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Contribution to the study of bundle-branch block
mechanism. No known explanation was given, however, why a constant anatomic lesion, such as was found, should provoke a c&G of hyl)ertension.
Mahaim, Ivan: Contribution to the Study Ann. di: mcci., 1927, xxii, 213.
of Bundle-Branch
Block.
The author reported five cases of bundle-branch block which conformed to the findings in the experimental work on this condition. -2 review of the lit.erature was given, the authors criticizing those reported C:ISCSwhich did not conform to experimental findings. The first, case, a woman fifty-four years old, had cardiac decompensation and a right bundle-branch block, depending on advanced pulmonary tuberculosis. Clinically, a presystolic gallop rhythm was present. The elect locardiogram showed a left ventricular predominance, the enlarged yentrirular complexes notched in all three leads, and the T-wave dipllilsic~. The picture was that of right bundle-branch blork. C)uabain was given at first, with some improvement. I;af er veneseetion with the use ot’ digitalis was employed with success. During digitalis therapy, extras)-stoles from the right and left sides were visible. Between courses of digitalis, no estrasystoles occurred on t,he blocked side. This indicates that digitalis acts on the terminations of the bundle. The second case was that of a woman oi’ fifty-seven years with pronounced decompensation. The electrocardiographic study showed a rapid fibrillation rate of 180. Digitalis was without effect, and quinidine was tried. As a result, a reduplication of the first heart sound developed ant1 the electrocardiogram showed n left preponderance with prolongation and not.ching of the ventricular complex. An increase in the quinidinc caused the signs of bloc?k to disappear, but on a further increase the reduplicated sound and the electrocardiographic changes returned. On stopping the use of quinidine, the tachycardia returned, and the first sound did not, show reduplication. Quinidinr was, therefore, again given (4.6 gm.) with a return oi’ the reduplicated first sound of the right bundle-branch block. A further dose of 1.4 gm. of the drug slowed the rate to 80, the reduplication disappeared, and the sinus rhythm was established with a normal jugular pulse. The quinidine was cont,inued with a small and diminishing dose, with continuation of the sinus rhythm. The author emphasized that bundlebranch block was no contraindication to quinidine thera.pp. The coincidence of reduplication of the first sound and the elect.rocardiographic evidence of bundle-branch block suggested that the former was of diagnostic importance. The third case, a man aged seventy-five, with syphilitic aortic stenosis, showed left preponderance with enlargement and notching of the ventricular complexes and diphasic T-waves. II clinical diagnosis of
380
THE
ANERI(‘AN
HEART
JOIJRNAL
syphilitic arteritis of the nutrient vessels to the right branch of the bundle was made. This proved to be true at, autopsy. The fourth patient was a girl of eighteen with a history 01’palpitation for from eight to ten months. The clectrocardiogral)hi~ tracings showed the presence of auricular estraqstoles. Quinidine was given in increasing doses with the rwdt~ that the estrasystoles diminished in num her, and in the estraspstolic cycles, the P-R interval was increased and the rentricular comples took the form of a levocardiogram. No sym~jtams accompanied this change. Bigger doses o 1’quinidine caused entire disappearance of the ectopie beats. Here the quinidine depressed the conductivit.y in the right branch of the bundle which, therefore, could 1::: transmit to the right ventricle the premature cscitation wave coming from the auricle. The iI-\- node and the left, brunch were unaffected. The final increase in 11~cdose of quinidine prevented altogether the occurrence of the auricular premature heat. Case 5 xvas that of a man, aged t,wcnty-srven years, with rheumatic mitral and aortic disease and decompensation. A diffuse block was present throughout the left l)ranch of the lnmdlr. as shown by right preponderance and an increase in the size and notchings of the QR,S complex. Digitalis produced a marked bradycardia, with h-17 block and auricular fibrillation. The ventricular complcses ceased to show the not~ching and became ~mre tlestrocardiograms. One assumed that the left bundle-branch block was here further exaggerated by the inability of’ the myocardium to transmit to the left ventricle the excitation wave coming from the right ventricle. The author concludes that bundle-branch block is not a contraindication to the use of digitalis or quinidine, although estrasystoles may appear in casesof bundle block by the use of the former, and bundle-branch block may result from the latter drug. The clinical evidence of complete bundle-branch block consists of a reduplication of the first heart sound ; a presystolic gallop rhythm accompanying a reduplication is less common.
