Bundle Branch Reentry Ventricular Tachycardia Research Articles

Selective and non-selective right bundle pacing for the diagnosis of bundle branch reentry ventricular tachycardia.

Bundle branch reentry ventricular tachycardia (BBRVT) can be seen in patients with conduction disease. In this report, we describe the use of conduction system pacing for its diagnosis. BBRVT was induced in two patients with infra-nodal conduction disease. Bundle branch reentry ventricular tachycardia with a left bundle branch block morphology was observed in the first patient (type A), whereas the second patient had a right bundle branch block morphology (type C).The diagnosis of BBRVT was confirmed in both patients by ventriculo-atrial dissociation, and the interdependence of the conduction system and the ventricular tachycardia cycle length variations.Selective and non-selective RB pacing was observed in the two patients during apical right ventricular pacing for entrainment of BBRVT with evidence of manifest entrainment with non-selective RB capture in the first patient, and concealed entrainment by selective RB capture in the second patient. Other criteria for entrainment including a short post-pacing interval at the right bundle pacing site were noted. Right bundle pacing is feasible in patients with BBRVT and may be a helpful manoeuver for the diagnosis of BBRVT.

Ventricular arrhythmias in patients with prior aortic valve intervention: Characteristics, ablation and outcomes.

Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation in patients with aortic valve (AV) intervention (AVI) is limited. Catheter ablation (CA) can be challenging given perivalvular substrate in the setting of prosthetic valves. We sought to investigate the characteristics, safety, and outcomes of CA in patients with prior AVI and ventricular arrhythmias (VA). We identified consecutive patients with prior AVI (replacement or repair) who underwent CA for VT or PVC between 2013 and 2018. We investigated the mechanism of arrhythmia, ablation approach, perioperative complications, and outcomes. We included 34 patients (88% men, mean age 64 ± 10.4 years, left ventricular (LV) ejection fraction 35.2 ± 15.0%) with prior AVI who underwent CA (22 VT; 12 PVC). LV access was obtained through trans-septal approach in all patients except one patient who had percutaneous transapical access. One patient had combined retrograde aortic and trans-septal approach. Scar-related reentry was the dominant mechanism of induced VTs. Two patients had bundle branch reentry VTs. In the VT group, substrate mapping demonstrated heterogeneous scar that involved the peri-AV area in 95%. Despite that, the site of successful ablation included the periaortic region only in 6 (27%) patients. In the PVC group, signal abnormalities consistent with scar in the periaortic area were noted in 4 (33%) patients. In 8 (67%) patients, the successful site of ablation was unrelated to the periaortic area. No procedure-related complications occurred. The survival and recurrence-free survival rate at 1 year tended to be lower in VT group than in PVC group (p = .06 and p = .05, respectively) with a 1-year recurrence-free survival rate of 52.8% and 91.7%, respectively. No arrhythmia-related death was documented on long-term follow-up. CA of VAs can be performed safely and effectively in patients with prior AVI.

Recurring episodes of bundle branch reentry ventricular tachycardia due to aortitis preceded by SARS-CoV-2 infection: a case report

