approach because they have a preserved left ventricular systolic function. Current risk stratification strategies focus on combinations of non invasive methods like T wave alternans, late potentials, heart rate turbulence, deceleration capacity and others, with invasive methods like the electrophysiologic study. In the presence of an electrically impaired substrate with formed post myocardial infarction fibrotic zones, programmed ventricular stimulation provides important prognostic information for the selection of the patients expected to benefit from an ICD implantation, while due to its high negative predictive value, patients at low risk level may also be detected. Clustering evidence from different research groups and electrophysiologic labs support an electrophysiologic testing guided risk stratification approach for sudden cardiac death.

A 33-year-old woman was referred for an electrophysiologic study because of a documented supraventricular tachycardia. Stimulation from the RV-apex showed retrograde conduction over the bundle of His without any evidence of an accessory pathway. Programmed atrial stimulation with one extra stimulus revealed a dual atrioventricular (AV) nodal physiology. …

The authors discuss the epidemiology and pathogenesis of Chagas' disease in Brazil, including the use of treatment with a cardioverter-defibrillator in patients with low ejection fraction. Select patients may benefit from resynchronization therapy associated with cardioverter-defibrillator treatment. Electrophysiologic study is indicated in the assessment of the potential utility of an implantable cardioverter-defibrillator.

A 20-year-old man was admitted to our hospital for treatment of verapamil sensitive idiopathic left ventricular tachycardia (ILVT). During the electrophysiologic study (EPS), no sustained ventricular tachycardia (VT) could be induced both at baseline and after infusion of isoproterenol. However, sustained clinical VT could be easily induced with single ventricular extrastimulation following intravenous administration of pilsicainide, a class Ic sodium channel blocker. The arrhythmia was ablated with radiofrequency catheter ablation.

OBJECTIVE: To assess the value of transthoracic echocardiography (TTE) as an image guide in placing a coronary sinus catheter into the coronary sinus. METHODS: Sixty consecutive patients undergoing electrophysiologic study were randomized to TTE (30 patients, "TTE group") or x-ray fluoroscopy (30 patients, "x-ray group") as an image guide to assist in the placement of a coronary sinus catheter. RESULTS: The success rate of placing the coronary sinus catheter was 96.7% in TTE group and 100% in x-ray group (P > 0.05). The procedure duration was 5.8 +/- 5.7 minutes in TTE group and 5.9 +/- 3.3 minutes in x-ray group (P > 0.05), The x-ray exposure time was 0.15 +/- 0 minute in TTE group and 4.2 +/- 2.8 minutes in x-ray group (P < 0.0001). CONCLUSION: Using TTE as an image guide, coronary sinus cannulation is feasible and as rapid as standard x-ray fluoroscopy, without the radiation risk.