Characterisation, cloning and sequencing of a conformation-dependent monoclonal antibody to the alphaIIbbeta3 integrin: interest for use in thrombus detection

The detection of newly formed thrombi is of primary importance in clinical medicine. The activated platelet is a potential target for the localization of thrombotic lesions in arteries. The integrin alpha(IIb)beta(3) membrane changes conformation upon activation. A novel anti-alpha(IIb)beta(3) monoclonal antibody (MAb), XIIF9, is described which recognizes an epitope whose expression was enhanced by activation. Radioiodinated XIIF9 bound to a single class of sites on the beta(3) subunit, with 13600 +/- 2000 molecules bound per unstimulated platelet and a K(d) of 34.5 nM. Platelets stimulated with 0.5 U/ml of thrombin bound 66000 +/- 4000 molecules/cell (K(d) = 51.6 nM). Moreover, XIIF9 binding to unstimulated platelets could be increased 4-fold by treatment of the alpha(IIb)beta(3) complex with 5 mM EDTA. Thus, XIIF9 recognized an epitope on the beta(3) subunit whose accessibility was increased upon thrombin activation or EDTA treatment. Sequence analysis of the gene segment encoding the XIIF9 heavy chain revealed interesting motifs shared with cyclic CX6-7C anti-alpha(IIb)beta(3) peptides or with AC7, a published MAb specific for activated alpha(IIb)beta(3). In vivo experiments in atherosclerotic rabbits followed by immunohistological analysis, revealed a specific binding of XIIF9 on platelets engaged in thrombus formation, demonstrating real clinical potential for such MAbs in imaging.

Assessment of brain natriuretic peptide in patients with suspected heart failure: comparison with radionuclide ventriculography data

BACKGROUND

The aim of the study was to prospectively evaluate patients with suspected or known heart disease using plasma brain natriuretic peptide (BNP) measurement and radionuclide ventriculography to examine whether left ventricular dysfunction is associated with an abnormal rise of BNP concentration.

METHODS

Patients (n=153) and controls (n=14) underwent radionuclide ventriculography to determine Left ventricular Ejection Fraction (LVEF) and measurement of plasma BNP concentration using a commercial kit.

RESULTS

Plasma BNP concentration in controls was significantly lower than that in patients whatever the stage of the disease, significantly lower than that of patients with normal LVEF (LVEF>55%); than that of patients with altered LVEF (LVEF< or =40%); and than that of patients with moderately reduced LVEF (40%<LVEF< or =5%). Comparisons between groups of patients showed that the more severe the disease, the higher the BNP level. From the ROC curve, a plasma BNP concentration of 52 pg/ml was attached to a 85% sensitivity and 82% specificity in identifying patients with LVEF< or =40%.

CONCLUSIONS

Plasma BNP concentration provides a reliable and sensitive marker of LV systolic dysfunction evaluated by a nuclear medicine technique, and could be a potential screening test to identify patients for additional investigations.

Feasibility of endocardial edge detection by using an inversion recovery artifact

An inversion recovery (IR) artifact was used to delineate the blood/wall boundary in left ventricles. The artifact consisted of a hypointensity signal in pixels located at the boundary of two contiguous tissues with different T(1) relaxation times. The feasibility of measuring the ejection fraction using the artifact was tested in ten healthy volunteers, with two IR snapshot-FLASH sequences possessing different times of repetition (TR = 11msec and TR = 3.5msec) and appropriate times of inversion. The comparison with a cine-MRI sequence showed that ejection fraction measurements are feasible when performed with a snapshot-FLASH sequence that has a sufficiently short TR (3.5msec).

Tuning of pulmonary arterial circulation evidenced by MR phase mapping in healthy volunteers

Magnetic resonance (MR) phase mapping was used to noninvasively assess both blood flow and cross-sectional area (CSA) in the main pulmonary artery (MPA) of 12 healthy volunteers. Flow and CSA patterns exhibited two positive peaks: high systolic and small diastolic. This finding can be explained using a simple "distributed" theoretical model that takes into account the role of a reflected pressure wave from pulmonary vascular impedance in generating a diastolic flow. The mean reflection coefficient of pressure wave, MPA input impedance, and pulmonary vascular impedance were assessed. We verified, in this series, that pressure wave velocity appears to be age-dependent. MR phase mapping has been used to observe the tuning (resonance) of the right cardiovascular system at rest under physiological conditions. MR phase mapping could be used to assess pathological modifications of the tuning that occurs in cases of pulmonary arterial hypertension.