BackgroundSARS-CoV-2 may trigger both vasculitis and arrhythmias as part of a multisystem inflammatory syndrome described in children as well as in adults following COVID-19 infection with only minor respiratory symptoms. The syndrome denotes a severe dysfunction of one or more extra-pulmonary organ systems, with symptom onset approximately 2–5 weeks after the COVID-19 infection. In the present case, a seemingly intractable ventricular tachycardia preceded by SARS-CoV2 infection was only managed following the diagnosis and management of aortitis.Case presentationA 69-year-old woman was hospitalized due to syncope, following a mild COVID-19 infection. She presented with paroxysmal atrial fibrillation and intermittent ventricular tachycardia interpreted as a septum-triggered bundle branch reentry ventricular tachycardia, unaffected by amiodaron, lidocaine and adenosine. A CT-scan revealed inflammation of the aortic arch, extending into the aortic root. In the following days, the tachycardia progressed to ventricular storm with intermittent third-degree AV block. A temporary pacemaker was implanted, and radiofrequency ablation was performed to both sides of the ventricular septum after which the ventricular tachycardia was non-inducible. Following supplemental prednisolone treatment, cardiac symptoms and arrythmia subsided, but recurred after tapering. Long-term prednisolone treatment was therefore initiated with no relapse in the following 14 months.ConclusionWe present a rare case of aortitis complicated with life-threatening ventricular tachycardia presided by Covid-19 infection without major respiratory symptoms. Given a known normal AV conduction prior to the COVID-19 infection, it seems likely that the ensuing aortitis in turn affected the septal myocardium, enabling the reentry tachycardia. Generally, bundle branch reentry tachycardia is best treated with radiofrequency ablation, but if it is due to aortitis with myocardial affection, long-term anti-inflammatory treatment is mandatory to prevent relapse and assure arrhythmia control. Our case highlights importance to recognize the existence of the multisystem inflammatory syndrome in adults (MIS-A) following COVID-19 infection in patients with alarming cardiovascular symptoms. The case shows that the early use of an CT-scan was crucial for both proper diagnosis and treatment option.

Alternating wide complex tachycardia after surgical aortic valve replacement

A 51-year-old male developed recurrent episodes of palpitations and pre-syncope after surgical aortic valve replacement. Electrocardiograms after surgery revealed a wide complex tachycardia with alternating left bundle branch and right bundle branch block morphologies. An electrophysiology study (EPS) demonstrated typical bundle branch reentry ventricular tachycardia (BBRVT) treated successfully with right bundle ablation. We demonstrate the key diagnostic features of BBRVT on EPS, describe the circuit of BBRVT with explanation of the HV pseudointerval, and highlight the association of BBRVT and valve replacement.

Catheter ablation of ventricular tachycardia in the pediatric patients: A single-center experience.

Ventricular tachycardia (VT) with or without structural heart disease is uncommon but well-recognized clinically in children. With this retrospective study, we collected the data from the in-hospital pediatric patients of VT with catheter ablation therapy. The purpose of this study is to assess the acute results and the long-term outcome of catheter ablation in pediatric patients of VT in our single pediatric center. This study included 53 consecutive children (male/female=33/20, mean age=8.2±3.4 years, mean bodyweight=32.6±13.7kg). All patients underwent electrophysiological study with an attempt of catheter ablation for clinical monomorphic VT. Acute and long-term success rate of catheter ablation for the treatment of VT were compared between right and left VT as well as fascicular VT (FVT) and nonfascicular VT. There were 53 idiopathic VT forms found in the children, including FVT (n=32), outflow tract VT (n=15), papillary muscle VT (n=5), and bundle branch reentry VT (n=1). Acute success of catheter ablations for VT was achieved in 57 of all the 59 ablation procedures (97%) with VT recurrence occurred in six of 53 patients (11%). During a mean follow-up period of 29.2±21.7 months (range 1-76 months) after hospital discharge, ablations in nonfascicular VT were as successful as FVT. There was no significant difference in the success rate between the right and left VT. Catheter ablation is an effective treatment for idiopathic VT in children. The acute and long-term success rates of catheter ablation for idiopathic VT in pediatric patients with normal heart structure are satisfying.

Catheter ablation for monomorphic ventricular tachycardia in Brugada syndrome patients: detailed characteristics and long-term follow-up.

Brugada syndrome (BrS) is a risk of sudden cardiac death due to polymorphic ventricular tachycardia and ventricular fibrillation with unusual monomorphic ventricular tachycardia (MVT). Detailed characteristics of MVT and long-term outcome of catheter ablation are still unknown. This study is aimed to identify the detailed characteristics and long-term follow-up of catheter ablation in BrS patients. We evaluated 188 patients who were diagnosed with BrS from March 1999 to March 2018. Of those, patients who developed MVT and underwent catheter ablation were included. We identified eight MVTs in seven BrS patients. Three of them already had implantable cardioverter-defibrillator, and MVTs were terminated by cardioversion or anti-tachycardia pacing. Four patients presented with MVT originating from the right ventricular outflow tract, one patient had MVT arising from the LV septum, one patient had MVT arising from the tricuspid annulus, and one patient had bundle branch reentry ventricular tachycardia. All MVTs were successfully treated by catheter ablation in the acute phase, and seven of eight (87.5%) were free from ventricular tachyarrhythmia during the long-term follow-up (median, 7.2years). All MVT cases were successfully treated by catheter ablation. We observed high ventricular arrhythmia free rate following catheter ablation during the long-term follow-up period. BrS patients who developed MVT should consider catheter ablation.

