Impact of peri-procedural management of direct oral anticoagulants on pocket haematoma after cardiac electronic device implantation: the StimAOD multicentre prospective study.

AIMS: The study aims to investigate the impact of direct oral anticoagulant (DOAC) management on the incidence of pocket haematoma in patients undergoing pacemaker or implantable cardioverter-defibrillator implantation. METHODS AND RESULTS: All consecutive patients receiving DOAC and undergoing cardiac electronic device implantation were included in a large multicentre prospective observational study (NCT03879473). The primary endpoint was clinically relevant haematoma within 30 days after implantation. Overall, 789 patients were enrolled [median age 80 (IQR 72-85) years old, 36.4% women, median CHA2DS2-VASc score 4 (IQR 0-8)], of which 632 (80.1%) received a pacemaker implantation. Antiplatelet therapy was combined with DOAC in 146 patients (18.5%). Direct oral anticoagulants (DOACs) were interrupted 52 (IQR 37-62) h before the procedure and resumed 31 (IQR 21-47) h later. Ninety-six percent of the patients had at least 12 h DOAC interruption before the procedure, and 78% had at least 12 h DOAC interruption after the procedure. Overall, anticoagulation was interrupted for 72 (IQR 48-96) h. Pre- or post-procedural heparin bridging was used in 8.2% and 3.9%, respectively. Timing of DOAC interruption of resumption was not associated with clinically relevant haematoma. Clinically relevant haematoma occurred in 26 patients (3.3%), and thromboembolic events occurred in 5 patients (0.6%). CONCLUSION: In this large real-life registry where most patients had DOAC interruption, clinically relevant haematoma was rare. Despite DOAC interruption and high CHA2DS2-VASc score, thromboembolic events occurred seldomly, highlighting that bleeding exceeds thromboembolic risk in this peri-procedural period. Future research is needed to identify risk factors for clinically relevant haematoma and meaningfully guide clinicians in optimizing DOAC management.

Replacement Myocardial Fibrosis in Patients With Mitral Valve Prolapse: Relation to Mitral Regurgitation, Ventricular Remodeling, and Arrhythmia.

BACKGROUND: Mitral valve prolapse (MVP) is a frequent disease that can be complicated by mitral regurgitation (MR), heart failure, arterial embolism, rhythm disorders, and death. Left ventricular (LV) replacement myocardial fibrosis, a marker of maladaptive remodeling, has been described in patients with MVP, but the implications of this finding remain scarcely explored. We aimed at assessing the prevalence, pathophysiological and prognostic significance of LV replacement myocardial fibrosis through late gadolinium enhancement (LGE) by cardiac magnetic resonance in patients with MVP. METHODS: Four hundred patients (53±15 years of age, 55% male) with MVP (trace to severe MR by echocardiography) from 2 centers, who underwent a comprehensive echocardiography and LGE cardiac magnetic resonance, were included. Correlates of replacement myocardial fibrosis (LGE+), influence of MR degree, and ventricular arrhythmia were assessed. The primary outcome was a composite of cardiovascular events (cardiac death, heart failure, new-onset atrial fibrillation, arterial embolism, and life-threatening ventricular arrhythmia). RESULTS: Replacement myocardial fibrosis (LGE+) was observed in 110 patients (28%; 91 with myocardial wall including 71 with basal inferolateral wall, 29 with papillary muscle). LGE+ prevalence was 13% in trace-mild MR, 28% in moderate MR, and 37% in severe MR, and was associated with specific features of mitral valve apparatus, more dilated LV and more frequent ventricular arrhythmias (45% versus 26%, P<0.0001). In trace-mild MR, despite the absence of significant volume overload, abnormal LV dilatation was observed in 16% of patients and ventricular arrhythmia in 25%. Correlates of LGE+ in multivariable analysis were LV mass (odds ratio, 1.01 [95% CI, 1.002-1.017], P=0.009) and moderate-severe MR (odds ratio, 2.28 [95% CI, 1.21-4.31], P=0.011). LGE+ was associated with worse 4-year cardiovascular event-free survival (49.6±11.7 in LGE+ versus 73.3±6.5% in LGE-, P<0.0001). In a stepwise multivariable Cox model, MR volume and LGE+ (hazard ratio, 2.6 [1.4-4.9], P=0.002) were associated with poor outcome. CONCLUSIONS: LV replacement myocardial fibrosis is frequent in patients with MVP; is associated with mitral valve apparatus alteration, more dilated LV, MR grade, and ventricular arrhythmia; and is independently associated with cardiovascular events. These findings suggest an MVP-related myocardial disease. Last, cardiac magnetic resonance provides additional information to echocardiography in MVP.

