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Biomedical subjects

H R Baur

Publications and source records attributed to H R Baur.

At least 37 records · Page 2Linked to original sources
PubMed1983

Hemodynamic changes after angiocardiography with a new low osmolar contrast medium (sodium-meglumin-joxaglat).

We evaluated the hemodynamic effects of sodium-meglumin-joxaglat (Hexabrix) compared to sodium-meglumin-diatrizoat (Urografin 76) after left ventriculography in a double-blind randomized study on 24 patients (12 patients per group). Hemodynamic measurements at rest and the extent of ischemic heart disease were comparable in the two groups. Measurements were made at rest and between the second and third minute, between the fifth and sixth minute, and between the eighth and ninth minute following injection of 0.7 ml/kg of contrast medium into the left ventricle. Additionally left ventricular volumes and ejection fraction of the second and fifth beat following the onset of injection were calculated. The discomfort was graded by the patients on a scale of 1-4. After 3 min there was a significant but comparable increase in right atrial, pulmonary artery, and pulmonary capillary wedge pressure (64, 35, and 61%, respectively for the Hexabrix group and 61, 36, and 58% for the Urografin group). Cardiac index and stroke volume index rose significantly higher in the Urografin group and left ventricular work index increased significantly only after injection of Urografin 76. Ejection fraction decreased 11% in the Hexabrix group and 9% in the Urografin group. The grade of discomfort was 1.83 +/- 1 in Hexabrix group and 2.83 +/- 0.8 in the Urografin group (p less than 0.05). Thus, Hexabrix represents an advance in angiocardiography, both from the subjective and objective standpoint.

Angiocardiography↗
PubMed1983

Cardiogoniometry: a new noninvasive method for detection of ischemic heart disease.

Cardiogoniometry is a new vectorcardiographic method. The vector-loops are constructed from three orthogonal ECG leads and registered on-line by a microprocessor. The angle between the maximal QRS and T vectors, as well as the spatial orientation of these vectors are very constant in healthy individuals. Deviations of these vectors and angles are sensitive indicators for changes in repolarization occurring, for instance, during coronary insufficiency. The changes in these variables were evaluated in 50 patients with suspected coronary artery disease and correlated with angiographic findings. Cardiogoniometry showed a sensitivity of 79% and a specificity of 82%, which is comparable to exercise testing. In contrast to the latter cardiogoniometry can be performed at rest, is free of risk, and therefore also suitable for elderly patients.

Computers↗
PubMed1983

Postoperative evaluation of composite aortic grafts: comparison of angiography and CT.

Postoperative angiography and computerised tomography were performed in 10 patients 8 to 57 months after surgical repair (nine composite, one distal graft) of aneurysms of the thoracic aorta (six dissecting, four true aneurysms). Angiography and angio-CT showed chronic dissection of the distal aorta in five of six patients with dissecting aneurysms and detected a pseudoaneurysm originating from the distal suture line in another patient. CT may serve as an initial procedure for postoperative examinations after surgery of aortic aneurysms to demonstrate the state of the false lumen and the formation of pseudoaneurysms. The coronary arteries and aortic valve function have to be evaluated by angiography.

Adult↗
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

New technique for retrograde left heart catheterization in aortic stenosis.

Retrograde catheterization of the left ventricle in patients with aortic stenosis is frequently difficult and occasionally impossible. We have developed a new technique to facilitate this problem. A standard #8 "pigtail" catheter is preformed with a 145 degrees angle 7 cm from the catheter tip. With this catheter in the ascending aorta, the preformed angle lifts the catheter tip leftward and superiorly, allowing a straight guidewire a direct approach to the orifice of the stenotic aortic valve. Utilizing this technique, we were able to cross the stenotic aortic valve in 26-29 consecutive patients with isolated aortic stenosis (mean gradient +/- 0.22 cm2, mean fluoroscopy time for crossing: 32 +/- 40 seconds). The 145 degree angle also lifts the catheter off the posterior wall of the left ventricle and allows a more parallel alignment of the catheter with the long axis of the left ventricle, leading to a more stable position with less ventricular dysrhythmias during angiography. Thus a preformed angle in the "pigtail" catheter facilitates crossing of the stenotic aortic valve and produces a more stable position in the left ventricle.

