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Biomedical subjects

F L Gobel

Publications and source records attributed to F L Gobel.

At least 37 records · Page 2Linked to original sources
PubMed1985

A less traumatic catheter for coronary arteriography.

A deformable soft-tipped angiographic catheter has been designed and developed to reduce vascular trauma during coronary arteriography. In order to test the ability of the catheter tip glide over vascular endothelium, the coefficient of resistance was tested using fresh human aortic tissue. The mean frictional coefficients of resistance (FRc) for the soft-tipped catheter, as compared with two commonly used catheters (N = 10/group), were .78 +/- .08 units for the soft-tipped catheter and 1.10 +/- .10 (p less than .006) and .98 +/- .10 (p less than .034) for the conventional catheters. This demonstrates a significant 23% reduction in FRc with the soft-tipped catheter. The ease of penetration into a wax media was also measured using the soft-tipped catheter and compared with the same two conventional catheters. The indentation depths for the soft-tipped catheter and the two other catheter groups (N = 7/group) were 140 +/- 18 micron, 246 +/- 15 micron and 318 +/- 20 micron, respectively. This represents a 56% decrease in indentation depth with the soft-tipped catheter. Histologic studies in canines have demonstrated considerably less endothelial damage and subsequent intimal proliferation in the aorta and coronary ostia with the soft-tipped catheters compared with control catheters. It is concluded that a soft-tipped angiographic catheter is less traumatic to vascular tissue and may offer a safer approach to intravascular studies.

Angiography↗
PubMed1985

The disease-free wall in coronary atherosclerosis: its relation to degree of obstruction.

Coronary atherosclerotic lesions are more often located eccentrically (70%) than concentrically (30%). In this study, the configuration of eccentric coronary artery atherosclerotic lesions was assessed by means of computerized planimetry in 100 specimens of eccentric arterial lesions. Special attention was given to the relation between the disease-free wall and the severity of obstruction. The mean disease-free wall are length measured between 17 and 23% of the total vessel circumference in eccentric coronary artery lesions that obstructed 50 to 90% of the cross-sectional area. This ratio persisted irrespective of the location of the lesion within the vessel and was not significantly different with vessels of different sizes. The presence of disease-free arcs of coronary artery wall as observed in this pathologic study may relate to three factors in clinical coronary artery disease: The published observations of spasm in segments of arteries harboring structural obstructive lesions may be explained by the frequent presence of uninvolved arcs of coronary artery walls. Multiple views during coronary arteriography are necessary to accurately reflect the degree of obstruction. The results of percutaneous transluminal coronary angioplasty may be influenced by both the disease-free arc and the atheromatous obstruction.

Angioplasty, Balloon↗
PubMed1982

Effects of sulfinpyrazone on early graft closure after myocardial revascularization.

The effect of sulfinpyrazone on the incidence of early postoperative closure of saphenous vein bypass grafts was compared with placebo in a prospective randomized study of 255 eligible patients. Treatment with sulfinpyrazone (800 mg/day) was started 24 hours after operation in 130 patients; 125 patients received placebo. Graft blood flow was measured at operation in 96 percent of all patients. Graft angiography was performed between the 7th and 14th postoperative days. There was no significant difference between the two groups in graft blood flow, number and diameter of the grafted arteries, left ventricular filling pressure or ejection fraction. During the study 73 patients (41 on sulfinpyrazone, 32 on placebo therapy) were excluded because graft angiography was contraindicated or because of concomitant use of anticoagulant or antiplatelet drugs. The incidence rate of early graft closure in the remaining 182 patients (43.1 grafts) was 3.8 percent (8 or 212) in the sulfinpyrazone group and 9.1 percent (20 of 219) in the placebo group (p less than 0.025). The incidence of graft closure for the sulfinpyrazone and placebo groups classified according to the recipient coronary arteries was: (1) left anterior descending artery; 3 of 98 versus 11 of 111; p less than 0.05; (2) left circumflex coronary artery: 3 of 50 versus 5 of 43; difference not significant; (3) right coronary artery: 2 of 64 versus 4 of 65; difference not significant. The incidence of closure in grafts with a flow of less than 30 ml/min did not differ significantly in the sulfinpyrazone and placebo groups (4 of 26 versus 6 of 22). These results suggest that sulfinpyrazone reduces the incidence of early graft closure in grafts with a flow rate greater than 30 ml/min.

Constriction, Pathologic↗
PubMed1982

The pathophysiology of angina pectoris and the effect of lidoflazine.