Catheter knot around the mitral valve apparatus: An exceptional complication of remote magnetic navigation.

Remote magnetic navigation (RMN) is as safe and effective as manual navigation for catheter ablation of ventricular arrhythmias. This case is the first description of a soft-tip ablation catheter entrapment in the mitral valve apparatus during an RMN ablation procedure. The tight knot created by the catheter around a mitral valve chordae required surgical removal. This complication, which has never been reported before, highlights the need for closer fluoroscopic monitoring when performing catheter loops inside the ventricles when using the RMN system.

How to use pace mapping for ventricular tachycardia ablation in postinfarct patients.

We aim to describe the technical aspects of pace mapping (PM), as well as the two typical patterns of pacing correlation maps during ventricular tachycardia (VT) ablation. The first main pattern is focal, with a gradual and eccentric decrease of the QRS correlation from the area with the best PM correlation. This focal pattern may be associated with two clinical situations: (1) with some endocardial points showing a good correlation compared to VT morphology: true endocardial exit of VT or endocardial breakthrough of either an intramural or an epicardial circuit; (2) without any endocardial points showing a good correlation compared to VT morphology: the VT may originate from the other ventricle, but the presence of an intramural or an epicardial circuit should be considered in patients with a structural heart disease. The second pattern is the presence of PM points exhibiting a good correlation close to other PM points showing a poor correlation compared to VT morphology: this abrupt change in paced QRS morphology over a short distance indicates divergence of activation wavefronts between these sites and suggests the presence of a slow conduction channel: the VT isthmus.

The prevalence of left and right bundle branch block morphology ventricular tachycardia amongst patients with arrhythmogenic cardiomyopathy and sustained ventricular tachycardia: insights from the European Survey on Arrhythmogenic Cardiomyopathy.

AIMS: In arrhythmogenic cardiomyopathy (ACM), sustained ventricular tachycardia (VT) typically displays a left bundle branch block (LBBB) morphology while a right bundle branch block (RBBB) morphology is rare. The present study assesses the VT morphology in ACM patients with sustained VT and their clinical and genetic characteristics. METHODS AND RESULTS: Twenty-six centres from 11 European countries provided information on 954 ACM patients who had ≥1 episode of sustained VT spontaneously documented during patients' clinical course. Arrhythmogenic cardiomyopathy was defined according to the 2010 Task Force Criteria, and VT morphology according to the QRS pattern in V1. Overall, 882 (92.5%) patients displayed LBBB-VT alone and 72 (7.5%) RBBB-VT [alone in 42 (4.4%) or in combination with LBBB-VT in 30 (3.1%)]. Male sex prevalence was 79.3%, 88.1%, and 56.7% in the LBBB-VT, RBBB-VT, and LBBB + RBBB-VT groups, respectively (P = 0.007). First RBBB-VT occurred 5 years after the first LBBB-VT (46.5 ± 14.4 vs 41.1 ± 15.8 years, P = 0.011). An implanted cardioverter-defibrillator was more frequently implanted in the RBBB-VT (92.9%) and the LBBB + RBBB-VT groups (90%) than in the LBBB-VT group (68.1%) (P < 0.001). Mutations in PKP2 predominated in the LBBB-VT (65.2%) and the LBBB + RBBB-VT (41.7%) groups while DSP mutations predominated in the RBBB-VT group (45.5%). By multivariable analysis, female sex was associated with LBBB + RBBB-VT (P = 0.011) while DSP mutations were associated with RBBB-VT (P < 0.001). After a median follow-up of 103 (51-185) months, death occurred in 106 (11.1%) patients with no intergroup difference (P = 0.176). CONCLUSION: RBBB-VT accounts for a significant proportion of sustained VTs in ACM. Sex and type of pathogenic mutations were associated with VT type, female sex with LBBB + RBBB-VT, and DSP mutation with RBBB-VT.

Long-Term Follow-Up of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator: The DAI-T4F Nationwide Registry.

