Biomedical subjects
Publications and source records attributed to F Brunotte.
The authors report a case of tamponade revealed by the discovery, during emergency radioisotope scanning of the lung, of an acquired right-to-left shunt which was reversed by surgical drainage. The patient was a 60-year old woman treated by anticoagulants for suspected pulmonary embolism who had sudden worsening of her symptoms on the 7th day of the disease.
The development of numerisation material in radiology currently permits to perform usual cardiovascular tests. The authors report a series of 48 patients who benefited from the determination by numerised left ventriculography, of their stroke volume (SV). In 37 cases, the peripheral venous route is used while in 11 cases the central venous route is used, in the pulmonary artery trunk. The SV values obtained with both methods (one advocated by the manufacture and another one developed by the authors), are correlated with the SV values obtained with the isotopic method, used as reference. The correlations are satisfactory, approximately 0.79 for all patients of the study, and markedly improve when the injection of the contrast material is performed in the pulmonary artery (approximately 0.95). The authors conclude that determination of the left ventricle SV by numerisation is an interesting technique in centers where there is no department of nuclear medicine, and is absolutely necessary to complement right catheterisation.
Tumor cells incubated with 67Ga-citrate plus lactoferrin showed a lactoferrin concentration-dependent increase of 67Ga uptake while for transferrin the effect was an inhibition. A correlation was observed between the binding of 131I-labelled lactoferrin or 131I-labelled transferrin and the uptake of 67Ga by the cells. Saturation with iron did not change significantly the effects of the iron-binding proteins. Preincubation with lactoferrin, transferrin or ferric citrate increased 67Ga uptake. The formation of a ternary complex in which 67Ga mimics iron is discussed.
Of 46 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) from April 1980 to August 1982 and who had a satisfactory angiographic result six months later, one died of cancer and 41 had a detailed evaluation with exercise single-photon emission computed tomography (SPECT, 40 patients) or repeat coronary angiography (one patient), 48-78 months after the procedure. During follow-up, two patients had recurrent angina due to progression of coronary artery disease requiring a second PTCA procedure of another coronary artery; one of them later had a limited myocardial infarction in an area supplied by the vessel initially dilated. At follow-up, only one patient had definite angina. All but one patient had a negative exercise test. Myocardial perfusion during exercise in the PTCA-related area, assessed by SPECT, was normal in 90% of the patients and showed a limited defect due to reversible ischaemia in the remaining four (10%). It is concluded that patients with a less than 50% stenosis six months after PTCA show sustained improvement in their functional status and myocardial perfusion, four to six years after the procedure suggesting continued patency of the coronary artery.
Haemorheological characteristics were measured in a group of 52 patients with essential arterial hypertension (HT), and were compared with those of a group of normotensive subjects. The relationships between the arterial blood pressure (BP), the echocardiographic indices of left ventricular hypertrophy (LVH), and the haemorheological measurements, were studied. The group of hypertensive patients was found to have a hyperviscosity syndrome with significant elevations of blood viscosity at all shear rates (for gamma = 0.20/s, 29.6 +/- 0.6 versus 28.0 +/- 0.3 mPa.s, P less than 0.01: for gamma = 128/s, 4.2 +/- 0.05 versus 4.1 +/- 0.02 mPa.s, P less than 0.02, of plasma viscosity (1.29 +/- 0.01 versus 1.22 +/- 0.06 cSt, P less than 0.001); of erythrocyte aggregation index (17.8 +/- 0.06 versus 14.6 +/- 0.4, P less than 0.001); of erythrocyte filterability index (13.3 +/- 0.5 versus 8.8 +/- 0.2, P less than 0.001) and plasma fibrinogen level (3.4 +/- 0.9 versus 2.8 +/- 0.6 g/l, P less than 0.02). The haematocrit did not differ from that of normotensive subjects (43.3 +/- 0.6 versus 44.7 +/- 0.5%, NS). The left ventricular mass was increased and was positively correlated with the blood viscosity at a high shear rate (r = 0.38, P less than 0.01) and with the erythrocyte aggregation index (r = 0.47, P less than 0.01). Systolic, diastolic, and mean arterial blood pressures were positively correlated with the left ventricular mass (r = 0.34-0.47, P less than 0.05) and with the erythrocyte aggregation index (r = 0.42-0.46, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
