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Biomedical subjects

H Kreuzer

Publications and source records attributed to H Kreuzer.

At least 145 records · Page 8Linked to original sources
PubMed1991

[ST segmental changes and arrhythmias in obstructive sleep apnea].

Patients with obstructive sleep apnea show a fall in arterial oxygen saturation during apneas. Whether this is causing myocardial ischemia and consecutively ST segment depressions in the electrocardiogram is not known. Therefore 15 consecutive patients (53 +/- 8 years, apnea index 45 +/- 28, minimal oxygen saturation 71 +/- 14%) with OSA were studied by Holter electrocardiogram and polysomnography. History and exercise testing gave no evidence of coronary heart disease. Three patients had ventricular arrhythmias Lown IVA and 10 had Lown I or III. Three patients showed unspecific negative T waves or ST segment elevations. In no patient significant ST segment depression was found. It is concluded that OSA does not lead to ischemic ST segment depression in the absence of coronary heart disease. The cause of ventricular arrhythmias in OSA seems not be related to myocardial ischemia.

Adult↗
PubMed1991

[Psychologic screening of patients of a cardiologic acute care clinic with the German version of the Hospital Anxiety and Depression Scale].

A German version of the HAD-scale which had originally been developed by Zigmond and Snaith for assessing psychological morbidity in medical patients was tested in 136 medical students, 18 psychiatric and 531 cardiologic patients. Its validity, reliability and acceptance were found to be satisfactory, its integration into medical routine did not raise any problems. Among 203 patients with suspected coronary heart disease (137 men, 66 women; mean age 54 +/- 10 years) the sub-group with high (vs. normal) HAD anxiety scores showed a significantly higher number of negative exercise tests (p less than .05) and coronary angiograms (p = .01; n = 60). Hence, the German HAD version seems to be suitable for a psychological screening of cardiologic patients. In patients with suspected coronary heart disease it improves the non-invasive differentiation between organic and functional causes of chest pain.

Anxiety Disorders↗
PubMed1990

Recanalization of chronic total coronary arterial occlusions by percutaneous excimer-laser and laser-assisted angioplasty.

A low primary success and high restenosis rate after recanalization of chronic total occlusions by conventional coronary angioplasty have encouraged the application of new interventional techniques like excimer-laser angioplasty. In 39 patients with a coronary occlusion for 1 to 12 months, recanalization was attempted by laser angioplasty through a multifiber-catheter coupled to a pulsed XeCl excimer laser. After successful passage of the occlusion by a standard guidewire in 27 patients (69%), the laser catheter was advanced over the central guidewire and crossed the occlusion in 25 patients (64%). In 2 patients with unsuccessful passage of the laser catheter, the subsequent attempt with a low profile balloon catheter also failed. In 19 of the 25 patients with successful laser recanalization, the residual stenosis exceeded 50% and was therefore followed by additional balloon angioplasty. The average residual stenosis after laser was 61 +/- 17% of the vessel diameter, and after balloon angioplasty 28 +/- 9% (n = 19), whereas after laser angioplasty alone it was 38 +/- 5% (n = 6). No complications associated with the laser application were observed. Angiographic control after 24 hours showed a reocclusion of 2 (8%) recanalized vessels. In this pilot study, laser angioplasty proved to be a safe and feasible method for the treatment of chronic total coronary occlusions. Because it was necessary to guide the catheter by a central wire, the primary success was limited by a successful passage of the wire of the occlusion. The rate of stand-alone laser angioplasty has to be increased by future improvements of the technique to enable a comparative evaluation of this method with conventional angioplasty.

Angioplasty, Laser↗
PubMed1990

[Intravascular ultrasonic diagnosis. In vivo findings before and after angioplasty in peripheral arterial occlusive disease].

