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Biomedical subjects

H R Baur

Publications and source records attributed to H R Baur.

At least 19 recordsLinked to original sources
PubMed1992

[Coronary thrombosis--an old concept in a new light].

The morphologic-clinical links in acute myocardial ischemia have been established in the last few years. Angiographic and biochemical investigations have contributed to the understanding of the connection between the acute coronary lesion (fissure or rupture of a plaque, dissection) and the dynamic process of thrombus formation, lysis and coronary spasm that occur during the first minutes and hours of acute myocardial ischemia. Deep arterial lesions with thrombotic tendency also occur after coronary bypass operations, thrombolysis and PTCA. Conventional antithrombotic substances like aspirin and heparin are only partially effective, and new compounds are tested which either inhibit platelet aggregation or thrombin formation more completely. Hopefully, these new drugs will prevent reocclusion after thrombolysis and restenosis after PTCA more effectively.

Antifibrinolytic Agents↗
PubMed1990

[Cardiac complications of American trypanosomiasis (Chagas disease). Various case reports and general observations].

Three young female patients with heart problems and positive serologic tests or characteristic histologic lesions for Chagas' disease (American trypanosomiasis) are reported, one of them having presented with acute anterior myocardial infarction with only minor coronary lesions. The most prominent features of the disease are discussed with emphasis on late cardiac complications. Chagas' cardiomyopathy is the leading cause of sudden death in Latin America, where an estimated 10 to 12 million people are infected in endemic areas from southern Mexico to southern Argentina. It has also been termed "emboligenic cardiomyopathy" since arterial embolism is a very frequent complication. Embolic obstruction of a coronary artery may therefore well be the most probable cause of myocardial infarction in young people with Chagas' disease, although other mechanisms cannot be excluded.

Adult↗
PubMed1989

[Swiss simvastatin multicenter study: 1. Efficacy of 10 mg simvastatin daily in patients with primary hypercholesterolemia].

In a Swiss multicenter study with determination of lipid and lipoprotein parameters in a central laboratory, the efficacy of simvastatin, MSD, was evaluated in patients with primary hypercholesterolemia. Lipid and lipoprotein values were determined in 109 patients before and after 6 weeks' therapy with 10 mg simvastatin per day. A significant decrease in total cholesterol, LDL-cholesterol and apo B, of 21.1, 25.8 and 24.1% respectively, was observed. No influence of simvastatin on apo A-II was found, but HDL-cholesterol and apo A-I were slightly increased (+6.1 and 4.4% respectively). The data show that HMG-CoA reductase inhibitors constitute a new class of effective drugs for the treatment of hypercholesterolemia.

Adult↗
PubMed1989

Fibrin formation and platelet activation in patients with myocardial infarction and normal coronary arteries.

Coronary spasm is the mechanism most often postulated to explain the rare combination of myocardial infarction and angiographically normal coronary arteries, although the reported evidence for its role is circumstantial rather than conclusive. Whereas the importance of thrombosis in myocardial infarction is uncontested in the presence of significant coronary artery disease, there is little in vivo evidence for thrombosis in angiographically normal coronary arteries. Among 11 consecutive patients with acute myocardial infarction undergoing thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) 3.2 +/- 0.7 h after onset of chest pain, and angiography 10.2 +/- 4.5 days later, three young men had normal coronary arteries. Their cases are documented electrocardiographically, enzymatically and angiographically. Mean plasma levels of fibrinopeptide A (FPA) and beta-thromboglobulin (BTG) were clearly elevated before and during rtPA therapy: FPA 52 +/- 41 ng ml-1, BTG 257 +/- 46 ng ml-1. They did not differ significantly from corresponding mean plasma levels in the eight patients with severe coronary artery disease: FPA 67 +/- 66 ng ml-1, BTG181 +/- 75 ng ml-1. We conclude that fibrin formation and platelet activation are probably equally important in the early hours of myocardial infarction, whether or not significant coronary artery disease is present.

Adult↗
PubMed1986

Flecainide: a new antiarrhythmic drug.

Flecainide acetate is a new class 1 c antiarrhythmic drug. It slows conduction in the working myocardium and the specialized conduction system and may depress sinus node activity in patients with pre-existing sinus node disease. Its hemodynamic effects are minimal. The drug is completely absorbed and shows a half-life of 7-22 hours. Elimination is mainly through the kidneys. Flecainide is highly effective in the treatment of ventricular arrhythmias, pre-excitation syndromes and AV reentry tachycardias. Side effects are mild and consist mostly of dizziness, visual disturbances, and nervousness. They rarely require discontinuation of therapy. Proarrhythmic effects have been reported. Caution is required in patients with congestive heart failure, AV block, and/or bundle-branch block or sinus node dysfunction.

Action Potentials↗
PubMed1986

Cold potassium cardioplegia versus topical hypothermia and intermittent aortic occlusion for myocardial protection during coronary artery surgery: a randomized clinical study.

