Ventricular Outflow Tract Tachycardia Research Articles

Catheter ablation of idiopathic ventricular tachycardia without the use of fluoroscopy

BackgroundCatheter ablation is the treatment of choice for many patients with idiopathic ventricular tachycardia (VT). Unfortunately, conventional catheter ablation is guided by fluoroscopy, which is associated with a small but definite radiation risk for patients and laboratory personnel. The aim of our study is to assess feasibility, success rate and safety of idiopathic VT ablation procedure performed without the use of fluoroscopy. MethodsNineteen consecutive patients undergoing idiopathic VT ablation at our institution have been included. The ablation procedures were performed under the guidance of electroanatomical mapping (EAM) system and intracardiac echocardiography (ICE). ResultsNineteen patients (mean age 38.7years) underwent ablation procedure for idiopathic VT. Twelve (63%) had outflow tract VT, 3 (18%) fascicular tachycardia, 2 (11%) peri-tricuspidal VT, 1 (5%) peri-mitral VT, and 1 (5%) lateral left free-wall VT. The mean procedural time was 170.2±45.7min. No fluoroscopy was used in any procedural phase. Acute success rate was 100%. No complication was documented in any patients. After a mean follow up of 18±4months, recurrences occurred in 2 patients. ConclusionsIn our preliminary experience idiopathic VT ablation without the use of fluoroscopy was feasible and safe, using a combination of EAM and ICE. Success rate was excellent with no complication.

Ablation of androgen receptor gene triggers right ventricular outflow tract ventricular tachycardia

BackgroundSex hormones and calcium (Ca2+) regulation play roles in the pathophysiology of ventricular tachycardia from right ventricular outflow tract (RVOT). The purpose of this study was to evaluate whether androgen receptor knockout (ARKO) can increase RVOT arrhythmogenesis through modulating RVOT electrophysiology and Ca2+ homeostasis. MethodsConventional microelectrodes were used to study the action potential (AP) in RVOT tissues prepared from wild type (WT) and ARKO mice (aged 6–10months) before and after caffeine (1mM), isoproterenol (1μM), adenosine (10μM) and flecainide (5μM) administration. The Fluo-3 fluorescence Ca2+ imaging with confocal microscopy and western blots were used to investigate intracellular Ca2+ (Ca2+i) transients, Ca2+ sparks, and the expressions of ionic channel proteins in ARKO and WT RVOT myocytes. ResultsWe found that ARKO RVOTs (n=13) had longer AP duration, faster burst firing (5.4±0.7 vs. 3.4±0.7Hz, P<0.05), and higher incidence of early afterdepolarizations (82% vs. 8%, P<0.001) than WT RVOTs (n=11). Adenosine and flecainide can suppress caffeine- or isoproterenol-induced spontaneous rates and burst firing in WT RVOTs, but not in ARKO RVOTs. ARKO RVOT myocytes had a higher frequency (7.7±2.8 vs. 1.3±0.4spark/mm/s, P<0.05) and incidence (89% vs. 47%, P<0.05) of Ca2+ sparks, and greater expressions of Cav1.2, NCX, phosphorylated RyR (s2814), phosphorylated phospholamban (Thr17), CAMKII and GRK2 than WT RVOT myocytes. However, ARKO and WT RVOT myocytes exhibit similar Ca2+i transients and SR Ca2+ content, and less expression of calsequestrin. ConclusionsARKO changes RVOT electrophysiology and Ca2+ homeostasis with increased ventricular arrhythmogenesis.

Better outcome of ablation for sustained outflow-tract ventricular tachycardia when tachycardia is inducible.