Adult↗
PubMed1982

Detection of left ventricular aneurysm on two dimensional echocardiography.

The differentiation of left ventricular aneurysm from diffuse left ventricular dilation and hypokinesia may have important therapeutic consequences. Thus the diagnostic accuracy of wide angle two dimensional echocardiography for the detection of left ventricular aneurysm was evaluated in a prospective study of 26 consecutive patients with the clinical suspicion of left ventricular aneurysm referred over a 10 month period. Every patients was examined with two dimensional echocardiography and left ventricular cineangiography, and findings were interpreted by two independent observers. A dilated hypokinetic left ventricle without aneurysm formation on cineangiography in nine patients was identified in all with two dimensional echocardiography. A left ventricular aneurysm on cineangiography in 17 patients was correctly identified in 14 with the two dimensional study, as were the site and extent of the lesion (apical in 12, anterior in 1 and inferior in 1). One apical aneurysm was interpreted on the two dimensional study as apical dyskinesia; one anterior and one posterobasal aneurysm were missed with this technique. Mural thrombi were correctly identified with two dimensional echocardiography in seven of seven patients. It is concluded that two dimensional echocardiography is an accurate noninvasive method that allows differentiation of left ventricular aneurysm from diffuse left ventricular dilation in the majority of patients. It provides information regarding the resectability of the aneurysm and may obviate cineangiography in many cases.

Coronary Disease↗
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↗
PubMed1979

Electrocardiographic changes after bilateral carotid sinus denervation in the rat.

The effect of bilateral carotid sinus denervation (CSD) on the ECG and on the monophasic ventricular action potential (MAP) was studied in 28 and 4 rats, respectively. After CSD, T wave changes, similar to those seen in man after carotid endarterectomy, were observed and mean Q-T prolongations of 19 ms were recorded (P less than 0.001). Mean MAP increased by 10 ms (P less than 0.02). P-QRS and heart rate remained stable. Propranolol, 10 mg/kg iv, before CSD and 10 mg.kg-1.day-1 iv for 2 days prevented all ECG abnormalities. Atropine, 1 mg/kg iv, before CSD and 2.5 mg.kg-1.day-1 iv for 2 days had no effect. Isoproterenol, 0.02-0.06 microgram iv, after CSD produced further lengthening of the MAP and Q-T interval. Blood gases and electrolytes remained unchanged, and cardiac histology was unremarkable. These results suggest that CSD produces alterations in cardiac sympathetic activity in the rat leading to MAP and Q-T prolongations and to changes in the T wave form. Similar mechanisms may be operative after carotid endarterectomy in man.

Action Potentials↗
PubMed1976

[Electrocardiographic changes after surgical manipulation of the carotid arteries (author's transl)].

Seven patients showed deep symmetrical T wave inversions in their electrocardiograms after bilateral carotid endarterectomy. There was no evidence for myocardial ischaemia. These changes reversed completely within three months. Similar disturbances of repolarisation were seen in rats after bilateral denervation of the carotid sinus. These changes are probably of neurogenic origin, like those seen with central nervous system disorders. Their origin seems to be correlated to the acute imbalance of the autonomic innervation of the heart after surgical disturbance of baro- and chemoreceptors.

Aged↗
PubMed1975

[Haemolysis after heart valve replacement (author's transl)].

Intravascular haemolysis is frequently seen in patients after heart valve replacement, but is often compensated. The cause of the haemolysis is traumatic damage of the red cells. It is more often seen after aortic, than after mitral replacement, because the transvalvular pressure gradient is higher and is more severe in ball valves than in disc valves. If substitution therapy with iron, folic acid, or even red cells fails, re-operation should be seriously considered.

Anemia, Hemolytic↗
PubMed1975

Severe hemolysis with a fabric-worn cloth-covered aortic valve prosthesis.

A patient developed severe hemolytic anemia one year after insertion of a cloth-covered aortic valve prosthesis (Starr-Edwards No. 2320). The cloth over the three struts was disrupted but showed coverage with mostly organized collagen. Hemolysis stopped after replacement with a porcine heterograft. Fabric wear seems to augment the hemolysis in patients with cloth-covered artificial valves.

Adult↗