The authors advocate a semiquantitative evaluation of mitral regurgitation (MR), based on the extent of the left intra-atrial systolic jet. Their study was performed in a series of 63 consecutive patients explored by: (1) catheterization with left ventriculography on two planes for either ischaemic heart disease (24 cases) or cardiac valve disease (39 cases including 2 with mitral valve prosthesis), and (2) pulsed Doppler ultrasound combined with two-dimensional echocardiography for evaluation of MR carried out 24 or 48 hours prior to catheterization. Five grades of MR (0 to IV) were determined by ventriculography according to the time and degree of left atrial opacification. Similarly, five grades of MR (0 to IV) were determined by Doppler ultrasound, considering only the maximum distance from the mitral annulus plane. This distance was evaluated on at least 3 projections: apical for the 4 and 2 cavities, parasternal for the greater axis. The Doppler method correlated fairly well with the angiography, whether or not grade 0 was included (r = 0.87 and r = 0.72 respectively). However, some major MR may be underestimated; thus, out of 13 RM of angiographic grade III or IV, three (23 p. 100) were graded II by the Doppler technique. Conversely, some minute or moderate MR may be overestimated: out of 33 MR of angiographic grade I or II, four (12 p. 100) were graded III or IV by the Doppler technique.(ABSTRACT TRUNCATED AT 250 WORDS)
The effects of citrate ion on in vitro and in vivo uptake of [67Ga]citrate by tumor cells have been studied. Carrier-free [67Ga]citrate seems to follow the physical diffusion of citrate ions into the cell, and the presence of carrier gallium inhibits that diffusion, reducing considerably its uptake. These results appear to support the hypothesis that increased permeability of tumor cells is the principal cause of [67Ga]citrate accumulation by tumors.
In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about 1/10 of 67Ga and 1/50 of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences.
Seventeen patients with stable congestive heart failure (class II and III New York Heart Association) received intravenous and oral enoximone in a 2-part study. Hemodynamic data were first obtained after intravenous administration of 0.75 mg/kg of enoximone; data were again obtained after 12 weeks of therapy with either oral enoximone (150 mg 3 times daily) or placebo. The efficacy and safety of oral enoximone were also studied in a 12-week, double-blind randomized format. In the intravenous study, enoximone was delivered over 5 minutes and hemodynamic data were measured for up to 12 hours after. Cardiac index increased 2.76 +/- 0.63 to 3.42 +/- 0.72 liters/min/m2), pulmonary wedge pressure decreased (19.5 +/- 8.8 to 14.6 +/- 8.0 mm Hg) as did mean arterial blood pressure (101 +/- 14.8 to 85 +/- 13.7 mm Hg) and systemic vascular resistance (1,880 +/- 573 to 1,254 +/- 383 dynes s cm-5). Heart rate increased slightly (82 +/- 17 to 86 +/- 14 beats/min). All these changes were maximal 1 to 2 hours after infusion and lasted 8 hours at least. Patients were then randomized double-blind to oral treatment. Baseline values showed that the 7 patients who received placebo had more severe CHF. Therefore, comparison might be biased. Patient overall assessment showed a continuous benefit in both groups. Ejection fraction improved from 30.1 +/- 6.8% to 33.9 +/- 9.9% in the enoximone group while it remained unchanged with placebo (23.4 +/- 6.5% to 23.4 +/- 1.5%).(ABSTRACT TRUNCATED AT 250 WORDS)
Three main nuclear medicine methods are used in paediatric cardiology: sequential first-pass radionuclide imaging of the cardiac cavities, radionuclide equilibrium ventriculography and radionuclide myocardial imaging. Valuable functional information is obtained, and invasive explorations can be avoided in an ever increasing number of cases. Of particular interest is left-to-right shunt measurement which indicates that atrial septal defects must be surgically corrected when the pulmonary/systemic flows ratio (QP/QS) is above 2. This technique is also useful to evaluate the tightness of repairs in ventricular and atrial septal defects. Radionuclide studies of the right and left ventricles may detect dysfunction in one or the other cavity. The left ventricular ejection fraction is reduced in myocardiopathy an in aortic or mitral valve diseases seen at a late stage. The right ventricular function is often abnormal, notably during exercise, after repair of the tetralogy of Fallot and after atrial correction of complete transposition of the great arteries. An altered ejection fraction in patients with single ventricle is also a sign of deterioration. Right ventricular diastolic overload evaluated by radionuclide equilibrium ventriculography correlates with the QP/QS ratio value in atrial septal defects and with the inducibility of ventricular tachycardia by endocavitary pacing in repaired tetralogy of Fallot. Thallium 201 myocardial imaging provides information on myocardial ischaemia, notably that associated with congenital abnormalities of the coronary arteries. Its use had now been extended, albeit with some limitations, to the evaluation of right ventricular systolic overload. Other radionuclide techniques are being developed with new tracers: Kryton 81m for studies of the right ventricle, short-lived radionuclides for first-pass studies, Iodine 123-labelled fatty acids for myocardial imaging. More recently, some substrates, such as deoxyglucose, have been labelled with positron emitters permitting in vivo metabolic studies.
