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At least 19 recordsLinked to original sources
PubMed1976

Lidocaine and His bundle extrasystoles. His bundle discharge conducted with functional right of left bundle-branch block, or blocked entirely (concealed).

In this patient, discharge from the bundle of His either conducted normally, conducted with functional right or functional left bundle-branch block, or blocked entirely (concealed), depending on the preceding cycle length and the coupling interval of the premature His bundle depolarization. The presence of both functional right and left bundle-branch block may have been attributable to differences in effective and functional refractory periods between the two bundle branches. Concealed His bundle extrasystoles mimicked first-degree, and types I and II second-degree AV block, according to the interval between His bundle discharge and the subsequent P wave. Lidocaine eliminated His bundle extrasystoles that blocked entirely (concealed) or conducted with functional left bundle-branch block by improving His-Purkinje conduction and by lengthening the coupling interval of the premature His bundle extrasystole. Lidocaine had no effect on AV nodal conduction time. This patient has been known to have concealed His bundle discharge for at least three years and has not required permanent pacemaker insertion.

Bundle of His↗
PubMed1978

Normalization of bundle branch block patterns by distal His bundle pacing. Clinical and experimental evidence of longitudinal dissociation in the pathologic his bundle.

Clinical and experimental observations in which bundle branch block patterns (BBBP) in ECG leads were normalized by distal His bundle (H) pacing are reported. The clinical material includes four patients with acute right BBBP secondary to anterior wall myocardial infarction and three patients with chronic left BBBP. Six of the seven patients had a prolonged H-V interval (60-85 msec) including three who showed evidence of an intra-H conduction delay (IHCD) with split H (H and H'). Distal H pacing from a right-sided electrode catheter normalized the BBBP with a stimulus-to-QRS (PI-V) interval 20-35 msec shorter than the H-V interval and almost identical to the H'-V interval in the three patients with documented IHCD. In 18 dogs ligation of the anterior septal artery resulted in IHCF with split H associated with right or left BBBP. Distal H pacing from catheter and/or plunge wire electrodes normalized the BBBP in 12 experiments (67%) with a PI-V interval identical to the H'-V interval. H pacing was selective and direct stimulation of myocardium was excluded by monitoring the high ventricular septal electrogram. The clinical and experimental observations are discussed as evidence that functional longitudinal dissociation is probably only operative in the pathologic H due to selectively greater depression of conduction in the transverse interconnections.

Animals↗
PubMed1977

His bundle electrocardiography in manifest and concealed right bundle branch extrasystoles.

His bundle electrocardiography was helpful in the diagnosis of impulse formation in the right bundle branch. Ten patients with narrow QRS complexes had ectopic beats with an "incomplete" left bundle branch pattern and almost simultaneous activation of His bundle and ventricles. Both QRS morphology and H- - V intervals depended on the more proximal or distal location of the ectopic focus. In four patients with "complete" right bundle branch block the morphology of ectopic ventricular complexes and H- - V intervals also depeneded on the presence or absence of retrograde block and differential degrees of forward and/or retrograde conduction delays. Nine patients with "complete" right bundle branch block and four with "complete" left bundle branch block had premature beats which could have originated in the proximal right bundle branch, proximal left bundle branch, or distal His bundle. In one patient with "complete" left bundle branch block, "concealed" His bundle depolarizations (probably originating in an ectopic focus located in the right bundle branch) produced pseudo Type II (Mobitz) A-V block. Although lidocaine appeared to have been more effective in patients with bundle branch block than in those with narrow QRS complexes, further studies are necessary to corroborate this impression.

Adult↗
PubMed1978

Reentry within the His-Purkinje system. Elucidation of reentrant circuit using right bundle branch and His bundle recordings.

Routes of impulse propagation during reentry in the His-Purkinje system (Re-HPS) in 13 patients were studied using the right ventricular extra stimulus (V2) method and right bundle branch (RBB) recordings in addition to the conventional His (H) bundle recordings. The H-V and RB-V intervals during sinus rhythm averaged 44.2 and 27.6 msec respectively, with the average antegrade H-RB interval 16.6 msec. All 13 patients demonstrated Re-HPS in the form of V3 showing a left bundle branch block (LBBB) pattern, and two of the 13 patients also manifested V3 with a right bundle branch block (RBBB) pattern. During Re-HPS showing a LBBB pattern, the retrograde activation of the His bundle (H2) in response to V2 occurred via the left bundle branch (LBB), as indicated by inscription of retrograde H2 prior to RB2 in nine of 13 cases (average H2-RB2 = 9.4 msec), and simultaneous incription of retrograde H2 and RB2 in the remaining four. When V3 showed a RBBB pattern the retrograde RB2 preceded H2, suggesting H2 activation via the RBB. These findings suggest that circuit of Re-HPS incorporates both bundle branches and the bundle of His. The H-RB recordings were also useful in distinguishing sustained Re-HPS from atrioventricular nodal reentry when in both instances the QRS complex showed a LBBB pattern.

Adult↗
PubMed1977

Pseudo bundle branch block produced by premature impulses arising in the bundle branches.

Pseudo bundle branch block, a previously unreported arrhythmia produced by concealed premature impulses arising in the bundle branches, was seen in two patients with sick sinus node syndrome. Although concealed conduction was not apparent in either the surface or intracardiac leads, the latter were essential in localizing the site of manifest impulse formation. Patient 1, with left bundle branch extrasystoles, had pseudo bundle branch block and pseudo atrioventricular block that depended on the timing and extent of concealment of premature depolarization. Because of the coexisting sinus bradycardia in this patient, electrical stimulation and the recording of the right ventricular apical electrograms gave additional information that helped corroborate the postulated mechanisms. Patient 2 had right bundle branch extrasystoles with sinus beats that showed a right bundle branch block pattern possibly caused by pseudo bundle branch block. In this case the possibility that both the automaticity and the conduction disturbance had a mechanical origin could not be excluded.