In patients presenting with spontaneous sustained ventricular tachycardia (VT) from the outflow-tract region without overt structural heart disease ablation may target premature ventricular contractions (PVCs) when VT is not inducible. We aimed to determine whether inducibility of VT affects ablation outcome. Data from 54 patients (31 men; age, 52 ± 13 years) without overt structural heart disease who underwent catheter ablation for symptomatic sustained VT originating from the right- or left-ventricular outflow region, including the great vessels. A single morphology of sustained VT was inducible in 18 (33%, SM group) patients, and 11 (20%) had multiple VT morphologies (MM group). VT was not inducible in 25 (46%) patients (VTni group). After ablation, VT was inducible in none of the SM group and in two (17%) patients in the MM group. In the VTni group, ablation targeted PVCs and 12 (48%) patients had some remaining PVCs after ablation. During follow-up (21 ± 19 months), VT recurred in 46% of VTni group, 40% of MM inducible group, and 6% of the SM inducible group (P = 0.004). Analysis of PVC morphology in the VTi group further supported the limitations of targeting PVCs in this population. Absence of inducible VT and multiple VT morphologies are not uncommon in patients with documented sustained outflow-tract VT without overt structural heart disease. Inducible VT is associated with better outcomes, suggesting that attempts to induce VT to guide ablation are important in this population.

OP-124 Clinical Characteristics and Acute Results of Catheter Ablation for Outflow Tract Ventricular Tachycardia

The aim of this study was to describe the clinical characteristics and the acute procedure success rate of patients who underwent an ablation procedure for outflow tract tachycardia (OTT) or ventricular premature beats (VPBs).

Idiopathic Ventricular Tachycardia: Transcatheter Ablation or Antiarrhythmic Drugs?

Ventricular tachycardia or frequent premature ventricular contractions (PVCs) can occur in the absence of any detectable structural heart disease. In this clinical setting, these arrhythmias are termed idiopathic. Usually, they carry a benign prognosis and any potential ablative intervention is carried out if patients are highly symptomatic or, more importantly, if frequent ventricular arrhythmias can lead to ventricular dysfunction. In this paper, different forms of idiopathic ventricular tachycardia are reviewed. Outflow tract ventricular tachycardia from the right ventricle is the most frequent form of the so-called idiopathic ventricular tachycardia. Other forms of idiopathic ventricular arrhythmias include ventricular tachycardia/PVCs arising from tricuspid annulus, from the mitral annulus, inter-fascicular ventricular tachycardia and papillary muscle ventricular tachycardia. When interventional treatment is deemed necessary, detailed mapping ( earliest activation during VT/PVC, pace mapping ) is crucial as to identify the successful ablation site. Catheter ablation more than antiarrhythmic drug treatment is usually highly effective in eliminating idiopathic ventricular arrhythmias and providing prevention of recurrence. Idiopathic VTs are not considered life-threatening arrhythmias and, prevention of recurrences is often achieved by means of catheter ablation that provides an improvement of quality of life. The overall acute success rate of catheter ablation is about 85-90% with a long-term prevention of arrhythmia recurrence of about 75-80%. It is advisable that the procedure is carried out by electrophysiologists with expertise in VT catheter ablation and extensive knowledge of cardiac anatomy as to ensure a high success rate and reduce the likelihood of major complications.

Ablation of outflow tract ventricular tachycardia.

Ventricular tachycardia in patients with structurally normal hearts is most frequently due to adenosine-sensitive, triggered activity. The most common sites of origin are the right and left ventricular outflow tracts. Patients may present with symptoms such as palpitations, or less commonly cardiomyopathy. Treatment options include beta blockers, calcium channel blockers, sodium channel blockers, potassium channel blockers, and catheter ablation. Catheter ablation is highly effective and when performed by a skilled electrophysiologist, can be considered first-line treatment. Knowledge of outflow tract and surrounding anatomy is vital to optimizing results. In this review, we discuss outflow tract anatomy and electrocardiographic morphology, as well as techniques for optimizing ablation outcomes.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches.

Unusual occurrence of ventricular tachycardia induced by single bee sting.

