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Thallium scintigraphy holds a unique position amongst the methods available for evaluating the prognosis of coronary patients: it enables quantification of underperfused myocardium and evaluates already constituted ventricular damage (irreversible necrosis) and areas at risk of future coronary events (viable but ischemic myocardium). In a series of 1,926 patients who underwent exercise stress or dipyridamole Thallium myocardial scintigraphy for angina pectoris and followed up fort an average of 34 months, the following features were observed: the long-term prognosis in patients with normal myocardial scintigraphy (715 patients) was identical to that of a normal population of the same age (0.11% cardiovascular deaths per year) whereas the cardiovascular mortality was 15 times higher in cases with a pathological scintigraphy: finally, the long-term prognosis (cardiovascular deaths, infarcts or secondary revascularisation) was directly related to the severity of the initial lack of Thallium uptake. This method was used to assess the prognosis and evaluate the myocardial ischaemia in 75 patients who underwent complete surgical revascularisation fort ischaemia, 50 of whom had previous myocardial infarction: all patients had at least one arterial bypass graft: 39% of the myocardium was underperfused before revascularisation; this procedure reduced by 80% (p < 0.0001) the zones of reversible underperfusion but also zones of irreversible underperfusion by 17% (p = 0.04). The results were particularly impressive in patients who underwent revascularisation with an arterial pedicle (left and right internal mammary, gastroepiploic alone or in association) as 91% of the ischemic territories recovered on average 13 days after revascularisation.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparative study of the diagnosis of intracardiac left-to-right shunts by isotope radiography on the one hand and oxymetry, abnormal catheter trajectory and angiocardiography on the other, was performed on a series of 110 patients, comprising 12 normals, 46 valvulopathies or cardiomyopathies without shunts, 23 ASDs, 22 VSDs, and 7 other shunts. Intravenous injection of Technetium 99 m with scintigraphic imagery and interpretation of time-activity curves detected even small left-to-right shunts and appeared to be more sensitive than oxumetry. The estimation of the size of the shunt correlated well with oxymetry for VSDs but not for ASDs. The localisation of the shunt was more difficult. The atrial level of the defect was detected in some but not the majority of cases. The isotopic technique appeared unreliable in the presence of severe haemodynamic disturbances. The isotopic method is a quick means of detecting left-to-right shunts without measurable risk, particularly useful in the investigation of children and young adults thought to have left-to-right shunts.

154 patients investigated for chest pain underwent 12 lead exercise electrocardiography and also exercise 201-Thallium myocardial scintigraphy performed at coronary angiography. 92 patients had typical angina; in this group the sensitivity and specificity of exercise electrocardiography was good (91% and 86% respectively) and exercise myocardial scintigraphy did not give significantly better results. On the other hand, in cases when exercise electrocardiography was negative (27%) exercise myocardial scintigraphy was positive in 75%. 201-Thallium did not discriminate between ischaemia and necrosis in patients with previous myocardial infarction, ischaemia alone causing hypofixation on basal myocardial scintigraphy. 62 patients had atypical chest pain. The low incidence of coronary artery disease in this group (30%) increases the value of exercise 201-Thallium scintigraphy as it is both more sensitive (59% compared to 21%, p less than 0,05) and more specific than exercise electrocardiography (43% compared to 85%, p less than 0,1). 29% monotruncular lesions had negative exercise electrocardiography and myocardial scintigraphy. However, multivessel and left main coronary disease may be excluded with great probability by a negative exercise 201-Thallium scintigraphy.

