Diseases of the chest and the principles of physical diagnosis . BiaJeK \U HjChT BsAfVCH af H|V ^^H\ Fig. 157.—Intraventiicular heart block. Right branch of Hiss bundle. From acase of decompensated myocarditis, which has been for two weeks on large doses ofdigitalis. Note the notching of <S and the prolonged deflection time of the R-S group(more than second). The P-R interval is prolonged to second. As both thesesigns continued after the cessation of digitalis, they were presumably due to deficient con-ductivity caused by organic changes. Note also the small U wave that is occasion
Diseases of the chest and the principles of physical diagnosis . BiaJeK \U HjChT BsAfVCH af H|V ^^H\ Fig. 157.—Intraventiicular heart block. Right branch of Hiss bundle. From acase of decompensated myocarditis, which has been for two weeks on large doses ofdigitalis. Note the notching of <S and the prolonged deflection time of the R-S group(more than second). The P-R interval is prolonged to second. As both thesesigns continued after the cessation of digitalis, they were presumably due to deficient con-ductivity caused by organic changes. Note also the small U wave that is occasionally seenin normal records. There is usually a high T wave, in the opposite direction to the largerof the initial deflections. If the right branch is deficient and .the im-pulse reaches the ventricle through the left branch, the picture resemblesthat of left ventricular hypertophy; and vice versa if the left branch isdeficient. This condition may be a permanent result of organic diseaseor a temporary result of digitalis. THE ELECTROCARDIOGRAPH 195. 196 THE EXAMINATION OF CIRCULATORY SYSTEM B. Arborization Block.—Oppenheinier and Rothschild have describedabnormal electrocardiograms, which they consider to be due to inter-ference with stimulus conduction bejond the two chief branches of thebundle of His, , in the arborization of the Purkinjefibers. Like bundlebranch block, this condition shows the notching and prolonged durationof the initial deflections; but differs in the low amplitude of the initialdeflections in all leads and in the absence of typical diphasic curveswith huge T waves. This form of electrocardiogram is probably morefrequent than that due to block of the main branch, and is important onaccount of its serious prognosis (Willius), and frequent association withcoronary thrombosis. Sino-auriadar.—In the rare condition of sino-auricular block, oc-casional cycles are entirely absent {, there is no evidence of eitherauricular or ventricular activity). It
Size: 1358px × 1841px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectdiagnos, bookyear1920