Sir, A 35-year-old female patient was admitted to our emergency room with palpitations, 1 h after a single bee sting in the left hand. She was previously in good health, not on any medications and did not have any past allergic reactions. Local inspection of the left hand revealed only mild erythema and swelling. Hemoglobin, thyroid-stimulating hormone, and serum electrolyte levels were within the normal range. Initial 12-lead electrocardiogram (ECG) showed short runs of the nonsustained ventricular tachycardia (VT) [Figure 1]. Only a few seconds later, she suddenly complained of chest discomfort, dizziness, and intensive palpitations. Repeat ECG showed wide QRS-complex tachycardia at a rate of 160 b.p.m. without detectable P-waves [Figure 2]. A bolus of 150 mg amiodarone i.v. was administered, which rapidly terminated VT and restored normal sinus rhythm [Figure 3]. The treatment was continued with bisoprolol 2.5 mg twice daily. Figure 1 Electrocardiogram showing standard Leads I, II, and III: Frequent ectopic ventricular beats with short runs of the nonsustained ventricular tachycardia Figure 2 Electrocardiogram showing standard Leads I, II, and III: Sustained ventricular tachycardia with the right bundle branch block pattern Figure 3 Electrocardiogram showing standard Leads I, II, and III: Regular sinus rhythm just after conversion with amiodarone Transthoracic echocardiography revealed only a mild mitral valve prolapse with mild mitral regurgitation. The patient refused to undergo further invasive investigations (namely coronary angiography and electrophysiological study) so we performed computed tomography-coronary angiography, which showed the normal anatomy of the coronary arteries and the absence of stenosis. The patient was discharged after 48 h and remained asymptomatic during the next 6 months follow-up. A 24-h-holter-ECG was performed after 1–6 months and was normal. Bee stings have been associated with a wide variety of local and systemic reactions including rarely, tachyarrhythmias, commonly occurring in individuals with preexisting heart disease such as left atrial enlargement and left ventricular failure.[1] Although the arrhythmogenic mechanism of the bee venom is still unknown, many pharmacologically active constituents of the bee venom have been isolated including histamine, serotonin, dopamine and noradrenaline, melittin, hyaluronidase, apamin, and phospholipase A2 which may induce tachyarrhythmias in the absence of anaphylaxis.[2] However, in the presence of anaphylaxis tachyarrhythmias are more common, and possible mechanisms include a direct antigen-antibody myocardial reaction, a pharmacological effect of mediators released during anaphylaxis, the effects of agents such as adrenaline used for treatment, hypoxia, hypotension, preexisting heart disease or a combination of several factors.[3] In this patient only mild mitral valve prolapse was demonstrated by transthoracic echocardiography; and to the best of our knowledge, this is the first reported case of VT in a patient with mild mitral valve prolapse-induced by single bee sting in the absence of anaphylaxis. Bee venom as a metabolic insult and resultant autonomic overactivity probably induced tachyarrhythmia in this case. Cardiac magnetic resonance imaging to look for myocardial scarring and electrophysiologic study to look for inducibility of idiopathic outflow tract VT would be indicated in the setting of purely monomorphic VT. Finally, this case implies the necessity of meticulous ECG monitoring in patients presenting with palpitations and ventricular ectopic beats after bee sting, because malignant tachyarrhythmias may occur even in the absence of anaphylaxis in the setting of only mild structural heart abnormalities, as reported here. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Malignant conversion of benign right ventricular outflow track ventricular tachycardia 18 years post-ablation

This case report describes the rare phenomenon of malignant conversion of benign right ventricular outflow tract ventricular tachycardia into idiopathic ventricular fibrillation 18 years after successful ablation, in the absence of any type of heart disease. We review the current literature looking at predictors for this event, with the conclusion that there are no reliable risk predictors available. Until clear guidelines exist, we suggest patients be informed and monitored for the possibility of “malignant conversion” following ablation for benign idiopathic outflow tract ventricular tachycardia.

Demonstration of a hidden interaction between the aortomitral continuity and the conduction system in a case of idiopathic left ventricular outflow tract ventricular tachycardia

We describe a case of idiopathic left ventricular outflow ventricular tachycardia. Monomorphic ventricular arrhythmia (VA) with a right bundle branch block morphology and an inferior axis was induced through exercise or isoproterenol infusion. During VA bigeminy, a spiked presystolic potential (PP) preceding the VA with a qrS pattern in the unipolar electrogram was recorded at the aortomitral continuity (AMC). Radiofrequency catheter ablation eliminated the VA despite the persistence of sinus-PP bigeminy. Furthermore, these PP rates were dependent on the preceding sinus rhythm rates. The present case suggests a hidden interaction between the AMC and the conduction system.

