Brugada Syndrome and Pulmonary Atresia with Intact Interventricular Septum: Fortuitous Finding or New Genetic Connection?

Brugada syndrome is a rare arrhythmogenic syndrome associated mainly with pathogenic variants in the SCN5A gene. Right ventricle outflow tract fibrosis has been reported in some cases of patients diagnosed with Brugada syndrome. Pulmonary atresia with an intact ventricular septum is characterized by the lack of a functional pulmonary valve, due to the underdevelopment of the right ventricle outflow tract. We report, for the first time, a 4-year-old boy with pulmonary atresia with an intact ventricular septum who harbored a pathogenic de novo variant in SCN5A, and the ajmaline test unmasked a type-1 Brugada pattern. We suggest that deleterious variants in the SCN5A gene could be implicated in pulmonary atresia with an intact ventricular septum embryogenesis, leading to overlapping phenotypes.

Case report: Resection of a giant right ventricular myxoma.

Myxoma constitutes the main subtype of all benign cardiac tumors, tending to be more common in women and occurring mostly in the left and right atria. Its classic clinical presentations are intracardiac obstruction, embolization, and systemic or constitutional symptoms, such as fever, in decreasing order. Several imaging techniques such as echocardiography, computed tomography, and angiocardiography contribute to the diagnosis of myxoma, ruling out significant coronary diseases, and assessment of myocardial invasion and tumor involvement of adjacent structures. Surgical resection is the only effective therapeutic option for patients with cardiac myxoma. Here, we report a unique case of a middle-aged man who presented with a giant myxoma and a 3-day history of chest tightness and shortness of breath after physical activity. Subsequently, transthoracic echocardiography revealed a mass of solid echodensity located within the right ventricle, complicated by abnormal hemodynamics. A cardiac computed tomographic angiography showed a large homogeneous density filling defect consuming most parts of the right ventricle and protruding from beat to beat. A surgical resection and histological study later successfully confirmed the diagnosis, and the patient's postoperative recovery course was found to be uneventful.

The right ventricle systolic force ratio could predict the severity of the tricuspid regurgitation-RIVIERA ratio.

PURPOSE: For assessing the severity of tricuspid regurgitation (TR), there is no gold standard. We developed a parameter, the right ventricular systolic force ratio-RIVIERA, using the continious wave Doppler analysis of TR and pulsed-wave analysis of the right ventricle outflow tract. We hypothesized that the RIVIERA would facilitate the ability to identify severe TR in clinical settings. MATERIALS AND METHODS: We obtained data from routine transthoracic echocardiograms. All records reporting no or mild TR (n = 732), moderate TR (n = 584), and severe TR (n = 519) TR were reanalyzed to measure vena contracta (VC) width, TR jet area, effective regurgitant orifice (EROA) derived with the proximal isovelocity surface area method, the RIVIERA, and right-sided chamber volumes. RESULTS: Significant linear trends were demonstrated for right atrial volume index, end-diastolic volume index, RVOT velocity time integral, TR jet area, TR-Vmax, TR-VTI, TR acceleration, VC width, EROA with increasing TR severity. Independent predictors of severe RT included RIVIERA <4.8, VC width ≥0.7 cm, TR jet area > 10 cm2 , and EROA ≥0.4 cm2 . CONCLUSION: The RIVIERA is a feasible, effective, and independent predictor of severe TR that enhances established techniques for estimating TR severity. For clinical decision-making and management, accurate measurement and classification of TR severity are essential. Therefore, it should be thought about include the RIVIERA in the integrative method to assessing TR severity.

Damage to the left descending coronary artery due to radiofrequency ablation in the right ventricular outflow tract: Clinical case series and anatomical considerations.

