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Biomedical subjects

K L Neuhaus

Publications and source records attributed to K L Neuhaus.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Ischemia--reliable results of therapy, operation and angioplasty--in coronary disease].

Randomized studies have shown that coronary bypass-surgery is effective in prolonging survival and reducing symptoms in various groups of patients with coronary artery disease, when compared with medical therapy alone. This effect is most pronounced and stable in patients who received an internal-mammary-artery graft. Therefore internal-mammary-artery grafting for lesions of the left anterior descending coronary artery is preferable whenever indicated and technically feasible. While percutaneous transluminal coronary angioplasty is effective in improving symptoms of angina pectoris, beneficial effects on survival have not yet been shown. In randomized trials of PTCA versus bypass-surgery acute results were comparable. During follow-up significantly less re-interventions and more angina-free patients were seen in the bypass-groups, indicating a more stable result after bypass surgery. In older patients with a higher mortality and rate of cerebral vascular events during surgery, a palliative PTCA of the culprit lesion may be superior to the bypass-operation. For the often used "unproven" indications for PTCA (silent ischemia, infarct-related artery in asymptomatic patients, isolated proximal LAD-stenosis, acute myocardial infarction, cardiogenic shock) larger randomized trials should be awaited to prove the effectiveness of PTCA in these settings.

Aged↗
PubMed1993

[New substances and dosages for thrombolysis in acute myocardial infarct].

The aim of thrombolytic therapy in acute myocardial infarction is the early, complete and sustained restoration of bloodflow in the infarct-related artery. In a randomized trial in 421 patients with acute myocardial infarction front-loaded rt-PA (100 mg in 90 min) showed a significantly higher 90-min patency (84.4%) in comparison with APSAC (70.3%). In-hospital mortality was significantly lower after rt-PA (2.4%) versus 8.1% after APSAC. While a single bolus injection of rt-PA produced lower patency and higher reocclusion rates, double bolus injections showed more promising results (90 min patency > 70%). A new recombinant plasminogen activator BM 06.022 (r-PA) with a longer half life can be given as a single bolus injection. In a dose-finding study r-PA produced rapid thrombolysis with a 90-min patency of 66% (10 MU) and 76% (15 MU). There was no excess in re-occlusions or bleeding complications. Although these results are quite promising, the search for the ideal thrombolytic strategy is still ongoing.

Coronary Circulation↗
PubMed1992

[Mitral insufficiency after percutaneous balloon valvuloplasty in mitral stenosis. Incidence and progression].

Percutaneous balloon valvoplasty of the mitral valve was performed in 126 patients (24 men, 102 women; mean age 55.0 +/- 12.1 years) with mitral stenosis. The mean transmitral valve gradient fell from 12.4 +/- 6.1 to 6.0 +/- 3.2 mmHg, while the valve opening area increased from 1.0 +/- 0.2 to 1.55 +/- 0.3 cm2. After percutaneous balloon valvoplasty 36 patients still had no mitral regurgitation, while the grade of mitral regurgitation remained the same in 47 (grade I: n = 35; grade I: n = 12). Mitral regurgitation, previously not present, occurred in 25 patients, but was severe in only three (grade III: n = 1; grade IV: n = 2). Previously present mitral regurgitation increased in 18 of 65 patients, in four to grade III, in one to grade IV. In three patients acute grade IV mitral regurgitation resulted from a tear in a leaflet of a fibrotic valve which was not or only slightly calcified, requiring emergency surgery. Followup observations over 16.9 (1-60) months showed no change in most patients, but three developed mitral regurgitation. The latter underwent elective surgery, as did one patient with acute mitral regurgitation. Thus a total of seven patients (5.6%) required surgery for mitral regurgitation after percutaneous balloon valvoplasty.

Adolescent↗
PubMed1992

Left main coronary stenosis by a mediastinal lymphoma.

