CLINICAL STUDY OF INCOMPLETE RIGHT BUNDLE BRANCH BLOCK ABOUT ITS PATTERN OF MITRAL VALVULAR DISEASE

Abstract

It is well known that incomplete right bundle branch block (I.R.B.B.B.) appears in the heart diseases with right ventricular hypertrophy, and recently it was suggested by Cabrera that diastolic overloading of the right ventricle produces frequently I.R.B.B.B., and an intermediary factor of the relation between I.R.B.B.B. and diastolic overloading is a dilatation of the right ventricle.In order to ascertain this theory, the comparison was made between E.C.G. and Xray in mitral valvular disease and the following were the results:1. Electrocardiographic polyphasic QRS patterns in V1 lead which were encountered statistically more frequently in mitral valvular disease than control group, were difined as I.R.B.B.B. pattern.2. Among 535 cases of mitral valvular disease, while heart-lung ratios were not so great so far as the patients with electrocardiographic right ventricular hypertrophy (R.V.H.), they were remarkably great concerned with the patients of I.R.B.B.B. patterns.3. The value of the longest distance between right phrenicocardiac angle and left third arch of cardiac silhouette divided by thorathic transverse diameter was difined as right ventricular index (R.V.I.). R.V.I. of the patients with I.R.B.B.B. patterns was statistically greater than that of the patients with R.V.H. patterns.4. During clinical course, I.R.B.B.B. patterns appeared hand in hand with the enlargement of cardiac silhouette and disappeared following the reduction of the enlargement in several cases.