The purpose of this paper was to highlight the importance of the anatomy of the right ventricular outflow tract (RVOT) and the proximity of the mid segment of the left anterior descending coronary artery (LAD) to the RVOT in the setting of ablation of ventricular arrhythmias in the RVOT. During the period from 2014 till 2017, five patients with injury to the LAD during ablation within RVOT were identified in three centers, in Belgium, Germany and Israel. The clinical characteristics, procedural data and follow up data, where available, are reported. The literature review over coronary artery damage during radiofrequency ablation procedures is provided and the anatomy of the RVOT and the neighboring vascular structures is discussed. We present five patients who underwent radiofrequency ablation of ventricular arrhythmias mapped to the inferior and anterior part of the RVOT, at the insertion of the right ventricular wall to the septum, whereby ablation resulted in occlusion in four and severe stenosis in one, of the mid segment of the LAD coronary artery. All patients underwent percutaneous coronary intervention and stenting, four of them immediately during the same procedure and one 3 days later because of lack of signs and symptoms of acute coronary occlusion. In conclusion, the mid segment of the LAD at the level of the second septal perforator/second diagonal branch runs in very close proximity to the endocardial aspect of the lower part of the RVOT and care should be taken during ablation of ventricular arrhythmias in this region. Additional imaging such as intracardiac echocardiography and coronary angiography may be helpful in avoiding complications.

Cardiac Metastasis Presenting As Right Ventricular Outflow Obstruction.

Right ventricular outflow tract obstruction (RVOTO) is characterized by an increased systolic pressure gradient between the right ventricle (RV) and the pulmonary artery. This rare condition can be diagnosed via echocardiography and may arise from various causes, including cardiac masses, pulmonary atresia with a ventricular septal defect, tricuspid valve thrombus, graft or wire calcification, or a cardiac tumor. We present the case of a 73-year-old male who was hospitalized after a syncope episode. Telemetry detected ventricular arrhythmia. Imaging identified a mass compressing the RV, causing RVOTO. A biopsy of the mass confirmed it as squamous cell carcinoma, which likely originated from the lung as a distant metastasis.

Palliation Strategy to Achieve Complete Repair in Symptomatic Neonates with Tetralogy of Fallot.

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005-2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight < 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score < - 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p < 0.001) were more common in RVOTI. Significant center differences were noted (p < 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63-1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93-4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36-3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p < 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p < 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI.

Outcomes after common arterial trunk repair: Impact of the surgical technique.

OBJECTIVES: We compared the risk of mortality and reintervention after common arterial trunk (CAT) repair for different surgical techniques, in particular the reconstruction of the right ventricle outflow tract with left atrial appendage (LAA) without a monocusp. METHODS: The study population comprised 125 patients with repaired CAT who were followed-up at our institution between 2000 and 2018. Statistical analysis included Cox proportional hazard models. RESULTS: Median follow-up was 10.6 years. The 10-year survival rate was 88.2% (95% confidence interval [CI], 80.6-92.4) with the poorest outcome for CAT type IV (64.3%; 95% CI, 36.8-82.3; P < .01). In multivariable analysis, coronary anomalies (hazard ratio [HR], 11.63 [3.84-35.29], P < .001) and CAT with interrupted aortic arch (HR, 6.50 [2.10-20.16], P = .001) were substantial and independent risk factors for mortality. Initial repair with LAA was not associated with an increased risk of mortality (HR, 0.37 [0.11-1.24], P = .11). The median age at reintervention was 3.6 years [7.3 days-13.1 years]. At 10 years, freedom from reintervention was greater in the group with LAA repair compared with the valved conduit group, 73.3% (95% CI, 41.3-89.4) versus 17.2% (95% CI, 9.2-27.4) (P < .001), respectively. Using a valved conduit for repair (HR, 4.79 [2.45-9.39], P < .001), truncal valve insufficiency (HR, 2.92 [1.62-5.26], P < .001) and DiGeorge syndrome (HR, 2.01 [1.15-3.51], P = .01) were independent and clinically important risk factors for reintervention. CONCLUSIONS: For the repair of CAT, the LAA technique for right ventricle outflow tract reconstruction was associated with comparable survival and greater freedom from reintervention than the use of a valved conduit.

Prospective use of ablation index for the ablation of right ventricle outflow tract premature ventricular contractions: a proof of concept study.

