Harold G Ostrow

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Left-ventricular (LV) ejection fraction (EF) was determined from ECG-gated images of the cardiac blood pool, by computing the relative change in net LV counts occurring in these images during systole. EFs obtained with this method gave satisfactory interobserver agreement in 20 studies reviewed by three independent observers (average r = 0.95) and also(More)
A minicomputer-based system is described that allows real-time construction and simultaneous display, in flicker-free movie format, of a cardiac-cycle-spanning sequence of ECG-gated scintigraphic images. In as little as 2 min, the endless-loop flicker-free movier clearly displays cardiac anatomy, time-dependent volume variations of cardiac chambers, and(More)
A nonimaging, ECG-gated scintillation-probe system is described that permits real-time quantification, at high temporal resolution, of the time variation of left ventricular (LV) volume over a complete, average cardiac cycle. Linearity between counting rate and volume, probe positioning, and background correction were investigated for both cylindrically(More)
The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equilibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on seven subjects in AF (mean heart rate 64 bpm), using a high-efficiency nonimaging detector. The(More)
The relation between nifedipine concentration and hemodynamic effects after sublingual administration of 10 or 20 mg was examined in 13 patients with nonobstructive hypertrophic cardiomyopathy (HC). Serum nifedipine concentrations were determined by gas chromatography and were not related to dose. Peripheral vascular resistance decreased as a function of(More)
To investigate the effects of verapamil on left ventricular systolic and diastolic function in patients with hypertrophic cardiomyopathy, we studied 14 patients at catheterization with a nonimaging scintillation probe before and after serial intravenous infusions of low-, medium-, and high-dose verapamil (total dose 0.17 to 0.72 mg/kg). Percent change in(More)
Left ventricular (LV) systolic timing and relative volume variations were simultaneously measured by electromagnetic flowmeter (EMF) and high frame rate ECG-gated blood pool scintigraphy in five baboons. No significant differences (p greater than 0.1, paired t test) were observed in the time (from R wave) to peak aortic flow (maximum LV ejection rate), time(More)
Ejection fraction, normalized peak ejection and filling rates, and the time of occurrence of these events relative to the R-wave were determined in each of 512 consecutive individual cardiac cycles in each of 30 patients using an ultra-high-efficiency nonimaging detector system. For a given patient the 512 measurements of each quantity were averaged and(More)