Segmented 5 versus nonsegmented flow quantitation: comparison of portal vein flow measurements

RATIONALE AND OBJECTIVES

Times of acquisition, mean velocities, mean flows, and their respective standard deviations provided by segmented and nonsegmented flow quantifications (FQ) were compared in the main portal veins of ten healthy adults.

METHODS

The segmented FQ performed five phase-encoding lines per segment. The authors successively applied the two electrocardiogram-triggered techniques in the same slice perpendicular to the portal flow direction. Their measurements were compared in particular by means of the statistical analysis proposed by Bland and Altman.

RESULTS

The segmented 5 FQ reduced the acquisition time by two compared with the nonsegmented FQ. The mean velocity and mean flow values of the two techniques were not significantly different. The standard deviations were similar.

CONCLUSIONS

The segmented 5 FQ showed its major advantage in the portal vein: the acquisition time was reduced without any loss of accuracy or any uncertainty enhancement.

Endocardial biventricular pacing

Simultaneous right and left ventricular pacing was performed in a 73-year-old man with coronary artery disease end-stage congestive heart failure and a DDD pacemaker implanted for sick sinus syndrome. An endocardial LV lead was introduced transseptally after unsuccessful attempts to enter the coronary sinus. This new approach for multisite pacing offers an alternative to epicardial LV from the coronary sinus or by thoracotomy.

A validation of a flow quantification by MR phase mapping software

AIM

We evaluated a Siemens software of flow quantification (FQ) by MR phase mapping, in the framework of a common practical use.

METHODS

Experiments with a laminar flow phantom and in vivo pulsatile flow were performed. In particular, FQ in ascending aorta was investigated in healthy volunteers.

RESULTS AND CONCLUSION

Flow phantom experiments reveal that the FQ slightly underestimates (8% on the average) actual velocities (mean velocities over a vessel area), and also that velocity uncertainties are related to the encoding velocity value, whatever the measured velocity. Furthermore, using well characterized working criteria, we found low intraobserver variability and negligible interobserver variability in ascending aorta FQs. The role played by the choice of reference area in FQ accuracy is emphasized. When recording several cardiac cycles during the same acquisition, it is shown that the FQ software may provide erroneous results. Several comments for FQ software use in the ascending aorta are added.

[Diagnosis of Conn's adenoma. Comparative study of x-ray computed tomography and scintigraphy using 19-noriodocholesterol]

OBJECTIVE

In order to differentiate an aldosterone producing adenoma (APA) and a bilateral adrenal hyperplasia (BAH) in case of primary hyperaldosteronism, an adrenal CT-scan is usually used as first line exploration. The contribution of adrenal 19-noriodocholesterol (NP59)-scintigraphy is controversial.

PATIENTS AND METHODS

We describe 17 cases of primary hyperaldosteronism referred to surgery for suspected APA. The value of abdominal CT-scan and of adrenal scintigraphy was studied.

RESULTS

After unilateral adrenalectomy, 15 cases with confirmed APA were cured and 2 cases with an unilateral hyperplastic macro nodule showed persistence of the disease. The pathologic findings were concordant with CT-scan in 76% (13/17) and with scintigraphy in 88% (15/17). Similar sensitivity was found for CT-scan and scintigraphy (86% and 88%) with 2 false negative results with both techniques. False positive results were observed only with CT-scan (2 cases) suggesting that scintigraphy has a better specificity. No case was misdiagnosed by both techniques.

CONCLUSION

These results suggest that NP59-scintigraphy is complementary to adrenal CT-scan for the recognition of APA and is particularly useful in case of a unilateral hyperplastic macro nodule mimicking an APA.

[Alteration of myocardial viability and systemic ventricular dysfunction after Senning procedure]