AIMS: Radiofrequency catheter ablation (RFCA) represents an effective option for idiopathic premature ventricular contractions (PVCs) treatment. Ablation Index (AI) is a novel ablation marker incorporating RF power, contact force, and time of delivery into a single weighted formula. Data regarding AI-guided PVCs RFCA are currently lacking. Aim of the study was to compare AI-guided and standard RFCA outcomes in patients with PVCs originating from the right ventricle outflow tract (RVOT). METHODS AND RESULTS: Consecutive patients undergoing AI-guided RFCA of RVOT idiopathic PVCs were prospectively enrolled. Radiofrequency catheter ablation was performed following per-protocol target cut-offs of AI, depending on targeted area (RVOT free wall AI cut-off: 590; RVOT septum AI cut-off: 610). A multi-centre cohort of propensity-matched (age, sex, ejection fraction, and PVC site) patients undergoing standard PVCs RFCA was used as a comparator. Sixty AI-guided patients (44.2 ± 18.0 years old, 58% male, left ventricular ejection fraction 56.2 ± 3.8%) were enrolled; 34 (57%) were ablated in RVOT septum and 26 (43%) patients in the RVOT free wall area. Propensity match with 60 non-AI-guided patients was performed. Acute outcomes and complications resulted comparable. At 6 months, arrhythmic recurrence was more common in non-AI-guided patients whether in general (28% vs. 7% P = 0.003) or by ablated area (RVOT free wall: 27% vs. 4%, P = 0.06; RVOT septum 29% vs. 9% P = 0.05). Ablation Index guidance was associated with improved survival from arrhythmic recurrence [overall odds ratio 6.61 (1.95-22.35), P = 0.001; RVOT septum 5.99 (1.21-29.65), P = 0.028; RVOT free wall 11.86 (1.12-124.78), P = 0.039]. CONCLUSION: Ablation Index-guidance in idiopathic PVCs ablation was associated with better arrhythmic outcomes at 6 months of follow-up.

Alterra Adaptive Prestent and SAPIEN 3 THV for Congenital Pulmonic Valve Dysfunction: An Early Feasibility Study.

OBJECTIVES: The aim of this study was to demonstrate the safety and functionality of the Alterra Adaptive Prestent and SAPIEN 3 transcatheter heart valve (THV) in patients with dysfunctional, dilated right ventricular outflow tract (RVOT) greater or equal to moderate pulmonary regurgitation (PR). BACKGROUND: Significant variations in the size and morphology of the RVOT affect the placement of transcatheter pulmonary valves. The Alterra Prestent internally reduces and reconfigures the RVOT, providing a stable landing zone for the 29-mm SAPIEN 3 THV. METHODS: Eligible patients had moderate or greater PR, weighed >20 kg, and had RVOT diameter 27 to 38 mm and length >35 mm. The primary endpoint was device success, a 5-item composite: 1 Alterra Prestent deployed in the desired location, 1 SAPIEN 3 THV implanted in the desired location within the Prestent, right ventricular-to-pulmonary artery peak-to-peak gradient <35 mm Hg after THV implantation, less than moderate PR at discharge, and no explantation 24 h post-implantation. The secondary composite endpoint was freedom from THV dysfunction (RVOT/pulmonary valve (PV) reintervention, greater or equal to moderate total PR, mean RVOT/PV gradient ≥ 35 mm Hg at 30 days and 6 months. Descriptive statistics are reported. RESULTS: Enrolled patients (N = 15) had a median age and weight of 20 years and 61.7 kg, respectively; 93.3% were in New York Heart Association functional class I or II. Device success was 100%. No staged procedures were necessary. No THV dysfunction was reported to 6 months. No serious safety signals were reported. CONCLUSIONS: This early feasibility study demonstrated the safety and functionality of the Alterra Adaptive Prestent in patients with congenital RVOT dysfunction and moderate or greater PR. Durability and long-term outcome data are needed.

Bi-ventricular repair of double outlet left ventricle: Experience and review of the literature.

BACKGROUND: Double-outlet left ventricle (DOLV) is a rare congenital cardiac anomaly. The aorta and the main pulmonary arterial trunk arises predominantly from the left ventricle and is associated with a malaligned ventricular septal defect, various degrees of hypoplasia of the right ventricle, and presence, or absence of pulmonary stenosis. Bi-ventricular repair is the preferred treatment option whenever possible. Multiple techniques for bi-ventricular repair have been described. The best option for DOLV correction is by translocating the pulmonary root from the left ventricle to the right ventricle. In this series, we report four patients who underwent biventricular repair of DOLV with excellent outcomes. METHODS: This is a retrospective study of four patients who underwent surgical correction of DOLV between January 2014 and December 2018. We collected all patient details from the institute patient record system. Echocardiographic data were obtained from the records. Intraoperative charts were reviewed for further information on the surgical procedure and cardiopulmonary bypass. Postoperative data included survival, functional status, and followup echocardiography. RESULTS: Of the four children, three underwent pulmonary root translocation, and one child underwent a Reparation al etage Ventriculaire (REV) procedure. There was no mortality in our series, and all children are in a stable clinical condition in the recent follow-up, and no re-operations or interventions were required following primary surgical correction. CONCLUSION: DOLV is anatomically and surgically a challenging subset. Pulmonary root translocation in this anatomy is technically challenging but safe and superior option when compared to other alternative surgical procedures. Pulmonary root translocation can be performed with excellent results, even in infants.