Electrocardiographic (ECG) clues to differentiate idiopathic right ventricular outflow tract tachycardia (RVOTT) from arrhythmogenic right ventricular cardiomyopathy (ARVC)

IntroductionArrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetic cardiomyopathy that most commonly affects young adults. The most commonly observed reason of death in patients suffering from ARVC/D is sudden cardiac death (SCD). On the other hand, idiopathic right ventricular outflow tract tachycardia (RVOT VT) usually has a benign course. Both of the entities may have ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern and inferior axis. We tried to propose new discriminating electrocardiographic indices for differentiation of foretold entities. Material and methodThis was a retrospective study. We reviewed records of patients admitted between 2003 and 2012 with the diagnosis of either ARVC/D or RVOT VT that presented with VT (LBBB morphology). ResultA total of fifty nine patients (30 RVOT VT and 29 ARVC/D) were enrolled. In ARVC/D group, men were dominant while the reverse was true of RVOT VT. Palpitation was more common in the RVOT VT group (90% vs. 66.7%), but aborted SCD and sustained VT were more common in ARVC/D group. The new ECG criteria proposed by us mean QRS duration in V1–V3, QRS difference in right and left precordial leads, S wave upstroke duration, JT interval dispersion, QRS and JT interval of right to left precordial leads were all significantly longer in ARVC/D when compared to RVOT VT patients (p < 0.001). ConclusionThe proposed ECG criteria can be used for non-invasive diagnosis of ARVC/D and incorporation in the future updates of ARVC/D task force criteria.

Discrete potentials guided radiofrequency ablation for idiopathic outflow tract ventricular arrhythmias.

Discrete potentials (DPs) have been recorded and targeted as the site of ablation of the outflow tract arrhythmias. The aim of the present study was to investigate the significance of DPs with respect to mapping and ablation for idiopathic outflow tract premature ventricular contractions (PVCs) or ventricular tachycardias (VTs). Seventeen consecutive patients with idiopathic right or left ventricular outflow tract PVCs/VTs who underwent radiofrequency catheter ablation were included. Intracardiac electrograms during the mapping and ablation were analysed. During sinus rhythm, sharp high-frequency DPs that displayed double or multiple components were recorded following or buried in the local ventricular electrograms in all of the 17 patients, peak amplitude 0.51 ± 0.21 mV. The same potential was recorded prior to the local ventricular potential of the PVCs/VTs. Spontaneous reversal of the relationship of the DPs to the local ventricular electrogram during the arrhythmias was noted. The DPs were related to a region of low voltage showed by intracardiac high-density contact mapping. At the sites with DPs, lower unipolar and bipolar ventricular voltage of sinus beats were noted compared with the adjacent regions without DPs (unipolar: 6.1 ± 1.8 vs. 8.3 ± 2.3 mV, P < 0.05; bipolar: 0.62 ± 0.45 vs. 1.03 ± 0.60 mV, P < 0.05). The targeted DPs were still present in 12 patients after successful elimination of the ectopies. Discrete potentials were not present in seven controls. Discrete potentials and related low-voltage regions were common in idiopathic outflow tract ventricular arrhythmias. Discrete potential- and substrate-guided ablation strategy will help to reduce the recurrence of idiopathic outflow tract arrhythmias.

New diagnostic criteria for identifying left-sided ventricular ectopy using non-contact mapping and virtual unipolar electrogram analysis.

