Bundle Branch Reentrant Ventricular Tachycardia Research Articles

Bundle branch reentrant ventricular tachycardia in a patient with Fabry disease

BackgroundBundle branch reentrant ventricular tachycardia is a unique type of VT that employs both bundles and the ventricular septum as integral components of a re-entrant circuit. It is usually observed in dilated cardiomyopathy, and its circuit depends exclusively on the specialized conduction system.Case presentationA 67-year-old man with a history of Fabry disease, and atrial fibrillation ablation, was admitted for a wide QRS tachycardia at 150 bpm, with an LBBB. Pharmacological therapy failed to stop the arrhythmia. Intracardiac recordings confirm the diagnosis. His Bundle recordings are essential, and Atrioventricular (AV) dissociation is typically present. The method used to induce left BBRVT is right ventricle apex stimulation. An electrophysiological study showed an AV dissociation a long HV sequence and a similar QRS morphology between VT and sinus rhythm. An overdrive stopped it. The same arrhythmia reappears and is restored to sinus rhythm by electrical cardioversion. We decided to implant an Implantable Cardiac defibrillator (ICD) with a backup pacing for secondary prevention and to ablate the right bundle branch.ConclusionBBRVT is a rare entity that is underreported. Pharmacological therapy is usually inefficient. An ICD is recommended for secondary prevention and can provide backup pacing, frequently required after catheter ablation to prevent the development of AV block or an excessive prolonged HV interval. Catheter ablation of the bundle branch is the first-line therapy.

Progressive outcomes of bundle branch reentrant ventricular tachycardia in patients without structural heart disease

Ablation strategies to treat bundle branch reentrant ventricular tachycardia (BBRT) are well described. However, reports of long-term follow-up outcomes in BBRT patients without structural heart disease (SHD) are limited. The purpose of this study was to investigate the long-term follow-up prognosis of BBRT patients without SHD. Changes in electrocardiographic and echocardiographic parameters were used to evaluate progression during follow-up. Potential pathogenic candidate variants were screened using a specific gene panel. Eleven consecutive BBRT patients without obvious SHD based on echocardiographic and cardiovascular magnetic resonance imaging results were enrolled. Median age was 20 (11-48) years, and median follow-up time was 72 months. During follow-up, PR interval [206 (158-360) ms vs 188 (158-300) ms; P = .018] and QRS duration [187 (155-240) ms vs 164 (130-178) ms; P = .008] each increased significantly compared with postablation. Right- and left-sided chamber dilation and reduced left ventricular ejection fraction (LVEF) also were observed. Clinical deterioration or events occurred in 8 patients: 1 sudden death; 3 both complete heart block and reduced LVEF; 2 significantly reduced LVEF; and 2 prolonged PR interval. Genetic testing results showed that 6 of 10 patients (excluding the patient with sudden death) had ≥1 potential pathogenic candidate variants. Further deterioration of His-Purkinje system conduction was observed in young BBRT patients without SHD after ablation. The His-Purkinje system may be the first target of genetic predisposition.

Left bundle branch re-entrant ventricular tachycardia in septal myocarditis with QRS narrowing after ablation.

Left bundle branch re-entrant ventricular tachycardia in septal myocarditis with QRS narrowing after ablation.

Bundle Branch Re-Entrant Ventricular Tachycardia after Minimal Invasive Cardiac Surgery

Background: Bundle branch re-entrant ventricular tachycardia (BBRVT) is a monomorphic ventricular arrhythmia with wide QRS complexes caused by re-entrant tachycardia between both bundle branches. BBRVT can occur in a variety of cardiac pathologies with His–Purkinje system (HPS) conduction abnormalities such as dilated cardiomyopathy, coronary artery disease, hypertrophic cardiomyopathy, valvular heart disease and even after aortic valve surgery. Case report: A 62-year-old male patient with an ischemic cardiomyopathy and implantable cardioverter defibrillator (ICD) underwent minimal invasive aortic valve replacement (Yil-AVR) and coronary artery bypass graft (CABG). He was remitted a week later because of relapsing sustained ventricular tachycardia (VT). Electrocardiogram showed a wide QRS tachycardia, which was remarkably similar to the patient’s sinus rhythm. Analysis of ICD revealed the presence of BBRVT. Catheter ablation of the right bundle branch (RBB) was performed. He is currently in clinical follow-up and no reoccurrence of VT has been recorded so far. Conclusion: Patients with known cardiomyopathy can develop BBRVT early after cardiac surgery. To our knowledge, this is the first time that BBRVT occurred after Yil-AVR.

