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Multiple diagnostic measures elicited during the stress ballistocardiogram.

Acceleration Bcgs were recorded on 22 subjects at rest and during acute elevation of blood pressure produced by isometric grip. Measurements on computer averaged graphic waveforms of H/I slope, I/J slope and I-J amplitude were made. The ratios of values during stress, to resting state, helped to select patients with 1,2 or 3 declines of 10% or more from the resting values. The method has the advantage of using each subject as his own control, and may help to elicit varying grades of myocardial pumping dysfunction not evident at rest.

Adult↗

[Experience with the intracardiac floating catheter in the diagnostics of cardiac function (author's transl)].

A report is made on the experience gained in more than 600 cardiac catheterizations using the Swan-Ganz-Intracardiac floating catheter. This procedure is an addition to the diagnostic possibilities and provides answers to cardiological and pulmonological questioning which, so far, had not been an indication for cardiac catheterism. Its advantage is the safety of application and little inconvenience to the patient with a high information content for the physician. If the investigations are carried out under ergometer load, new aspects of functional diagnostics arise with respect to problems requiring intimate knowledge of the myocardial function.

Arrhythmias, Cardiac↗

[Unruptured aneurysms of Valsalva sinus of septal origin].

Aneurysms of Valvsalva sinus unruptured into a cavity, but developing into the membranous and even muscular interventricular septum are exceptional. Two cases illustrating this fact are reported. In one of them, a massive mitral incompetence by elongated chordae tendinae related to the presence of a voluminous intra-septal pouch. Atrio-ventricular and intraventricular conduction disturbances were present in both patients. The interest of supra-valvar angiography which makes it possible to advise operation before the eventual rupture is underlined.

Adult↗

[Ischemic lesions of the left branch of the bundle of His. Their relation of left hemiblock].

The term "hemiblock of the left branch of the bundle of His" seems to a histologist to be too precise to be accepted without reservation. Ten cases with septal infarction, with or without left intraventricular conduction problems, were studied by serial sectioning of the heart; these are used as a basis for a discussion of the concepts of electrocardiography, and its implications in the prognosis of patients with myocardial necrosis.

Bundle of His↗

[Tachycardia-dependent paroxysmal block in the bundle of His. Electrophysiological demonstration].

The authors report the case of a patient who presented with angina of effort followed by transient loss of consciousness or syncope. Clinical examination yielded little information. The electrocardiogram showed signs of an old antero-septal infarct, and a slightly prolonged PR interval at 0.22 s. A recording of the activity of the bundle of His showed a double H potential, whose two components were separated by an interval of 80 ms. This interval increased progressively under the influence of atrial stimulation. At a critical frequency of 125/mn, a complete block below the bundle of His was produced; this only reverted after slowing or cessation of stimulation. The same phenomenon occurred at rates between 125/mn and 150/mn. By contrast stimulation at 170/mn was followed by a 2:1 block below the bundle of His. It is to be presumed that the complete A-V block was occasioned by latent conduction of the impulse in the injured area. If the rate was increased yet again, the level of the block became displaced to the upper limit of this area. The absence of latent conduction then allowed the abnormal fibres to recover. The present study thus demonstrates the existance of a special type of paroxysmal A-V block: a bundle block which is dependant upon tachycardia.

Aged↗

["Habitual" left branch block alternating with 2 "disguised" bracnch block].

Two cases of alternating left bundle branch block and "masquerading block" (with left bundle branch morphology in the stnadard leads and right bundle branch block morphology in the precordial leads) were studied by serial tracings and his bundle electrocardiography. In case 1 "the masquerading" block was associated with a first degree AV block related to a prolongation of HV interval. This case is to our knowledge the first cas of alternating bundle branch block in which his bundle activity was recorded in man. In case 2, the patient had atrial fibrilation and His bundle recordings were performed while differents degrees of left bundle branch block were present: The mechanism of the alternation and the concept of "masquerading" block are discussed. It is suggested that this type of block represents a right bundle branch block associated with severe lesions of the "left system".