After a Senning procedure for transposition of the great arteries (TGA), systolic dysfunction of the right ventricle (RV) is common. Pre and peroperative chronicale hypoxia may be the cause of this ventricular myocardial alteration. In order to detect abnormalities of myocardial viability and to study their relationship to RV function, the authors studied 41 patients (pts), 11.3 +/- 3 years after a Senning procedure. All patients underwent myocardial scintigraphy of the RV under basal conditions. 1 hour after injection of 1.5 mCi of Thallium 201. The RV ejection fraction (n = 41) and at peak effort (n = 25). Exercise ability and aerobic capacity were assessed by exercise testing (Bruce) with gas exchange measurement and compared with 41 normal matched subjects. The cardiorespiratory response to exercise was altered in the Senning group : duration of effort (10.5 +/- 2 vs 13.2 +/- 2 min; p < 0.0001), peak VO2 (33 +/- 5 vs 44.4 +/- 6 ml/min/kg; p < 0.0001), anaerobic threshold (6 +/- 1 vs 8.4 +/- 1.9 min; p < 0.05) were lower compared to controls. Abnormalities of RV viability were observed in 18/41 pts (44%), moderate in 12 cases and severe in 6 cases. Resting and exercise RVEF were significantly lower in patients with myocardial defects (45 +/- 5 vs 51 +/- 7%; p < 0.0005, and 49 +/- 9 vs 58 +/- 9%; p < 0.05 respectively). In conclusion, after the Senning procedure for TGA, scintigraphic abnormalities of the systemic ventricule are common and associated with an alteration of systolic function at rest and on exercise.

Cardiorespiratory response to exercise after venous switch operation for transposition of the great arteries

STUDY OBJECTIVES

This study reports on the cardiorespiratory response to graded exercise in patients after venous switch operation for transposition of the great arteries.

DESIGN

Several small studies have documented a diminished exercise tolerance after Mustard repair for transposition of the great arteries, little information exists, however, about long-term cardiorespiratory exercise performance in patients who have had the Senning procedure.

PATIENTS

This prospective study reports on the serial long-term (mean, 11 +/- 2.8 years) cardiopulmonary exercise performance of 43 patients (age, 12 +/- 3.1 years) who underwent a Senning procedure, with no significant postoperative abnormalities. Forty-three matched healthy children were also studied as a control group.

MEASUREMENTS AND RESULTS

All underwent exercise testing (Bruce protocol) with metabolic gas exchange to determine parameters at 3 min, anaerobic threshold, similar heart rate (150 beats/min), and peak exercise. Time of exercise was 10.5 +/- 1.9 min in patients and 13.4 +/- 2 min in control subjects (p = 0.0001). Overall, patients reached 73% of peak oxygen uptake achieved by control subjects (32.6 +/- 5.6 vs 44.7 +/- 6 mL/kg/min). Chronotropic response (188 +/- 15.7 vs 166.5 +/- 19.6 beats/min [p = 0.0001]) and oxygen pulse (7.4 +/- 2.9 vs 10.7 +/- 4.2 mL/beat [p = 0.0002]) were lower in patients at peak exercise. Patients had a greater respiratory response to exercise: both respiratory rate and ventilatory equivalent for carbon dioxide were significantly higher at all stages of exercise. Exercise capacity assessed by peak oxygen uptake was correlated with time elapsed since surgical repair (r = 0.48; p = 0.001).

CONCLUSIONS

It is concluded that even in asymptomatic patients, exercise endurance and respiratory response are generally altered as much as 11 +/- 2.8 years after venous switch operation, although early surgical repair is predictive of a better long-term functional result.

[Value and limits of exercise radionuclide ventriculography in chronic aortic insufficiency. Apropos of 47 operated cases]

The role of exercise radionuclide angiography in the therapeutic strategy of chronic aortic insufficiency remains controversial. In order to assess the value of this technique, 47 patients with pure chronic aortic insufficiency were evaluated before and one year after valve replacement. The preoperative EF decreases or does not increase on exercise (51.9% vs 48 +/- 10%; p < 0.001) in the majority of patients (78%), whereas, after surgery, the EF tends to increase on exercise (55 +/- 11% vs 57 +/- 11%; NS). Despite optimal surgical correction, 16 of the surviving 46 patients still had left ventricular dysfunction at one year after surgery. The preoperative parameters correlating with this dysfunction were, in order, resting radionuclide EF (r = 0.65; p = 0.0001) and the echocardiographic parameters: left ventricular endosystolic dimension, fractional shortening, and the radius/thickness ratio. The preoperative exercise radionuclide parameters did not correlate with postoperative left ventricular dysfunction. In patients without postoperative left ventricular dysfunction, the EF increased on exercise, contrary to the other group. The exercise EF remains valuable for retrospective evaluation of surgical benefit. The exercise radionuclide EF does not reflect myocardial contractile reserve alone but also the conditions of left ventricular load. This study confirms the superiority of the resting radionuclide EF and echocardiographic parameters over exercise radionuclide EF for the prediction of postoperative left ventricular dysfunction.

