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Biomedical subjects

L F Satler

Publications and source records attributed to L F Satler.

At least 199 records · Page 11Linked to original sources

Arterial responses to balloon coronary angioplasty: an intravascular ultrasound study.

OBJECTIVES: The purpose of this study was to examine the coronary artery response to percutaneous transluminal coronary angioplasty by using intravascular ultrasound. BACKGROUND: The immediate effects of coronary angioplasty on arterial wall geometry and surface appearance are understood poorly. Most of the available data are derived from small necropsy series, inferred from animal models or extrapolated from in vitro studies. High frequency intravascular ultrasound provides transmural images of coronary arteries in vivo. METHODS: We used intravascular ultrasound to study 29 patients before or after, or both, successful coronary angioplasty. RESULTS: The angiographic diameter narrowing was 72 +/- 13% before and improved to 19 +/- 11% after angioplasty. Calcium was visualized in 7 (24%) of the 29 angioplasty sites by fluoroscopy versus 15 (52%) of sites by intravascular ultrasound (p = 0.022). Arterial dissection after angioplasty was observed in 8 (27%) of cases by contrast angiography versus 24 (83%) by intravascular ultrasound (p less than 0.001). Intravascular ultrasound detected extensive dissection at the angioplasty site in 11 (73%) of the 15 calcified plaques and in only 3 (21%) of the 14 noncalcified plaques (p = 0.024). Arterial expansion (defined as the area within the external elastic membrane at the angioplasty site greater than that of the proximal reference segment) occurred in 29% of calcified plaques compared with 86% of noncalcified plaques (p = 0.007). CONCLUSIONS: Intravascular ultrasound is more sensitive than angiography for identifying arterial calcium and dissection at the site of angioplasty. At the site of angioplasty, arterial dissection occurred more frequently in calcified plaques whereas arterial expansion occurred more frequently in noncalcified plaques. Successful angioplasty causes a continuum of arterial responses that vary importantly with plaque composition.

Angioplasty, Balloon, Coronary↗

Intravascular ultrasound evaluation of the effect of rotational atherectomy in obstructive atherosclerotic coronary artery disease.

BACKGROUND: High-speed rotational atherectomy uses a diamond-coated, elliptical burr to abrade occlusive atherosclerosis, especially noncompliant calcified plaque. METHODS AND RESULTS: Intravascular ultrasound (IVUS) was used to analyze 28 patients after atherectomy. Arteries treated and imaged were left main (three), left anterior descending (12), left circumflex (five), right coronary (seven), and saphenous vein graft (one). Twenty patients had adjunct balloon angioplasty. Twenty-two (79%) target lesions were calcified; the intimal arc of calcium was 160 +/- 126 degrees (range, 0-360 degrees). After atherectomy, the intima-lumen interface was unusually distinct and circular. The lumen was larger than the largest burr used for both stand-alone (1.19 +/- 0.19-fold the largest burr size) and adjunct balloon procedures (1.30 +/- 0.15-fold the largest burr). Three-dimensional reconstruction of the ultrasound images showed a smooth lumen, especially in calcified plaque. Deviations from cylindrical geometry occurred only in areas of soft plaque or superficial tissue disruption of calcified plaque. Five patients were studied before and after rotational atherectomy. IVUS showed an increase in lumen size, a decrease in plaque-plus-media area and in arc of target lesion calcification, and no change in target lesion external elastic membrane cross-sectional area. CONCLUSIONS: Rotational atherectomy causes atheroablation with only moderate evidence of barotrauma in heavily calcified arteries, even after adjunct balloon angioplasty. The lumen is cylindrical, especially in areas of calcified plaque, and somewhat larger than the largest burr tip used.

Angioplasty, Balloon, Coronary↗

Effects of high-density lipoprotein on acetylcholine-induced coronary vasoreactivity.

Recent evidence suggests that high-density lipoprotein (HDL) cholesterol has important vasoactive properties which may contribute to its beneficial effects on atherosclerotic coronary artery disease. The endothelium-dependent vasodilator acetylcholine has been used in a number of experimental studies to assess endothelial function. The relation between serum lipoproteins and acetylcholine-induced coronary vasoreactivity was investigated in patients (n = 27) undergoing elective coronary arteriography. Mean serum cholesterol, low-density lipoprotein cholesterol, HDL cholesterol and triglyceride levels were 189 +/- 7 (4.84 +/- 0.18 mmol/liter), 134 +/- 6 (3.47 +/- 0.15 mmol/liter), 41 +/- 3 (1.06 +/- 0.08 mmol/liter) and 106 +/- 30 mg/dl (1.20 +/- 0.03 mmol/liter), respectively. After a baseline arteriogram, acetylcholine was infused into the left main coronary artery and percent change from baseline dimension was determined in 27 angiographically smooth coronary artery segments and in 14 arterial segments with evidence of mild atherosclerotic disease. Intact vascular smooth muscle function was then confirmed in all segments by dilation to intracoronary nitroglycerin. Acetylcholine produced significant vasoconstriction of both angiographically smooth (13 +/- 4%, p less than 0.05 vs baseline) and diseased (19 +/- 4%, p less than 0.05 vs baseline) coronary segments. A positive correlation was observed between HDL cholesterol and normal acetylcholine-induced coronary vasoreactivity in both angiographically smooth (r = 0.59, p less than 0.001) and diseased (r = 0.62, p less than 0.02) coronary segments. No significant correlation was observed, however, between total and low-density lipoprotein cholesterol, or between total cholesterol to HDL ratio and the response of coronary artery diameter to acetylcholine infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