In 15 patients (13 men, two women, mean age 63 [47-75] years) with peripheral arterial occlusive disease in stages IIB-IV (Fontaine) intravascular ultrasound findings were compared with the angiographic results before and after treatment. In 12 patients stenosis (n = 10) or occlusion (n = 2) of the iliac artery (n = 2) or the superficial femoral artery (n = 10) were treated by conventional balloon angioplasty; in three patients with occlusion of the superficial femoral artery excimer laser angioplasty was performed. There was good correlation between measurements of vessel diameter by the two techniques (r = 0.93, P less than 0.001). Ultrasound scanning provided additional informations regarding the thickness of the plaque, the density or firmness of the stenosis and the degree of calcification. The therapeutic outcome was quantified by measuring the gain in lumen diameter. The authors also assessed the morphological changes following angioplasty in the vicinity of the obstructing plaque. In the light of the ultrasound findings it was considered necessary to undertake further dilatation in four out of the 12 patients treated by balloon dilatation. The results indicate that intravascular ultrasound imaging is a valuable complement to angiography for monitoring of therapeutic results after vascular interventions.

Aged↗
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

[Percutaneous transluminal coronary angioplasty in patients over 75 years old with acute myocardial infarct or unstable angina pectoris].

Both increasing frequency and technical improvements of percutaneous transluminal coronary angioplasty (PTCA) have focussed attention on possible applications of PTCA in elderly patients with coronary artery disease. From January 1986 to June 1989, among 1872 patients treated with PTCA in our hospital, 42 patients (2.3%) were 75 or more years old. Of these patients, 14 presented with unstable angina, 28 patients suffered from acute myocardial infarction. PTCA was performed on stenoses of left anterior descending artery (43%), circumflex coronary artery (18%), and right coronary artery (39%), respectively. In patients with unstable angina, PTCA in 81% could reduce diameter stenoses of culprit lesions to 50% or less. 43% of patients with acute myocardial infarction had received previous thrombolytic therapy with streptokinase or urokinase applied either systemically or intracoronarily. On cardiac catheterization, 39% of patients presenting with acute myocardial infarction showed total occlusion of the infarct-related vessel. In 75% of patients with acute myocardial infarction, after PTCA, patency of the infarct-related artery (diameter stenoses 50% or less) was observed. In-hospital mortality of patients with acute myocardial infarction subjected to PTCA was 10%, two patients dying in prolonged cardiogenic shock, one in septic shock. In 20% of cases, coronary dissection was observed after PTCA. Non-Q-wave infarction developed in one patient. Three patients had a peripheral vascular complication, and in one patient a transient ischemic attack was observed. No severe catheter-related complications occurred after thrombolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[Coronary angioplasty with the implantation of a vascular support (stent)].

Coronary angiography in a 55-year-old man with coronary heart disease and typical physical activity-induced angina revealed a subtotal stenosis in the middle third of the right coronary artery while left ventricular function was normal. Percutaneous transluminal coronary angioplasty (PTCA) was performed in January 1989, achieving a residual stenosis of less than 50%. However, restenosis of more than 90% developed within six months, necessitating another PTCA, followed immediately by implantation of a metal (Palmaz-Schatz) stent in the stenotic area. No stenosis was demonstrable afterwards. Maintenance medication with anticoagulants (phenprocoumon) and platelet-function inhibitors (aspirin and dipyridamole) was instituted and repeat angiography three months later demonstrated good dilatation results without any restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1990

[Thrombolysis in resuscitated patients with pulmonary embolism].