A human monoclonal antibody obtained from EBV-transformed B cells with specificity for myosin

We describe the preparation of a stable human lymphoblastoid cell line obtained during ex vivo studies in which peripheral blood lymphocytes of a Glanzmann's thrombasthenia patient were transformed with Epstein-Barr virus. Somatic hybrids secreted an IgM monoclonal antibody (B7) that reacted with the myosin heavy chain of human platelets by immunoblotting. Flow cytometry showed that B7 barely recognized unstimulated intact platelets, but bound abundantly after permeabilization of fixed cells with Triton X-100. The reactivity of the antibody on thin sections of human myocardium and aorta was studied by immunohistochemistry. B7 specifically stained myosin of myocytes, but there was no labelling of aortic smooth muscle cells. The epitope was conserved in cardiac or skeletal myosin prepared from pig or rabbit. Measurement of the dissociation constant in a competitive ELISA showed that B7 bound with high affinity (10(-8) M). Purified Fab fragments retained their ability to bind to myosin, suggesting that B7 may be useful in the imaging of myocardial necrosis after myocardial infarction, myocarditis, cardiac drug toxicosis or graft rejection. This work also shows that EBV transformation of B cells may uncover naturally occurring autoantibodies which under normal circumstances are inhibited by the immune surveillance system.

Shunt failure in adult hydrocephalus: flow-controlled shunt versus differential pressure shunts--a cooperative study in 289 patients

BACKGROUND

In order to assess the efficiency of flow-controlled shunts in reducing shunt failure in the treatment of adult hydrocephalus (with a special focus on overdrainage complications), a series of 289 patients was analyzed through a retrospective and comparative study performed in three neurosurgical departments.

METHODS

A group of 142 adult patients suffering from hydrocephalus were operated on using a conventional differential pressure (DP) shunt and compared with a group of 147 adult patients operated on using flow-controlled (FC) system (Orbis-Sigma, Cordis). Only the first complication, which required a surgical revision within the first 2 years after shunt implantation, was taken into account for each patient and analyzed using life-table methods.

RESULTS

The actuarial risk of shunt infection in the two groups is respectively 8.3% and 10.9% at 1 year (nonsignificant difference). The actuarial risk of mechanical complications at 1 year is 38% for the DP patients and 10% for the FC patients (p = 0.0001); this difference is largely due to a decrease of complications related to overdrainage phenomenon (14/142 subdural collections were observed in the DP group versus 1/147 in the FC group) (p = 0.0001).

CONCLUSION

The conclusion of this cooperative and retrospective study is that the use of a flow-controlled system decreases the risk of mechanical complications related to the hydrodynamic properties of the shunts used in the treatment of adult hydrocephalus, especially those related to overdrainage.

[Complementary value of the isoprenaline test and high-amplification ECG in the diagnosis of arrhythmogenic dysplasia of the right ventricle]

Arrhythmogenic dysplasia of the right ventricle is a common cause of ventricular arrhythmia. It is important to reach a diagnosis, due to the risk of sudden death, particularly as this may be the first sign of the disease. Diagnosis is based on the angiographic demonstration of a morphological or structural abnormality of the right ventricle, and non-invasive tests are relatively insensitive. From a case investigated in 1984, the authors carried out a prospective determination of the diagnostic value of the isoprenaline test in 61 patients suffering from arrhythmogenic dysplasia of the right dysplasia confirmed by angiography. High concentrations (8-30 micrograms/min) of isoprenaline were continuously infused over a period of 3 minutes, regardless of the heart rate achieved. In a control group of 50 subjects with no myocardial disorder, isoprenaline induced monomorphic wave-burst arrhythmia in only one patient (2%). In the subjects affected by right ventricular arrhythmogenic dysplasia, isoprenaline induced one or more episodes of wave-burst ventricular arrhythmia in 52 patients (85%): one triplet in four patients, several episodes of wave-burst arrhythmia in 31 patients and prolonged ventricular tachycardia in 17 patients. Polymorphic arrhythmia occurred in 80% of cases, but left lag forms predominated. High-amplification ECG demonstrated late potentials in 66% of cases, i.e. in 80 and 62% of patients with and without prolonged VT respectively. The isoprenaline test or high-amplification ECG gave abnormal results in 58 of the 61 patients, with a cumulative sensitivity of 95 percent.