To determine the value of gated equilibrium angiography in secundum atrial septal defect (ASD) in children, the first pass pulmonic/systemic flow ratio (Qp/Qs) was compared with diastolic count ratio (DCR) and stroke count ratio (SCR) of the two ventricles. In 50 children we have found a correlation between Qp/Qs and DCR (r = 0.71) and between Qp/Qs and SCR (r = 0.66). For detection of significant atrial shunt (QP/Qs greater than 1.5) the sensitivity of DCR greater than 2 was 0.81 and the specificity 0.75. For SCR greater than 1.5 we sensitivity and specificity values of 0.87 and 0.71 respectively. Left and right ventricular ejection fractions were normal (0.67 +/- 0.08 and 0.50 +/- 0.07).
The study of 67Ga-citrate uptake and calcium transport in Ehrlich ascites tumour cells seems to indicate that their peculiar characteristic of increased permeability to extracellular calcium ion might be responsible for their 67Ga accumulation. Experiments performed under different conditions of extracellular calcium, temperature, and presence of ionophore and other plasma membrane modifying agents such as lanthanum appear to corroborate this hypothesis.
Exercise tests involving isotopes were evaluated in 38 subjects presenting inferior myocardial necrosis. Cardiographic data were used to calculate sensitivity and specificity of the method in detection of subjects requiring surgical treatment. Sensitivity was 90% and specificity 62% when three criteria were employed: ECG of positive exertion, reversible diminished accumulation of thallium 201 outside the necrotic site or decrease in the fraction of ejection force. Examination of the fraction of ejection force improved the results of myocardial scanning using thallium and increased detection of subjects requiring surgery from 61% to 90%.
Radio-nuclide angiography after surgical correction of tetralogy of Fallot (TOF) allows measurement of the ejection fraction, especially of the right ventricle, under basal conditions and on effort, parameters which are difficult to measure by other non-invasive methods. Twenty-two children with a mean age of 12.6 +/- 6.9 years who had undergone complete correction of TOF at a mean age of 6.7 +/- 3.8 years underwent Technetium 99m blood pool studies at equilibrium. The results were compared with those of a control group of children with a mean age of 10.2 +/- 3.3 years. No first passage studies were performed because the frequency of postoperative pulmonary regurgitation does not allow quantification of the shunt due to a possible residual ventricular septal defect. No significant difference was found between the patients and control subjects at rest: LV ejection fraction (66.7 +/- 11 p. 100 vs 63 +/- 7.7 p. 100), RV ejection fraction (50.3 +/- 7.2 p. 100 vs 54 +/- 14.8 p. 100). The response to effort of the right and left ventricles depends on the type of exercise. The LV ejection fraction increased normally whilst the RV ejection fraction showed a lot of individual variation. Equilibrium radionuclide angiography was also used to calculate the ratio of right to left end diastolic ventricular volumes. This ratio indicates the degree of RV diastolic overload when LV diastolic volumes are normal, which was the case in our series. The study group showed a significant increase in this ratio compared to control subjects (1.94 +/- 0.65 vs 1.2 +/- 0.23). Exercise radionuclide imagery should provide more accurate assessments of the surgical results and prognosis of these children providing standardised protocols are used. These investigations are best performed in patients over 15 years old, so as to avoid the technical difficulties related to small size. Resting studies are possible at all ages.
