Patients with left bundle branch block (LBBB) often show abnormal images on exercise thallium (T1)-201 scintigraphy without evidence of significant coronary stenosis. We investigated the mechanism for this phenomenon. Six patients with LBBB and without significant coronary stenosis underwent T1-201 SPECT, ECG-gated SPECT imaging with Tc-99m-methoxyisobutyl-isonitrile (MIBI), and atrial pacing s...

Background This study is the first to use quantitative perfusion CMR to evaluate regional differences in myocardial blood flow (MBF) in patients with left bundle branch block (LBBB). LBBB is often associated with underlying CAD but its presence can limit the diagnostic accuracy of non-invasive imaging tests. In particular, there is a high incidence of false-positive results with exercise SPECT ...

BackgroundProlongation of ventricular depolarization time (QRS duration), particularly in left bundle branch block (LBBB), is commonly associated with many cardiac diseases. We posit that the QRS duration and degree of left-axis deviation (LAD) identify significant left ventricular (LV) systolic dysfunction in patients with LBBB. MethodsIn this prospective study, 150 patients with diagnosis of ...

BACKGROUND Assessment of ventricular dyssynchrony in patients with heart failure is used for selecting candidates for cardiac resynchronization therapy (CRT). The patterns of regional distribution of dyssynchrony in a population with LBBB with and without heart failure have not been well delineated. This aspect forms the object of the study. METHODS Tissue Doppler Imaging (TDI) data of consec...

BACKGROUND Electrical fusion between left ventricular pacing and spontaneous right ventricular activation is considered the key to resynchronisation in sinus rhythm patients treated with single-site left ventricular pacing. AIM Use of QRS morphology to optimize device programming in patients with heart failure (HF), sinus rhythm (SR), left bundle branch block (LBBB), treated with single-site ...

BACKGROUND Previous studies have shown that intraventricular conduction defect is associated with increased mortality in heart failure (HF) population. However, it is conflicting whether left bundle branch block (LBBB) or right bundle branch block (RBBB) is a better predictor for mortality. OBJECTIVE To evaluate the relationship between patterns of bundle branch block (BBB) and all-cause mort...

BACKGROUND The sequence of left ventricular (LV) systolic emptying is not completely understood. Using real-time 3-dimensional echocardiography, we investigated this sequence and LV synchronicity in physiological and pathological conditions. METHODS AND RESULTS The study population consisted of 116 healthy volunteers, 20 top-level athletes, 35 patients with LV dysfunction, and 84 patients wit...

This manuscript adopted the cardiac modeling and simulation method to study problems of physiological pacing in clinical application. A multiscale rabbit ventricular electrophysiological model was constructed. We simulated His-bundle (HBP) treatment for left bundle branch block (LBBB) atrioventricular (AVB), (LBBP) LBBB by setting various moments stimulus. The synthetic ECGs detailed electrical...

OBJECTIVE To determine the left ventricular (LV) activation pattern in patients with chronic heart failure and left bundle branch block (LBBB) on ECG. DESIGN Prospective study. SETTING Tertiary cardiology referral centre in Hong Kong. PATIENTS Seven patients with LV ejection fraction < 35% and typical LBBB on ECG with QRS duration > or = 130 ms were recruited. Five of them had non-ischaem...