BACKGROUND: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease, and sudden cardiac death represents an important mode of death in these patients. Data evaluating the implantable cardioverter defibrillator (ICD) in this patient population remain scarce. METHODS: A Nationwide French Registry including all patients with tetralogy of Fallot with an ICD was initiated in 2010 by the French Institute of Health and Medical Research. The primary time to event end point was the time from ICD implantation to first appropriate ICD therapy. Secondary outcomes included ICD-related complications, heart transplantation, and death. Clinical events were centrally adjudicated by a blinded committee. RESULTS: A total of 165 patients (mean age, 42.2±13.3 years, 70.1% males) were included from 40 centers, including 104 (63.0%) in secondary prevention. During a median (interquartile range) follow-up of 6.8 (2.5-11.4) years, 78 (47.3%) patients received at least 1 appropriate ICD therapy. The annual incidence of the primary outcome was 10.5% (7.1% and 12.5% in primary and secondary prevention, respectively; P=0.03). Overall, 71 (43.0%) patients presented with at least 1 ICD complication, including inappropriate shocks in 42 (25.5%) patients and lead dysfunction in 36 (21.8%) patients. Among 61 (37.0%) patients in primary prevention, the annual rate of appropriate ICD therapies was 4.1%, 5.3%, 9.5%, and 13.3% in patients with, respectively, 0, 1, 2, or ≥3 guidelines-recommended risk factors. QRS fragmentation was the only independent predictor of appropriate ICD therapies (hazard ratio, 3.47 [95% CI, 1.19-10.11]), and its integration in a model with current criteria increased the 5-year time-dependent area under the curve from 0.68 to 0.81 (P=0.006). Patients with congestive heart failure or reduced left ventricular ejection fraction had a higher risk of nonarrhythmic death or heart transplantation (hazard ratio, 11.01 [95% CI, 2.96-40.95]). CONCLUSIONS: Patients with tetralogy of Fallot and an ICD experience high rates of appropriate therapies, including those implanted in primary prevention. The considerable long-term burden of ICD-related complications, however, underlines the need for careful candidate selection. A combination of easy-to-use criteria including QRS fragmentation might improve risk stratification. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03837574.

Outcomes after catheter ablation of ventricular tachycardia without implantable cardioverter-defibrillator in selected patients with arrhythmogenic right ventricular cardiomyopathy.

AIMS: The roles of implantable cardioverter-defibrillators (ICDs) and radiofrequency catheter ablation (RCA) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and well-tolerated monomorphic ventricular tachycardia (MVT) are debated. In this multicentre retrospective study, we aimed at reporting the outcome of selected patients with ARVC after RCA without a back-up ICD. METHODS AND RESULTS: Patients with ARVC who underwent RCA of well-tolerated MVT at 10 tertiary centres across 5 countries, without an ICD before and 3 months after RCA, without syncope or electrical storm, and with left ventricular ejection fraction ≥50% were included. In total, 65 ARVC patients [mean age 44.5 ± 13.2 years, 78% males] underwent RCA of MVT between 2003 and 2016. Clinical presentation was palpitations in 51 (80%) patients. One (2%) patient had >1 clinical MVT. At the ablative procedure, clinical MVTs (mean rate 185 ± 32 b.p.m.) were inducible in 50 (81%) patients. Epicardial ablation was performed in 19 (29%) patients. Complete acute success was achieved in 47 (72%) patients. After a median follow-up of 52.4 months (range 12.3-171.4), there was no death or aborted cardiac arrest, and VT recurred in 19 (29%) patients. Survival without VT recurrence was estimated at 88%, 80%, and 68%, 12, 36, and 60 months after RCA, respectively, and was significantly associated with the approach and the procedural outcome. CONCLUSION: In patients with ARVC, well-tolerated MVT without a back-up ICD did not lead to fatal arrhythmic event after RCA despite VT recurrences in some. Our data suggest that RCA may be an alternative to ICD in selected ARVC patients.

Development and Validation of a New Risk Prediction Score for Life-Threatening Ventricular Tachyarrhythmias in Laminopathies.

