Persistent Left Bundle Branch Block Research Articles

Postoperative permanent pacemaker implantation in patients undergoing trans-catheter aortic valve implantation: what is the incidence and are there any predicting factors?

A best evidence topic was written according to a structured protocol. The issue was to determine the incidence and predictors of postoperative permanent pacemaker (PPM) implantation in patients undergoing trans-catheter aortic valve implantation (TAVI) for symptomatic calcific aortic stenosis and to compare this to the known risks of this complication following surgical aortic valve replacement (AVR). Using the reported search method 3071 articles were identified, of which 94 were relevant to the procedure of TAVI and 14 were deemed to represent the best evidence. All 14 studies, including both multi-centre registries and single-centre retrospective case series containing ≥30 patients, reported incidence of postoperative PPM implantation. Five of these studies also assessed predictors of the need for postoperative PPM implantation. The author, journal, date and country of publication, study type, level of evidence, patient group, outcomes and results were tabulated for these studies. We conclude that the current best available evidence suggests that the mean incidence of PPM implantation following TAVI is 14.2% (range 0-34%, median 9.7%), although this appears higher with the CoreValve prosthesis (five studies, mean 20.8%, range 9.3-30.0%) than with the Edwards-Sapien prosthesis (six studies, mean 5.4%, range 0-10.1%). The mean incidences of PPM implantation overall and when using the CoreValve prosthesis are higher than the mean incidence of 7.0% (range 3-11.8%, median 7.2%) following conventional AVR and may be explained by distinct differences between the patient groups involved and the procedure performed. Indications for PPM implantation appear to occur early in the postoperative period following TAVI and there is little evidence of recovery following atrioventricular block (AVB). New onset persistent left bundle branch block is common following TAVI but the significance and follow-up required is unclear. Independent predictors of PPM requirement following TAVI include use of the CoreValve prosthesis and evidence of conduction system dysfunction, either pre-existing right bundle branch block or AVB at the time of TAVI. All patients should be made aware of the high risk of PPM implantation with TAVI.

Persistent Left Bundle Branch Block in a Patient With Dilated Cardiomyopathy That Improved With Low Dose Carvedilol Therapy

A 43-year-old Japanese woman with dilated cardiomyopathy had complete left ventricular bundle branch block (CLBBB), which had persisted for at least two years. At the time of admission, the serum brain natriuretic peptide (BNP) concentration was 502 pg/mL (normal range, 0-18 pg/mL), the left ventricular diastolic dimension (LVDd) was 59 mm, the left ventricular systolic dimension (LVDs) was 54 mm, the %fractional shortening (FS) was 8%, and the left ventricular ejection fraction (LVEF) was 19.7% by echocardiography. Low dose carvedilol was initiated for the treatment of heart failure. Adverse effects, such as progression of cardiac conduction disturbances, did not occur after initiation of carvedilol therapy. About one year after initiation of carvedilol therapy, the CLBBB disappeared and a significant improvement in left ventricular function was noted. The LVDd was 44 mm, the LVDs was 30 mm, the %FS was 33%, and the LVEF was 61%, and the serum BNP concentration was decreased to 18.5 pg/mL. We describe a case in which low dose carvedilol was effective for treating both CLBBB and left ventricular function.

Clinical profile and prognosis of patients with intermittent versus persistent left bundle branch block

Clinical profile and prognosis of patients with intermittent versus persistent left bundle branch block

New persistent and rate-related left bundle branch block in 116 apparently healthy males: correlation with coronary angiography and cardiac risk factors

New persistent and rate-related left bundle branch block in 116 apparently healthy males: correlation with coronary angiography and cardiac risk factors

New bundle branch block after coronary artery bypass grafting— evaluation by CK-MB isoenzyme analysis and transoesophageal echocardiography

Twelve patients with a new complete bundle branch block after coronary artery bypass grafting underwent transoesophageal echocardiography (TEE). The results of TEE were compared with the pre-operative ventriculography, CK-MB isoenzyme time-release curves and clinical course. In eight patients with transient right bundle branch block or bifascicular block, low CK-MB activities and an uncomplicated postoperative course, transoesophageal echocardiography showed no new segmental wall motion abnormalities apart from a paradoxical septal movement in five. A persistent right or left bundle branch block was associated with either elevated isoenzyme activities, transoesophageal echocardiographic evidence of new segmental wall motion disturbance or both in four patients. One patient died because of fatal arrhythmia and one suffered from a prolonged low cardiac output syndrome. A transient bundle branch block is usually a benign electrocardiographic finding. In case of a persistent bundle branch block associated with elevated CK MB isoenzymes, new left ventricular wall motion disturbances indicating a peri-operative myocardial injury are easily detected by transoesophageal echocardiography.

Fascicular conduction disturbances after coronary bypass surgery

Two hundred patients undergoing coronary bypass graft surgery were studied to determine the frequency and significance of new fascicular conduction disturbances. The follow-up period ranged from 13 to 39 months. New disturbances developed in 39 patients (20 percent). Isolated right bundle branch block (6 percent) and left anterior hemiblock (6 percent) were the most common disturbances. Right bundle branch block was usually transient and was not associated with further complications in the follow-up period. However, patients with either transient or persistent left bundle branch block or left anterior hemiblock, or both, had (1) increased late mortality compared with patients without new fascicular conduction disturbances (5 of 26 versus 11 of 161; P < 0.02), and (2) increased late myocardial infarction (2 of 26 versus 2 of 161; P < 0.05). New left fascicular conduction disturbances after coronary surgery identified a subset of patients with more extensive ischemic heart disease, suggesting that these patients require close follow-up care.