Mahaim, Ivan: Contribution to the Study Ann. di: mcci., 1927, xxii, 213.
of Bundle-Branch
Block.
The author reported five cases of bundle-branch block which conformed to the findings in the experimental work on this condition. -2 review of the lit.erature was given, the authors criticizing those reported C:ISCSwhich did not conform to experimental findings. The first, case, a woman fifty-four years old, had cardiac decompensation and a right bundle-branch block, depending on advanced pulmonary tuberculosis. Clinically, a presystolic gallop rhythm was present. The elect locardiogram showed a left ventricular predominance, the enlarged yentrirular complexes notched in all three leads, and the T-wave dipllilsic~. The picture was that of right bundle-branch blork. C)uabain was given at first, with some improvement. I;af er veneseetion with the use ot’ digitalis was employed with success. During digitalis therapy, extras)-stoles from the right and left sides were visible. Between courses of digitalis, no estrasystoles occurred on t,he blocked side. This indicates that digitalis acts on the terminations of the bundle. The second case was that of a woman oi’ fifty-seven years with pronounced decompensation. The electrocardiographic study showed a rapid fibrillation rate of 180. Digitalis was without effect, and quinidine was tried. As a result, a reduplication of the first heart sound developed ant1 the electrocardiogram showed n left preponderance with prolongation and not.ching of the ventricular complex. An increase in the quinidinc caused the signs of bloc?k to disappear, but on a further increase the reduplicated sound and the electrocardiographic changes returned. On stopping the use of quinidine, the tachycardia returned, and the first sound did not, show reduplication. Quinidinr was, therefore, again given (4.6 gm.) with a return oi’ the reduplicated first sound of the right bundle-branch block. A further dose of 1.4 gm. of the drug slowed the rate to 80, the reduplication disappeared, and the sinus rhythm was established with a normal jugular pulse. The quinidine was cont,inued with a small and diminishing dose, with continuation of the sinus rhythm. The author emphasized that bundlebranch block was no contraindication to quinidine thera.pp. The coincidence of reduplication of the first sound and the elect.rocardiographic evidence of bundle-branch block suggested that the former was of diagnostic importance. The third case, a man aged seventy-five, with syphilitic aortic stenosis, showed left preponderance with enlargement and notching of the ventricular complexes and diphasic T-waves. II clinical diagnosis of
380
THE
ANERI(‘AN
HEART
JOIJRNAL
syphilitic arteritis of the nutrient vessels to the right branch of the bundle was made. This proved to be true at, autopsy. The fourth patient was a girl of eighteen with a history 01’palpitation for from eight to ten months. The clectrocardiogral)hi~ tracings showed the presence of auricular estraqstoles. Quinidine was given in increasing doses with the rwdt~ that the estrasystoles diminished in num her, and in the estraspstolic cycles, the P-R interval was increased and the rentricular comples took the form of a levocardiogram. No sym~jtams accompanied this change. Bigger doses o 1’quinidine caused entire disappearance of the ectopie beats. Here the quinidine depressed the conductivit.y in the right branch of the bundle which, therefore, could 1::: transmit to the right ventricle the premature cscitation wave coming from the auricle. The iI-\- node and the left, brunch were unaffected. The final increase in 11~cdose of quinidine prevented altogether the occurrence of the auricular premature heat. Case 5 xvas that of a man, aged t,wcnty-srven years, with rheumatic mitral and aortic disease and decompensation. A diffuse block was present throughout the left l)ranch of the lnmdlr. as shown by right preponderance and an increase in the size and notchings of the QR,S complex. Digitalis produced a marked bradycardia, with h-17 block and auricular fibrillation. The ventricular complcses ceased to show the not~ching and became ~mre tlestrocardiograms. One assumed that the left bundle-branch block was here further exaggerated by the inability of’ the myocardium to transmit to the left ventricle the excitation wave coming from the right ventricle. The author concludes that bundle-branch block is not a contraindication to the use of digitalis or quinidine, although estrasystoles may appear in casesof bundle block by the use of the former, and bundle-branch block may result from the latter drug. The clinical evidence of complete bundle-branch block consists of a reduplication of the first heart sound ; a presystolic gallop rhythm accompanying a reduplication is less common.