A 50-year-old patient presented with a 3-month history of chest pain, a pathological result on electrocardiogram stress test, and signs of coronary heart disease on myocardial scintigraphy. Coronary angiography showed an isolated, moderate tubular stenosis of the left main coronary artery. Coronary bypass surgery was carried out, and intraoperative examination revealed a mediastinal lymphoma which caused the stenosis of the left main artery by external compression.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Improved thrombolysis in acute myocardial infarction with front-loaded administration of alteplase: results of the rt-PA-APSAC patency study (TAPS)

Thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) and anisoylated plasminogen streptokinase activator (APSAC) in myocardial infarction has been proved to reduce mortality. A new front-loaded infusion regimen of 100 mg of rt-PA with an initial bolus dose of 15 mg followed by an infusion of 50 mg over 30 min and 35 mg over 60 min has been reported to yield higher patency rates than those achieved with standard regimens of thrombolytic treatment. The effects of this front-loaded administration of rt-PA versus those obtained with APSAC on early patency and reocclusion of infarct-related coronary arteries were investigated in a randomized multicenter trial in 421 patients with acute myocardial infarction. Coronary angiography 90 min after the start of treatment revealed a patent infarct-related artery (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3) in 84.4% of 199 patients given rt-PA versus 70.3% of 202 patients given APSAC (p = 0.0007). Early reocclusion within 24 to 48 h was documented in 10.3% of 174 patients given rt-PA versus 2.5% of 163 patients given APSAC. Late reocclusion within 21 days was observed in 2.6% of 152 patients given rt-PA versus 6.3% of 159 patients given APSAC. There were 5 in-hospital deaths (2.4%) in the rt-PA group and 17 deaths (8.1%) in the APSAC group (p = 0.0095). The reinfarction rate was 3.8% and 4.8%, respectively. Peak serum creatine kinase and left ventricular ejection fraction at follow-up angiography were essentially identical in both treatment groups. There were more bleeding complications after APSAC (45% vs. 31%, p = 0.0019).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Pharmacokinetics and fibrin specificity of alteplase during accelerated infusions in acute myocardial infarction.

Pharmacokinetics and fibrin specificity of alteplase (recombinant tissue-type plasminogen activator) were determined in 10 patients with acute myocardial infarction undergoing an accelerated infusion regimen during the alteplase/anistreplase patency study (TAPS). Fifteen milligrams of alteplase was administered as an intravenous bolus injection, followed by infusions of 50 mg over 30 min and 35 mg over a further 60 min. Mean steady state plasma concentrations of alteplase during the initial 30 min were 3.2 +/- 0.84 micrograms/ml, measured immunochemically, and 2.1 +/- 0.23 micrograms/ml, measured using a functional activity assay. These values were 45% and 51% higher, respectively, than those during the standard infusion schedule (p less than 0.01). However, the predominant plasma half-life determined by model fitting based on either assay (3.3 to 3.5 min) was unaltered compared with the standard regimen. Maximal concentrations of fibrin and fibrinogen degradation products were 5.1 +/- 2.2 and 1.9 +/- 1.1 micrograms/ml, respectively. Plasminogen decreased to 70% and alpha 2-antiplasmin to 35% of values before infusion. The results indicate that 1) improved coronary patency rates during "front-loaded" infusions can be rationalized in terms of higher plasma concentrations of both free and immunoreactive alteplase, 2) kinetic variables are comparable with those of other dosing strategies, and 3) fibrin specificity is not diminished relative to that of the standard infusion regimen.

Aged↗
PubMed1991

[Percutaneous balloon valvuloplasty in mitral stenosis].

Between June 1986 and June 1989, percutaneous balloon valvuloplasty (PBV), using the transseptal, single-balloon technique, was performed in 50 consecutive patients (38 women and 12 men; mean age 54 +/- 14 years) with mitral stenosis. The procedure was technically successful in 48 patients (in one patient the atrial septum could not be crossed, in the other cardiac tamponade occurred). The mean diastolic gradient was decreased from 12.5 +/- 6.6 to 6.1 +/- 3.1 mmHg, mean pulmonary artery pressure (PAP) reduced from 29 +/- 12 to 22 +/- 6 mmHg, and valve opening area increased from 1.0 +/- 0.25 to 1.6 +/- 0.4 cm2. Redilatation had to be undertaken in four patients because of restenosis. Commissurotomy had to be performed in one patient, valve replacement in nine (restenosis in 4, poor primary results in 3, increase in regurgitation in 2). One patient died of a noncardiac cause. Follow-up observations for an average of 14 (3-36) months indicated in 30 of the remaining 33 patients without additional intervention a stable clinical improvement of at least one class (NYHA classification), as well as stable haemodynamic findings (gradient: 6.0 +/- 2.7 mmHg, valve opening area 1.5 +/- 0.3 cm, PAP 23 +/- 7 mmHg. Thus PBV achieved, at least in the medium term, clinical improvement in about two thirds of patients, and an operation was avoided.