The effect of two different myocardial preservation techniques on perioperative myocardial necrosis during coronary artery bypass surgery was assessed by serial myocardial creatine kinase determinations in 100 consecutive patients operated on by the same surgeon. Topical hypothermia with cold potassium cardioplegia was used randomly in 50 patients (group 1), and topical hypothermia with local interruption of the coronary circulation was used in the other 50 patients (group 2). Myocardial creatine kinase was measured by column chromatography every 6 hours for 36 hours after surgery. There was no significant difference between the two groups in terms of age, sex, functional class, extent of coronary artery disease, number of bypassed arteries, ejection fraction, or cardiopulmonary bypass time. Myocardial creatine kinase release (mean +/- standard error of the mean) was 193 +/- 33 IU/L X hours in group 1 patients operated on with cardioplegia and 210 +/- 31 IU/L X hours in group 2 patients operated on with topical hypothermia (p greater than 0.5). Myocardial creatine kinase peaks were 9.2 +/- 1.9 IU/L and 10.0 +/- 1.6 IU/L, respectively (p greater than 0.5). Perioperative myocardial infarction, as defined by serum enzyme activity and electrocardiographic criteria, occurred in 4 patients in group 1 and 3 patients in group 2. Thus, the addition of cardioplegia to topical hypothermia, although perhaps offering technical advantages, does not appear to improve myocardial protection over topical hypothermia with local interruption of the coronary circulation during coronary artery bypass surgery.

Aorta, Thoracic↗
PubMed1986

[Risk of reoperations and acute interventions in valvular surgery].

Reoperations in valvular surgery can be subdivided into procedures following reconstructive measures (group A) and interventions following implantation of a valve prosthesis (group B). In group A (valve replacement after conservative mitral surgery, 41 cases from 1976 to 1984 in our institution), operative mortality does not significantly differ from patients undergoing primary isolated mitral valve replacement (7.3% v. 4.4%). In group B, however, the risk of prosthetic valve reoperation mainly depends on the morphological alterations implying the surgical intervention. Among these conditions, prosthetic valve endocarditis has the poorest prognosis (operative mortality 25% in our own experience), especially if an emergency intervention is mandatory as a result of severe heart failure. In contrast to this high risk group, patients being reoperated on an elective basis due to paraprosthetic leakage or recurrent arterial embolism, do not show a higher risk when compared to first procedures. The risk of emergency surgery on native heart valves is discussed under the consideration of patients suffering from acute infective endocarditis (AIE). As in reoperations, the preoperative cardiac functional status and the urgency of the surgical intervention are the principal determinants for the operative risk. Both for reoperations and emergency procedures surgical timing is of great importance in the management of valvular patients; when ever possible, surgery should be carried out before the development of advanced ventricular failure necessitates an intervention under emergency conditions.

Aortic Valve↗
PubMed1985

[Hemodynamic effects of a new long-acting isosorbide dinitrate].

The following hemodynamic parameters were measured at rest and 1, 2, 4, 6, 8, 12 and 24 hours after 100 mg of ISDNSR p.o. in 10 patients with dilated cardiomyopathy (NYHA class III-IV): mean pulmonary artery, pulmonary capillary wedge (PCW) and arterial pressures (AP), and cardiac output (thermodilution). Plasma levels of ISDN were determined by capillary gas chromatography at the same intervals and correlated with the hemodynamic changes. PCW fell from 24 +/- 1.5 (SE) to 18 +/- 1.8 mm Hg after 1 hour (p less than 0.05) and after 2 hours to 16.9 +/- 1.6 mm Hg. This change was sustained for 8 hours. At 12 hours PCW had increased again to 21 +/- 1.5 mm Hg and at 24 hours to 22 mm Hg. AP dropped from 89 +/- 5 to 81 +/- 4 mm Hg at 1 hour (p less than 0.2) and remained 80-84 mm Hg for 8 hours. It returned to baseline levels at 12 hours. Heart rate, cardiac index, systemic vascular resistance, stroke index and left ventricular work index did not change significantly during the observation period. Plasma levels of ISDN remained between 3 and 12 ng/ml for 16 hours. Thus, ISDNSR is an effective long-acting nitrate preparation which reduces preload for 8-12 hours. After this interval, nitrate tolerance starts to develop.

Blood Pressure↗
PubMed1985

[Radiologic follow-up of the replacement of the ascending aorta with a composite graft. Comparison of angiography and computed tomography].

Only a few long-term results after replacement of the ascending aorta with a composite graft are available. Twelve patients were therefore evaluated clinically, by computer tomography (CT) and angiography 8-102 months postoperatively. 7 patients had a type I dissecting aneurysm, 1 patient a type II and 4 patients a true aneurysm. Clinically there were no signs of valvular dysfunction or symptoms of lower limb ischemia. All patients were in functional class I or II. On CT all patients with a type I aneurysm showed a chronic dissection with a perfused false lumen extending into the descending aorta. Opacification of the coronary ostia was possible in 4 patients. In 1 patient a false aneurysm at the distal suture line was visualized. Angiography confirmed all CT findings. Coronary angiography demonstrated widely patent coronary ostia. No false aneurysm around the implants was found. Thus, functional results after composite graft operation are good despite the persistence of massive chronic dissection in all patients with a type I aneurysm. CT is an ideal method of evaluating the extent of this dissection. Angiography is necessary to visualize the anatomy of the aortic root and of the coronary ostia.