The right ventricular ejection fraction is rarely measured, as conventional diagnostic methods (radiology, echocardiography) are confronted with the problem of representing the right ventricle as a simple tridimensional geometrical model. This is not necessary with the radio-isotopic techniques. However, all those used for the measurement of right ventricular ejection fraction lead to important methodological problems. We have therefore developed a technique of measuring this parameter with an infusion of 81 m Kr. This radioactive gas is pure gamma-ray emitter with a 13 second period. Dissolved and infused intravenously, it is eliminated during the first passage through the lung. The continuous separation of the generator of 81 m Kr is performed with isotonic dextrose solution which is then infused for a period of 7 minutes. During this time, the activity detected by the scintillation camera inclined in the 30 degrees RAO projection is stored, together with the electrocardiogram in a computer. The precordial radioactivity of the retrocardiac lung tissue is subtracted after injection of 74 MBq of 99 mTc microspheres. A graph of right ventricular activity can then be reconstructed and the right ventricular ejection fraction calculated. The left ventricular ejection fraction is then measured with 99 mTc--labelled RBCs. This method allows the right ventricular ejection fraction to be measured in the RAO projection, the best incidence for the separation of the right atrial from the right ventricular activity without interference from left ventricular activity because of the pulmonary elimination of the Krypton radioactivity. The measurement performed on a large number of cardiac cycles allows a continuous study of the right ventricular ejection fraction. At the end of the infusion there is no circulating radioactivity so that the measurement can be repeated. This technique was used in 17 patients with acute myocardial infarction. In the 7 patients with anterior infarcts reduction of the left ventricular ejection fraction was the predominant finding (21,6 +/- 6,8%). The right ventricular ejection fraction was 34,2 +/- 6,4%. On the other hand, patients with a postero-inferior infarction had little change in left ventricular ejection fraction (59,2 +/- 12%) but those with right ventricular extension of their infarcts had very reduced right ventricular ejection fractions (less than 23%). The measurement of right ventricular ejection fraction with 81 m Kr is a reliable atraumatic method for diagnosing right ventricular infarction by the quantification of its functional impairment.

The aims of this comparative study by vectorcardiography and myocardial scintigraphy in the topographical analysis of primary inferior and/or posterior wall infarction, were: to obtain data confirming the value of identifying true posterior wall infarction; to confirm the diagnostic value of vectorcardiography in this condition. The patients in this retrospective study were admitted to hospital for primary inferior and/or posterior wall infarction and underwent vectorcardiography and myocardial scintigraphy either with Thallium 201 (137 patients) or 99m Technetium (88 patients) in the acute phase. The scintigraphies of all patients included showed hypofixation compatible with inferior and/or posterior infarction as this was used as the topographical reference. The results of vectorcardiography and myocardial scintigraphy were concordant in 164 of the 225 patients (72.8%), 18 with true posterior infarction [%), 110 with inferior wall infarction (48.8%) and 36 with postero-inferior wall infarction (16%). The results were discordant in 61 patients (27.1%); infarcts of the inferior or posterior walls according to one technique, were observed on the posterior or inferior walls with the other. The majority of these cases had postero-inferior wall changes on vectorcardiography and inferior wall infarction alone on scintigraphy (35 patients: 15.5%). The specificity of the vectorcardiographic signs of true posterior wall infarction remained satisfactory.(ABSTRACT TRUNCATED AT 250 WORDS)

The aim of this study was to compare the diagnostic value of exercise stress testing, Thallium 201 myocardial scintigraphy or after administration of dipyridamole and left ventricular angioscintigraphy performed either during a static (handgrip) or dynamic exercise (bicycle ergometry) for the positive diagnosis of stenosing coronary artery disease. The exercise angioscintigraphy was performed at equilibrium with 99m Tc red blood cell labelling. The global ejection fraction and that of seven radial segments of the left ventricle were measured, the data being recorded within a period of 2 minutes. The handgrip consisted in compressing a dynamometric ball at 1/3 maximal force for 3 minutes, with both hands; the ergometric exercise was increased by 30 Watt 2 minute increments until a positive ECG or 85% of the theoretical maximal heart rate for age was obtained. Normal subjects (n = 29) increased their global (+ 8%) and regional ejection fractions in each of the seven segments (p less than 0.05) during ergometric exercise: there was no significant change of global (-3% NS) or segmental ejection fractions during the handgrip exercise. In the coronary group (at least one greater than 70% stenosis) (n = 61) the fall in global ejection fraction was the same (-14%) with both forms of exercise; a similar fall in the segmental ejection fraction in the territory distal to the stenosis was observed with the handgrip (-22%) and bicycle ergometry (-28% NS). Dynamic exercise testing seemed superior to handgrip exercise. Therefore, the finding of an abnormal global ejection fraction on exercise (i.e. either a global ejection fraction less than the lower limit of normal on exercise, or lower than the global ejection fraction at rest), or of an abnormal regional ejection fraction (i.e. either a regional ejection fraction less than the lower limit of normal over at least 3 segments, or a regional ejection fraction on exercise lower than the regional ejection fraction at rest over at least 3 segments) detected coronary artery disease with a sensitivity of 94% and a specificity of 72%. Dynamic exercise angiography seemed to be more sensitive than maximal ECG stress testing (94% compared to 64%) more rapidly positive (p less than 0.05), as sensitive (94% compared to 83% NS) than Thallium myocardial scintigraphy, but less specific (72% compared to 90%, p less than 0.05), and as unspecific as ECG stress testing.(ABSTRACT TRUNCATED AT 400 WORDS)

