Incidence Of Right Bundle Branch Block Research Articles

Right bundle branch block: Prevalence, incidence, and cardiovascular morbidity and mortality in the general population

Background: Right bundle branch block (RBBB) is among the most common electrocardiographic abnormalities.Objectives: To establish the prevalence and incidence of RBBB in the general population without cardiovascular events (CVE) and whether RBBB increases cardiovascular morbidity and mortality compared with patients with a normal electrocardiogram (ECG).Methods: A historical study of two cohorts including 2981 patients from 29 primary health centres without baseline CVE. Cox (for CVE) and logistic (for cardiovascular factors) regression was used to assess their association with RBBB.Results: Of the patients (58% women; mean age 65.9), 92.2% had a normal ECG, 4.6% incomplete RBBB (iRBBB) and 3.2% complete RBBB (cRBBB). Mean follow-up was five years. Factors associated with appearance of cRBBB were male sex (HR = 3.8; 95%CI: 2.4–6.1) and age (HR = 1.05 per year; 95%CI: 1.03–1.08). In a univariate analysis, cRBBB was associated with an increase in all-cause mortality but only bifascicular block (BFB) was significant after adjusting for confounders. cRBBB tended to increase CVE but the results were not statistically significant. Presence of iRBBB was not associated with adverse outcomes. Patients with iRBBB who progressed to cRBBB showed a higher incidence of heart failure and chronic kidney disease.Conclusion: In this general population cohort with no CV disease, 8% had RBBB, with a higher prevalence among men and elderly patients. Although all-cause mortality and CVE tended to increase in the presence of cRBBB, only BFB showed a statistically significant association with cRBBB. Patients with iRBBB who progressed to cRBBB had a higher incidence of CVE. We detected no effect of iRBBB on morbidity and mortality.

Interventricular conduction disorders after orthotopic heart transplantation: risk factors and clinical relevance.

Causes and significance of interventricular conduction disorders (IVCDs) after orthotopic heart transplantation (OHT) are still unknown. We retrospectively researched the presence of IVCDs in 240 patients who underwent bicaval OHT in three time periods: at day 1, after 1year, and after 3years from OHT. To evaluate the impact of the surgical technique, a control population treated with biatrial anastomosis was used. The most common IVCD was right bundle branch block (RBBB). Its presence at day 1 correlated with transpulmonary gradient before OHT. Its presence after 1year and its development correlated with a 1-month acute rejection score≥2 (p=.050 and p=.006). The incidence of RBBB was higher in the biatrial control population (40.7% vs 23.8%, p<.001). RBBB is the most common IVCD. Its presence can be explained by a susceptibility of the right branch to heart positioning, pressure overload, and acute rejection. IVCDs do not affect prognosis.

Clinical significance of fat infiltration in the moderator band and right ventricular myocardium in multislice CT, and its association with abnormal conduction seen in electrocardiogram

PurposeWe evaluated the clinical significance of fat infiltration in the moderator-band (MB) of the right ventricle (RV) and in the RV myocardium (RVM) and its association with conduction abnormalities in the electrocardiogram. Materials and methods132 subjects (58 male; age 59±27years) with no findings of organic-disease (all right and left side hearts were normal) undergoing electrocardiogram-gated non-contrast multislice-CT (Light-Speed-Ultra-16) were retrospectively analyzed for the presence of fat infiltrating the MB or RVM. ResultsMB fat infiltration was detected in 42 subjects, but these individuals showed no significant differences in the incidence of right bundle branch-block, mean QRS-width or standard-deviation of the QRS-axis, which would have suggested the presence of hemi left bundle branch-block. Only age (64.3 vs 57.9years, p=0.025) was significantly different in subjects with MB fat infiltration. But logistic regression showed none of the factor associated with increased presence of MB fat infiltration. RVM fat infiltration was detected in 35 subjects, again with no significant differences in the incidence of right bundle branch-block, QRS width or standard-deviation of the QRS axis. Only age (65.9 vs 57.8years, p=0.001) and gender (71% vs 51% female, p=0.033) were significantly different in subjects with RVM fat infiltration. Logistic regression showed age (Odd-ratio=1.05 and 95% CI=1.01–1.08 p=0.008) and female sex (Odd-ratio=2.44 and 95% CI=1.03–5.88; p=0.043) were associated with increased RV fat infiltration. ConclusionsMB or RVM fat infiltration seen on CT may not indicate organized abnormal myocardial conduction, but RVM fat infiltration may indicate only degeneration due to aging, especially in females.

