[Contribution of self-surveillance of the personnel by electronic radiation dosemeters in invasive cardiology]. / Apport de l'autosurveillance des opérateurs par dosimètres électroniques sur la radioprotection en cardiologie invasive.

The methods of surveillance of coronary angiography or angioplasty operators vary from team to team. The choice of method implies evaluation of the level of exposition of unprotected areas. The usual methods of surveillance by dosimetry may be complemented by an electronic device used for industrial radiological protection against X and Gamma rays. This instrument emits a sound each time a micro sievert is detected: the operator perceives the photons of diffused rays. The value of protective screens is then directly audible. This instrument does not detect X rays with an energy of less than 50 KeV but there is a good correlation with results measured by thermoluminescent dosimetry. The measurement of irradiation were noted at three points on the body before and after the use of complementary protection which certain operators hesitated to use before this study. The results confirmed the value of these protections: the suspended lead screen reduced cervical irradiations by a factor of 15 and that of the left wrist by 8. Lower down, a flexible lead skirt reduced irradiation of the ankle by a factor of 19. These results underestimate the efficacy of the screen as low energy X rays were not measured and are even more easily absorbed by the screens.

[Exercise test under catheterization in mitral stenosis]. / L'épreuve d'effort au cours du cathétérisme des rétrécissements mitraux.

The sensitivity of basal hemodynamic data and the value of those observed during exercise in the diagnosis of severe mitral stenosis (MS) were investigated by comparing the results under basal conditions and during dynamic exercise with the operative findings in 55 patients with pure MS, aged between 18 and 73 years (average, 43 years), 29 with mild stenosis (Group I) and 26 with severe stenosis (Group II). Under basal conditions, mean pulmonary capillary pressure (PCP) was significantly higher in Group II than in Group I (15.7 +/- 4.4 mm Hg compared to 12.2 +/- 3.5 mm Hg, p less than 0.01). The same difference was observed in mean pulmonary arterial pressure: Group I, 18.2 +/- 5.4 mm Hg; Group II: 23.0 +/- 6.1 mm Hg, p less than 0.01; but cardiac and systolic indices were comparable in the two groups. On exercise, only PCP (Group I: 29.6 +/- 6.8; Group II: 34.7 +/- 4.9 mm Hg) and systolic index (Group I: 39.9 +/- 10.0; Group II: 33.4 +/- 8.2 ml/m2) were significantly different (p less than 0.01). Pulmonary capillary and arterial pressures rose in the same proportion in the two groups on exercise but systolic index fell in severe MS (-4 p. 100) and rose in mild MS (+30 p. 100) (p less than 0.001). The formulae for calculating mitral valve surface area only give discriminating results between the two groups when the hemodynamic data on exercise are used.(ABSTRACT TRUNCATED AT 250 WORDS)

[Echocardiographic anomaly of septal contraction after open heart surgery]. / Anomalie échocardiographique de la contraction septal après chirurgie à coeur ouvert.

The function of the interventricular septum (IVS) was studied by M mode echocardiography one month after open-heart surgery in 256 patients with valvular heart disease and without any accepted mechanism of abnormal septal motion. Systolic anterior motion of the IVS was observed in 44% of all the patients and was found to be more common in patients undergoing corrective aortic procedures (64%) than in patients undergoing corrective mitral (36%, p less than 0,01) or mitro-aortic (45% , p less than 0,01) procedures. In technically very adequate studies of 43 patients (33 with systolic anterior motion of the IVS) and 10 normal controls, the following observations were made: - the systolic anterior motion of the IVS was greater after aortic procedures than after mitral ones (-5,64 +/- 1,44 mm, and -2,14 +/- 2,66 mm, p less than 0,005); - patients with systolic anterior motion of the IVS had reduced percentage systolic septal thickening (30,9 +/- 19,0%, p less than 0,02) and normal controls (56,1 +/- 21,0%, p less than 0,005); -the systolic anterior motion of the posterior epicardial echo was more pronounced in post-operative patients, both with abnormal (7,9 +/- 1,8 mm) and normal (7,8+/- 2,2 mm) septal motion, than in normal controls (4,8 +/- 0,7 mm p less than 0,001 and p less than 0,005, respectively); - no other known cause of systolic anterior septal motion were present in the post-operative patients. In conclusion, patients undergoing cardio-pulmonary bypass demonstrated increased systolic anterior motion of the whole heart, which was thought to be related to the partial removal and/or the non-closure of the pericardium. However, this feature was not the only mechanism for the abnormal post-operative motion of the IVS, as reduced contraction of the IVS was always found in these patients. This finding could be ascribed to myocardial per-operative injury, the exact nature of which remains unknown.

[Physiopathological study of coupled electric stimulation]. / Etude physiopathologique de la stimulation électrique couplée.

The charges of left ventricular function provoked by coupled electrical stimulation were studied in 17 patients with severe chronic aortic incompetence and 9 controls. These results were compared with those obtained after isolated extrasystole in 24 cases of aortic incompetence and 10 controls, and during paired electrical stimulation in 12 cases of aortic incompetence. Left ventricular function increased uniformly after post-extrasystolic potentiation whatever the mode of stimulation. The preload did not change significantly, the increased ventricular function being mainly due to increased contractility. Coupled electrical stimulation mobilised the greatest contractility reserve (ejection fraction : +32 % in controls and +37 % in aortic incompetence and averaged circumferentiel fibre shortening +55 % in controls and +47 % in aortic incompetence). The contractility reserve is inversely proportional to the initial ejection fraction except when its value is less than 35 %. The myocardial response then becomes variable so that left ventricles with probable irreversible hypocontractility may be distinguished from those whose ventricular funciton would improve after surgical correction.

[Evaluation of the contractile reserve of the myocardium by post-extrasystolic potentiation in aortic insufficiency]. / Evaluation de la réserve contractile du myocarde par la potentiation post extra-systolique dans l'insuffisance aortique.

Calculations were made of the indices of ventricular performance during the ejectional phase in 10 patients with a normal left ventricle and in 24 patients with aortic aneurysm, both under basal conditions and in the presence of extrasystoles produced incidentally during left biplanar cineventriculography. The fact that these indices were constantly raised implies the presence of post-extrasystole potentiation associated with an increase in contractility without significant changes in load. This technique, which provides a dynamic study of the behavior of the left ventricle in aortic incompetence allows us to assess the contractile reserve, and thus to give a more accurate prediction of the potential for recovery after operation.