Bundle Branch Reentry: Mechanisms, diagnosis and management

ISBN: 978938605679

Bundle branch reentry: A mechanism of ventricular tachycardia in the absence of myocardial or valvular dysfunction

AbstractObjective, The aim of this study was to present bundle branch recentry as the mechanism of sustained ventricular tachycardia in the absence of myocardial or valvular dysfunction.Background. Previous reports have documented the relation between structural heart disease and bundle branch reentrant ventricular tachycardia. Myocardial or valvular dysfunction has thus far been recognised as the only anatomic substrate for the development of this tachycardia.Methods. Three patients with a wide QRS complex tachycardia underwent noninvasive and invasive cardiac evaluation and electrophysiologic studies to identify the substrate and mechanism of tachycardia. Catheter ablation of the right bundle branch using radiofrequency current was performed in each patient.Results. The patients were ail men (aged 54, 34 and 72 years) who presented with presyncope, palpitation and cardiac arrest, respectively. Electrocardiography during sinus rhythm revealed nonspecific intraventricular conduction delay in all three patients. Cardiac evaluation revealed no evidence of myocardial or valvular dysfunction in any patient. The baseline HV interval was prolonged in each patient (90, 100 and 75 ms, respectively). Programmed right ventricular stimulation initiated bundle branch reentrant tachycardia with typical left (three patients) and right (one patient) bundle branch block pattern. Catheter ablation of the right bundle branch using radiofrequency current abolished bundle branch reentry in all three patients. After 26-, 13- and 8-month follow-up periods, complete right bundle branch block persisted, and all three patients remained asymptomatic without antiarrhythmic drugs.Conclusions. Sustained bundle branch reentry can be a clinical arrhythmia in patients with no identifiable myocardial or valvular dysfunction except for isolated conduction abnormalities in the His-Purkinje system. This mechanism of tachycardia should be recognized during electrophysiologic evaluation, given the seriousness of this arrhythmia and the availability of effective treatment

Ablation of left free-wall accessory pathways using radiofrequency energy at the atrial insertion site: transseptal versus transaortic approach

INTRODUCTION: Transcatheter ablation of the left free-wall atrioventricular accessory pathways (AP) by delivery of radiofrequency current at the ventricular insertion site has been shown to be effective. The efficacy of such a technique targeting the atrial insertion site of the AP was evaluated. METHODS AND RESULTS: One hundred consecutive patients with left free-wall APs and symptomatic supraventricular tachyarrhythmias were included. APs were manifest in 55 patients and concealed in 45. There were 55 men and 45 women with a mean age of 35 years. A total of 107 left free-wall APs were identified in these patients. In these 100 patients, successful ablation was accomplished in all by using a transseptal (45 patients) or transaortic (54 patients) technique. In one patient, ablation was accomplished from within the coronary sinus. Seven patients required a repeat ablative procedure, which was performed successfully. During 107 ablative procedures, six were associated with nonfatal complications including pericardial effusion (hemopericardium) in two patients, mild mitral regurgitation in two patients, swelling of the left arm in one patient, and staphylococcal bacteremia in one patient. Eighty-two (82%) patients underwent a repeat electrophysiologic study 6 to 8 weeks after successful ablation and were found to have no functioning AP or inducible supraventricular tachycardia. During a mean follow-up of 20 +/- 8 months, none of the 100 patients had a recurrence of tachyarrhythmias. CONCLUSION: These data indicate that the atrial insertion site of the AP can be successfully ablated in the majority of patients with left free-wall APs by using either a transseptal or transaortic approach. Furthermore, both techniques are associated with minimal morbidity and no mortality