Radionuclide angiographic monitoring in patients treated with potentially cardiotoxic cytostatic drugs.

A prospective study of 120 patients with cancer was carried out to evaluate the effects of potentially cardiotoxic anticancer drugs using radionuclide cardiovascular studies. Five groups were studied: 7 patients received 4'-demethoxydaunorubicin, 23 4'-deoxydoxorubicin, 34 4'-epidoxorubicin, 49 mitoxantrone and 7 4'-(9-acridinylamino)-methan-sulphon-m-anisidide (amsa). Two patients receiving 4'-demethoxydaunorubicin, 7 on 4'-deoxydoxorubicin, 11 on 4'-epidoxorubicin, 21 on mitoxantrone and 3 on amsa had falls of greater than or equal to 10% in their left ventricular ejection fraction. Using data from this study, the recommended guidelines are set out.

The effects of denervation and acute rejection on left ventricular volumes measured by radionuclide ventriculography following cardiac transplantation in the chacma baboon.

Seven baboons underwent autotransplantation of the heart or heart and both lungs (group A). Eleven allografts were performed (group B) (nine orthotopic heart transplants and two en bloc transplants of the heart and both lungs). Radionuclide ventriculography was performed both pretransplant and at intervals posttransplant in all animals, and provided measurements of ejection fraction (EF) and left ventricular volumes (LVv) (end-diastolic volume [EDV], end-systolic volume [ESV], and stroke volume [SV]). In seven animals, a total of 20 endomyocardial biopsies were taken. Correlation was made between histopathological features of acute rejection seen on endomyocardial biopsy and changes in EF and LVv measured by radionuclide imaging. A significant increase of 12% in the EF (P less than 0.01) and significant falls in the LVv were observed in all animals (groups A and B) on the first posttransplant day, presumably a result of total cardiac denervation. EDV was reduced by 50% (P less than 0.005), ESV by 62% (P less than 0.0001), and SV by 43% (P less than 0.0001). In autografted baboons (group A) EF and LVv showed no further changes until reinnervation of the heart had occurred, when they reverted to pretransplant levels. In the allografted baboons (group B) further significant reductions in the LVv occurred as acute cardiac rejection progressed. From the first post-transplant day to the time of the final study before the animals' death, the EF decreased by 10% (P less than 0.01), the EDV by 38% (P less than 0.005), and SV by 73% (P less than 0.003): the decrease in ESV did not reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of penbutolol on glomerular filtration.

Penbutolol, a new beta-adrenoceptor blocker, was found to increase the glomerular filtration rate (GFR) significantly (16%) relative to placebo when administered orally in a dose of 40 mg daily for 7 consecutive days to healthy males. Measurements were performed after the seventh dose. In contrast, a single acute intravenous dose of penbutolol 4 mg did not influence the GFR, which was determined by means of a gamma counter after intravenous injection of technetium-99m diethylenetriaminepenta-acetic acid. Since penbutolol possesses moderate beta-adrenomimetic activity, it is postulated that the observed increase in the GFR after oral penbutolol could be due to increased cardiac output at rest.

Digoxin, whole body potassium and the electrocardiogram.

Previous studies have shown a significant linear relationship between the PTQ-index (a combination function of the PR-interval, corrected QT-time and T-wave depression in the ECG) and serum digoxin level in chronically treated patients. The relationship was confirmed in the present study and it was shown that it could be changed by concomitant administration of potassium chloride or furosemide, and that there was marked interindividual variation in response. An inverse linear relationship between PTQ-index and whole body potassium was found during chronic administration of a constant daily dose of digoxin, but no such relationship was found for serum potassium.