[Macronodule associated with bilateral adrenal hyperplasia. A rare misleading cause of primary aldosteronism (two cases)]

Aldosterone-producing adrenal adenoma and bilateral hyperplasia are the two predominant subtypes of primary aldosteronism. Their recognition is based essentially on adrenal CT scan and on measurements of plasma aldosterone and 18-hydroxycorticosterone (18-OHB) concentrations in response to postural testing. We report 2 cases of primary aldosteronism associated with a unilateral hyperplastic macronodule resembling an aldosterone-producing adenoma on CT scan. Plasma aldosterone and 18-OHB concentrations were consistent with this diagnosis in one patient. In the light of these two cases and of those previously published, the investigations needed for the etiological diagnosis of primary aldosteronism are discussed.

Distinctive response of arrhythmogenic right ventricular disease to high dose isoproterenol

Arrhythmogenic right ventricular disease is a potential cause of ventricular arrhythmias. Diagnosis is important due to the risk of sudden death, particularly as first symptom. Diagnosis is based on the angiographic demonstration of abnormal right ventricular morphology and function, while the sensitivity of noninvasive tests is relatively low. Following a particular observation studied in 1984, we prospectively assessed the diagnostic value of high dose isoproterenol infusion in 44 patients with an angiographically determined arrhythmogenic right ventricle. A continuous infusion of isoproterenol (8-30 micrograms/min) was administered during a 3-minute period, regardless of the obtained heart rate. In a control group of 50 patients without structural heart disease, isoproterenol induced a monomorphic ventricular tachycardia salvo in only one patient (2%). In patients with an arrhythmogenic right ventricle, isoproterenol induced one or more ventricular tachycardia runs in 39/44 cases (88%): one triplet in three patients, several runs in 23 patients and a sustained ventricular tachycardia in 13 patients. Arrhythmia was polymorphous in 85% of cases, but left bundle branch block morphology was the predominant pattern. In conclusion, high dose isoproterenol is a highly sensitive test for the diagnosis of arrhythmogenic right ventricular disease.

Cardioprotective effect of trimetazidine in severe ischemic cardiomyopathy

The aim of this study was to assess the value of long-term treatment with 60 mg per day of trimetazidine, a cellular antiischemic agent, in comparison with placebo, in patients with ischemic cardiomyopathy controlled by conventional treatments. Twenty patients, with a mean age of 59.5 +/- 1.6 years, suffering from severe ischemic cardiomyopathy (NYHA IV, 6 patients; NYHA III, 14 patients) confirmed by coronary angiography, were included in the study; four of them suffered from residual angina. All of these patients were receiving long-term treatment with long-acting nitrates associated with digitalis (9 patients), diuretics (15 patients), anticoagulants (13 patients), and antiarrhythmics (11 patients), and were considered to be stabilized at the time of inclusion in the study. The examinations consisted of clinical and laboratory assessment, resting ECG, 24-hour ECG monitoring, X-ray evaluation of cardiac volume (CV), and evaluation of echocardiographic left ventricular shortening (ELVS) and of isotopic ejection fraction (EF). These three parameters were expressed as a percentage variation with respect to the initial value, and their variation between the two groups was compared by means of two-way analysis of variance. Clinically, the therapeutic benefit provided by trimetazidine resulted in: a) an improvement of dyspnea in all patients treated with trimetazicine compared with only one patient with placebo (p less than 0.001), b) resolution of residual angina, which was unchanged with placebo, c) reduced requirements for complementary treatments (a single case versus eight cases in the placebo group; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic value of a cardioprotective agent in patients with severe ischaemic cardiomyopathy

Trimetazidine (TMZ) has been shown to have anti-ischaemic properties improving exercise tolerance without haemodynamic effects. A 6-month double-blind placebo-controlled study was carried out in 20 patients, mean age 59 +/- 6 years, to examine the benefit of adding 60 mg of TMZ vs placebo to the classical therapy, excluding those previously treated with calcium-antagonists, conversion enzyme inhibitors, vasodilators and antiplatelet agents. All patients had severe ischaemic cardiomyopathy, confirmed by coronary angiography; six were in NYHA class IV; 14 in NYHA class III; four had mild recurrent angina pectoris. assessment included clinical and biological evaluation, electrocardiography (ECG), 24-h ECG monitoring, cardiac volume evaluation with chest X-ray, left ventricular fractional shortening by echocardiography, left ventricular ejection fraction by radionuclide angiography. Baseline characteristics were similar in placebo (11 patients) and TMZ (nine patients) groups. Eighteen patients (nine in each group) were followed up for 6 months. In eight patients of the placebo group, treatment had to be modified (addition of calcium antagonists: four patients, conversion enzyme inhibitors: two patients; digitalics: one patient; diuretics: one patient). In the TMZ group, digitalic therapy was withdrawn in one patient and added in one patient (P less than 0.01). At 6 months, all TMZ group patients were free from angina; dyspnoea was improved in all TMZ patients and in only one placebo patient (P less than 0.001). Ejection fraction, increased by 9.3% in the TMZ group and decreased by 15.6% in the placebo group (P less than 0.018), CV decreased by 7% with TMZ, increased by 4% with placebo. (P = 0.034).(ABSTRACT TRUNCATED AT 250 WORDS)