Adult↗
PubMed1985

[Sudden cardiac death].

Sudden cardiac death, most often due to ventricular fibrillation, is caused by three vessel coronary disease in over 90% of the cases. At autopsy acute coronary thrombosis superimposed on an arteriosclerotic plaque is often found. However, a terminal myocardial ischemia can also develop without coronary thrombosis. In these cases platelet thrombi or coronary spasm may be the cause of ventricular fibrillation. In approximately one fourth of all patients with coronary disease sudden death is the first manifestation of the patient's illness. After myocardial infarction a high risk patient group can be detected by non-invasive methods: patients with cardiac failure, high enzyme values, a positive exercise-ECG and malignant ventricular arrhythmias three weeks after myocardial infarction have a significantly higher mortality in the following 12 months than patients without these complications. In this group of patients prevention of sudden death should be tried by an aggressive management of myocardial ischemia, heart failure and ventricular arrhythmias.

Coronary Disease↗
PubMed1985

[Quality of life following heart valve prosthesis].

The subjective and objective health status of 69 patients with a mean age of 58 +/- 9 years was evaluated 2-4 years after replacement of the aortic or mitral valve. All findings were compared to the preoperative status. Subjectively, 80% of all patients felt a considerable improvement following surgery and the mean NYHA functional class dropped postoperatively from 2.68 +/- 0.63 to 1.32 +/- 0.53 (p less than 0.001). 66% of all patients felt better mentally as well. However, 64% of all patients indicated that their intellectual capacity had decreased postoperatively. Objectively the signs of congestive heart failure had decreased significantly (edema -50%, rales -83%, neck vein distention -87%). Cardiomegaly and redistribution had improved in 77% and 80% of all patients, and left ventricular hypertrophy on ECG had disappeared in 46% of all cases. Despite this important subjective and objective improvement, there was little change in the degree of postoperative employment. Thus, valve surgery leads to a dramatic subjective and objective improvement of cardiac performance and quality of life. However, the improvement has little influence on postoperative resumption of work. Results of this study also suggest that cardiac surgery has a negative effect on intellectual capacity.

Adult↗
PubMed1985

Fibrin formation and platelet aggregation in patients with severe coronary artery disease: relationship with the degree of myocardial ischemia.

Fibrinopeptide A (FpA) concentrations in plasma and in 24 hr urine specimens as well as beta-thromboglobulin (BTG) in plasma were measured in 17 patients with severe angina pectoris, including both stable and unstable angina, and in 19 patients with acute myocardial infarction. Patients with unstable angina had plasma FpA and BTG levels of 5.2 +/- 1.7 ng/ml and 91 +/- 23 ng/ml, respectively. The corresponding concentrations of FpA in the 24 hr urine specimens were 8.2 +/- 1.4 micrograms/24 hr. These values were similar to those measured in patients with acute myocardial infarction and higher than the corresponding levels in patients with stable angina (p less than .05) and in normal control subjects (p less than .01). The similarity of the platelet and coagulation findings in patients with unstable angina and in those with myocardial infarction favors the hypothesis that coronary thrombosis may play a major role in the pathogenesis of acute myocardial infarction.

Angina Pectoris↗
PubMed1985

[Echocardiography detection of intracavitary ventricular tumors].

Intracavitary ventricular tumors were found in 3 male patients (newborn, and 18 and 23 years old) by 2-D echocardiography (metastasis of an osteogenic sarcoma in the right ventricle, teratoma embryonale growing from the retroperitoneum into the right ventricle, rhabdomyoma of the left ventricle). They all showed a uniform echo pattern and two of them were pedunculated. Wall motility, valves and cardiac dimensions were normal. In each case diagnosis was confirmed intraoperatively or at autopsy. Clinically the metastasis of the osteogenic sarcoma presented as obstruction of the superior vena cava, whereas the teratoma embryonale imitated tricuspid valve disease. The rhabdomyoma caused a systolic murmur and severe postpartal sinus bradycardia. It was successfully removed on the basis of echocardiography alone. 2-D echocardiography is a reliable, noninvasive diagnostic tool for evaluation of intracavitary, ventricular tumors.

Adolescent↗
PubMed1984

[Long-term therapy of congestive heart failure and dilatative cardiomyopathy].

Although therapy of congestive heart failure has to remain symptomatic in many cases, diagnostic evaluation should always precede initiation of therapy. Goals are (1) improvement of contractility (digitalis; other positive inotropic substances are in evaluation) and (2) decrease of preload and afterload by diuretics and vasodilators. Those therapeutic principles are briefly discussed. Symptomatic therapy certainly improves quality of life, but it remains unclear whether survival is improved as well.

Cardiomyopathies↗