Category: Men's Health

Considerations of Right Bundle Branch Block and Frontal Plane QRS Axis in Apparently Healthy Men

right ventricleThis study presents longitudinal data on RBBB in a highly selected cohort of North American men. Thus, caution should be exercised when extrapolating these data to the general population. However, the relatively young age at entry of the majority of this cohort permits more accurate estimation both of the age at onset of RBBB and freedom from preexisting disease than is possible in studies commencing with older age groups. It also provides longitudinal data on this conduction disturbance from a young age. Other cautions include the problem of measuring A QRS in the right bundle. The exact time during the QRS that activation of the right ventricle occurs is not always apparent or predictable for each individual case. Although much of the interest is centered on extremes of axis deviation, the small number of cases in some subgroups of A QRS is also a concern. Another precaution in the extrapolation of these results is the different lengths of follow-up within each age group. Those 30 years of age and younger at detection of RBBB have been under observation for almost 30 years, but the length of follow-up is decreased in older age groups.

The present study demonstrated that the ominous prognosis attributed to RBBB and marked right or left axis deviation in patients with heart disease should not be applied to persons without heart disease who have the same ECG finding recorded on a routine examination.

Outcomes of Right Bundle Branch Block and Frontal Plane QRS Axis in Apparently Healthy Men

myocardial infarction

Prognosis

The RBBB group has been under observation for 936 person-years, an average of 15.9 ± 1.6 (SEM) years per case. During this time the following were noted: one case of myocardial infarction at age 68 years, 20 years after RBBB; one case of angina pectoris at age 46 years, one year after RBBB; and no ischemic heart disease deaths. To determine the expected number of ischemic heart disease cases in this group, the ischemic heart disease incidence rate was calculated for age groups at five-year intervals consisting of those free of RBBB and ischemic heart disease. Based on the age distribution and length of follow-up of the RBBB group, 6.77 ischemic heart disease cases were expected. The observed number, two, is less than but not significantly (x2 2.7, df = 1) different from expected, although the small number of cases observed and expected is a concern for statistical testing.

During the observation period for the entire group, there was no occurrence of advanced degrees of heart block (second- or third-degree AV block). Also, no sudden deaths were noted.

The length of follow-up and status of cases with marked left (—45° to —90°) and right axis (+120° to +180°) deviation of frontal plane QRS vector are illustrated in Figure 2. Seven cases in which marked left axis deviation developed after RBBB are also considered. Almost all are still living. The majority have been followed-up for more than ten years, and some as long as 30 years. Only one case of ischemic heart disease (myocardial infarction) occurred, 21 years after onset of RBBB in a man with marked left axis deviation who later died of a noncardiac cause. It is naturally to take under control your health but My Canadian Pharmacy makes it faster and more surely.

My Canadian Pharmacy: Right Bundle Branch Block and Frontal Plane QRS Axis in Apparently Healthy Men

right bundle branch blockThe natural history of right bundle branch block (RBBB) has been studied primarily from the perspective of its prognostic importance in patients with organic heart disease. The limited number of studies that included primarily persons without heart disease were mainly conducted before attention was focused on the potential importance of deviations in the mean frontal plane QRS vector (A QRS) as a possible indicator of impaired conduction in the left bundle branch system. Marked left axis deviation may be due to impaired conduction in the anterosuperior part of the left bundle branch, and marked right axis deviation to impaired conduction in the posteroinferior part of the left bundle branch system. These deviations in A QRS in conjunction with complete RBBB suggest impaired conduction in both the right and left bundle branch system.