Electrocardiographic Features and Prevalence of Bilateral Bundle-Branch Delay

Abstract

ElectrocardiogramsDuring electrophysiology study or device implantation, the surface ECG was monitored continuously and stored on a computer-based digital recording system (LabSystemPro, Bard Electrophysiology, Lowell, MA).© 2014 American Heart Association, Inc. Original ArticleBackground-Definitive diagnosis of bilateral bundle-branch delay/block may be made when catheter-induced right bundlebranch block (RBBB) develops in patients with baseline left bundle-branch (LBB) block. We hypothesized that a RBBB pattern with absent S waves in leads I and aVL will identify bilateral bundle-branch delay/block. Methods and Results-Fifty patients developing transient RBBB pattern in lead V1 during right heart catheterization were studied.Patients were grouped according to whether the baseline ECG demonstrated a normal QRS, left fascicular blocks, or LBB block pattern. The RBBB morphologies in each group were compared. The prevalence of bilateral bundle-branch delay/block pattern was examined in our hospital ECG database. All patients with baseline normal QRS complexes (n=30) or left fascicular blocks (4 anterior, 5 posterior) developed a typical RBBB pattern. Among the 11 patients with a baseline LBB block pattern, 7 developed an atypical RBBB pattern with absent S waves in leads I and aVL and the remaining 4 demonstrated a typical RBBB. The absence of S waves in leads I and aVL during RBBB was 100% specific and 64% sensitive for the presence of pre-existing LBB block. Among the consecutive 2253 hospitalized patients with RBBB, 34 (1.5%) had the bilateral bundle-branch delay/block pattern. Conclusions-An ECG pattern of RBBB in lead V1 with absent S wave in leads I and aVL indicates concomitant LBB delay.Pure RBBB and bifascicular blocks are associated with S waves in leads I and aVL. (Circ Arrhythm Electrophysiol. 2014;7:640-644.)Key Words: bundle-branch block ◼ heart block

<p>Masquerading Bundle Branch Block in a Patient with Heart Failure in Nigeria</p>

“…Lenègre also reported similar findings of severe damage in RBB and LBB in patients with MBBB pattern. 6 Tzogias et al 7 in their study of patients who developed RBBB from catheter induced trauma to the right bundle branch during right heart catheterization, having divided the patients into normal, left anterior or posterior fascicular block and left bundle branch block group based on their background ECG morphology. They reported that MBBB pattern (RBBB in lead V1 with absent S wave in leads I and aVL) was seen only among the group with background LBBB among the 3 groups, while the remaining groups developed the typical RBBB pattern.…”

“…7,8 They may require permanent pacemaker insertion. 7,14 From a Brazilian registry, MBBB was associated with an estimated 4-year mortality and pacemaker insertion ratio of 41.4% and 38.9%, respectively. 16 MBBB sometimes present with syncope due to complete AV block necessitating pacemaker insertion.…”

“…16 MBBB sometimes present with syncope due to complete AV block necessitating pacemaker insertion. 7,17 This patient already has a first-degree AV block, and requires close monitoring in case he develops a complete AV block requiring pacemaker insertion. Dhanse et al 1 reported a case of heart failure with reduced ejection fraction symptomatic over 3 months, with three vessel disease on coronary angiogram and masquerading bundle branch block on electrocardiogram whose condition deteriorated and died while on admission in the hospital awaiting coronary artery bypass grafting (CABG).…”

Bundle branch reentry: A novel mechanism for sustained ventricular tachycardia in Chagas heart disease

“…An atypical RBBB ECG pattern with absent or minimal S waves in leads I and aVL, also referred to as bilateral bundle-branch delay/block, was noted after RBB ablation ( Figure 3B ). 6 After ablation, repeat ventricular stimulation showed no inducible ventricular arrhythmias and the patient's ICD was reprogrammed to atrial sensed biventricular pacing. After over 4 years of follow-up no arrhythmias were detected by the ICD, and ultimately the patient underwent heart transplantation owing to worsening heart failure.…”

A Narrow QRS Tachycardia—What Is the Diagnosis?

“…In the setting of a pre-existing LBBB, with the exception of bilateral bundle branch delay, the onset of supra-VT would not result in narrowing of the QRS complex. 2 The relatively narrow QRS duration could be explained by the presence of VT involving electrical capture of the His-Purkinje system. In our patient's case, the VT must have entered the His-Purkinje system below the site of LBBB, with conduction down the Purkinje fibers resulting in a narrow QRS complex.…”