Combined evaluation of first pass radionuclide angiography and equilibrium radionuclide ventriculography in the diagnosis of coronary artery disease. II. Results during exercise

Results of 203 patients who underwent first pass radionuclide angiography (FP) and quantitative equilibrium radionuclide ventriculography (qERNV) were stored in a data base system and evaluated statistically. Eighty eight of these patients also underwent exercise equilibrium radionuclide ventriculography (E-qERNV). In patients with coronary artery disease (CAD) without previous myocardial infarction (MI), evaluation of global and regional ejection fraction (gEF, rEF) at rest revealed a poor sensitivity of 64%, the specificity was about 71% (qERNV). FP at rest revealed similar values of sensitivity (69%) and specificity (83%). Additional assessment of stress induced changes of gEF, significantly (P less than 0.05) improved sensitivity of qERNV in CAD patients without a history of previous MI to 84% (specificity 86%). In patients with one previous MI, however, similar values of sensitivity were found (R-FP: 87%, R-qERNV: 84%, E-qERNV: 93%). In patients with several MI's, sensitivity was above 90% at rest and during exercise (R-FP: 96%, R-qERNV: 93%, E-qERNV: 100%).

Beurteilung der Adriamycin-Kardiotoxizität mittels der Äquilibrium-Radionuklid-Ventrikulographie

Results of 606 equilibrium radionuclide ventriculographies (ERNV) performed in 348 non-selected patients receiving Adriamycin (ADM) therapy were stored in a data base system. The aim of the study was to assess the influence of a potential cardiotoxic therapy on left ventricular pump function. Increasing ADM doses yielded a significant (p <0.05) decrease of the resting ejection fraction (R-gEF), the peak ejection rate and the peak filling rate. Enddiastolic and endsystolic volumes increased significantly. Stroke volume, heart rate and time to peak filling rate did not change significantly. 368 follow-up studies were performed in 128 patients: 65/128 patients presented a decrease of R-gEF, but only in 45 of these patients R-gEF values fell into the pathologic range. In 44 of these follow-ups, R-gEF remained unchanged. In 19 patients, a R-gEF increase was observed. At the beginning of ADM therapy 14% of the patients had subnormal R-gEF values. With increasing ADM doses pathologic findings increased to 86% in patients with ADM doses higher than 500 mg/m2.

Beurteilung der Adriamycin- Kardiotoxizität mittels der Äquilibrium-Radionuklid- Ventrikulographie

The aim of the study was to evaluate the influence of a cardiotoxic therapy with Adriamycin (ADM) on left ventricular pump function. In 348 patients with malignant tumors, 606 equilibrium radionuclide ventriculographies (ERNV) were performed. In 90 patients, resting studies (R-ERNV) were followed by studies during exercise (E-ERNV). Results were evaluated statistically to determine whether E-ERNV provides more reliable parameters in the early detection of Adriamycin cardiomyopathy (ADM-CMP) than R-ERNV. The following left ventricular parameters were evaluated: global ejection fraction (gEF); enddiastolic, endsystolic, stroke volume (EDV, ESV, SV); peak filling rate, peak ejection rate (pFR, pER); time to peak filling rate (TpFR) and heart rate. Increasing ADM doses yielded a significant decrease (p <0.05) of resting values of gEF, pER, pFR. In contrast, stress-induced increases of gEF, pER, pFR were found independent of accumulative ADM doses and independent of the resting values of these parameters. An increase of gEF resulted from a significant decrease of ESV. In most cases, pathologic results at rest were detected earlier than subnormal changes of exercise values. Therefore, E-ERNV does not have a significantly higher sensitivity in the early detection of ADM-CMP than R-ERNV and is not required for the surveillance of patients under ADM therapy.

Simulation of pharmacokinetic behaviour of drug-cyclodextrin complexes

Complexation with cyclodextrin decreases the hydrophobicity of poorly soluble drugs and results in enhanced dissolution rates and higher solubility. In vivo experiments showed that this "molecular encapsulation" of drugs leads to enhanced bioavailability, which is controlled by the solubilities, stability constants of the complexes, the molar ratio of drug: cyclodextrin, etc. This modification of the pharmacokinetic processes has been simulated by computing the theoretical blood level curves. These computer-simulated curves seem to be appropriate models of the experimental observations. Knowing the numerical values of the parameters utilized in these computer simulations, the modification of the pharmacokinetics can be predicted when using cyclodextrin complexes in oral dosage forms.

Comparative studies on cardiotoxicity of some anthracycline antitumor antibiotics

Isolated atria of guinea-pigs showed negative inotropic and negative chronotropic responses after violamycin B I (V), carminomycin (C) and daunomycin (D), respectively. The mean effective concentrations in reducing amplitude (IC50) were 5.9 x 10(-4) mol x 1(-1) for V and 1.3 x 10(-4) mol x 1(-1) for C and D. In rabbits, intravenous injections of different doses of the antibiotics twice weekly for one month produced histopathological alterations in the myocardial tissue, which were smaller after D than after C or V.