BUNDLE BRANCH REENTRANT VENTRICULAR TACHYCARDIA AFTER TRANSCATHETER AORTIC VALVE REPLACEMENT

New onset left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR) is associated with an increased risk of sudden death. While this is often due to complete heart block (CHB), bundle branch reentrant ventricular tachycardia (BBRVT) can occur. A 69 year old male with

Long-Term Clinical Outcome of Radiofrequency Catheter Ablation for Treatment of Bundle Branch Re-Entrant Ventricular Tachycardia

Long-Term Clinical Outcome of Radiofrequency Catheter Ablation for Treatment of Bundle Branch Re-Entrant Ventricular Tachycardia

Bundle Branch Re-Entrant VentricularTachycardia: Novel Genetic Mechanisms in a Life-Threatening Arrhythmia.

This study sought to investigate for an underlying genetic etiology in cases of apparent idiopathic bundlebranch re-entrant ventricular tachycardia (BBRVT). BBRVT is a life-threatening arrhythmia occurring secondary to macro-re-entry within the His-Purkinje system. Although classically associated with dilated cardiomyopathy, BBRVT may also occur in the setting of isolated,unexplained conduction system disease. Cases of BBRVT with normal biventricular size and function were recruited from 6 North American centers. Enrollment required a clinically documented wide complex tachycardia and BBRVT proven during invasive electrophysiology study. Study participants were screened for mutations within genes associated with cardiac conductionsystem disease. Pathogenicity of identified mutations was evaluated using in silico phylogenetic and physicochemical analyses and invitro biophysical studies. Among 6 cases of idiopathic BBRVT, each presented with hemodynamic compromise and 2 suffered cardiac arrests requiring resuscitation. Putative culprit mutations were identified in 3 of 6 cases, including 2 in SCN5A (Ala1905Gly [novel] and c.4719C>T [splice site mutation]) and 1 in LMNA (Leu327Val [novel]). Biophysical analysis of mutant Ala1905Gly Nav1.5 channels in tsA201 cells revealed significantly reduced peak current density and positive shiftsin the voltage-dependence of activation, consistent with a loss-of-function. The SCN5A c.4719C>T splice sitemutation has previously been reported as disease-causing in 3 cases of Brugada syndrome, whereas the novel LMNA Leu327Val mutation was associated with a classic laminopathy phenotype. Following catheter ablation, BBRVT was noninducible in all cases and none experienced a clinical recurrence during follow-up. Our investigation into apparent idiopathic BBRVT has identified the first genetic culprits for this life-threatening arrhythmia, providing further insight into its underlying pathophysiology and emphasizing a potentialrole for genetic testing in this condition. Our findings also highlight BBRVT as a novel genetic etiology ofunexplainedsudden cardiac death that can be cured with catheter ablation.

Abstract 12229: Bundle Branch Reentrant Ventricular Tachycardia: Novel Genetic Mechanisms in a Life-Threatening Arrhythmia

Introduction: Bundle branch reentrant ventricular tachycardia (BBRVT) is a life-threatening ventricular arrhythmia occurring secondary to macroreentry within the His-Purkinje system. Although classically associated with dilated cardiomyopathy, BBRVT may also occur in the setting of isolated, unexplained conduction system disease. Hypothesis: Idiopathic BBRVT may be secondary to genetic mutations associated with conduction system disease. Methods & Results: We identified 6 cases of BBRVT associated with normal biventricular size and function from 6 centers across North America. Study participants were screened for mutations within pre-specified genes linked to cardiac conduction system disease. Putative culprit mutations were identified in 3 of 6 cases, including 2 in SCN5A (Ala1905Gly [novel] and c.4719C>T [splice site mutation]) and 1 in LMNA (Leu327Val [novel]). Biophysical analysis of mutant Ala1905Gly Na v 1.5 channels in tsA201 cells revealed significantly reduced peak current density and positive shifts in the voltage-dependence of activation consistent with a loss-of-function. The SCN5A c.4719C>T splice-site mutation has previously been reported as disease causing in 3 cases of Brugada syndrome, while the novel LMNA Leu327Val mutation was associated with a classic laminopathy phenotype. Following catheter ablation, BBRVT was non-inducible in all cases and no clinical recurrences were observed during follow-up. Conclusions: Our investigation into apparent idiopathic BBRVT has identified the first genetic culprits for this life-threatening ventricular arrhythmia. This provides further insight into its underlying pathophysiology and emphasizes that conduction system disease, in the absence of ventricular dilation, serves as a sufficient substrate for BBRVT. Our findings also highlight BBRVT as a novel genetic etiology of unexplained sudden cardiac death that can be cured with catheter ablation.