BACKGROUND: An accurate estimation of the risk of life-threatening (LT) ventricular tachyarrhythmia (VTA) in patients with LMNA mutations is crucial to select candidates for implantable cardioverter-defibrillator implantation. METHODS: We included 839 adult patients with LMNA mutations, including 660 from a French nationwide registry in the development sample, and 179 from other countries, referred to 5 tertiary centers for cardiomyopathies, in the validation sample. LTVTA was defined as (1) sudden cardiac death or (2) implantable cardioverter defibrillator-treated or hemodynamically unstable VTA. The prognostic model was derived using the Fine-Gray regression model. The net reclassification was compared with current clinical practice guidelines. The results are presented as means (SD) or medians [interquartile range]. RESULTS: We included 444 patients, 40.6 (14.1) years of age, in the derivation sample and 145 patients, 38.2 (15.0) years, in the validation sample, of whom 86 (19.3%) and 34 (23.4%) experienced LTVTA over 3.6 [1.0-7.2] and 5.1 [2.0-9.3] years of follow-up, respectively. Predictors of LTVTA in the derivation sample were: male sex, nonmissense LMNA mutation, first degree and higher atrioventricular block, nonsustained ventricular tachycardia, and left ventricular ejection fraction (https://lmna-risk-vta.fr). In the derivation sample, C-index (95% CI) of the model was 0.776 (0.711-0.842), and the calibration slope 0.827. In the external validation sample, the C-index was 0.800 (0.642-0.959), and the calibration slope was 1.082 (95% CI, 0.643-1.522). A 5-year estimated risk threshold ≥7% predicted 96.2% of LTVTA and net reclassified 28.8% of patients with LTVTA in comparison with the guidelines-based approach. CONCLUSIONS: In comparison with the current standard of care, this risk prediction model for LTVTA in laminopathies significantly facilitated the choice of candidates for implantable cardioverter defibrillators. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03058185.

An efficient algorithm based on electrograms characteristics to identify ventricular tachycardia isthmus entrance in post-infarct patients.

AIMS: Our study assesses the value of electrograms (EGMs) characteristics to identify a ventricular tachycardia (VT) isthmus entrance in patients with post-infarct VT. Post-infarct VTs are mostly due to a re-entrant circuit. A pacemapping (PM) approach is able to localize the VT isthmus during sinus rhythm. Limited data are available about the role of local EGMs in defining VT isthmus location. METHODS AND RESULTS: Twenty consecutive patients (70% male) referred for post-infarct VT catheter ablation were included in the present study. The VT isthmus was defined according to the PM method. At each recording site, 10 characteristics of the local EGM were assessed to predict the location of the VT isthmus entrance. In total, 924 EGMs were acquired, of which 127 were located in the VT isthmus entrance. Logistic regression analysis showed that bipolar voltage, number of EGM positive peaks, and sQRS interval were independently associated with VT isthmus entrance location. The ROC curve best fitted the model at the cut-off 0.1641 (sensitivity 72%, specificity 75.2%, positive predictive value 31.3%, negative predictive value 94.4%, area under the curve 0.78, P < 0.001). Based upon these results, we developed an algorithm implemented in an automatic calculator to determine the likelihood that an EGM is located at a VT isthmus entrance. CONCLUSION: Our study suggests that three EGM characteristics: bipolar voltage, number of positive peaks, and sQRS interval can successfully identify a VT isthmus entrance in post-infarct patients.

Atrial tachycardias: Cause or effect with ablation of persistent atrial fibrillation?

INTRODUCTION: It is largely believed that atrial tachycardias (ATs) encountered during ablation of persistent atrial fibrillation (PsAF) are a byproduct of ablative lesions. We aimed to explore the alternative hypothesis that they may be a priori drivers of AF remaining masked until other AF sources are reduced or eliminated. METHODS AND RESULTS: Radiofrequency ablation of fibrillatory drivers mapped by electrocardiographic imaging (ECGI; ECVUE™, Cardioinsight Technologies, Cleveland, OH, USA) terminated PsAF in 198 (73%) out of 270 patients (61 ± 10 years, 9 ± 9 m). Two hundred and six ATs in 158 patients were subsequently mapped. Their anatomic relationship to the fibrillatory drivers prospectively identified by ECGI was then established. There were 26 (13%), 52 (25%), and 128 (62%) focal, localized, and macrore-entrant ATs, respectively. In focal/localized re-entrant ATs, 64 (82%) were terminated within an AF-driver region, in which 26 (81%) among 32 focal/localized ATs analyzed with 3-D-mapping system merged to driver map occurred from AF-driver regions in 1.0 ± 1.0 cm distance from the driver core. Importantly, there was no attempt at ablation of the associated AF-driver region in 25 of 64 (39%) of focal/localized re-entrant ATs. The sites of ATs origin generally had low-voltage, fractionated, and long-duration electrograms in AF. All but two focal/localized re-entrant ATs were successfully ablated. CONCLUSION: The majority of post-AF-ablation focal and localized re-entrant ATs originate from the region of prospectively established AF-driver regions. A third of these are localized to regions not subsequently submitted to ablation. These data suggest that many ATs exist, although not necessarily manifest independently, prior to ablation. They may have a role in the maintenance of PsAF in these individuals.