Adolescent↗
PubMed1991

Intravenous streptokinase in acute myocardial infarction (I.S.A.M.) trial: serial evaluation of left ventricular function up to 3 years after infarction estimated by radionuclide ventriculography. I.S.A.M. Study Group.

The Intravenous Streptokinase in Acute Myocardial Infarction (I.S.A.M.) trial was a prospective, placebo-controlled, double-blind multicenter trial of high-dose short-term intravenous streptokinase in acute myocardial infarction administered within 6 h after the onset of symptoms. Global and regional left ventricular ejection fractions were determined by radionuclide ventriculography in a subset of 120 patients 3 days, 4 weeks, 7 months, 18 months and 3 years after acute myocardial infarction. In patients with anterior myocardial infarction, left ventricular ejection fraction was higher in the streptokinase than in the placebo group 3 days after acute infarction (49 +/- 14% vs. 40 +/- 11%, p = 0.02). This difference of about 10% units in ejection fraction persisted during the 3 year follow-up period. Among streptokinase-treated patients, regional left ventricular ejection fraction was higher within the infarct zone as well as in remote myocardium throughout the follow-up period. Among patients with inferior infarction, no significant differences between the treatment and control groups were demonstrable with respect to global and regional left ventricular ejection fraction. Thus, intravenous administration of streptokinase within 6 h after the onset of symptoms of acute myocardial infarction preserves left ventricular function over a period of greater than or equal to 3 years in patients with acute anterior myocardial infarction. It improves regional myocardial function within the infarct zone as well as in remote areas. In patients with acute inferior myocardial infarction, benefit from intravenous streptokinase is of only minor degree.

Creatine Kinase↗
PubMed1990

[Atrial natriuretic factor levels and pressure in the pulmonary circulation before and after coronary dilatation].

According to several reports of close correlations between pulmonary artery pressure and ANF plasma levels it would be convenient to replace invasive pressure monitoring by ANF determination. Mean pulmonary artery and right atrial pressures and pulmonary artery as well as peripheral venous ANF plasma concentrations were measured in 24 patients before and after coronary angioplasty (PTCA) continuously at rest and during exercise: At rest, both pressure and ANF-values remained unchanged before and after PTCA. At exercise, there was a decrease of mean pulmonary artery pressure (from 41.3 +/- 8.6 to 31.5 +/- 7.4 mmHg, p less than 0.001), mean right atrial pressure (from 11.9 +/- 3.0 to 9.0 +/- 2.3 mmHg, p less than 0.001), pulmonary artery (282.5 +/- 191.0 to 207.3 +/- 157.2 pg/ml, p less than 0.05) and peripheral venous (112.7 +/- 48.0 to 97.1 +/- 53.2 pg/ml, n.s.) ANF concentration after PTCA. We found no correlation between PTCA-induced changes of right arterial pressures and ANF concentrations, while changes of pulmonary artery pressures were significantly correlated to changes of peripheral venous (r = 0.79, p less than 0.001) as well as pulmonary artery (r = 0.59, p less than 0.01) ANF concentrations at exercise. In 6 of the 24 patients, however there was an inverse relationship between changes of pulmonary artery pressures and ANF concentrations. - Our data demonstrate a significant correlation between changes of ANF plasma level and pulmonary artery pressure values at exercise after PTCA. In the individual case however invasive pressure monitoring cannot be replaced by determination of ANF plasma levels.

Adult↗
PubMed1990

Controversial indications. Rationale for thrombolysis: later than 4-6 h from symptom onset, and in patients with smaller myocardial infarctions. The ISAM Study Group.

To evaluate the effect of late reperfusion of an infarct-related coronary artery on left ventricular (LV) function in the month after myocardial infarction (MI), findings from 386 patients in the Intravenous Streptokinase in Acute Myocardial Infarction (ISAM) trial were studied. All patients had a late peaking in the creatine kinase-MB serum time-activity curve, suggesting absence of early reperfusion. Significantly better LV function associated with patency of the infarct artery at angiography 1 month after the acute event confirmed the beneficial effect of reperfusion even if achieved beyond the time window for myocardial salvage. Thrombolysis commenced later than 4-6 h after symptom onset will be of benefit as long at it reopens infarct arteries more often and earlier than occurs spontaneously or from anticoagulation. The value of the size of the sum of ST-segment elevation (sigma ST increases) on admission ECG was evaluated from the total ISAM study population. The relation between sigma ST increases and final infarct size as well as mortality risk was highly significant. However, weak correlations largely limit the value of sigma ST increases to predict the outcome in an individual patient. Thus, whatever the relative beneficial effect in patients with smaller or larger MI may be, it would be unwarranted to withhold thrombolytic therapy from patients with smaller sigma ST increases on admission ECG.

