[Newly acquired right bundle branch block. Association with heart disease and risk factors in the Reykjavik Study.].
OBJECTIVE
To find risk factors for the appearance of right bundle branch block (RBBB) and to assess the prognosis of people with it.


METHODS
Subjects were participants in the Reykjavik Study who had acquired RBBB following an examination in a previous stage in this prospective population study, carried out in five stages in 1967-1991. Cases with two matched controls were recruited for a special examination in 1992.


RESULTS
Acquired RBBB was seen in 33 men and 14 women. Multivariate analysis showed, compared to the total population, that men with RBBB more often had cardiomegaly (odds ratio=OR 1.7;confidence limit=CL 1.2-2.5) women more often took antihypertensive drugs (OR 2.5; CL 1.5-4.1) and had lower diastolic blood pressure (OR 0.97; CL 0.95-0.99). Predictive factors in people with acquired RBBB were age (men: relative risk=RR 1.08; CL 1.05-1.11, women: RR 1.09; CL 1.02-1.17) and antihypertensive medication in women (RR 3.5; CL 1.2-10.4). There was no significant difference between cases and controls regarding examination, echocardiography and mortality.


CONCLUSIONS
Factors associated with the appearance of RBBB are mainly age, cardiomegaly and antihypertensive medication.
Thrainsdottir
I S
IS
Hardarson
T
T
Thorgeirsson
G
G
Danielsen
R
R
Sigvaldason
H
H
Sigfusson
N
N