Electrophysiologic Substrate, Safety, Procedural Approaches, and Outcomes of Catheter Ablation for Ventricular Tachycardia in Patients After Aortic Valve Replacement

This study sought to investigate the substrate, procedural strategies, safety, and outcomes of catheter ablation (CA) for ventricular tachycardia (VT) in patients with aortic valve replacement (AVR). VT ablation in patients with AVR is challenging, particularly when mapping and ablation in the periaortic region are necessary. We identified consecutive patients with mechanical, bioprosthetic, and transcatheter AVR who underwent CA for VT refractory to antiarrhythmic drugs and analyzed VT substrate, approach to LV access, complications, and long-term outcomes. Overall, 29 patients (87% men, mean age 67.9 ± 9.8 years, left ventricular ejection fraction 39 ± 10%) with prior AVR (13 mechanical, 15 bioprosthetic, 1 transcatheter AVR) underwent 40 ablations from 2004 to 2016. Left-sided mapping/CA was performed in 27 patients (36 procedures). Access was retrograde aortic in 11 procedures (all bioprosthetic), transseptal in 24 (13 mechanical; 10 bioprosthetic; 1 transcatheter AVR), or transventricular septal in 1. Periaortic bipolar or unipolar scar was detected in all 24 patients in whom detailed periaortic mapping was performed. Clinical VT circuit(s) involved the periaortic region in 10 patients (34%), 2 (7%) had bundle branch re-entry VT, and 17 (59%) had substrate unrelated to AVR. There were 2 major complications (both related to vascular access). Only 2 patients (9.1%) had VT recurrence. Over median follow-up of 12.8 months, 11 patients died (none as a result of recurrent VT). Whereas most patients undergoing CA for VT after AVR had VT from substrate unrelated to AVR, periaortic scar is universally present and bundle branch re-entry can be the VT mechanism. CA can be safely performed with excellent long-term VT elimination.

Electrophysiological Characteristics of Bundle Branch Reentry Ventricular Tachycardia in Patients Without Structural Heart Disease

The distinct electrophysiological features of bundle branch reentry ventricular tachycardia (VT) in patients without structural heart disease have not been systemically characterized. Nine patients (mean age, 29.6 years) with normal left ventricular function were enrolled. Bundle branch reentry VT with right and left bundle branch block (BBB) patterns was induced in 1 and 9 patients, respectively. The right bundle was attempted to record by a 6F decapolar or quadripolar catheter. Electroanatomic mapping of the left ventricle was performed in 6 patients. In all left BBB pattern VT, the mean VT cycle length was 329.3±89.1 ms, and the median HV interval during tachycardia was longer than that of baseline (78 [73-100] versus 71 [64.5-88] ms; P=0.11). The H-RB interval during VT was slightly shorter (P=0.14); however, the median RB-V interval was markedly longer than that during sinus rhythm (50 [29.5-83] versus 30 [8-51] ms; P=0.043]. In 6 patients with 3-dimensional mapping of the left ventricle, a slow anterograde or retrograde conduction over left HIS-Purkinje system with normal myocardial voltage was identified. In addition, Purkinje-related VTs (1.0±1.3 types) were also induced in 5 patients. Ablation was applied in distal left BB in patients with baseline left BBB and in one narrow QRS patient with sustained Purkinje-related VT, whereas right BB was targeted in other patients. During a mean follow-up of 31.4 months, frequent premature ventricular contractions occurred in one patient, and new VT developed in the other patient. Bundle branch reentry VT can occur in young patients with extensive conduction disturbances within HIS-Purkinje system. Ablation targeting at the distal left BB which bifurcates into left posterior and anterior fascicle can preserve the residual atrioventricular conduction, but intensive follow-up is needed.