Aged↗
PubMed1990

Intravenous streptokinase in acute myocardial infarction (I.S.A.M.): assessment of left ventricular function 1 and 7 months after infarction by radionuclide ventriculography.

I.S.A.M. was a prospective, placebo-controlled, double-blind multicentre trial of high-dose short-term intravenous streptokinase in acute myocardial infarction (AMI) within 6 h of the onset of symptoms. Determination of left ventricular ejection fraction (LVEF) by radionuclide ventriculography was performed 1 and 7 months after AMI in a subset of 192 patients at rest and, in 140 of them, also during exercise. Regional myocardial function was analysed in all 145 patients with neither a history of a previous myocardial infarction nor revascularization procedures or reinfarction within the 7-month follow-up period. One month after AMI, mean LVEF was higher in the streptokinase group in patients with anterior AMI (50 +/- 15% vs 42 +/- 16%, P = 0.013). This difference was more marked in the subgroup treated within 3 h (53 +/- 14% vs 42 +/- 15%, P = 0.004), whereas patients treated 3-6 h after the onset of symptoms did not differ from respective controls (41 +/- 16% vs 41 +/- 18%). In patients with inferior AMI, the difference in mean LVEF was small (57 +/- 11% vs 55 +/- 12%, P = 0.47). After anterior AMI benefit due to streptokinase therapy was preserved up to 7 months (52 +/- 14% vs 44 +/- 17%, P = 0.013). During exercise, the increase of mean LVEF was greater in the streptokinase group at both dates, especially 7 months after AMI (4.1 +/- 6.1% vs 1.2 +/- 6.3%, P = 0.015). In streptokinase-treated patients with anterior AMI, regional LVEF at rest was higher at both dates compared with controls, within the infarct zone as well as in remote myocardium. No treatment-control differences were demonstrable in patients with inferior AMI. During exercise, regional contractile reserve was better in the streptokinase group within the infarct zone as well as in remote myocardium, irrespective of the site of infarction. Thus, intravenous streptokinase within 3 h after the onset of AMI preserves global left ventricular function in anterior AMI over a period of at least 7 months. Intravenous streptokinase improves regional myocardial function within the infarct zone as well as in remote areas. In inferior AMI investigation solely at rest may underestimate the benefit of streptokinase therapy.

Aged↗
PubMed1990

Delayed improvement of myocardial function after recanalization of a chronic coronary occlusion in a patient with intractable heart failure.

This case report describes the delayed improvement of left ventricular function by recanalization of an occluded coronary artery in a patient with intractable heart failure and three-vessel disease. The left anterior descending coronary artery was occluded distal to the first septal branch, the dominant right coronary artery had a diameter stenosis of 70-80% in its middle part, and the circumflex artery a proximal stenosis of 50%. Ventriculography revealed globally depressed left ventricular function with an ejection fraction of 16%. Successful recanalization and angioplasty of the occluded coronary artery resulted in a slow improvement of left ventricular function. Ultimate recovery of systolic performance (increase of ejection fraction from 16% to 48-51%) required more than half a year. It is speculated that stunned myocardium following chronic ischaemia is a consequence of vascular dysfunction.

Angioplasty, Balloon, Coronary↗
PubMed1990

[Acute coronary thrombosis and myocardial ischemia following chemotherapy of Hodgkin's disease].

A 37 year old man without coronary risk factors or known heart disease showed progression of Hodgkin's disease after radiation and multiple chemotherapy. One day after the first cycle of chemotherapy with methotrexate, Ifosfamide and etoposide, he had an acute myocardial ischemia. The creatinin-kinase was elevated up to 325 U/l. Coronary angiography showed a thrombus in the left anterior descending coronary artery (LAD), while the other coronary arteries were normal. Ventriculography showed an apical akinesia. After 7 days of treatment with heparin coronary angiogram was normalized, without any stenosis in the LAD. To our knowledge this is the first documented case of a coronary artery thrombosis and myocardial ischemia after chemotherapy in a patient without coronary heart disease. We conclude that chemotherapy can cause myocardial ischemia by coronary artery thrombosis in patients without prior heart disease.

Adult↗
PubMed1989

Improved thrombolysis with a modified dose regimen of recombinant tissue-type plasminogen activator.