"Heart Oddity": Intrinsically Reduced Excitability in the Right Ventricle Requires Compensation by Regionally Specific Stress Kinase Function.

The traditional view of ventricular excitation and conduction is an all-or-nothing response mediated by a regenerative activation of the inward sodium channel, which gives rise to an essentially constant conduction velocity (CV). However, whereas there is no obvious biological need to tune-up ventricular conduction, the principal molecular components determining CV, such as sodium channels, inward-rectifier potassium channels, and gap junctional channels, are known targets of the "stress" protein kinases PKA and calcium/calmodulin dependent protein kinase II (CaMKII), and are thus regulatable by signal pathways converging on these kinases. In this mini-review we will expose deficiencies and controversies in our current understanding of how ventricular conduction is regulated by stress kinases, with a special focus on the chamber-specific dimension in this regulation. In particular, we will highlight an odd property of cardiac physiology: uniform CV in ventricles requires co-existence of mutually opposing gradients in cardiac excitability and stress kinase function. While the biological advantage of this peculiar feature remains obscure, it is important to recognize the clinical implications of this phenomenon pertinent to inherited or acquired conduction diseases and therapeutic interventions modulating activity of PKA or CaMKII.

Ablation for the treatment of Brugada syndrome: current status and future prospects.

Introduction: Brugada syndrome (BrS) is an inherited disease characterized by an increased risk of sudden cardiac death (SCD). Therapeutic options in symptomatic patients are limited to implantable cardioverter defibrillator (ICD) and quinidine, but catheter ablation of the right ventricular outflow tract (RVOT) offers a potential cure. Different ablation strategies have been used to treat patients with symptomatic Brugada syndrome. Epicardial radiofrequency substrate ablation of the RVOT/right ventricle (RV) has emerged as a promising tool for the management of the disease.Areas covered: The historical management of BrS, endocardial and epicardial ablation techniques, the use of sodium channel blockers (SCB) and complications are summarized here.Expert opinion: Ventricular fibrillation (VF)-triggering premature ventricular contractions (PVCs) in patients with BrS are unpredictable, spontaneous ones are rarely present to be mapped, making this approach impractical. Furthermore, endocardial mapping for BrS substrates does not seem effective due to the epicardial pathological substrate localization. The size variation of the BrS substrate areas during SCB infusion suggests a dynamic process as arrhythmogenic basis and SCB infusion should guide BrS epicardial ablation of all abnormal potentials areas. If BrS epicardial ablation can truly provide long-term prevention of ventricular arrhythmias it may potentially become an alternative to ICD therapy.

Conduction in the right and left ventricle is differentially regulated by protein kinases and phosphatases: implications for arrhythmogenesis.