Bundle branch reentry: A rare mechanism of ventricular tachycardia in endomyocardial fibrosis, without ventricular dilation

IntroductionBundle branch reentry as a mechanism of ventricular tachycardia (VT) in endomyocardial fibrosis (EMF) is not described. Case reportA 52-year-old woman with left ventricular (LV) EMF had VT needing cardioversion. She had mitral regurgitation and left bundle branch block, but no LV dilation or heart failure. During electrophysiological study, clinical VT could be easily induced, and it was confirmed to be bundle branch reentrant VT (BBRVT). She was treated with ablation of the right bundle branch. ConclusionBBRVT can occur in EMF even without cardiac dilatation. Its recognition is important, as radiofrequency ablation can be curative.

Rare Cause of Wide QRS Tachycardia.

Cardiac involvement is a well-known feature of neuromuscular diseases. Most commonly cardiac manifestations occur later in the course of the disease. Occasionally severe cardiac disease, including conduction disturbances, life-threatening arrhythmias, and cardiomyopathy, with its impact on prognosis, may be dissociated from peripheral myopathy. We report a case of bundle branch reentrant ventricular tachycardia as primary manifestation of myotonic dystrophy and discuss associated diagnostic and treatment challenges.

Bundle Branch Reentrant Ventricular Tachycardia in a patient with Brugada syndrome who survived from ventricular fibrillation

Bundle Branch Reentrant Ventricular Tachycardia in a patient with Brugada syndrome who survived from ventricular fibrillation

Bundle Branch Reentrant Ventricular Tachycardia With Wide and Narrow QRS Morphology

Bundle branch reentrant ventricular tachycardia (BBR-VT) is generally recognized as VT with wide QRS complexes that includes the His-Purkinje system and ventricle in its circuit. BBR-VT is well known to be commonly associated with structural heart diseases and left ventricular dysfunction.1 We report a rare case of BBR-VT displaying wide and narrow type QRS complexes in a patient without obvious structural heart disease or overt ventricular conduction disturbance. Editor’s Perspective see p e92 A 39-year-old man with episodes of wide QRS tachycardia was referred to our institution for electrophysiological study and catheter ablation. ECG during his clinical tachycardia showed left axis deviation and left bundle branch block (LBBB)–type morphology. Baseline 12-lead ECG showed sinus rhythm with no remarkable abnormalities, except for slight right axis deviation (Figure 1A). Transthoracic echocardiography was also normal, with normal values for left ventricular size (diastolic diameter, 46 mm) and systolic function (ejection fraction, 62%). There was nothing suggestive in the patient’s medical history, such as syncope, nor was there any family history of sudden cardiac death. Figure 1. Twelve-lead ECG of sinus rhythm and ventricular tachycardia (VT). A , Sinus rhythm showed slight right axis deviation. B , VT1 showed left bundle branch block pattern. C , VT2 had narrow QRS complexes and similar morphology to that of sinus rhythm. D , VT3 with right bundle branch block morphology was observed after spontaneous conversion from VT2. Diagnostic electrophysiological study demonstrated a normal A-H interval of 78 ms and an H-V interval of 48 ms during sinus rhythm. Programmed ventricular stimulation with single extrastimulus delivered from right ventricular apex revealed decremental ventriculoatrial conduction as S1S2 interval shortened, and V3 phenomenon was observed by an S1S2 interval of 280 ms.2 Sustained LBBB forms wide QRS tachycardia with QRS width of 144 ms and cycle length of 270 …