To improve further the patency rate of infarct-related coronary arteries, the following accelerated dosage regimen of recombinant tissue-type plasminogen activator (rt-PA) was administered to 80 patients with acute myocardial infarction of less than or equal to 6 h duration: 15 mg intravenous bolus, 50 mg infusion over 30 min and 35 mg infusion over the following 60 min. After coronary angiography at 90 min coronary angioplasty was performed in 16 patients and additional thrombolysis in 3 patients. Six patients were not included in the final angiographic analysis, mostly because of borderline ST segment elevations, in order to avoid overestimation of the efficacy of this dose regimen. Four of these had a patent infarct artery; no early angiogram was performed on two. Sixty minutes after the start of infusion, 54 (74%) of 73 patients had a patent infarct-related artery (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3) as did 67 (91%) of 74 patients at 90 min. At 24 h, 61 (92.4%) of 66 patients showed a patent infarct artery. Recurrent myocardial ischemia was noted in 12 patients, 7 (9.4%) of whom experienced reinfarction during the hospital stay. Minor local bleeding complications were observed in 14 patients (17.5%). There were four in-hospital cardiac deaths; one patient who underwent additional thrombolysis for recurrent ischemia died from bleeding complications. These results show that a rapid infusion of 100 mg of rt-PA over 90 min yields a high early patency rate of the infarct-related artery without an increase in reocclusion rate and adverse reactions.

Adult↗
PubMed1989

Impact of late coronary artery reperfusion on left ventricular function one month after acute myocardial infarction (results from the ISAM study).

To evaluate the impact of late reperfusion of an infarct-related coronary artery on left ventricular (LV) function in the month after myocardial infarction, findings from 368 patients in the Intravenous Streptokinase in Myocardial Infarction study are presented. All patients had a late peaking in the creatine kinase-MB serum time-activity curve, suggesting absence of early reperfusion. Contrast angiography was performed 1 month after the acute event. The infarct-related coronary artery was patent in 74 of 116 (64%) streptokinase-treated patients and 141 of 252 (56%) patients treated with anticoagulant therapy (placebo group). In all baseline variables, including the actually developed enzymatic and electrocardiographic infarct sizes, there were no differences between the patent- or occluded-artery groups. A patent infarct artery 1 month after infarction was associated with significantly better LV function regardless of the vessel involved and whether or not patients had been treated with streptokinase. Ejection fraction in patients with patent versus occluded artery was 56 +/- 13 versus 50 +/- 14 (p less than 0.0005). Most benefit was noted in patients in whom the proximal left anterior descending coronary artery was affected: ejection fraction was 52 +/- 14 versus 36 +/- 12% (p less than 0.0005). Our data confirm that restoration of adequate flow through an infarct-related coronary artery beyond the time window for actual salvage of ischemic myocardium has a definite beneficial effect on LV function.

Aged↗
PubMed1989

[Balloon catheter arterial occlusion before high-risk splenectomy and nephrectomy].

Balloon catheter occlusion of the splenic or renal artery was undertaken in 10 patients (7 men and 3 women, aged 20-76 years) 30 to 120 min before a splenectomy (n = 8) or nephrectomy (n = 2), for the purpose of preventing a high intra- and post-operative blood loss and facilitating the technical procedure of removing an often markedly enlarged spleen. The operation time after balloon catheter occlusion was only 60-140 min; intra- and post-operative complications did not occur, other than one instance of pneumonia and one of subcutaneous haematoma. This method would seem to be suitable for reducing the operative risk of splenectomy or nephrectomy in the presence of a giant spleen or reduced tolerance of operation.

Adult↗
PubMed1989

[Infarct-typical changes in the electrocardiogram following chemotherapy with vinblastine].

Left-chest pain and infarct-like ECG changes occurred in a 47-year-old man who had had an orchiectomy for embryonic carcinoma of the testes and was receiving the second cycle of chemotherapy with vinblastine, bleomycin and cisplatin. Only creatine kinase was slightly elevated (90 U/l) among the heart-specific enzymes. Coronary angiography did not demonstrate any coronary abnormalities, but the ventriculogram showed apical akinesia. Chest pain and similar ECG changes again occurred during the third treatment cycle, this time without bleomycin. This sequence would suggest that vinblastine was the cause of the myocardial damage, although its pathogenesis is uncertain.

Antineoplastic Combined Chemotherapy Protocols↗