The "stress" kinases cAMP-dependent protein kinase (PKA) and calcium/calmodulin-dependent protein kinase II (CaMKII), phosphorylate the Na+ channel Nav1.5 subunit to regulate its function. However, how the channel regulation translates to ventricular conduction is poorly understood. We hypothesized that the stress kinases positively and differentially regulate conduction in the right (RV) and the left (LV) ventricles. We applied the CaMKII blocker KN93 (2.75 µM), PKA blocker H89 (10 µM), and broad-acting phosphatase blocker calyculin (30 nM) in rabbit hearts paced at a cycle length (CL) of 150-8,000 ms. We used optical mapping to determine the distribution of local conduction delays (inverse of conduction velocity). Control hearts exhibited constant and uniform conduction at all tested CLs. Calyculin (15-min perfusion) accelerated conduction, with greater effect in the RV (by 15.3%) than in the LV (by 4.1%; P < 0.05). In contrast, both KN93 and H89 slowed down conduction in a chamber-, time-, and CL-dependent manner, with the strongest effect in the RV outflow tract (RVOT). Combined KN93 and H89 synergistically promoted conduction slowing in the RV (KN93: 24.7%; H89: 29.9%; and KN93 + H89: 114.2%; P = 0.0016) but not the LV. The progressive depression of RV conduction led to conduction block and reentrant arrhythmias. Protein expression levels of both the CaMKII-δ isoform and the PKA catalytic subunit were higher in the RVOT than in the apical LV (P < 0.05). Thus normal RV conduction requires a proper balance between kinase and phosphatase activity. Dysregulation of this balance due to pharmacological interventions or disease is potentially proarrhythmic. NEW & NOTEWORTHY We show that uniform ventricular conduction requires a precise physiological balance of the activities of calcium/calmodulin-dependent protein kinase II (CaMKII), PKA, and phosphatases, which involves region-specific expression of CaMKII and PKA. Inhibiting CaMKII and/or PKA activity elicits nonuniform conduction depression, with the right ventricle becoming vulnerable to the development of conduction disturbances and ventricular fibrillation/ventricular tachycardia.

Hybrid procedure of right ventricle outflow tract stenting in small infants with pulmonary atresia and ventricular septal defect: early and mid-term results from a single centre.

IntroductionPulmonary atresia, ventricular septal defect, major aorto-pulmonary collateral arteries, and pulmonary arteries hypoplasia are rare and complex congenital defects that require early interventions to relieve cyanosis and enhance the growth of native pulmonary arteries. The treatment of these patients is still controversial. Surgical techniques require cardiopulmonary bypass which is poorly tolerated by small infants. Percutaneous techniques such as radiofrequency perforation can be challenging. The hybrid technique consists of perventricular stenting of the right ventricle outflow tract through medial sternotomy, to restore native pulmonary flow. METHODS: We retrospectively reviewed the cardiovascular database of our centre in order to analyse our experience in hybrid procedure. We detected six patients who underwent hybrid first approach between November 2007 and December 2015. We report our early results and mid-term outcomes. RESULTS: Median age at the procedure was 26 days, median weight was 3150 g, and median Nakata index was 52 mm2/m2. All procedures were successful except for one: this patient underwent a surgical shunt. No immediate and early deaths or major complications occurred and oxygen saturation levels increased in all the patients. Patients were followed up for a period of 12-103 months, and four of them underwent a procedure of unifocalisation at the mean age of 12.5 months. CONCLUSIONS: We reported data from the largest series of patients who underwent this hybrid procedure. Our experience demonstrated encouraging results to expand the use of this approach to bridge high-risk patients with diminutive pulmonary arteries to a second step of surgical repair.

Rapid cardiac ventricular pacing to facilitate embolization of vein of Galen malformations: technical note.

In BriefBabies born with life-threatening brain blood-vessel malformations can be helped with new heart pacemaker technology to temporarily stop the flow of blood in their bodies during surgery, for inducing hypotension to aid in controlled embolization.

Prediction of stenting related adverse events through patient-specific finite element modelling.

Right ventricular outflow tract (RVOT) calcific obstruction is frequent after homograft conduit implantation to treat congenital heart disease. Stenting and percutaneous pulmonary valve implantation (PPVI) can relieve the obstruction and prolong the conduit lifespan, but require accurate pre-procedural evaluation to minimize the risk of coronary artery (CA) compression, stent fracture, conduit injury or arterial distortion. Herein, we test patient-specific finite element (FE) modeling as a tool to assess stenting feasibility and investigate clinically relevant risks associated to the percutaneous intervention. Three patients undergoing attempted PPVI due to calcific RVOT conduit failure were enrolled; the calcific RVOT, the aortic root and the proximal CA were segmented on CT scans for each patient. We numerically reproduced RVOT balloon angioplasty to test procedure feasibility and the subsequent RVOT pre-stenting expanding the stent through a balloon-in-balloon delivery system. Our FE framework predicted the occurrence of CA compression in the patient excluded from the real procedure. In the two patients undergoing RVOT stenting, numerical results were consistent with intraprocedural in-vivo fluoroscopic evidences. Furthermore, it quantified the stresses on the stent and on the relevant native structures, highlighting their marked dependence on the extent, shape and location of the calcific deposits. Stent deployment induced displacement and mechanical loading of the calcific deposits, also impacting on the adjacent anatomical structures. This novel workflow has the potential to tackle the analysis of complex RVOT clinical scenarios, pinpointing the procedure impact on the dysfunctional anatomy and elucidating potential periprocedural complications.