To assess the efficacy of non-contact mapping for outflow tract premature ventricular contraction (PVC) and ventricular tachycardia (VT) ablation in patients without structural heart disease and a precordial transition at V3 or later and to determine the diagnostic accuracy of new virtual unipolar electrogram criteria for distinguishing left from right-sided foci using a multi-electrode array positioned within the right ventricular outflow tract. Virtual unipolar electrograms at early activation (EA) and break out (BO) sites in 100 patients (36 left-sided foci) who underwent acutely successful outflow tract ablation were analysed and voltage and timing-based criteria measured. The best performing parameters were then re-assessed in 41 patients (14 left-sided) prospectively. Of the candidate criteria for determining a left from right-sided focus, the voltage at 20 ms after EA (EA-V20) and the time from BO to QRS onset (BO-QRS) were the best discriminators with area under the curve (AUC) values based on receiver operator characteristics (ROCs) of 0.947 (0.905-0.989), P < 0.001, and 0.951 (0.907-0.995), P < 0.001, respectively. These two parameters were subsequently assessed prospectively in a further 41 patients (14 left-sided) using the pre-specified cut-off values of -2 mV for EA-V20 and 10 ms for BO-QRS which demonstrated excellent diagnostic accuracy and sufficient inter-beat and inter-observer reproducibility. This large single-centre experience demonstrates that a strategy for outflow tract PVC/VT ablation using non-contact mapping allows for excellent success rates. Furthermore, detailed analysis of virtual unipolar electrograms allows accurate and reproducible determination of left from right-sided foci that may be used to guide mapping and ablation.

Adenosine-insensitive right ventricular tachycardia: novel variant of idiopathic outflow tract tachycardia.

A hallmark of idiopathic right ventricular outflow tract (RVOT) tachycardia is its sensitivity to adenosine (ADO), which is consistent with a triggered mechanism. We have identified a novel group of patients with ADO-insensitive, non-reentrant RVOT tachycardia. This study aimed to identify the clinical and electrophysiologic characteristics of ADO-insensitive RVOT tachycardia. The response of ventricular tachycardia (VT) to ADO was evaluated in 46 consecutive patients with inducible sustained idiopathic RVOT tachycardia. The clinical and electrophysiologic characteristics of patients with ADO-insensitive RVOT tachycardia were compared with patients with ADO-sensitive VT and arrhythmogenic right ventricular cardiomyopathy (ARVC) VT. Sustained RVOT tachycardia terminated with ADO in 41 patients (89%), while 5 patients (11%) had ADO-insensitive VT. The electrophysiology study findings of patients with ADO-sensitive and ADO-insensitive RVOT tachycardia were similar. Compared with a group of 10 patients with ARVC, patients with ADO-insensitive RVOT tachycardia had no ARVC-associated electrocardiographic or right ventricular morphologic findings, as well as fewer inducible VT morphologies. Analysis of myocardial biopsies at VT origin sites from 3 of 5 patients with ADO-insensitive RVOT tachycardia demonstrated somatic mutations in the A1 ADO receptor (R296C) in 1 patient and in the inhibitory G protein (F200L) in another patient, as described previously. These mutations were not identified at remote myocardial sites. Over a median follow-up period of 4.8 years, no patients insensitive to ADO developed an ARVC phenotype. Although most forms of idiopathic RVOT tachycardia are characterized by ADO sensitivity, we described a variant of ADO-insensitive VT that, in some cases, can be linked to somatic myocardial mutations involving the A1 ADO receptor-associated cyclic adenosine monophosphate-mediated pathway.

Preexcited Tachycardia Mimicking Outflow Tract Ventricular Tachycardia Ablated from the Left Coronary Cusp