Arrhythmia, Sinus↗
PubMed1977

Transient unifascicular, bifasicular and trifascicular block: electrophysiologic correlations in a patient with rate-dependent left bundle branch block and transient right bundle branch block.

Correlations of the His to ventricular (H-V) conduction time were made with the surface electrocardiogram during normal intraventricular conduction, unifascicular block (right bundle branch block), bifascicular block (left bundle branch block) and trifascicular block (right and left bundle branch block) in a patient with rate-dependent left bundle branch block who had transient right bundle branch block during recording of the His bundle electrogram. The results provide a functional confirmation of the theory that a prolonged H-V time is a manifestation of trifascicular disease.

Bundle of His↗
PubMed1979

Morphology of the atrioventricular node, bundle and proximal bundle branches: a study employing computerized reconstruction.

The morphology of the human atrioventricular node, atrioventricular bundle and bundle branches is described. A block of tissue bounded by the ostium of the coronary sinus, the pars membranacea, the septal leaflet of the tricuspid valve and the atrial and ventricular septa is removed. The block is then sectioned serially from the right endocardial surface in the frontal plane of the heart. Sectioning in this way produces fewer sections than from techniques previously described. Outlines of the atrioventricular node, atrioventricular bundle and proximal bundle branches are digitally registered and stored in a computer. Three dimensional reconstructions of the structures are then generated by computer and displayed on an oscilloscope so that the entire three dimensional image can be rotated in any plane. Stereoscopic image pairs are produced to assist perception of the shape of the atrioventricular node, bundle and branching patterns of the bundles. This technique is unique in that it describes a method from which a relatively small number of histologic sections are generated permitting not only a complete histologic examination, but also a study of the morphology of the area.

Adult↗
PubMed1979

His bundle block and concealed His bundle premature depolarization.

His bundle electrocardiograms were recorded from a patient with previously unexplained PR prolongations or shortenings suggestive of both type I and II second degree AV block. The conduction disturbances were due to the association of concealed His bundle depolarizations (H') not propagated to atria or ventricles with first degree AV block in the His bundle. These data strongly suggest that frequent spontaneous His bundle depolarizations are another manifestation of a disease process involving the His bundle, a kind of "Sick--His bundle syndrome".

Bundle of His↗
PubMed1979

The histology of retinal nerve fiber layer bundles and bundle defects.

The fiber bundle striations recognized clinically in normal monkey eyes appear to be bundles of axons compartmentalized within glial tunnels formed by Müller's-cell processes, when viewed histologically. The dark boundaries that separate individual bundles are the broadened foot endings of these cells near the inner surface of the retina. Within one week after focal retinal photocoagulation, characteristic fundus changes could be seen in experimental eyes. In histologic sections of the involved retina, there was marked cystic degeneration of the retinal nerve fiber layer. Within one month, atrophy of distal axon segments was complete. With the drop-out of damaged axons and thinning of individual fiber bundles, retinal striations became less prominent. The resulting fundus picture in these experimental eyes is similar to fiber bundle defects that can be seen clinically in various neuro-ophthalmic disorders.

Animals↗
PubMedDate not supplied

Transient right bundle branch block during His bundle electrogram in a case with ventricular parasystole.

A case with ventricular parasystole and transient right bundle branch block during His bundle electrogram is reported. Although on surface electrocardiogram no preexisting atrioventricular (A--V) conduction disturbances could be noted, His bundle electrogram showed latent infrahisian conduction changes. This suggests a susceptibility for induced right bundle branch block during right heart catheterization and may take part in the mechanism of the ventricular ectopic activity of the patient.

Adult↗
PubMed1978

De subitaneis mortibus. XXIX. Randomly distributed focal myocardial lesions causing destruction in the His bundle or a narrow-origin left bundle branch.

Most focally destructive lesions of the heart (e.g., myocarditis) have an essentially random distribution. Any mechanical significance of such diseases depends primarily on there being a very large number of foci. However, single even very small lesions can have profound electrophysiological significance if appropriately located within the cardiac conduction system. Two cases of sudden unexpected death are here reported which had destructive lesions involving the His bundle and a narrow-origin left bundle branch. Not much is known of the electrical or mechanical effects of acute left branch block which is due to complete anatomical transection of that structure in the human heart, and some possible consequences (including sudden unexpected death) are considered. Myocarditis or any other focally destructive disease in the heart may be of little functional importance if it is not widespread, unless some of the lesions happen to damage any of several small but crucially important sites in the cardiac conduction system. Studies to determine the presence or absence of this precise type of damage should be done especially in cases of sudden unexpected death.

Adolescent↗
PubMed1977

The atrioventricular node, His bundle and bundle branches-a new histologic technique.

A technique for examination of the conducting system of the heart is described. A block of tissue embracing the ostium of the coronary sinus, the pars membranacea, the septal leaflet of the tricuspid valve, and appropriate amounts of interatrial and interventricular septum is flattened and fixed in a Kaiserling I solution. Blocks are subsequently cleared in methyl salicylate and trimmed. Sections are cut from the blocks after paraffin embedding beginning from the endocardial surfaces of the right heart chambers. The sections are mounted and stained on 35 mm unperforated leader film and covered with an acrylic preservative. For examination of the conducting system many fewer sections are required than with previous techniques.

Atrioventricular Node↗