Is mesocardia with left-sided caval vein draining to coronary sinus a contraindication for a percutaneous pulmonary valve implantation? A case description.

Introduction Although the right jugular vein approach for percutaneous pulmonary valve implantation is well described, there are no reports that describe a percutaneous pulmonary valve implantation through a left superior caval vein to coronary sinus pathway. Case A 14-year-old female with tetralogy of Fallot, mesocardia, left superior caval vein draining into the coronary sinus, and hemiazygos continuation of the inferior caval vein underwent ventricular septal defect closure, with homograft insertion from the right ventricle to the pulmonary artery, patch augmentation of the left pulmonary artery, and creation of an atrial communication. Thereafter followed numerous catheterisations and interventions with stent implantation for stenosis of the left pulmonary artery and the homograft, as did device closure of the atrial communication. When she was a 12-year-old, the indications for a percutaneous pulmonary valve implantation were fulfilled and she underwent implantation of a 22 mm Melody® valve through the left superior caval vein. The extra-stiff exchange wire was pre-formed into a "U-spiral"-type configuration, according to the underlying anatomy, in order to provide a smooth route for the delivery of stents, to create the landing zone, and for the implantation of the Melody "ensemble". The procedure was performed under deep sedation according to our standard protocol. The duration of the procedure was 172 min and the radiation time was 24.9 min. CONCLUSION: On the basis of this unique experience, percutaneous pulmonary valve implantation is safe and feasible even in patients with unusual anatomy. Crucial is the "U-spiral" shaped configuration of the guide wire.

Automatic activation mapping and origin identification of idiopathic outflow tract ventricular arrhythmias.

PURPOSE: Activation mapping is used to guide ablation of idiopathic outflow tract ventricular arrhythmias (OTVAs). Isochronal activation maps help to predict the site of origin (SOO): left vs right outflow tract (OT). We evaluate an algorithm for automatic activation mapping based on the onset of the bipolar electrogram (EGM) signal for predicting the SOO and the effective ablation site in OTVAs. METHODS: Eighteen patients undergoing ablation due to idiopathic OTVAs were studied (12 with left ventricle OT origin). Right ventricle activation maps were obtained offline with an automatic algorithm and compared with manual annotation maps obtained during the intervention. Local activation time (LAT) accuracy was assessed, as well as the performance of the 10ms earliest activation site (EAS) isochronal area in predicting the SOO. RESULTS: High correlation was observed between manual and automatic LATs (Spearman's: 0.86 and Lin's: 0.85, both p<0.01). The EAS isochronal area were closely located in both map modalities (5.55 ± 3.56mm) and at a similar distance from the effective ablation site (0.15±2.08mm difference, p=0.859). The 10ms isochronal area longitudinal/perpendicular diameter ratio measured from automatic maps showed slightly superior SOO identification (67% sensitivity, 100% specificity) compared with manual maps (67% sensitivity, 83% specificity). CONCLUSIONS: Automatic activation mapping based on the bipolar EGM onset allows fast, accurate and observer-independent identification of the SOO and characterization of the spreading of the activation wavefront in OTVAs.

A Membranous Septal Aneurysm Causing Right Ventricular Outflow Tract Obstruction in an Adult.

We describe a case of a 69-year-old female referred for the evaluation of exertional dyspnea, with a small membranous ventricular septal defect (VSD) and right ventricle (RV) outflow tract obstruction. Using transthoracic echo was diagnosed VSD with left to right shunting and transesophageal echo (TEE) was used to a better anatomical characterization. TEE showed a perimembranous subaortic VSD that developed a high-velocity flow in RV. Pulmonary valve appears normal and right ventricular infundibular hypertrophy or double-chambered RV was excluded from the study. Furthermore, TEE showed a malaligned VSD and the presence of perimembranous mobile tissue protruding in RV. We hypothesized that this tissue can be attributed to broken septum aneurysm and protruding during systole, it causes a dynamic RV output tract obstruction.