[Contribution of Doppler echocardiography and thallium in cases of major ST segment depression in athletes]

False-positive responses to exercise tests have been reported as been more frequent in athletes than in the general population and attributed to physiological hypertrophy of the athlete's heart. In this study, we have investigated the significance of major ST depression (-3.55 +/- 1.8 mm) in a group of 13 athletes aged 40 +/- 9 years who had normal coronary angiography. All subjects underwent a standard exercise test followed by a second one after administration of nitroglycerin; the post-test probability of coronary was evaluated by multivariate analysis of the results. Myocardial perfusion was studied in 9 subjects by stress thallium 201 scintigraphy, and the data obtained were compared with those of angiography. Left ventricular hypertrophy was systematically looked for by calculating the myocardial mass index at echocardiography. The subjects were also investigated for possible alteration of the diastolic function, using doppler ultrasound. The mean follow-up period was 5 +/- 2 years. The mean performance at exercise tests was 238 +/- 118 watts. The Q wave significantly increased at exercise (-0.61 +/- 0.8; p less than 0.05), whereas the R wave remained constant (-0.95 +/- 4.5 mm; N.S.). The mean probability or coronary disease was 0.49 +/- 0.41, which justified the thallium scintigraphy test. This test was abnormal in 8 out of 9 cases. The myocardial mass index was slightly increased up to 138 +/- 25 g/m2, reflecting a very moderate physiological hypertrophy, as testified by the normality of diastolic function related to age in 8/9 cases. There was no obvious correlation between ST depression amplitude and myocardial mass index.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of trimetazidine in the long-term treatment of cardiomyopathies of ischemic origin]

The effect of a cellular anti-ischemic, trimetazidine (TMZ) in ischemic cardiomyopathies, was evaluated in a double-blind versus-placebo (P) trial, over a period of six months. 20 patients, mean age: 59.5 years, with advanced ischemic cardiomyopathy, demonstrated by left catheterization and coronary angiography, with a past history of myocardial infarction, received either 60 mg per day of TMZ (nine patients) or the placebo (eleven patients) in addition to a basic treatment of digitalis, diuretics and nitrated medications. A complete, clinical, biological and paraclinical evaluation, including chest X-ray, ultrasonography, isotopic ventriculography and 24 h-ECG, was performed upon inclusion in the study; and after three and six months of treatment. Two patients from the placebo group were not reevaluated at six months. The clinical condition, according to the NYHA classification, improved in all patients from the TMZ group, deteriorated in eight on nine patients from the placebo group (p less than 0.001). The isotopic stroke volume is preserved with TMZ, deteriorated with P. The cardiac volume decreases with TMZ, increasing with P. TMZ is beneficial clinically and functionally in advanced ischemic cardiomyopathies.

Magnetic resonance imaging of an anomalous origin of the left coronary artery from the pulmonary artery

This report describes a 34-year-old woman with an anomalous origin of the left coronary artery from the pulmonary artery. The angiographic pattern was clearly demonstrated by magnetic resonance imaging (MRI) performed before surgery. This case suggests that MRI could play an important role in the pre-operative assessment of coronary anomalies.

Bronchogenic carcinoma staging: CT versus MR imaging. Assessment with surgery

One hundred and twenty patients with bronchogenic carcinoma were prospectively studied by both computed tomography (CT) and magnetic resonance imaging (MRI) during the 2 weeks preceding thoracotomy or mediastinoscopy. MRI scans included contiguous axial and coronal slices. Results of CT and MRI studies were compared with the surgical and pathological findings on the basis of the TNM classification. Although no significant difference was found between the two imaging methods for the evaluation of tumour extent, MRI appears to be a valuable imaging technique for left upper lobe and apical neoplasms. Comparison between the two techniques for mediastinal node evaluation showed that sensitivity of MRI is superior to CT in the left paratracheal, aortopulmonary and subcarinal node areas.