Journal of Cardiovascular ElectrophysiologyVolume 25, Issue 6 p. 653-656 Case Report Preexcited Tachycardia Mimicking Outflow Tract Ventricular Tachycardia Ablated from the Left Coronary Cusp JAYAPRAKASH SHENTHAR M.D., D.M., F.A.C.C., Corresponding Author JAYAPRAKASH SHENTHAR M.D., D.M., F.A.C.C. Electrophysiology Unit, Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, IndiaAddress for correspondence: Jayaprakash Shenthar, M.D., D.M., F.A.C.C., Sri Jayadeva Institute of Cardiovascular Sciences & Research, Bannerghatta Road, Jayanagar 9th Block, Bangalore 560069, Karnataka, India. Fax: +91-802-653-4477; E-mail: jshenthar@yahoo.comSearch for more papers by this authorMANEESH K. RAI M.D., D.M., MANEESH K. RAI M.D., D.M. Electrophysiology Unit, Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, IndiaSearch for more papers by this author JAYAPRAKASH SHENTHAR M.D., D.M., F.A.C.C., Corresponding Author JAYAPRAKASH SHENTHAR M.D., D.M., F.A.C.C. Electrophysiology Unit, Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, IndiaAddress for correspondence: Jayaprakash Shenthar, M.D., D.M., F.A.C.C., Sri Jayadeva Institute of Cardiovascular Sciences & Research, Bannerghatta Road, Jayanagar 9th Block, Bangalore 560069, Karnataka, India. Fax: +91-802-653-4477; E-mail: jshenthar@yahoo.comSearch for more papers by this authorMANEESH K. RAI M.D., D.M., MANEESH K. RAI M.D., D.M. Electrophysiology Unit, Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, IndiaSearch for more papers by this author First published: 21 March 2014 https://doi.org/10.1111/jce.12412Citations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume25, Issue6June 2014Pages 653-656 RelatedInformation

Tachycardia-induced cardiomyopathy due to repetitive monomorphic ventricular ectopy in association with isolated left ventricular non-compaction : online article - case report

Isolated left ventricular non-compaction is a rare genetic disorder manifesting mainly with heart failure, ventricular arrhythmias and systemic embolism. Isolated ventricular tachycardia originating from the right ventricular outflow tract is an arrhythmia that can be treated medically and/or by radiofrequency catheter ablation. Here, we report a case of an asymptomatic 16-year-old boy with a new diagnosis of dilated cardiomyopathy, left ventricular noncompaction and right ventricular outflow tract tachycardia. Electrophysiological studies and radiofrequency ablation of the right ventricular outflow tract tachycardia resulted in normalisation of left ventricular systolic function. This is the first case reporting left ventricular non-compaction in association with tachycardia-induced cardiomyopathy secondary to repetitive monomorphic right ventricular outflow tract tachycardia.

Metastatic Melanoma of the Right Ventricular Outflow Tract as a Cause of Ventricular Tachycardia

A 47-year-old woman with a history of melanoma metastatic to her stomach and esophagus presented with palpitations and shortness of breath. Her heart rate was 182 beats/min and her blood pressure was 124/54 mmHg. A new grade 3/6 systolic murmur was present over the left precordium. An electrocardiogram showed a wide QRS complex tachycardia with left bundle branch block, inferior axis, and ventriculoatrial dissociation compatible with a right ventricular outflow tract (RVOT) ventricular tachycardia (Fig. 1). She was cardioverted to sinus rhythm. After cardioversion, she displayed an rSR' QRS morphology in lead V1 and T-wave inversions, with a slow S-wave upstroke in the anterior precordial leads (V1 and V2) (Fig. 2). These findings are associated with right ventricular conduction delay and cardiomyopathy. She had no electrolyte abnormalities. Fig. 1 The 12-lead electrocardiogram at presentation shows a wide QRS complex tachycardia with left bundle branch, inferior axis, and ventriculoatrial dissociation (arrows point to P waves). Fig. 2 Post-cardioversion 12-lead electrocardiogram shows an rSR' QRS morphology in lead V1, as well as T-wave inversions and a slurred S-wave upstroke in the anterior precordial leads. A nuclear stress test showed normal left ventricular function and perfusion. Imaging with both transthoracic echocardiography (Fig. 3) and cardiac magnetic resonance (CMR) (Fig. 4) revealed a mass infiltrating the RVOT. On both T1- and T2-weighted imaging, the mass had high signal intensity consistent with melanoma.1,2 Unfortunately, the mass was inoperable, the patient was not a candidate for further chemotherapy, and she died one year later. Fig. 3 A) Transthoracic echocardiogram (basal short-axis view) shows a mass infiltrating the right ventricular outflow tract (arrow). B) Color-flow Doppler mode at the same location shows turbulent flow in the right ventricular outflow tract as a result of the ... Fig. 4 Cardiac magnetic resonance image shows a mass in the right ventricular outflow tract (*) with high signal intensity on both A) T1-weighted and B) T2-weighted imaging. LV = left ventricle; RV = right ventricle