Bundle branch reentry VT : Diagnosis, mapping, and ablation

Macroreentry in the His-Purkinje system can result in sustained ventricular tachycardia (VT) termed bundle branch reentry VT. Bundle branch reentry is usually associated with His-Purkinje disease and depressed left ventricular function. In the case of typical bundle branch reentry, the right bundle is activated in the anterograde direction and ventricular depolarization begins at the distal end of the right bundle on the ventricular septum generating atypical left bundle branch block QRS morphology. However, atypical surface ECGs can also be found in patients with severe left ventricular dysfunction and involvement of the right ventricle complicating the diagnosis of bundle branch reentry VT. It is important to diagnose bundle branch reentry VT because patients with bundle branch reentry VT may suffer from ahigh rate of serial implantable cardioverter defibrillator (ICD) interventions based on VT recurrences due to immediate reinitiation of the arrhythmia. Ablation of the right bundle branch easily cures bundle branch reentry VT and can prevent frequent ICD interventions. After ablation of bundle branch reentry VT, mortality remains high due to the severe left ventricular dysfunction in many patients, and the patients are candidates for cardiac resynchronization therapy (CRT-D).

Cardiac Manifestations of Myotonic Dystrophy - Complexities in Diagnosis and Management

Myotonic dystrophy (DM) is a multisystem disorder with autosomal dominant inheritance. Cardiac abnormalities may represent initial manifestations of DM even before neuromuscular involvement. Two such cases of DM are illustrated. A 14-year-old boy presents with exertional syncope and atrial flutter. After DC cardioversion, ECG demonstrated first degree atrioventricular block (AVB), left bundle branch block (LBBB). Electrophysiology study (EPS) revealed a HV interval of 79ms. A loop recorder is implanted. With further syncope, interrogation revealed paroxysmal atrial fibrillation and rapid tachycardia (ventricular rate 230bpm), with LVEF 35%, prompting insertion of a cardiac resynchronisation therapy defibrillator. Neurogenetic testing confirmed DM type 1, with CTG trinucleotide repeat expansion in DMPK gene. A 27-year-old male presents with rest syncope. Conduction disease (first degree AVB and HV interval (90ms)) was noted on ECG and EPS. Cardiac MRI revealed mild biventricular impairment. He developed recurrent broad complex tachyarrhythmias with LBBB morphology, consistent with bundle branch re-entry ventricular tachycardia (BBRVT), and underwent cardiac defibrillator implantation. Despite multiple appropriate shocks, non-compliance has delayed further treatment. Clinical features of DM are noted (frontal balding and myotonia) and neurogenetic testing is pending. Cardiac manifestations of DM include atrial/ventricular arrhythmias, conduction disease, cardiomyopathy and sudden cardiac death (SCD). The cardiac features can precede clinical diagnosis of DM. Furthermore, progression of conduction disease in DM is unpredictable, and VT (especially BBRVT) is common, so early invasive strategies are recommended. Awareness of this diagnosis is vital for timely management and prevention of SCD.

Monomorphic ventricular tachycardia in patients with Brugada syndrome: A multicenter retrospective study