Myocardial salvage after failed coronary angioplasty.

UNLABELLED: Patients undergoing coronary angioplasty have a 2% to 7% risk of requiring emergency coronary artery bypass graft surgery for impending infarction. These patients provide a unique model of early reperfusion because the exact time of compromise to blood flow and the composition of the reperfusion solution are known. However, the amount of myocardium salvaged is unknown. Between December 1981 and September 1985, 859 patients underwent coronary angioplasty. Forty-two patients had emergency surgery for objective evidence of impending infarction. Five patients died. Thirty-six patients were contacted for follow-up; 21 (58%) of 36 had a radionuclide ventriculogram performed at a mean of 39 +/- 13 months after surgery. These radionuclide studies were compared with the patient's preangioplasty contrast ventriculogram. One patient had a myocardial infarction 3 years after surgery. Eleven (55%) of the remaining 20 patients had a normal radionuclide ventriculogram at follow-up study (ejection fraction 65 +/- 9%). Five (25%) of the 20 patients had a depressed ejection fraction (46 +/- 4%) with wall motion abnormalities, but these were unchanged from the preangioplasty studies. Four patients (20%) had a significant decrease in ejection fraction over baseline (37 +/- 10%) with new wall motion abnormalities. IN CONCLUSION: 1) there is an 80% chance that left ventricular function will be unchanged at 3 year follow-up study in patients surviving emergency bypass grafting for failed angioplasty; 2) these data suggest that early revascularization for impending infarction in this setting is associated with a good late outcome; and 3) this patient group offers a unique opportunity to study the effects of early reperfusion in a human model.

Angioplasty, Balloon, Coronary↗

Reduction in coronary heart disease: clinical and anatomical considerations.

Coronary artery bypass surgery, percutaneous transluminal coronary angioplasty and thrombolytic therapy in acute myocardial infarction have relieved symptoms, preserved myocardium, and prolonged life but have not modified the progression of atherosclerosis in the coronary arteries. In the last 10 years, however, progress has been made in establishing the cholesterol-atherogenesis hypothesis. Epidemiologic studies have demonstrated that the higher the total plasma cholesterol and low density lipoprotein cholesterol (LDL-C), the greater the risk that coronary artery disease will develop. Recently, clinical trials including the Coronary Drug Project, the Lipid Research Clinics Coronary Primary Prevention Trial (LRC-CPPT), and the Helsinki Heart Study provided evidence that lowering cholesterol reduces the frequency of fatal and nonfatal coronary events. In addition, the National Heart, Lung, and Blood Institute (NHLBI) Type II Coronary Intervention Study and the Cholesterol Lowering Atherosclerosis Study demonstrated that lowering of cholesterol was associated with a decreased incidence of progression of coronary disease, as well as with the potential for reduction in the atherosclerotic plaque. Beneficial effects of diet and lifestyle changes also have an important effect on atherosclerosis. The impact of lowering cholesterol has been limited primarily by pharmacologic programs which lower cholesterol only 10-20% and are associated with a high incidence of intolerable side effects. With the recent introduction of the HmG co-A reductase inhibitors and their more profound effect on serum lipids, it may be possible to further promote plaque regression. The future of all these interventions, however, must still be assessed by overall mortality; studies to date have demonstrated beneficial effects on cardiovascular mortality but age-adjusted total mortality has remained unchanged. Future management of patients with acute and chronic coronary artery disease will involve a collaboration of cardiologists, endocrinologists, and epidemiologists to coordinate screening, recognition, and treatment of this disease.

Adult↗

Changing outcome in acute myocardial infarction.

Beta blockers, glucose-insulin-potassium, nitrates, and thrombolytic interventions have been demonstrated to reduce the mortality of acute MI. Because of the number of interventions available, it will become progressively more difficult to isolate their additional benefits. The next challenge will be to determine the ideal combination of interventions to limit infarct size maximally in the context of early reperfusion, thereby limiting reperfusion injury and further improving salvage.

Arrhythmias, Cardiac↗

Late angiographic follow-up after successful coronary arterial thrombolysis and angioplasty during acute myocardial infarction.