Noninvasive electrocardiographic mapping to guide ablation of outflow tract ventricular arrhythmias

BackgroundLocalizing the origin of outflow tract ventricular tachycardias (OTVT) is hindered by lack of accuracy of electrocardiographic (ECG) algorithms and infrequent spontaneous premature ventricular complexes (PVCs) during electrophysiological studies.ObjectivesTo prospectively assess the performance of noninvasive electrocardiographic mapping (ECM) in the pre-/periprocedural localization of OTVT origin to guide ablation and to compare the accuracy of ECM with that of published ECG algorithms.MethodsPatients with symptomatic OTVT/PVCs undergoing clinically indicated ablation were recruited. The OTVT/PVC origin was mapped preprocedurally by using ECM, and 3 published ECG algorithms were applied to the 12-lead ECG by 3 blinded electrophysiologists. Ablation was guided by using ECM. The OTVT/PVC origin was defined as the site where ablation caused arrhythmia suppression. Acute success was defined as abolition of ectopy after ablation. Medium-term success was defined as the abolition of symptoms and reduction of PVC to less than 1000 per day documented on Holter monitoring within 6 months.ResultsIn 24 patients (mean age 50 ± 18 years) recruited ECM successfully identified OTVT/PVC origin in 23/24 (96%) (right ventricular outflow tract, 18; left ventricular outflow tract, 6), sublocalizing correctly in 100% of this cohort. Acute ablation success was achieved in 100% of the cases with medium-term success in 22 of 24 patients. PVC burden reduced from 21,837 ± 23,241 to 1143 ± 4039 (P < .0001). ECG algorithms identified the correct chamber of origin in 50%–88% of the patients and sublocalized within the right ventricular outflow tract (septum vs free-wall) in 37%–58%.ConclusionsECM can accurately identify OTVT/PVC origin in the left and the right ventricle pre- and periprocedurally to guide catheter ablation with an accuracy superior to that of published ECG algorithms.

Catheter ablation of right ventricular outflow tract tachycardia using contact force guidance

Outflow tract tachycardias (OTT) originating from the right or left ventricular outflow tract are thought to be benign. However, symptoms can be disabling and deterioration of left ventricular function may occur with a high arrhythmia burden. Catheter ablation has a high acute success rate of up to 90 %, but recurrences are not uncommon [1, 2]. Novel catheter designs, and mapping and ablation technologies aim to improve procedural outcome, lower the complication rate, and increase the long-term success rate [3]. The TactiCath® catheter (TactiCath®, Endosense, SA Meyrin/Geneva, Switzerland, distributed by Biotronik, Berlin, Germany) is a contact force (CF) sensing radiofrequency ablation catheter that provides real-time assessment of tip-to-tissue CF during ablation [4]. Until now, it has only been used in ablation of supraventricular tachycardias, mainly atrial fibrillation. In this report, we describe the case of a patient who underwent successful ablation of right ventricular OTT and ventricular premature beats (VPBs) using CF guidance. To the best of our knowledge, this is the first case ever described of OTT ablation using CF with the TactiCath® catheter.

Arrhythmogenic right ventricular dysplasia masquerading as right ventricular outflow tract tachycardia

Introduction: Ventricular tachycardia is a frequent complication in patients affected by arrhythmogenic right ventricular dysplasia. the disease is characterized by malignant ventricular arrhythmias with poor outcome, right ventricular dilation and replacement of the myocardium with fatty and fibrous tissue. On the other hand, right ventricular outflow tract tachycardia does not appear to have any significant effect on cardiac mortality as it arises in the absence of any structural heart disease. case report: Herein, we discussed a 62-year-old female patient with ventricular tachycardia that suggested right ventricular outflow tract tachycardia. based on echocardiography, electrophysiological study and magnetic resonance imaging the final diagnosis was arrhythmogenic right ventricular dysplasia. During electrophysiological study two ventricular