[Myocardial radionuclide tomography using Thallium 201 and detection of coronary re-stenosis after single-vessel angioplasty]. / Tomoscintigraphie myocardique au Thallium 201 et détection de la resténose coronaire après angioplastie monotronculaire.

Among non-invasive methods for the detection of coronary restenosis after successful transluminal coronary angioplasty, the contribution of exercise myocardial Thallium 201 tomoscintigraphy (MTS) was assessed in a prospective study involving 168 patients with a mean age of 56 (range 32-75) who had undergone 174 successful single vessel angioplasties (86 AIV, 35 Cx, 53 RC) with residual stenosis of 50% or less. After an interval of 6 +/- 2 months, patients were reassessed without treatment by a maximum exercise test (ET) combined with Thallium 201 MTS, 24 hours before follow-up coronary arteriography. Restenosis, defined by a greater than 50% loss of the gain achieved by the initial angioplasty, was seen in 53 patients (30.4%). MTS, with the exception of any necrosed area, was read as positive in case of reversible exercise hypofixation with redistribution. Sixty seven tests were positive, 49 corresponding with restenosis. Four were normal despite restenosis. The diagnostic values of the 3 methods of angina, ET and MTS were 0.43, 0.74 and 0.92 respectively for sensitivity, 0.89, 0.85 and 0.85 for specificity, 0.64, 0.68 and 0.73 for positive predictive value and 0.78, 0.88 and 0.96 for negative predictive value. In total, MTS at 6 months had the best sensitivity for the detection of coronary restenosis after single vessel angioplasty and an excellent negative predictive value (96% alone, 100% combined with ET), eliminating the need for coronary arteriography when it is negative.

Captopril induces correction of postrenal transplant erythremia.

Kidney transplant patients may develop post-transplant erythremia (PTE), and in order to avoid thromboembolism venesection, anticoagulation and native kidney removal have been suggested. We propose captopril as an alternative therapy for PTE. Seven hypertensive PTE patients, aged 42 +/- 10 years with stable renal function, were investigated to exclude primary or secondary polycythemia. All patients manifested true erythrocytosis [red blood cells (RBC) mass greater than 20% of predicted level] with concomitant increases in hematocrit and hemoglobin levels. Captopril was introduced in gradually increasing doses up to 75 mg/day under careful monitoring of blood pressure and renal function. Weekly follow-up was arranged to evaluate drug efficacy. After captopril, a significant reduction with normalization of the RBC mass (42 +/- 4 vs 31 +/- 5 ml/kg: P less than 0.005) was observed. The RBC counts and hematocrit and hemoglobin levels also decreased. One patient had recurrent erythrocytosis after captopril withdrawal. Captopril may be a simple, effective, and non aggressive treatment for postrenal transplant erythremia.

[Radioisotope and ultrasonic diagnosis of a localized form of infarction of the right ventricle]. / Diagnostic radio-isotopique et échographique d'une forme localisée d'infarctus du ventricule droit.

We are reporting the case of a localized form of right ventricle infarction. The right catheterization, on which the diagnosis usually rests, is completely normal. Cardiac gamma-angiography and bi-dimensional sonography demonstrate, on the contrary, a localized dyskinesis of the inferior wall of the right ventricle which is not dilated and retains its ejection fraction. The failure of right catheterization in the diagnosis of infarction of the right ventricle is usually attributed to hypovolemia or a delay in the performance of the catheterization, which is not the case here. Therefore, this case demonstrates the existence of infarction of the right ventricle without total diastolic or systolic dysfunction, the diagnosis of which may be made with isotopic and sonographic methods.

[Antiarrhythmic effects of intravenous magnesium sulfate in torsade de pointes. Apropos of 6 cases]. / Effets anti-arythmiques du sulfate de magnésium intraveineux dans les torsades de pointes. A propos de 6 observations.

The antiarrhythmic properties of magnesium salts, known for many years, are periodically recalled but rarely used in daily clinical practice. They are usually used in digitalis-induced arrhythmias and are rarely indicated in other conditions; they are often reserved for cases in which a magnesium deficiency is suspected. In 6 cases of torsades de pointes, magnesium sulphate was administered at a dose 1 to 3 g by direct intravenous injection. Although hypokalaemia was a common finding, a low magnesium concentration was only found in one case. The ventricular arrhythmia regressed completely at the end of the injection in 4 cases (one after two injections). One positive but incomplete response was observed in the only case of magnesium deficiency, probably due in retrospect to inadequate dosage. Finally, one patient with very poor ventricular function had recurrence after a good initial response. The diversity of the clinical and biological findings in this series suggests a specific antiarrhythmic action of the magnesium ion, apparently independant of the correction of magnesium deficiency; experimental studies suggest that the mode of action is a direct antagonism of Mg++-K+ and/or Mg++-Ca++. Compared to usual means of treatment of torsades de pointes (isoprenaline infusion or pacing) the advantages of intravenous magnesium sulphate are clear-cut: innocuity, simplicity and rapidity of administration, and almost immediate efficacy.