Thallium 201 is fixed rapidly by the healthy mocardium, and its emissions are easily recordable with a scintillation camera; it was used to discover and localise zones of ischaemia. This radio-isotope was injected into 40 patients during an exercise test. The results from this so-called exercise scintigraphy were compared with those of the exercise ECG, with the findings on coronary arteriography in 32 cases, and in 14 cases with those obtained by injecting thallium 201 into the patient while at rest (the so-called scintigram at rest). The results obtained from exercise scintigraphy correlate well with those from the exercise ECG and coronary arteriography. It would seem to have an important place in monitoring the permeability of aorto-coronary bypasses.

Unlabelled: Between January 1983 and May 1984, 104 patients with no known cardiac pathology were referred by their cardiologist for diagnosis of chest pain. They all underwent coronary angiography which was used as the reference investigation and the following sequential Bayes' analysis was performed. The percentage probability of coronary artery disease was estimated from clinical date (age, sex, characteristics of the chest pain subdivided into 3 groups); an exercise ECG was performed in all cases (classified as positive, negative or non diagnostic); if the probability of coronary artery disease was greater than 95% (or less than 5%) after exercise stress testing the patients was diagnosed as having (or not having) coronary artery disease. If the probability was between 6 and 94% the patient underwent Thallium myocardial scintigraphy (Thallium dipyridamole; analysis on a colour television screen); the coronary risk probability before Thallium was that calculated after exercise stress testing. If after myocardial scintigraphy the coronary risk remained between 6 and 94%, an exercise angioscintigraphy was performed and interpreted in the same way. The clinical and complementary date was analysed on a mini-computer, the values of the sensitivity and specificity of the tests used for the calculation of the probability of coronary artery disease were those previously published by our group., Results: 31/88 (35%) of patients were classified in the 5% risk groups after exercise stress testing (24 coronary artery disease; 7 normals: no errors of classification). Fifty six out of the 88 patients (65%) were classified in the 5% risk group after myocardial scintigraphy (42 patients with coronary artery disease with 41 abnormal coronary angiographies and 14 normal patients, all of whom had normal coronary angiographies; this represents a 1.8% divergence of classification compared with coronary angiography). Angioscintigraphy only classified 3 of the remaining patients, one wrongly, and did not seem to be useful diagnostically as a third-line investigation after Thallium scintigraphy or as a second-line investigation instead of Thallium scintigraphy. This strategy is less costly than carrying out coronary angiography systematically in these patients: if diagnostic coronary angiography is performed alone in patients with a risk of 6 to 94% the cost is 4 800 FF vs 10 400 FF per patient; if coronary angiography is performed in all patients in whom coronary artery disease is possible or certain (all patients with a risk of over 5%), the cost is 8 400 FF vs 10 400 FF per patient, a saving of 20%.(ABSTRACT TRUNCATED AT 400 WORDS)

The pyrophosphate of Tc99m attaches itself to ischaemic myocardial cells, and therefore makes it possible to obtain a scintigram of necrotic or necrosing myocardium. In a series of 65 cases the scintigram was positive in every case in which there had been a recent transmural infarct (17 cases). The results showed greater variation in the other ischaemic conditions involving the myocardium (limited infarcts or simple angina). The progress as a function of time was stuided in a series of fairly recent and older infarcts. The limitations and future prospects of this investigations are discussed.

Rheoplethysmography with occlusion (RPO) is useful in the diagnosis of deep venous thrombosis. Bilateral phlebography with cavography performed afterwards as an emergency gives information as to the embolic potential of the thrombosis and orientates treatment towards surgical interruption of the inferior vena cava. In the C.H.U. at Grenoble 83 clips, 25 umbrella filters and 2 ligatures were placed on the inferior vena cava from 1974 to 1977. Prevention of pulmonary emboli was achieved in 99% cases with lower limb embolic foci. Follow-up by RPO and isotopic phlebography showed that the course of venous thrombosis of the lower limbs seemed to be unchanged by partial interruption of the inferior vena cava, provided that elastic stockings and adequate anticoagulant therapy adapted to venous haemodynamics are used.