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Biomedical subjects

G S Uhl

Publications and source records attributed to G S Uhl.

4 recordsLinked to original sources

Analysis of exercise-induced R wave amplitude changes in detection of coronary artery disease in asymptomatic men with left bundle branch block.

The exercise electrocardiograms of 44 asymptomatic men with acquired left bundle branch block were analyzed for changes in R wave amplitude. Results were correlated with findings on selective coronary angiography. There were two subgroups: 7 men with significant angiographic coronary artery disease (Group I) and 37 with normal coronary angiograms (Group II). Exercise induced an increase in R wave amplitude in all seven men with coronary artery disease but in only 10 of the 37 men without significant coronary artery disease. This criterion thus had a sensitivity of 100 percent but a poor specificity of 73 percent, a predictive value of 41 percent and an accuracy rate of 77 percent for the diagnosis of coronary artery disease. The greater the increase in R wave amplitude the greater was the likelihood of some degree of left ventricular dysfunction as measured by wall motion abnormalities and elevated left ventricular end-diastolic pressure. The increase in R wave amplitude with exercise appears to be a sensitive test in identifying coronary artery disease in asymptomatic men with acquired left bundle branch block.

Adult

Pericardial tamponade in systemic sclerosis (scleroderma).

The frequency of pericardial disease in scleroderma found at necropsy in high. The clinical recognition of pericarditis with or without effusion is rare and tamponade with haemodynamic impairment is exceptional. Three patients with scleroderma presented with an acute syndrome of dyspnoea, chest pain, and cardiomegaly requiring pericardiocentesis for relief of pericardial tamponade. One patient died. The mechanism of the pericardial effusion remains unknown. The haemodynamic data recorded from one patient suggested that pericardial fibrosis in scleroderma may predispose to pericardial tamponade.

Adolescent

Myocardial supply-demand ratio in aortic regurgitation.

To analyze the relationship between the myocardial supply and demand for oxygen in patients with aortic regurgitation, the ratio of the diastolic pressure-time index (DPTI) over the systolic pressure-time index (SPTI) was derived from recordings of pressure during cardiac catheterization in 24 patients with aortic regurgitation, and this ratio was compared with that in 14 normal subjects and in ten patients with congestive cardiomyopathy (an ejection fraction less than 0.30). Patients with aortic regurgitation had a DPTI/SPTI of 0.75 +/- 0.06 (mean +/- SE), which was lower than in the normal subjects (1.24 +/- 0.06) and patients with cardiomyopathy (1.06 +/- 0.03) (P less than 0.001). Among the patients with aortic regurgitation, the 13 with a DPTI/SPTI below 0.70 had more severe aortic regurgitation than the 11 with a DPTI/SPTI above 0.70. Aortic regurgitation results in a reduced myocardial supply-demand ratio, as measured by the DPTI/SPTI, which is related to the severity of the valvular regurgitation and is not present in patients with left ventricular dysfunction secondary to congestive cardiomyopathy.

Adult