Editor’s Perspective: Bundles Branch Reentry

Among the most memorable classic bedside teaching discussions in electrophysiology is the consideration of a narrow complex beat in a patient with fixed bundle branch block. The discussion would frequently extend to questioning how narrow complex tachycardias can arise from the ventricles. As in many aspects of medicine, exceptional cases serve to further understanding of fundamental concepts germane to frequently encountered arrhythmias. In this installment of the Teaching Rounds in Cardiac Electrophysiology, Kusa et al1 continue this educational tradition by guiding us through an intriguing case of ventricular tachycardia (VT) with multiple morphologies that was successfully ablated at a single location. They teach us about the need to think imaginatively, yet logically, when considering the components of the infra-Hisian conduction system that may participate in tachycardia. After combining insight and electrogram analysis and excluding some candidate possibilities, they hypothesize one possible explanation for their findings and success with ablation of the right bundle branch. Article see p e87 A commonly asked question is whether the H-V interval measured during bundle branch reentrant VT is shorter or longer than the H-V interval measured in sinus rhythm. Figure A illustrates the important distinction between true and pseudo-intervals in electrophysiology. The H-V interval in sinus rhythm is a true conduction interval with conduction passing through the region of the recording electrodes near the His bundle and then exiting to the ventricles through the distal bundle branches such that it truly reflects the conduction time from His depolarization to ventricular activation. However, during typical bundle branch reentry, conduction proceeds from a common branch point (marked as A) to the His and concurrently down the right bundle toward the ventricular exit. Thus, there is no actual linear conduction from the His to the V but rather from a common branch point to both of …

Incessant slow bundle branch reentrant ventricular tachycardia in a young patient with left ventricular noncompaction

A 15-year-old girl was admitted to the cardiology outpatient clinic due to mild palpitations and documented incessant slow ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern. The baseline electrocardiogram revealed first-degree atrioventricular block and intraventricular conduction defect. Transthoracic echocardiography showed prominent trabeculae and intertrabecular recesses suggesting left ventricular noncompaction (LVNC), which was confirmed by cardiac magnetic resonance imaging. During electrophysiological study, a sustained bundle branch reentrant VT with LBBB pattern and cycle length of 480 ms, similar to the clinical tachycardia, was easily and reproducibly inducible. As there was considerable risk of need for chronic ventricular pacing following right bundle ablation, no ablation was attempted and a cardioverter-defibrillator was implanted. To the best of our knowledge, no case reports of BBR-VT as the first manifestation of LVNC have been published. Furthermore, this is an extremely rare presentation of BBR-VT, which is usually a highly malignant arrhythmia.

Incessant slow bundle branch reentrant ventricular tachycardia in a young patient with left ventricular noncompaction

A 15-year-old girl was admitted to the cardiology outpatient clinic due to mild palpitations and documented incessant slow ventricular tachycardia (VT) with left bundle branch block (LBBB) pattern. The baseline electrocardiogram revealed first-degree atrioventricular block and intraventricular conduction defect. Transthoracic echocardiography showed prominent trabeculae and intertrabecular recesses suggesting left ventricular noncompaction (LVNC), which was confirmed by cardiac magnetic resonance imaging. During electrophysiological study, a sustained bundle branch reentrant VT with LBBB pattern and cycle length of 480 ms, similar to the clinical tachycardia, was easily and reproducibly inducible. As there was considerable risk of need for chronic ventricular pacing following right bundle ablation, no ablation was attempted and a cardioverter-defibrillator was implanted. To the best of our knowledge, no case reports of BBR-VT as the first manifestation of LVNC have been published. Furthermore, this is an extremely rare presentation of BBR-VT, which is usually a highly malignant arrhythmia.

