Right bundle branch block and middle septal fiber block with or without left anterior fascicular block manifested as aberrant conduction in apparent healthy individuals: Electro-vectorcardiographic characterization

Masquerading bundle branch block obscuring the diagnosis of Brugada syndrome: an electrocardiographic and vectorcardiographic study

“…In contrast, leads V1, V2, and V3 showed right BBB pattern with an initial q wave. This narrow q wave mimicking septal necrosis was not present in the baseline ECG and indicates lack of septal activation by the left midseptal fascicle . The VCG showed that the first vector was oriented downwards, slightly leftwards, and backwards.…”

“…The final electrical forces were directed forwards and downwards, but not as rightward as in a typical RBBB because they were counterbalanced by the delayed activation of the interventricular septum. Both the ECG and the VCG showed a masquerading BBB with delayed activation of the right bundle, left anterior fascicle, and left midseptal fascicle [7]. The wide QRS in the right precordial leads with slurring of the terminal portion of the QRS made the onset of the T wave difficult to determine.…”

“…Masquerading BBB is a frequently unrecognized intraventricular conduction disorder [4]. Although previously considered a conduction disturbance occurring in abnormal hearts, we have recently shown that masquerading BBB can be observed in patients without structural heart disease during aberrant ventricular conduction elicited by premature atrial beats [7]. We have now shown that this conduction disturbance can also be elicited following ajmaline administration.…”

Transient prominent anterior QRS forces in the setting ST segment elevation coronary syndrome: Left septal fascicular block

“…Left septal fascicular block (LSFB) has been described in the following scenarios: critical proximal obstruction of the LAD before its first septal perforator branch [1] with ACS [2], Wellens' syndrome [3], chronic chagasic myocarditis in Latin America [4], Kearns-Sayre syndrome [5], self-expandable percutaneous transcatheter aortic valve implantation for severe aortic stenosis [6], diabetes mellitus [7], and manifested as aberrant conduction in apparent healthy individuals [8]. Unlike left anterior and left posterior fascicular blocks, which modify the ECG in the frontal plane, LSFB exclusively affects the precordial leads, causing PAF with anterior displacement of the QRS electromotive forces.…”

Electrocardiogram (ECG) patterns of left anterior fascicular block and conduction impairment in ventricular myocardium: a whole-heart model-based simulation study

“…Recent studies showed that LAFB in elderly patients could be a useful clinical marker for various cardiovascular diseases, and is associated with an increased risk of atrial fibrillation, heart failure, and even death (Mandyam et al, 2013;Nielsen et al, 2014). LAFB has recently attracted increasing attention (Acunzo et al, 2013;Lu et al, 2015;Nguyen et al, 2016).…”