Unresolved questions associated with the management of ventricular preexcitation syndrome.

BACKGROUND: Many recent recommendations concern the management of preexcitation syndrome. In clinical practice, they are sometimes difficult to use. The purpose of the authors was to discuss the main problems associated with this management. Three problems are encountered: (1) the reality of the absence of symptoms or the interpretation of atypical symptoms, (2) the electrocardiographic diagnosis of preexcitation syndrome that can be missed, and (3) the exact electrophysiological protocol and its interpretation used for the evaluation of the prognosis. Because of significant progress largely related to the development of curative treatment, it seems easy to propose ablation in many patients despite the related risks of invasive studies and to minimize the invasive risk by only performing ablation for patients with at-risk pathways. However, there is a low risk of spontaneous events in truly asymptomatic patients and the indication of accessory pathway ablation should be discussed case by case.

Does the age of evaluation change the long-term follow-up of untreated pre-excitation syndrome?

BACKGROUND: Due to high rates of ablation at the time of diagnostic EP study, follow-up of the natural history of untreated pre-excitation syndrome has become difficult. We present patients in which such data is available and study the effect of initial age on the evolution. METHODS: In this retrospective review, 126 patients, 47 aged ≤19 years, 79 aged more than>19 underwent 2 similar electrophysiological studies (EPS) within 1 to 25 years of one another (8.8 ±â€¯6.8) for occurrence of symptoms or new evaluation. First EPS was indicated for syncope (10), atrioventricular re-entrant tachycardias (AVRT) (58), atrial fibrillation (AF) (5), spontaneous PS-related adverse event (7) or asymptomatic PS (46). RESULTS: Clinical data remained unchanged in 76 patients (60.3%). AVRT symptom was more frequently unchanged than other symptoms. Electrophysiological data remained unchanged in 105 patients (82%), but signs of initial malignant signs were variable with a disappearance in 53.5% of patients. At EPS1, AF induction was rarer in patients ≤19 years. Syncope had a low predictive value of malignant form. AVRT induction at EPS1 was not predictive of AVRT occurrence. Maximal rate over accessory pathway increased, but unexpected changes could occur. After multivariate analysis, data of first EPS were limited for the prediction of AVRT or adverse event; effect of age was not significant. CONCLUSIONS: Clinical data remained unchanged in 60.3% of patients and electrophysiological data in 82%. Initial age of evaluation did not change the modifications. Electrophysiological signs associated with sudden death varied over time. Clinical AVRT was inconstantly related to inducible AVRT (78.5%).

Adaptive step size LMS improves ECG detection during MRI at 1.5 and 3 T.

OBJECTIVE: We describe a new real-time filter to reduce artefacts on electrocardiogram (ECG) due to magnetic field gradients during MRI. The proposed filter is a least mean square (LMS) filter able to continuously adapt its step size according to the gradient signal of the ongoing MRI acquisition. MATERIALS AND METHODS: We implemented this filter and compared it, within two databases (at 1.5 and 3 T) with over 6000 QRS complexes, to five real-time filtering strategies (no filter, low pass filter, standard LMS, and two other filters optimized within the databases: optimized LMS, and optimized Kalman filter). RESULTS: The energy of the remaining noise was significantly reduced (26 vs. 68%, p < 0.001) with the new filter vs. standard LMS. The detection error of our ventricular complex (QRS) detector was: 11% with our method vs. 25% with raw ECG, 35% with low pass filter, 17% with standard LMS, 12% with optimized Kalman filter, and 11% with optimized LMS filter. CONCLUSION: The adaptive step size LMS improves ECG denoising during MRI. QRS detection has the same F1 score with this filter than with filters optimized within the database.