Detection of anomalous systemic venous return and intraatrial baffle leakage by radionuclide angiocardiography

The case presented here is a 27-year-old patient who was born with common atrium and left superior vena cava (LSVC). Construction of interatrial septum and intraatrial baffle with pericardium was performed 16 years ago. Radionuclide angiocardiography (RAC) showed that a substantial amount of blood flow from the LSVC was directed to the inferior vena cava through the hemiazygos vein (HAV). It also detected a baffle leak and a left to right shunt at the atrial level. Subsequent RAC after reoperation initially showed insignificant flow through the atrial baffle, major flow through the HAV, and no shunt. Repeat RAC one year after surgery showed increased flow through the baffle and diminished flow through the HAV, without a satisfying explanation. This case illustrates the value of RAC in detecting various types of cardiovascular abnormality and subtle hemodynamic changes.

[Malignant lymphoma of the heart. Contribution of modern technics of medical imaging]

Although rarely encountered, tumours of the heart are now more easily and frequently diagnosed owing to the availability of non-invasive imaging methods, notably echocardiography. With echocardiography the cardiac extension of the tumour is perfectly visualized, but its connections with the mediastinum are less readily accessible. The case presented here of a female patients with a malignant lymphoma involving the heart (right ventricle and atrium, pericardium) and the mediastinum illustrates the complementary nature of echocardiography, computerized tomography and magnetic resonance imaging.

[Simultaneous occurrence of left heart block and chest pain during exertion]

Two principal theories have been formulated to explain the simultaneous occurrence of a left bundle branch system block (LBBsB) and a stress-induced chest pain: initial stage of the permanent LBBsB of a primary myocardiopathy, or original clinical expression of coronary insufficiency. In the case presented here, the similarity of symptoms, the improvement observed in ergometric exercise tests under nitroglycerin and the increase of lactate concentrations in the coronary sinus were in favour of the second theory. However, the results of a radionuclide myocardial perfusion study and a radionuclide ventriculography were not sufficiently specific to support this assumption. The lack of free interval between the LBBsB and the angina-like chest pain (neurosensorial reflex) stands against an ischaemic mechanism. The initial intermittent LBBsB phase found in our patient during the exercise test might correspond to this free interval. The favourable prognosis and the uncertain effectiveness of treatment are suggestive of a very early stage in either primary cardiomyopathy or coronary disease.

Test of a versatile on-line distortion corrector for a gamma-camera

A gamma-camera on-line distortion corrector, based on a fast microprocessor, has been tested on two cameras. The original electronic design and the software algorithm are described. Performance measurements on phantoms and clinical results show an improvement of the pictures.

Unsuccessful lung scan due to major right-to-left shunt through a sinus venosus septal defect

In a patient with a prior history of cerebral abscess and cerebral ischemia, an unsuccessful perfusion lung scan led to a radionuclide angiocardiogram using an arm vein injection. This showed a total right-to-left (R-L) shunt from the superior vena cava (SVC) to the left atrium. Repeat radionuclide study, through a leg vein, demonstrated a moderate R-L shunt and an interpretable lung scan could be obtained. Catheterization and contrast cineangiogram did not provide the exact diagnosis, the preoperative conclusion being anomalous drainage of the SVC into the left atrium, with atrial septal defect (ASD) and partial anomalous pulmonary venous connection to the SVC. The operative diagnosis was high atrial (sinus venosus) septal defect. This example of major but clinically unsuspected R-L shunt emphasizes the value of performing a perfusion lung scan, preferably in conjunction with radionuclide angiocardiography in patients with a prior history of unexplained cerebral abscess or systemic ischemia. Implications of the site of an ASD on quantitation of L-R shunts by radionuclide methods are also discussed.

Quantitative analysis of left-ventricular function using gated single photon emission tomography

We describe a quantitative method that measures segmental motion of the left ventricle, using tomographic slices obtained by gated single photon emission tomography (GSPECT). These slices contain the major axis of the left ventricle and are presumed to show wall motion directed towards a center of contraction. Values of parameters describing segmental wall motion in GSPECT were obtained from 61 patients, who received a left cardiac catheterization 1 hr later. These values were compared with results of similar calculations applied to data from contrast ventriculography. We conclude that GSPECT allows a detailed and quantitative, noninvasive study of wall motion of all left ventricular segments, with high inter- and intraobserver reproducibility.