Emergency percutaneous transluminal coronary angioplasty (PTCA) is accepted as an important reperfusion intervention for acute myocardial infarction (AMI). Although its primary success rate is well documented, the frequency of restenosis after this procedure is unclear. The frequency of restenosis was determined in patients undergoing emergency PTCA at least 6 months after PTCA was performed during AMI. Of 66 consecutive patients undergoing emergency PTCA, 25 had a second, elective catheterization at an average of 22 months after AMI and 6 underwent repeat catheterization because of recurrent chest pain. Restenosis of the PTCA site was found in 10 of the 31 patients (32%) restudied. Also, 14 (45%) of these 31 patients showed progression of narrowing in the non-infarct-related coronary arteries. In summary, patients in whom AMI is treated by PTCA are at risk for restenosis and for progressive narrowing of the non-infarct artery.

Angioplasty, Balloon↗

Assessment of residual coronary arterial stenosis after thrombolytic therapy during acute myocardial infarction.

Maximal myocardial salvage appears to be related to the severity of residual coronary arterial stenosis after thrombolysis. The degree of residual infarct vessel stenosis was assessed in 119 consecutive patients with patent arteries who received streptokinase during acute myocardial infarction. After administration of streptokinase, 99 of 119 patients (83%) had a residual stenosis 70% or more in diameter. Assuming that a residual diameter stenosis of at least 70% is flow limiting, the feasibility for percutaneous transluminal coronary angioplasty (PTCA) was determined by the following criteria: length less than 10 mm, no significant distal narrowing or left main stenosis, and an adequate-sized distal artery. In 81 of 99 patients (82%), arterial anatomy was suitable for PTCA. Thus, after therapy with streptokinase for acute myocardial infarction, most patients have a significant infarct arterial residual stenosis and are candidates for PTCA.

Aged↗

Metabolic support during coronary reperfusion.

The limitation of infarct size by thrombolysis could potentially be improved by an early metabolic intervention. We therefore evaluated the effects of a 48-hour infusion of glucose-insulin-potassium (GIK) in patients with anterior infarctions. Seventeen patients were randomized to receive intravenous GIK (n = 10) or placebo (n = 7). All patients additionally received streptokinase. Changes in left ventricular function were assessed by comparing the global ejection fractions and the regional infarct area ejection fractions of the first ventriculogram with the 10-day second ventriculogram. There was a significantly greater improvement in the global ejection fraction of patients receiving GIK (increases 0.07 +/- 0.04) than in those randomized to placebo (decreases 0.08 +/- 0.04) (p less than 0.02). There was also a much greater improvement in the area ejection fractions of the group receiving GIK vs the group receiving placebo in the anterolateral (increases 0.24 +/- 0.07 vs decreases 0.02 +/- 0.04 [p less than 0.02]) and diaphragmatic (increases 0.08 +/- 0.08 vs decreases 0.17 +/- 0.05 [p less than 0.005]) segments. Thus in patients with anterior infarctions receiving streptokinase, GIK improves ventricular function and reduces the size of the segmental wall motion abnormality.

Adult↗

Progressive heart failure secondary to a high output state.

A high cardiac output state has been an infrequent but previously reversible cause of heart failure in patients with hemodialysis fistulas. A patient with two proximal upper extremity fistulas was found to have progressive depression in his left ventricular function and a high output state. His symptoms did not respond to the removal of the most prominent fistula, suggesting that chronic volume overload from the high output state may irreversibly depress left ventricular function.

Adult↗

Noninvasive detection of coronary artery patency using continuous ST-segment monitoring.

Continuous ST-segment Holter recordings were analyzed from 46 patients with acute myocardial infarction (AMI) receiving intracoronary streptokinase (SK) during the first 48 hours of hospitalization. Changes in ST deviation and the time periods of these changes were quantitated and correlated with angiographic evidence of reperfusion. Thirty-six patients had total occlusion of the infarct vessel and 10 had subtotal occlusion. Of the 36 vessels that were totally occluded, 19 were reperfused and 17 were not. In patients in whom reperfusion was successful, an ST steady state was achieved 55 +/- 32 minutes after SK administration. In patients in whom it was not successful, a steady state was achieved in 219 +/- 141 minutes (p less than 0.001). Achievement of steady state within 100 minutes after SK reperfusion indicated successful reperfusion with 89% sensitivity and 82% specificity. All patients with subtotal occlusion achieved an ST steady state before SK infusion. No patient with total occlusion achieved a steady state before SK. Achievement of ST steady state before SK infusion was 100% sensitive and 100% specific for subtotal occlusion at initial angiography. Continuous, quantitative ST-segment analysis is a sensitive and specific noninvasive technique for following coronary artery patency during AMI.

Coronary Vessels↗