Functional bundle-branch block - 12/10/17
Abstract |
Two cases of functional bundle-branch block with short P-R interval occurring in healthy young subjects with normal cardiovascular systems are here reported. Both of the patients were subject to attacks of supraventricular paroxysmal tachycardia.
During attacks of paroxysmal tachycardia the QRS complexes in both cases were entirely normal in form, duration and electrical axis. Upon cessation of the attacks and during the interval between attacks, the electrocardiograms assumed the form of right bundle-branch block.
In one case, upon release of vagal tone by the administration of 1 mg. of atropine sulphate subcutaneously, the electrocardiogram gradually reverted to the normal mechanism with a normal electrical axis. In the other case, while atropinization produced no change in the form of the electrocardiogram, a distinct change in the form of the ventricular complex could be produced by indirect vagal stimulation. In both cases the electrocardiograms during the interval were characteristic of right, not left, bundle-branch block.
It may be concluded that:
1. | a. Aberrant ventricular complexes of the type generally recognized as bundle-branch block may occur in healthy individuals without heart disease. |
2. | b. Vagal influence or aberrant distribution of the vagi may be responsible for intraventricular block in healthy subjects. Release of vagal tone may produce a reversion of the abnormal to normal mechanism. |
3. | c. Functional bundle-branch block, which is probably of vagal origin, occurs and is not a sign of heart disease. |
| ☆ | From the Department of Medicine, Peiping Union Medical College, Peiping, China. |
Vol 11 - N° 1
P. 89-98 - janvier 1936 Retour au numéro
Article précédent
- Clinical results from oral administration of thevetin, a cardiac glucoside
- William S. Middleton, K.K. Chen
- Heart failure in hypertension
- Samuel H. Averbuck
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