OBJECTIVES The goal of this study was to examine the relative impact of QRS morphology and duration in echocardiographic responses to cardiac resynchronization therapy (CRT) and clinical outcomes. BACKGROUND At least one-third of all patients treated with CRT fail to derive benefit. Patients without left bundle branch block (LBBB) or patients with smaller QRS duration (QRSd) respond less or n...

OBJECTIVES The purpose of this research was to examine the prognostic value of ST-segment changes (concordant ST-segment elevation and/or precordial V1 to V3 ST-segment depression) during presumed-new left bundle branch block (LBBB) in patients receiving fibrinolytic therapy. BACKGROUND These patients are often considered high-risk, but their outcome is not well-defined. METHODS The Hirulog...

An issue, which is not addressed by the guidelines, is whether, in the absence of Sgarbossa’s criteria, the association of acute coronary syndrome (ACS) type chest pain and left bundle branch block (LBBB) falls within the province of non-ST segment elevation ACS (nSTE-ACS) or whether it falls within the province of acute myocardial infarction. Strictly speaking, it is only when Sgarbossa’s crit...

BACKGROUND The purpose of this study was to assess the independent contribution of left bundle-branch block (LBBB) on cause-specific 1-year mortality in a large cohort with acute myocardial infarction (MI). METHODS AND RESULTS We studied a prospective cohort of 88,026 cases of MI from the Register of Information and Knowledge about Swedish Heart Intensive care Admissions in 72 hospitals in 19...

BACKGROUND Transcatheter aortic valve implantation (TAVI) is a novel therapy for treatment of severe aortic stenosis. Although 30% to 50% of patients develop new left bundle-branch block (LBBB), its effect on clinical outcome is unclear. METHODS AND RESULTS Data were collected in a multicenter registry encompassing TAVI patients from 2005 until 2010. The all-cause mortality rate at follow-up ...

AIMS To quantify left ventricular (LV) dyssynchrony in patients with left bundle branch block (LBBB) and in patients after myocardial infarction (MI) applying an accelerated three-dimensional (3D) tagging cardiac magnetic resonance (CMR) technique, and to combine dyssynchrony information with viability data obtained by late gadolinium enhancement (LGE) CMR. METHODS AND RESULTS Thirty-two pati...

BACKGROUND Although left bundle branch block (LBBB) alters the electrical activation of the heart, it is unknown how it might change the process of myocardial coordination (MC) and how it may affect the left ventricular (LV) systolic function. The present study assessed the effects of LBBB on MC in patients with LBBB with and without dilated (DCMP) or ischemic cardiomyopathy (ICMP). METHODS T...

Left bundle branch block (LBBB) is an electrophysiological abnormality that can have profound acute and chronic hemodynamic effects. Intermittent LBBB has been noted to occur with accelerations in heart rate, typically during exercise (known as rate-dependent LBBB). This has been associated with acute deteriorations in cardiac systolic function through the development of left ventricular (LV) d...

Left bundle branch block (LBBB) is considered a marker of underlying structural cardiac disease. To determine whether LBBB is cause or consequence of deterioration of left ventricular (LV) function is difficult as both are often diagnosed concomitantly. We discuss a patient where reversal of LBBB and subsequent normalization of LV function was observed after 2 different therapies, first after s...

Rate dependent left bundle branch block (LBBB) occasionally occurs during anaesthesia when the heart rate exceeds a critical value. Transient LBBB has been associated with increased heart rate under general and local anesthesia and without obvious aetiologic factors during anaesthesia [1]. It is usually a benign disorder but it may mask the ECG manifestations of ischemia. This case report descr...