Isolated cases of monomorphic ventricular tachycardia (MVT) in patients with Brugada syndrome (BrS) have been reported. We aimed to describe the incidence and characteristics of MVT in a cohort of patients with BrS who had received an implantable cardioverter-defibrillator (ICD). Data from 834 patients with BrS implanted with an ICD in 15 tertiary hospitals between 1993 and 2014 were included. The mean age of enrolled patients was 45.3 ± 13.9 years; 200 patients (24%) were women. During a mean follow-up of 69.4 ± 54.3 months, 114 patients (13.7%) experienced at least 1 appropriate ICD intervention, with MVT recorded in 35 patients (4.2%) (sensitive to antitachycardia pacing in 15 [42.8%]). Only QRS width was an independent predictor of MVT in the overall population. Specifically, 6 (17.1%) patients presented with right ventricular outflow tract tachycardia (successfully ablated from the endocardium in 4 and epicardial and endocardial ablation in 1), 2 patients with MVT arising from the left ventricle (1 successfully ablated in the supra lateral mitral annulus), and 2 (5.7%) patients with bundle branch reentry ventricular tachycardia. Significant structural heart disease was ruled out by echocardiography and/or cardiac magnetic resonance imaging. In this retrospective study, 4.2% of patients with BrS implanted with an ICD presented with MVT confirmed as arising from the right ventricular outflow tract tachycardia in 6, patients with MVT arising from the left ventricle in 2, and patients with bundle branch reentry ventricular tachycardia in 2. Endocardial and/or epicardial ablation was successful in 80% of these cases. These data imply that the occurrence of MVT should not rule out the possibility of BrS. This finding may also be relevant for ICD model selection and programming.

Reverse BBRVT in a structurally normal heart

We present a case of bundle-branch reentry ventricular tachycardia with RBBB morphology (reverse BBRVT) in a patient with preexisting right bundle-branch block and without apparent structural heart disease. The diagnosis of BBRVT may be very challenging due to the similar wide QRS morphology during tachycardia and in sinus rhythm, rather suggesting a supraventricular origin. BBRVT should be suspected even in the absence of structural heart disease, but especially in patients with extensive underlying His-Purkinje conduction disorders. The aetiology, mechanism, diagnostic issues and treatment are briefl y reviewed.

Bundle branch re-entry ventricular tachycardia in a patient with myotonic dystrophy

Bundle branch re-entry (BBR)-ventricular tachycardia (VT) is relatively rare with an incidence of about 6% in sustained monomorphic VT series. However, physicians unexpectedly encounter it in clinical practice. BBR-VT is associated with serious hemodynamic decompensation, and the clinical presentation in approximately 75% of patients with inducible BBR-VT is syncope or cardiac sudden death. Thus, precise mapping of His-Purkinje and bundle branch potentials is necessary for an accurate diagnosis and treatment of re-entrant mechanisms especially for BBR-VT. However, simultaneous recording of both the left-bundle (LB) and right-bundle (RB), as well as His-bundle (HB), potentials is often difficult during tachycardia. Here we report the clear documentation of the activation sequence of the His-Purkinje system during BBR-VT, which could be readily and completely treated by radiofrequency catheter ablation in a myotonic dystrophy patient.

Bundle branch reentry ventricular tachycardia in arrhythmogenic right ventricular dysplasia

A 42-year-old male had history of recurrent palpitation and was documented to have wide QRS tachycardia. Magnetic resonance imaging angiogram showed evidence of arrhythmogenic right ventricular dysplasia and severe right ventricular dysfunction. Electrophysiology study showed evidence of bundle branch reentry ventricular tachycardia. It was successfully treated by radiofrequency ablation of right bundle branch. This is probably the first case of bundle branch reentry as a mechanism for ventricular tachycardia in a case of arrhythmogenic right ventricular dysplasia.

Catheter Ablation of Ventricular Tachycardia

A B S T R A C T Catheter ablation is highly successful and may be considered as the first line treatment in all symptomatic idiopathic forms of ventricular tachycardia (VT). Also ablation plays an important role in recurrent VTs associated with structural heart disease and relatively preserved left ventricular ejection fraction (>35%) and/or bundle branch reentry VT. It also constitutes the preferable treatment modality in incessant VTs of any origin and in patients with implantable defibrillator (ICD) devices who present with recurrent VTs and/or an electrical storm leading to multiple ICD shocks Catheter ablation appears to improve arrhythmia control in about two thirds of patients with structural heart disease and mappable VTs. Novel substrate and/or noncontact mapping techniques suggest that even hemodynamically unstable VTs and/or VTs of multiple morphologies can be successfully ablated. As the ablation method is not curative and there remains the risk of dying suddenly in patients with depressed left ventricular ejection fraction, the majority of patients with VT associated with structural heart disease also receive an ICD.