Single photon emission computed tomography (SPECT), planar scintigraphy, and transmission computed tomography: a comparison of accuracy in diagnosing focal hepatic disease

A prospective evaluation of conventional planar scintigraphy (PS), single photon emission computed tomography (SPECT), and transmission computed tomography (TCT) was performed in 98 patients with suspected focal hepatic disease (FHD). The three examinations were performed on the same day. TCT had slightly higher sensitivity (91%) and specificity (96%) than either PS or SPECT. The sensitivity and specificity of TCT was also higher than that of the combination of PS and SPECT, which was more accurate than either radionuclide technique alone, with a sensitivity of 85-87% and a specificity of 90%. These differences were not statistically significant. However, receiver operating characteristic (ROC) analysis showed that the performance of TCT was significantly better. The ROC curves also showed, without statistical significance, that SPECT appears to have better diagnostic accuracy than PS and that it seems desirable to complement SPECT imaging with PS views, to reduce the number of equivocal results.

Radionuclide studies in postoperative evaluation of the Fontan procedure

Radionuclide studies were performed on 12 patients who had had a Fontan operation for cyanotic congenital heart disease, six of whom had undergone a prior palliative Glenn procedure. The patients without prior Glenn anastomoses were studied by radionuclide first-pass angiocardiography, using a right antecubital vein injection of 99mTc pertechnetate. The patients with Glenn anastomoses required two injections, one by femoral vein to study the Fontan procedure, using bolus injection of 99mTc pertechnetate or microspheres, and the second by right antecubital vein to study the Glenn anastomosis and right lung, using a bolus of microspheres. Gated cardiac blood-pool scintigraphy was used to measure right atrial and left ventricular ejection fraction in three patients. In nine patients, contrast angiography confirmed that these techniques allowed recognition of residual right-to-left shunts, right atrial stasis, right atrial outflow obstructions, left ventricular dysfunction, and right lung arteriovenous fistulas. Noninvasive radionuclide methods seem to be dependable in the postoperative evaluation of patients after the Fontan procedure. First-pass angiocardiography is most helpful in evaluating the dynamics and distribution of blood flow, especially the right atrial output, and gated blood-pool scintigraphy offers a better evaluation of right atrial and left ventricular contraction, so both supply complementary information.

Radionuclide angiocardiography in the diagnosis of congenitally corrected transposition of the great arteries

Congenitally corrected transposition of the great arteries (CTGA) may constitute a pitfall for interpretation of radionuclide angiocardiography, since the two anatomic discordances cancel each other from a physiologic point of view. However, the unusual shape of the ventricles (due to ventricular discordance) and the relative position of the great arteries (due to transposition) can allow a clear scintigraphic diagnosis, especially for CTGA with mild or absent associated congenital anomalies. Five cases are described. Gated cardiac blood pool imaging is particularly helpful since it permits multiple views, allowing a more detailed study of the scintigraphic signs.

Cerebrospinal shunt flow in adults: radionuclide quantitation with emphasis on patient position

Radionuclide quantitation of cerebrospinal fluid (CSF) flow through a ventricular shunt using a Cordis-Hakim valve was performed in 78 adults (138 studies). All remained supine for at least two hours before the study to avoid possible depletion of ventricular CSF. The absolute flow rate distinguished shunt adequacy from patency by defining flow of less than 0.1 ml/min. as abnormal. Measurements were performed with the patient first supine and then erect. When abnormal supine flow was the criterion of malfunction, all obstructions were detected but there were 6 false positives. When abnormal erect flow was considered, there were 5 false negatives. Abnormal flow in both supine and erect positions is a reliable indication of malfunction. The authors conclude that this technique is valuable for neurosurgical management of ventricular shunts.

Radionuclide angiographic demonstration of systemic lung arterialization with arteriovenous fistulas

Radionuclide angiography has diagnosed systemic arterialization of the right lung base in a patient presenting with a basal thoracic bruit. The bruit was due to high flow in the systemic artery and development of arteriovenous fistulas, confirmed by TCT scan and contrast aortography. But the parenchyma of the right lung base appeared normally aerated on the radiographic studies, and Xe-133 ventilation scintigraphy was normal. This case was therefore classified as systemic arterialization of lung without sequestration.