Diagnosis and Ablation of Multiform Fascicular Tachycardia

Fascicular tachycardia (FT) is an uncommon cause of monomorphic sustained ventricular tachycardia (VT). We describe 6 cases of FT with multiform QRS morphologies. Six of 823 consecutive VT cases were retrospectively analyzed and found attributable to FT with multiform QRS patterns, with 3 cases exhibiting narrow QRS VT as well. All underwent electrophysiology study including fascicular potential mapping, entrainment pacing, and electroanatomic mapping. The first 3 cases describe similar multiform VT patterns with successful ablation in the upper mid septum. Initially, a right bundle branch block (RBBB) VT with superior axis was induced. Radiofrequency catheter ablation (RFCA) targeting the left posterior fascicle (LPF) resulted in a second VT with RBBB inferior axis. RFCA in the upper septum just apical to the LBB potential abolished VT in all cases. Cases 4 and 5 showed RBBB VT with alternating fascicular block compatible with upper septal dependent VT, resulting in bundle branch reentrant VT (BBRT) after ablation of LPF and left anterior fascicle (LAF). Finally, Cases 5 and 6 demonstrated spontaneous shift in QRS morphology during VT, implicating participation of a third fascicle. In Case 6, successful ablation was achieved over the proximal LAF, likely representing insertion of the auxiliary fascicle near the proximal LAF. Multiform FTs show a reentrant mechanism using multiple fascicular branches. We hypothesize that retrograde conduction over the septal fascicle produces alternate fascicular patterns as well as narrow VT forms. Ablation of the respective fascicle was successful in abolishing FT but does not preclude development of BBRT unless septal fascicle is targeted and ablated.

A case of an infant with bundle branch reentrant ventricular tachycardia

Catheter ablation of the right bundle branch was performed on an 11-month-old infant for the treatment of drug-resistant bundle branch reentrant ventricular tachycardia. The occurrence of right bundle branch block could not be used as an endpoint of treatment because the patient had presented with incomplete right bundle branch block pattern during sinus rhythm. We performed ablation of the right bundle branch and utilized changes of duration and morphology of the QRS complex as indicators. Eight years have passed with no development of any atrioventricular block or tachycardia episode.

Electrical storm in a patient with dilated non-ischaemic cardiomyopathy

Bundle-branch re-entrant ventricular tachycardia (BBRVT) is usually seen in patients with dilated cardiomyopathy. The diagnosis should be suspected in case the QRS morphology during the tachycardia is identical to that in sinus rhythm. Identifying patients with BBRVT is important because they can be easily treated by catheter ablation.This report describes a patient previously implanted with a cardiac resynchronization therapy defibrillator (CRT-D) presenting with an electrical storm due to BBRVT.

Characteristics of bundle branch reentrant ventricular tachycardia with a right bundle branch block configuration: feasibility of atrial pacing

We assessed the inducibility of bundle branch reentrant ventricular tachycardia (BBR-VT) with a right bundle branch block (RBBB) configuration in patients with BBR-VT. Eight consecutive patients (5 men, 45+/-18 years old) with inducible BBR-VT were included. We evaluated the clinical and electrophysiological characteristics in these patients to explore the inducible factors of BBR-VT with an RBBB configuration. Six of eight patients had inducible BBR-VT with an RBBB configuration, including four patients with a clinical VT with the same QRS morphology. All patients exhibited an LBBB or RBBB type intraventricular conduction disturbance during sinus rhythm. The mean HV interval at baseline was 79+/-18 ms. The reproducibility of the BBR-VT with an RBBB pattern was achieved by incremental atrial pacing during an isoproterenol infusion in 4/6 patients (67%) and by programmed ventricular stimulation in the other two. After a right bundle ablation, the BBR-VT was no longer inducible in any of the cases. Our results indicate that it is not rare to induce BBR-VT with an RBBB configuration. For the induction of an RBBB type BBR-VT, incremental atrial pacing may play a significant role in addition to ventricular pacing.

Catheter ablation of bundle branch reentrant ventricular tachycardia

Bundle branch reentrant ventricular tachycardia (BBR-VT) is a form of macroreentrant tachycardia involving the bundle of His, both bundle branches, and the ventricular myocardium in the circuit. It generally occurs in the background of dilated cardiomyopathy, prior valve surgery, or other cardiac disease with an underlying His-Purkinje system (HPS) disease. Clinically, BBR-VT usually results in marked hemodynamic compromise and often presents with syncope, presyncope, or sudden cardiac arrest. When a ventricular tachycardia is induced, the presence of His deflections preceding every ventricular deflection should alert one to the possibility of this entity. It is important to show that oscillations in the H-H cycle length results in variations in V-V cycle length. Entrainment of the tachycardia from atrium and right ventricular apex and characteristics of postpacing intervals can be used to differentiate this arrhythmia from intramyocardial reentry and supraventricular tachycardia with aberrancy. Right bundle branch ablation usually cures the tachycardia, and recurrence is uncommon. The underlying cardiac disease and ventricular dysfunction dictate the prognosis and choice of device therapy in these patients.