Bundle branch re-entry ventricular tachycardia in a patient with complete heart block

A 58-year-old male patient presented episodes of palpitations in the context of atrioventricular block treated by a dual-chamber pacemaker. Clinical and electrophysiological studies identified the tachyarrhythmia to be bundle branch re-entrant ventricular tachycardia, which was successfully treated by radiofrequency ablation of the proximal right bundle branch.

10 Long-term prognosis in patients following catheter ablation for bundle branch reentry ventricular tachycardia

10 Long-term prognosis in patients following catheter ablation for bundle branch reentry ventricular tachycardia

10 Long-term prognosis in patients following catheter ablation for bundle branch reentry ventricular tachycardia

10 Long-term prognosis in patients following catheter ablation for bundle branch reentry ventricular tachycardia

Bundle-branch reentry and the postpacing interval after entrainment by right ventricular apex stimulation: a new approach to elucidate the mechanism of wide-QRS-complex tachycardia with atrioventricular dissociation.

Diagnosis of bundle-branch reentry ventricular tachycardia (BBR-VT) by the standard approach is challenging, and this may lead to nonrecognition of this tachycardia mechanism. Because the postpacing interval (PPI) after entrainment has been correlated with the distance from the pacing site to the reentrant circuit, BBR-VT entrainment by pacing from the right ventricular apex (RVA) should result in a PPI similar to the tachycardia cycle length (TCL). This factor may differentiate BBR-VT from other mechanisms of wide-QRS-complex tachycardia with AV dissociation, such as myocardial reentrant VT (MR-VT) or AV nodal reentrant tachycardia (AVNRT), in which the circuit is usually located away from the RVA. Transient entrainment by RVA pacing was attempted in 18 consecutive BBR-VTs and finally achieved in 13. Results were compared with those found in 59 consecutive MR-VTs and 50 consecutive AVNRTs. The mean PPI-TCL difference was significantly (P:<0.0001) shorter in the BBR-VT group (9+/-11 ms) than in the MR-VT (109+/-48 ms) and the AVNRT (150+/-29 ms) groups. No BBR-VT showed a PPI-TCL >30 ms (range -12 to 24 ms). Except for 2 MR-VTs, no MR-VT (range 21 to 211 ms) or AVNRT (range 100 to 215 ms) showed a PPI-TCL <30 ms. A PPI-TCL >30 ms, after entrainment by RVA stimulation, makes BBR-VT unlikely. Conversely, a PPI-TCL <30 ms is suggestive of BBR-VT but should lead to further investigation by use of conventional criteria.

Ablation Therapy for Cardiac Arrhythmias

Ablation has become an important and, in some cases, the first-line therapy for a number of tachyarrhythmias. The feasibility of treating arrhythmias with ablation was initially demonstrated with surgical ablation techniques. Recently, catheter ablation techniques have replaced the surgical approach in nearly all cases. Catheter ablation is highly effective for the Wolff-Parkinson-White syndrome, atrioventricular nodal reentry, and atrial ectopic tachycardia. It is effective for atrial flutter, although approximately one quarter of patients treated with catheter ablation continue to require therapy for concomitant atrial fibrillation. The surgical maze procedure has proved to be feasible for preventing atrial fibrillation. The risks and long-term efficacy of catheter ablation maze procedures for atrial fibrillation need to be defined. The efficacy of ablation for ventricular tachycardia varies with the type of tachycardia. Catheter ablation is very effective for the rare idiopathic ventricular tachycardias that occur in structurally normal hearts and for bundle-branch reentry ventricular tachycardia, which occurs most frequently in patients with dilated cardiomyopathy. When performed at an experienced center, surgical ablation is an excellent option for selected patients with ventricular tachycardia due to prior myocardial infarction who have a discrete aneurysm but otherwise well-preserved ventricular function. Catheter ablation shows promise for this arrhythmia, but it can be offered only to those patients who have relatively slow tachycardias that allow catheter mapping. Substantial advances in mapping and ablation technology will continue to occur, allowing nonpharmacologic control of cardiac arrhythmias to be achieved in an ever greater number of patients.