Aged↗

Wolff-Parkinson-White syndrome type A obscured by left bundle branch block.

2 patients are presented whom the presence of left bundel branch block obscured the signs of the Wolff--Parkison--White syndrome expected with a bypass on the left side of the heart. While it was possible to infer the presence of both disorders from the surface ECGS, electrophysiological studies proved invaluable in defining the precise situation in both cases. When atypical electrocardiographic appearances are observed in the Wolff-Parkinson-White syndrome, careful investigation may reveal the cause to be bundle branch block on the same side of the hear as the anomalous pathway. In both patients there was in addition evidence of sinoatrial disease, which was associated with the occurrence of arrythmias, and this was also confirmed with intracardiac studies.

Adult↗

[State of the heart conduction system in the sick sinus syndrome (according to the recording of the bundle of His potentials and the atrial stimulation test)].

It was established that the presence of Samoilov-Wenckebach's periods and prolongation of the H--V interval at low frequency of the imposed rhythm as well as periods of asystolia of more than 1,200 msec are most typical for these patients. An attempt was made to determine the type of cardiac stimulation indicated for such patients from the character of the disorders of rhythm observed in them and the initial frequency of their own cardiac contractions.

Action Potentials↗

[Treatment of severe ventricular arrhythmia by means of repeated cardiac stimulation].

The overdrive pacing method is widely used now in clinical practice for prevention and treatment of severe ventricular disorders of the cardiac rhythm. The mechanisms of arrhythmia suppression by means of this stimulation is analysed. Indications are determined for the choice of the site of stimulation and optimal impulce frequency in ischemic heart disease, and overdosage with digitalis drugs, as well as in myocardiopathy.

Adult↗

'Supernormal' phase in hemiblock conduction.

A case is described where the basic sinus rhythms is associated with an advanced degree of left anterior hemiblock. The rhythm is complicated by atrial extrasystoles, associated with a lesser degree of left anterior hemiblock. This paradox of 'supernormality' is explained on a critical interplay of differential refractoriness within the divisions of the left bundle-branch.

Adult↗

Electrophysiological properties of intravenous metoprolol in man.

Electrophysiological changes produced by intravenous (0.1 mg/kg) metoprolol, a new selective beta 1-blocking agent devoid of intrinsic activity, were studied in 16 subjects with estimated normal impulse formation and conduction. The most important effects were sinus bradycardia, mild increase of sinoatrial conduction time, depression of intranodal conduction, and prolongation of AV node refractory periods. Sinus node recovery time and atrial refractory periods were unmodified. Infranodal conduction and the refractory periods of the His-Purkinje system, as well as of the bundle-branches, were unchanged. These effects are compared with those observed after intravenous propranolol, pindolol, and oxprenolol.

Adult↗

Mahaim conduction producing left axis deviation and normal QRS.

An unusual patient is described in whom electrophysiological studies strongly suggest the occurrence of Mahaim conduction. The patient whose electrocardiogram previously showed a left anterior hemiblock pattern then developed advanced atrioventricular (AV) block (AH block). Beats conducted through the atrioventricular node always had a short HV interval (20 ms) and QRS complexes of left anterior hemiblock pattern. Junctional escape beats always had a normal HV interval (50 ms) with normal intraventricular conduction. His bundle pacing showed the StV interval and QRS contour of escape beats. These findings suggest the existence of an accessory pathway (Mahaim fibres) passing from the area of block, presumably the uppermost portion of the His bundle, to the posteroinferior division of the left bundle-branch. The surface electrocardiogram did not show the characteristic delta wave of the Wolff-Parkinson-White syndrome. Our observations suggest that patients in whom there is conduction along Mahaim fibres may show only the pattern of intraventricular conduction defect without a delta wave.

Cardiac Complexes, Premature↗