Angina pectoris results from a deficiency in myocardial oxygen supply. The rate-pressure product is an important predictor of myocardial oxygen requirements in patients with ischemic heart disease and in normal persons. The rate-pressure product at the onset of angina pectoris is reproducible under a variety of circumstances with a suitable protocol. In some patients, coronary artery spasm may reduce myocardial blood flow and contribute to the development of angina pectoris. Lidoflazine is a synthetic drug that appears to be a calcium-entry blocker and results in symptomatic improvement in patients with angina pectoris. Lidoflazine reduces the exercising rate-pressure product by its effect on heart rate and by decreasing systemic vascular resistance. It decreases coronary vascular resistance and antagonizes processes leading to an increase in coronary vasomotor tone.

Angina Pectoris↗
PubMed1981

Electrocardiographic changes after cervical laminectomy.

Striking T-wave inversions were observed in the postoperative electrocardiograms of a 64-year-old woman following an extensive cervical laminectomy. Except for the presence of a trace amount of CK-MB in a single serum specimen all her enzyme and isoenzyme studies were negative, and her clinical course was not suggestive of myocardial ischemia. Coronary angiography, including an ergonovine study, done 6 mth following the laminectomy were normal. Because of the nature of this patient's neurogenic origin of these T-wave changes is suspected.

Cervical Vertebrae↗
PubMed1981

Predictors of perioperative myocardial infarction in coronary artery operation.

Postoperative graft patency and thirteen perioperative variables were evaluated as potential risk factors for perioperative myocardial infarction (MI) in 102 consecutive patients undergoing coronary artery bypass grafting. Also, the incidence of perioperative MI and the amount of CK-MB released in the postoperative period were compared in three groups of patients selected according to the myocardial preservation technique employed: (1) topical hypothermia with and (2) without aortic cross-clamping and (3) cardioplegia. A perioperative MI as detected by electrocardiogram, enzymes, and myocardial scintigraphy with technetium 99 developed in 15 patients. Most important predictors of perioperative MI were found to be (1) left main and triple-vessel coronary artery disease, (2) a left ventricular end-diastolic pressure greater than or equal to 15 mm Hg, (3) a decreased ejection fraction (p < 0.05), and (4) cardiopulmonary bypass time > 120 minutes (p < 0.01). The incidence of perioperative MI was 50% in patients with three or more risk factors and 7% in those with less than three risk factors (p < 0.001). Graft patency was similar in patients with or without perioperative MI. Differing myocardial preservation techniques did not influence CK-MB release or the incidence of perioperative MI. Thus, the severity of ischemic heart disease and the length of the cardiopulmonary bypass time were important predictors of perioperative MI while graft patency and myocardial preservation technique did not appear to be related to its incidence in this study.

Aged↗
PubMed1978

Cardiac amyloidosis in hereditary neuropathic amyloidosis diagnosed by endomyocardial biopsy.

A 57 year old male first developed progressive neuropathy of the lower extremities and then similar involvement in the upper extremities. Two years later he developed dyspnea and then complete atrioventricular block requiring the use of a permanent cardiac pacemaker. An older brother had an almost identical clinical course, including the installation of a permanent pacemaker. Both died of left ventricular failure. An endomyocardial biopsy revealed extensive amyloidosis and fibrosis of the myocardium. This is the first report of a myocardial biopsy showing amyloid on electron microscopy.

Amyloidosis↗
PubMed1978

The rate-pressure product as an index of myocardial oxygen consumption during exercise in patients with angina pectoris.

In order to evaluate hemodynamic predictors of myocardial oxygen consumption (MVO2), 27 normotensive men with angina pectoris were studied at rest and during a steady state at sympton-tolerated maximal exercise (STME). Myocardial blood flow (MBF) was measured by the nitrous oxide method using gas chromatography. MBF increased by 71% from a resting value of 57.4 +/- 10.2 to 98.3 +/- 15.6 ml/100 g LV/min (P less than 0.001) during STME while MVO2 increased by 81% from a resting value of 6.7 +/- 1.3 to 12.1 +/- 2.8 ml O2/100 g LV/min (P less than 0.001). MVO2 correlated well with heart rate (HR) (r = 0.79), with HR x blood pressure (BP) (r = 0.83), and, adding end-diastolic pressure and peak LV dp/dt as independent variables, slightly improved this correlation (r = .86). Including the ejection period (tension-time index) did not improve the correlation (r = 0.80). Thus, HR and HR x BP, both easily measured hemodynamic variables, are good predictors of MVO2 during exercise in normotensive patients with ischemic heart disease. Including variables reflecting the contractile state of the heart and ventricular volume may further improve the predictability.

Adult↗