Harold G. Ostrow

The Measurement of Left Ventricular Function and the Detection of Wall Motion Abnormalities with High Temporal Resolution Ecg-Gated Scintigraphic Angiocardiography

An ECG-gated, scintigraphic imaging procedure is described in which a complete, average cardiac cycle is visualized with high temporal resolution. The ability of this method to detect wall motion abnormalities and quantitate left ventricular function is illustrated in a patient with severe coronary artery disease. These results are compared to (contrast) angiographic findings in the same patient.

Relation between serum nifedipine concentration and hemodynamic effects in nonobstructive hypertrophie cardiomyopathy

The relation between nifedipine concentration and hemodynamic effects after sublingual administration of 10 or 20 mg was examined in 13 patients with nonobstructive hypertrophie cardiomyopathy (HC). Serum nifedipine concentrations were determined by gas chromatography and were not related to dose. Peripheral vascular resistance decreased as a function of nifedipine concentration (r = −0.63, p 120 ng/ml (40 ± 3 to 38 ± 4 ml/m2, p 120 ng/ml (11 ± 2 to 16 ± 4 mm Hg, p 120 ng/ml were associated with increased end-diastolic and end-systolic volumes, reduced ejection fraction and end-systolic pressure-volume ratio. No beneficial effects on LV diastolic function were observed at these higher concentrations, as the time constant of isovolumic relaxation increased (32 ± 13 to 60 ± 11 ms, p < 0.01). These results indicate that the hemodynamic effects of nifedipine are related closely to nifedipine concentration in patients with nonobstructive HC. Peripheral vasodilating effects are evident over a wide range of nifedipine levels. At low and medium concentrations, these effects result in augmentation of LV ejection performance; however, negative inotropic effects predominate at high concentrations.

Development of an ATM-based radiology consultation workstation for radiotherapy treatment planning

The radiology consultation workstation is a multimedia, medical imaging workstation being developed for use in an electronic radiology environment, utilizing a prototype asynchronous transfer mode telemedicine network, in support of radiotherapy treatment planning. A radiation oncologist in the radiation oncology department, and a radiologist in the Diagnostic Radiology Department, will be able to consult, utilizing high-quality audio/video channels and high-resolution medical image displays, prior to the design of a treatment plan. Organ and lesion contouring is performed via a shared-cursor feature, in a consultation mode, allowing medical specialists to fully interact during the identification and delineation of lesions and other features.

A Computer System For Clinical Nuclear Cardiology

The advent of nuclear cardiology has resulted in computers playing an increasingly prominent role in nuclear medicine. Frequently, the requirements of nuclear cardiology - especially first pass and gated equilibrium studies - set the hardware and software requirements for the entire nuclear medicine computer system. As nuclear cardiology is a relatively new field (at least at the non-research level) many commercial computer systems with cardiac capabilities are being modified as feedback is obtained from the increasing number of users and studies. At the NIH we have performed over 1500 gated equilibrium nuclear cardiac studies, both at rest and during exercise, using software of our own design. During this time our computer system has evolved considerably. Although our current system is by no means an optimum one, the considerable experience we have had developing it has given us many insights into what we believe are the desirable features of a system for nuclear cardiology in a clinical setting. The purpose of this paper is to present what we believe to be the important features of such a system. We will begin by presenting the hardware and software features of our own (non-optimum) system. An examination of how these features meet (or fail to meet) the clinical need will hopefully point out the features (and their rationale) which should be present in a more optimum system. For the sake of brevity, we will concentrate primarily on gated equilibrium studies, although the system requirements of first transit and other techniques have also been considered in the system design.