Biomedical subjects
Publications and source records attributed to R Grolleau.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
An anatomoclinical study of a case of Kearns' syndrome is reported. Neuro-ophthalmic symptoms appeared when the child was 13 year-old. Two and a half years later occurred an episode of paroxystic atrioventricular block, after which the triad characterising the syndrome was completed: retinitis pigmentosa, ophthalmoplegia, disorder of heart conduction. The course was unfavorable despite pacemaker insertion. Study of the central nervous system showed spongiosis of the subcortical white substance, of the basal ganglia and of the cranial nerve nuclei. The specialized heart conduction tissue was the site of apparently primary degeneration. The extension of the visceral involvement is discussed in the light of published data.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The localisation of a pheochromocytoma is difficult and sometimes hazardous. There are many radiological techniques of varying sensitivity and the risks of hypertensive crises or of cardiovascular collapse are not negligeable (especially during arteriography and venography). Abdominal computerised axial tomography (CAT) would appear to be of considerable value. It gives a very precise localisation without any risk. Three personal cases confirm this opinion. The first case was of a 38 year old man with an extra-adrenal pheochromocytoma localised in the pelvis of the left kidney by CAT (after negative intravenous urography); the second case was of a 54 year old man with a left adrenal pheochromocytoma confirmed on CAT (after 2 negative aortic arteriogrammes and adrenal venography); the third case was of a 39 year old woman with a para aortic pheochromocytoma, diagnosed on CAT (after negative intravenous urography). These three cases bring to 43 the total number of reports of pheochromocytoma localised by abdominal CAT. When this method is compared with intravenous urography and aortic arteriography, abdominal CAT is over three times more sensitive than intravenous urography (90% compared to 26%) and also more sensitive than arteriography (90% compared to 76%). The false negative results on CAT usually involve small tumours (diameter less than 30 mm). The new generation of CAT should reduce these errors. The great advantage of this investigation should change the order of the radiological examinations in the localisation of pheochromocytoma. It would seem logical to carry out an abdominal CAT as soon as biological confirmation of the hypersecretion of catecholamines had been obtained. The other radiological investigations (especially aortic arteriography) should be reserved for cases with negative abdominal CAT.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The possibility of preexcitation pathways exhibiting automatic activity was demonstrated in 3 cases: in two cases electrophysiological studies supported this diagnosis which was confirmed in the third case by histological examination of the preexcitation pathway. During sinus node dysfunction, spontaneous or induced (by rapid right atrial pacing or by a reciprocating tachycardia), the substitute rhythm arose from the Kent Bundle either transiently or for a longer period: rhythms arising from the Kent Bundle can only be diagnosed after eliminating the possibility of an atrioventricular junctional rhythm conducted to the ventricles by Mahaïm fibres.
Right axial deviation and delay between stimulation and ventricular response was observed during pacing of the apex of the right ventricle in Prinzmetal angina. The degree of deformation of the ventricular complex and the length of this delay appear to be related to the severity of the anginan, the length of the preceding diastolic period and the amplitude of stimulation. This observation demonstrates the presence of conduction defects at the heart of ischaemic myocardium and may explain the failure of prophylactic pacing in Prinzmetal angina complicated by paroxysmal atrioventricular block.
The asynchronism of ventricular activation resulting from a major degree of left bundle branch block (QRS greater than or equal to 0.12 s) may be suppressed by stimulation of the distal portion of the His Bundle, whether the block be intermittent (3 cases) or permanent (17 cases). The selective stimulation of the His Bundle normalises ventricular depolarisation whilst non-selective stimulation narrows the QRS complex by the fusion of the activation wave fronts from the His Bundle and the interventricular septum. The reestablishment of synchronous ventricular conduction by His Bundle stimulation is generally interpreted as a sign of longitudinal dissociation in the proximal portion of the His Bundle. This results does not, however, exclude the possibility of a very localised lesion at the origin of the left bundle, responsible for a conduction delay, and suppressed by stimulation carried out close to the zone of block (summation effect, electrotonic influence).
Paroxysmal tachycardia in Type A Wolff-Parkinson-White syndrome was due to a reciprocating rhythm involving a left lateral Kent Bundle in the retrograde direction. Spontaneous interruption of the reentry resulted not from block in the normal or accessory atrioventricular pathways but from an intraatrial conduction defect: delay in conduction between the left and right atria on intraatrial reentry terminated the tachycardia.
Explore the source record for details and available documents.
The blood and oxygen needs of the heart are considerable. At rest, the left ventricle uses twenty times as much oxygen as skeletal muscle and on effort its consumption is five times greater again. The level of extraction of oxygen from coronary blood by the myocardium is very high at rest and thus can only increase by limited amounts on effort. Coronary venous blood is the most desaturated in the body. Furthermore, the anaerobic capacity of the heart is limited. As a result, the increased oxygen needs of the heart on effort can be dealt with only an increase in coronary flow. There is in fact a balance between myocardial oxygen supply and needs.
Explore the source record for details and available documents.
A negative P wave in D1 with a mean atrial vector which is horizontal or descending in the frontal plane, occurring during paroxysmal tachycardial due to reciprocal rhythm or after ventricular stimulation suggests atrial depolarisation which starts in the left auricle at some distance from the A-V node and near the pulmonary veins. In the absence of an external anterograde ventricular pre-excitation, such P waves may indicate the presence of a hidden bundle of Kent posterolaterally on the left, allowing retrograde conduction during the tachycardia by a reciprocal rhythm.
Two cases with treated transposition of the great vessels and incompetence of the left atrioventricular valve showed a type B preexcitation syndrome. In one case, this consisted of a typical W.P.W. syndrome in which the second PR interval was not shortened, but rather consisted of a delta wave and a widened QRS complex. Post mortem examination showed an abnormal connection between the bundle of His and the ventricular septum, and a low insertion of the inverted tricuspid valve. The published cases of W.P.W. syndrome in cases with treated transposition are reviewed, and the mechanism of preexciation discussed in the light of the anatomical peculiarities of the malformation and of the abnormalities which are a feature of Ebstein's syndrome.