Risk of right bundle-branch block and complete heart block during pulmonary artery catheterization.

The need for the prophylactic insertion of a pacemaker before pulmonary artery catheterization in patients with pre-existing left bundle-branch block (LBBB) is controversial. To determine the incidence of new right bundle-branch block (RBBB) and complete heart block during bedside pulmonary artery catheterization, 293 patients undergoing 307 pulmonary artery catheterizations were prospectively studied. Nine patients had pacemaker rhythms and 19 patients had an RBBB on their precatheterization ECGs and therefore were excluded from analysis. In the remaining 279 pulmonary artery catheterizations, eight (3%) were associated with the development of a new RBBB. None of the 14 patients with a pre-existing LBBB developed complete heart block. The incidence of complete heart block during pulmonary artery catheterization of patients with previous LBBB was not higher than the incidence of RBBB in patients without underlying conduction defects. Because of the rare but grave consequences of RBBB in patients with pre-existing LBBB, we recommend the use of standby external pacemakers and equipment for transvenous pacemaker insertion in these patients during pulmonary artery catheterization. We do not recommend prophylactic pacemaker insertion.

Ischemic blocks during early phase of anterior myocardial infarction: correlation with ST-segment shift.

Of 760 consecutive cases with anterior acute myocardial infarction (AMI), 55 developed acute bundle-branch block (BBB), fascicular block, or high-degree atrioventricular block during the hyperacute ECG stage of AMI. According to the direction of the ST segment during the acute ischemic episode, patients were divided into two groups. Group A consisted of 32 patients who developed BBB during ST-segment elevation, positive T wave, and absent or minimal Q wave. Group B consisted of 23 patients who developed BBB during ST-segment depression and evolved into anterior AMI. Group A was characterized by a higher incidence of right BBB and left anterior hemiblock [91% vs. 26% and 56% vs. 13%, respectively (p less than 0.005)]. Group B was characterized by a higher incidence of left BBB and left posterior hemiblock [57% vs. 9% and 26% vs. 12%, respectively (p less than 0.001)]. The BBB was transient (disappearing within hours to one day) in 14 patients in Group A and in 5 patients in Group B. The incidence of progression to high-degree atrioventricular block was almost equal in the two groups (25% and 26%). The mortality rate was very high in both groups, but higher in Group B [74% vs. 59% (p = NS)] especially in those with LBBB (85%). Most patients died on the day of occurrence of BBB [Group A, 50% vs. Group B, 70% (p = NS)]. The causes of death in both groups were cardiogenic shock and/or electromechanical dissociation.(ABSTRACT TRUNCATED AT 250 WORDS)

Is right bundle branch block aviodable in surgical correction of tetralogy of Fallot?

Right bundle branch block (RBBB) is usually considered almost unaviodable after repair of teralogy of Fallot (TOF). By modifications of the standard technique, its frequency has been decreased to 32% in a series of 1000 consecutive patients. These modifications are: (1) a very short right ventricular incision avoiding the ventriculotomy-induced RBBB pattern; (2) an infundibular resection limited to the septal attachment of the infundibular septum; and (3) closure of the ventricular septal defect with a patch sutured to the very edge of the muscular septum, avoiding injury to the right bundle along the right aspect of the septum. No patient in this series sustained permanent complete atrioventricular heart block. Among patients with RBBB, five had a left anterior hemiblock. Postoperative intraventricular conduction was related to age at operation: The incidence of RBBB was significatively higher in infants. The beneficial effects of a low incidence of postoperative RBBB after repair of TOF are not known.