Search PubMed⌕ Search

Biomedical subjects

E R Bates

Publications and source records attributed to E R Bates.

115 records · Page 7Linked to original sources
PubMed1984

The chronic coronary flow reserve provided by saphenous vein bypass grafts as determined by digital coronary radiography.

Intraoperative measurements following aortocoronary revascularization have demonstrated a reduced coronary flow reserve (CFR) in saphenous vein bypass grafts. To determine whether chronic bypass graft flow reserve returns to normal, we studied patients in the cardiac catheterization laboratory by means of a newly developed digital coronary radiographic technique. CFR ratios were determined for 54 arterial distributions from 33 men. Twenty-two distributions were normal (group I) 22 had saphenous vein bypass grafts (group II), seven had high-grade stenoses, which were subsequently bypassed (group III), and three were bypassed but had flow-limiting stenoses (group IV). Group II arteries had approximately half the CFR of group I arteries (1.40 +/- 0.17 vs 1.78 +/- 0.31; p less than 0.0001) but significantly improved CFR compared to group III arteries (1.40 +/- 0.17 vs 1.05 +/- 0.13; p less than 0.002) or group IV arteries (1.40 +/- 0.17 vs 1.05 +/- 0.12; p less than 0.02). These results indicate that regional CFR is improved by nonstenotic saphenous vein bypass grafts but does not return to normal.

Adult↗
PubMed1984

Criteria for successful coronary angioplasty as assessed by alterations in coronary vasodilatory reserve.

Currently, the success of coronary angioplasty is defined by anatomic criteria. Because of the known limitations of coronary arteriography, the translesional pressure gradient and coronary vasodilatory reserve were studied in 15 patients undergoing coronary angioplasty with the intent of defining a physiologically successful result. Coronary vasodilatory reserve was measured by a digital radiographic technique that has been previously validated against directly measured coronary sinus flow (r = 0.90, p less than 0.0001). A significant reduction in luminal stenosis from 71 +/- 12 to 34 +/- 11% (p less than 0.001) was accompanied by a reduction in translesional gradient from 47 +/- 19 to 21 +/- 12 mm Hg (p less than 0.001) and an increase in coronary vasodilatory reserve from 1.03 +/- 0.15 to 1.29 +/- 0.13 (p less than 0.001). There was a significant correlation between changes in luminal stenosis and changes in translesional gradient (r = 0.61, p less than 0.05), although a change of 20% or less in luminal diameter was accompanied by no change in pressure gradient. A more significant relation between changes in gradient and in coronary hyperemic reserve existed (r = 0.77, p less than 0.005). The relation was accurate even for small changes in gradient. Because saphenous vein bypass grafts have been shown to increase coronary vasodilatory reserve to at least 1.20, it is proposed that this physiologic criterion be used to define the success of revascularization by angioplasty. In patients in whom this value was achieved, translesional gradient was invariably 25% or less of ostial pressure and 20 mm Hg or less.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1984

Coronary flow reserve measured during cardiac catheterization.

The degree of arteriographically visualized narrowing in coronary arteries has been the most important criterion for evaluating coronary disease for more than 20 years. Increasing data, however, suggest that anatomy alone does not predict the physiologic consequence of individual stenoses. We have applied a new digital arteriographic method for measuring coronary flow reserve (CFR) in patients undergoing diagnostic, postbypass, and postangioplasty catheterizations. All vessels with high-grade stenoses (greater than or equal to 70%) were found to have lower CFRs than those of normal arteries (1.01 +/- 0.15 v 1.84 +/- 0.36). However, considerable CFR variability was found in vessels of lesser stenoses. Coronary arteries that had undergone successful bypass surgery or angioplasty had intermediate CFR levels (1.44 +/- 0.18 and 1.51 +/- 0.16, respectively). Our study suggests that CFR assessed during cardiac catheterization may be useful for evaluating intermediate coronary lesions and the efficacy of interventions.

Adult↗
PubMed1981

Oral hydralazine therapy for acute pulmonary embolism and low output state.

Shortly after pelvic surgery, massive bilateral pulmonary emboli and shock developed in an elderly woman. Despite fluids, dopamine hydrochloride, and heparin sodium, her condition steadily deteriorated. Two trials of hydralazine hydrochloride were given and each was associated with pronounced clinical and hemodynamic improvements. Ninety minutes and 24 hours after the first trial, her pulmonary vascular resistance decreased 44% and 67%, respectively, and cardiac index increased 40% and 90%, respectively. There were insignificant changes in heart rate and blood pressure. The hemodynamic improvements reversed when the hydralazine therapy was stopped but improved again during the second trial. Hydralazine may be of substantial benefit to patients with hemodynamic compromise secondary to pulmonary embolism.

Administration, Oral↗
PubMed1979

Acid mine drainage and subsidence: effects of increased coal utilization.

The increases above 1975 levels for acid mine drainage and subsidence for the years 1985 and 2000 based on projections of current mining trends and the National Energy Plan are presented. No increases are projected for acid mine drainage from surface mines or waste since enforcement under present laws should control this problem. The increase in acid mine drainage from underground mines is projected to be 16 percent by 1985 and 10 percent by 2000. The smaller increase in 2000 over 1985 reflects the impact of the PL 95-87 abandoned mine program. Mine subsidence is projected to increase by 34 and 115 percent respectively for 1985 and 2000. This estimate assumes that subsidence will parallel the rate of underground coal production and that no new subsidence control measures are adopted to mitigate subsidence occurrence.

Acids↗