This study compared the phase images of 12 normal subjects and 14 patients with right ventricular and 5 patients with left ventricular preexcitation. The phase images obtained from equilibrium radionuclide ventriculographies in the left anterior oblique portion with an ECG trigger: Fourier analysis was used to measure the phase and amplitude of the variations. In normal subjects the mean difference in phase was nearly zero: in 12 of the 14 patients with right ventricular preexcitation, right ventricular preceded left ventricular contraction (LV phase - RV phase = + 23 degrees); injection of Ajmaline normalised the ECG and suppressed the premature right ventricular contraction during right ventricular preexcitation (LV phase - RV phase = nearly zero), demonstrating a direct relationship between the abnormal depolarisation and abnormal contraction. In left sided Kent bundles, phase imaging did not seem to show significant premature ventricular contraction under basal conditions. Atrial pacing, which accentuated both left and right electrical preexcitation, increased the difference in ventricular phase. Finally, a satisfactory correlation was observed between the presumed locations of the accessory pathways and the zones of premature right and left ventricular contraction.
A brief description is presented of the long-term follow-up of four commonly encountered cardiopathies undergoing early surgical correction. Sequelae are not increased and probably even less frequent when compared to children undergoing surgery after two years of age. It is still too early, however, to establish whether or not certain manifestations, such as rhythm or conduction disturbances and ventricular dysfunction will develop at a later date. The prognosis of coarctation of the aorta depends to a great extent on other associated lesions which can become serious over time and require additional surgical procedures. In the past, early surgery for large ventricular septal defects was poorly tolerated, but now the prognosis is particularly favorable. Persistent hemodynamic abnormalities such as stenoses of the pulmonary outflow tract can worsen the prognosis in tetralogy of Fallot. In addition, it is especially important to recognize subsequent ventricular dysrhythmias due to their potentially serious nature. The most common procedures for transposition of the great arteries consist of auricular transposition of the venous returns which may later cause rhythm disturbances or venous stenoses. The long-term functional capacity of the right ventricle as a pump for the systemic circulation is not known. A general outline of follow-up care is presented.
Twenty-two infants aged 5 days to one year (mean: 3.8 months), consisting of 17 with tetralogy of Fallot and 5 with pulmonary atresia-ventricular septal defect, were prospectively investigated by two dimensional echocardiography (2 D echo) in order to evaluate the severity of the impairment of the pulmonary outflow tract and value of 2 D echo in the preoperative evaluation. Right pulmonary artery (PA), observed by angiography in 20 patients, was correctly recorded and could be measured in all cases (20/20), whereas the left PA was seen in 19 patients (19/20). Pulmonary confluence was recognized in 20/20 cases and its absence in 2 cases. In one patient without pulmonary confluence, a large substituted systemic vessel was mistaken for right PA. Echo established in the 22 patients (100%) the presence (17 cases) or absence (5 cases) of continuity between the right ventricle and the PA. Echo demonstrated 2 out of the 3 stenoses of the branches found by angiography. The internal diameter of PA measured by echo, ranging from 3 to 9 mm, was compared with angiographic measurements. A significant linear correlation was observed for each diameter (ring, trunk and branches) between the two techniques. However, echo slightly under-estimated the angiographic diameters. These results show that 2 D echo is a reliable method to determine the severity of impairment of the pulmonary outflow tract in infants with tetralogy of Fallot. They suggest that is may be used to guide the choice of surgical procedure and is adequate, in selected patients, to carry out a palliative intervention without open surgical procedure.
Blood plasma from tumor-bearing rats was incubated with 67Ga-citrate, and two fractions of high molecular weight (proteins) and low molecular weight were isolated by dialysis and by gel-filtration chromatography. Both fractions showed a different in vivo uptake by DS-sarcoma-bearing animals, the high molecular weight fraction being accumulated to a lesser extent. Compared to 67Ga-citrate the low molecular weight fraction showed a different uptake which for most tissues was significatively higher. This behavior suggests the presence of 67Ga in chemical forms other than citrate in the low molecular weight fraction. The lower uptake of the blood protein fraction is discussed.