Lawrence M. Vincent

The influence of age and gender on left ventricular response to supine exercise in asymptomatic normal subjects

The performance of normal subjects during radionuclide ventriculography has been related to age, but the combined effects of age and sex on exercise ventricular function are not well described. We studied 55 normal volunteers, 27 men (age = 30 +/- 10 years) and 28 women (age = 33 +/- 14 years), free of chest pain syndromes, during supine rest/exercise radionuclide ventriculography performed to fatigue. Resting left ventricular ejection fraction did not differ between male and female subjects (64 +/- 5.4 vs 64 +/- 6.1; p = NS). Both the peak left ventricular ejection fraction (78 +/- 4.4 vs 72 +/- 9.2; p less than 0.001) and the change in ejection fraction with exercise (14 +/- 4.0 vs 7.9 +/- 7.0; p less than 0.001) were significantly greater in men compared to respective values in women. Regression analysis showed that sex (r = 0.51; p less than 0.001) but not age (r = -0.18; p = 0.19) was a significant predictor of change in ejection fraction with exercise. Data on left ventricular volume response to exercise, available in 43 subjects, revealed that men had a greater percentage of decline in end-systolic volume with exercise than women (-47 +/- 15 vs -24 +/- 26; p less than 0.001). It is concluded that sex exerts a significant influence on normal left ventricular response to fatigue-limited supine exercise and that the gender difference is mediated, in part, by left ventricular end-systolic volume response to exercise.

Extramedullary hematopoiesis. Demonstration by transmission and emission computed tomography.

Extramedullary hematopoiesis occurring in the thorax is a well-known complication of a number of various blood dyscrasias, and its appearance with planar Tc-99m sulfur colloid marrow scintigraphy and transmission computed tomography (CT) has been described previously. The authors present a case of thoracic extramedullary hematopoiesis evaluated by CT and emission computed tomography (ECT).

Gas within hemophiliac pelvic pseudotumors: CT demonstration.

Three hemophiliac patients are presented who had gas within their pelvic pseudotumors demonstrated by computed tomography. Etiologies of the gas included iatrogenically introduced gas from infection, failed tube drainage of the pseudotumor, and a communication between the pseudotumor and the bladder containing a Foley catheter.

Ozone-Induced Changes in the Pulmonary Clearance of 99Tc-DTPA in Han

Abstract Ozone is a respiratory irritant that has been shown in animals to increase the permeability of the respiratory epithelium. Ve have recently reported that respiratory epithelial permeability vas similarly affected in eight healthy non-smoking young men exposed to ozone (ARRD, 135 (1987) 1124-8). Permeability vas evaluated by determining the pulmonary clearance of inhaled aerosolized 99mTc-DTPA with sequential posterior lung imaging by a computer-assisted gamma camera. Ve nov report our findings for an additional 16 subjects. In a randomized crossover design, the 16 young men vere exposed for 2 h to purified air and 0.4 ppm ozone while performing intermittent high intensity treadmill exercise; forced vital capacity (FVC) vas measured before and at the end of exposures. The pulmonary clearance of 99mTc-DTPA vas measured 75 minutes after the exposures. Ozone exposure vas associated vith a mean endexposure FVC decrement of 0.50 liters (10Z of baseline; p - 0.007). The mean (± SEM) 99mTc-DTPA pulmonary clearance rate of 1.16 ± 0.08 X/min observed after ozone exposure vas over 60Z greater than the rate of 0.71 ± 0.08 X/ain following air exposure (p > 0.001). The results demonstrate that ozone exposure increased respiratory epithelial permeability. Such an Increase may be a manifestation of direct ozone-induced epithelial cell injury, lung inflammation or both.

Postperfusion ventilation studies in the diagnosis of pulmonary embolism. An economic appraisal.

Postperfusion lung ventilation imaging with xenon-127 (Xe-127) gas was evaluated from an economic perspective. Results of five years experience at a tertiary referral center suggest that the use of postperfusion lung ventilation techniques can significantly reduce patient costs for diagnostic studies and may reduce institutional costs for radiopharmaceuticals.

Medial splenic tubercle: Potential radionuclide ventriculography pitfall

Blood pool activity in a medial splenic tubercle produced an apparent apical wall motion abnormality during radionuclide ventriculography.