Evolution of Clinical and Electrophysiological Data in Children with a Preexcitation Syndrome.

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.

Sudden QRS morphology change during ventricular pacing in a scar-related isthmus What is the mechanism?

We present an example of sudden modification in QRS morphology during ventricular pacing inside a scar-related isthmus. This is explained by a "concealed" sudden block in both the orthodromic and antidromic wavefront directions, allowing then the activation to proceed through a now overt antidromic conduction.

Impact of Electrode Type on Mapping of Scar-Related VT.

BACKGROUND: Substrate-based VT ablation is mostly based on maps acquired with ablation catheters. We hypothesized that multipolar mapping catheters are more effective for identification of scar and local abnormal ventricular activity (LAVA). METHODS AND RESULTS: Phase1: In a sheep infarction model (2 months postinfarction), substrate mapping and LAVA tagging (CARTO® 3) was performed, using a Navistar (NAV) versus a PentaRay (PR) catheter (Biosense Webster). Phase2: Consecutive VT ablation patients from a single center underwent NAV versus PR mapping. Point pairs were defined as a PR and a NAV point located within a 3D-distance of ≤3 mm. Agreement was defined as both points in a pair being manually tagged as normal or LAVA. Four sheep (4 years, 50 ± 4.8 kg) and 9 patients were included (53 ± 14 years, 8 male, 6 ischemic cardiomyopathy). Mapping density was higher within the scar with PR versus NAV (3.2 vs. 0.7 points/cm2 , P = 0.001) with larger bipolar scar area (68 ± 55 cm2 vs. 58 ± 48 cm2 , P = 0.001). In total, 818 point pairs were analyzed. Using PR, far-field voltages were smaller (PR vs. NAV; bipolar: 1.43 ± 1.84 mV vs. 1.64 ± 2.04 mV, P = 0.001; unipolar; 4.28 ± 3.02 mV vs. 4.59 ± 3.67 mV, P < 0.001). More LAVA were also detected with PR (PR vs. NAV; 126 ± 113 vs. 36 ± 29, P = 0.001). When agreement on LAVA was reached (overall: 72%; both LAVA, 40%; both normal, 82%) higher LAVA voltages were recorded on PR (0.48 ± 0.33 mV vs. 0.31 ± 0.21 mV, P = 0.0001). CONCLUSION: Multipolar mapping catheters with small electrodes provide more accurate and higher density maps, with a higher sensitivity to near-field signals. Agreement between PR and NAV is low.

Factors of negativity of electrophysiological study in children and teenagers complaining of tachycardia and prognostic significance.

When non-invasive studies remain negative, the diagnosis of unexplained tachycardia in the young is a dilemma. The purpose of the study was to determine the factors of negativity of transesophageal electrophysiological study (EPS) in children/teenagers complaining of tachycardia and the prognostic value. Two hundred and seventy-three children with a normal ECG in sinus rhythm, aged from 6 to 19 years (15 ± 3), complained of tachycardia. Transesophageal EPS consisted of atrial stimulation in control state and after isoproterenol. Supraventricular tachycardia (SVT) was induced in 149 patients (group I) and EPS remained negative in 124 (group II). Age did not differ (15 ± 3 vs 15 ± 3). Female gender and familial history of SVT were as frequent in group I (47, 11%) than in group II (55%, p = 0.15; 7%;p = 0.2). Feeling of dizziness/syncope with tachycardia was less frequent in group I (12%) than in group II (48%) (p < 0.0001). Feeling of chest pain with tachycardia was less frequent in group I (2%) than in group II (28%) (p < 0.0001). The presence of non-cardiac disease was less frequent in group I (1.3%) than in group II (6.4%) (p < 0.025). Patients with negative study remained free of SVT after a follow-up of 3.5 ± 3 years, but one had a complete AV block. In children with apparently normal ECG in sinus rhythm, who complained of tachycardia clinical history (association with syncope, chest pain, or the presence of another disease) can predict negativity of EPS with a relatively high accuracy; EPS may not be necessary. In very symptomatic patients, transesophageal EPS, which is inexpensive and non-invasive, might be performed to stop investigations.