A retrospective analysis is presented of data from 17 patients with proven pulmonary embolism (10 women, 7 men, mean age 50.8 [18-76] years) who had received short-term high dosage thrombolytic therapy shortly before or after (less than 24 h) undergoing mechanical resuscitation. The mean duration of resuscitation was 76 (20-160) minutes. Two patients had already been resuscitated half an hour and one hour, respectively, before the commencement of thrombolysis. In nine other patients thrombolysis was commenced during resuscitation. Hospital mortality in the latter group was amazingly low (four of nine patients died). In contrast, out of six patients who required resuscitation shortly after the commencement of thrombolysis, not one survived. Haemorrhagic complications occurred in four out of the 17 patients, but only in two were they directly attributable to the resuscitation: one female patient developed an extensive haematoma in the sternal region, and two days after resuscitation another female patient had a haemorrhage into the capsule of the liver during thrombolytic therapy which had been continued because of leg vein thrombosis. In the light of these results it seems justifiable, even on mere clinical suspicion of pulmonary embolism, to initiate short-term high dosage thrombolytic therapy during or after resuscitation.

Adolescent↗
PubMed1990

Embolic mononeuropathy in subacute bacterial endocarditis.

A 49-year-old man presented with temperature up to 39.5 degrees C, a sudden peroneal nerve lesion, and a cardiac murmur. The peroneal nerve lesion was likely caused by an embolic occlusion of an artery supplying the nerve. Until now, six cases of embolic mononeuropathy in endocarditis have been reported in the literature. Embolic mononeuropathy is a very rare manifestation of subacute bacterial endocarditis and quite often complicates, as do other more common embolic manifestations, the correct diagnosis.

Embolism↗
PubMed1990

Influence of long-term treatment with ketanserin on blood pressure, pulmonary artery pressure, and cardiac output in patients with heart failure.

Ketanserin is a selective serotonin2-receptor blocker and by this mechanism decreases peripheral resistance and blood pressure in hypertensives. We examined the hemodynamic effects of ketanserin during long-term treatment in patients with heart failure. Five male patients with coronary artery disease and heart failure (NYHA classes II-III) were treated with ketanserin (80 mg daily) for 12 months. Before treatment, after 4 weeks, and after 12 months treatment, a Swan-Ganz catheter was placed into the pulmonary artery and pulmonary wedge pressure, cardiac output, mean arterial pressure, and heart rate were measured at rest and on exertion. The pulmonary wedge pressure at rest decreased from 8 mmHg before to 6 mmHg after 4 weeks and 12 months treatment; on exertion, it decreased from 31 mmHg before treatment to 24 mmHg after 4 weeks treatment and to 21 mmHg after 12 months treatment. The mean arterial pressure also decreased at rest and on exertion after 4 weeks treatment as well as after 12 months treatment. Cardiac output increased slightly and heart rate was unaltered. No serious side effects occurred. Ketanserin could become an alternative vasodilator drug in the treatment of patients with heart failure.

Aged↗
PubMed1990

Impaired relationship between Doppler echocardiographic parameters of diastolic function and left ventricular filling pressure during acute ischemia.

The relationship between left ventricular filling pressure and Doppler echocardiographic parameters of diastolic mitral flow (MF) was evaluated in patients with ischemic heart disease during acute ischemia induced by percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending artery. Thirty-two patients were examined by simultaneous recordings of the Doppler MF signal and the mean pulmonary capillary wedge pressure (PCm) as an approximation of left ventricular filling pressure. At rest PCm was correlated with the early/late velocity integral ratio (Ei/Ai: r = 0.62: p less than 0.0001; n = 32). In 25 of 32 patients the recordings during PTCA could be evaluated. At the end of the inflation (duration: 69 +/- 24 seconds) PCm increased from 11.2 +/- 5.5 to 17.2 +/- 7.2 mm Hg (p less than 0.001), and total MF integral as an index of systolic ventricular function decreased by 14.9 +/- 12.8% (p less than 0.001). Inasmuch as both early and late velocity integrals were reduced during PTCA, the Ei/Ai ratio did not change significantly (1.41 +/- 0.51 to 1.34 +/- 0.60; NS). In a subgroup of inflations without ECG signs of ischemia, Ei was decreased without a concomitant decrease in Ai, thus leading to a decrease in the Ei/Ai ratio (1.36 +/- 0.43 to 1.17 +/- 0.31; p less than 0.05). Summarizing the events during PTCA, a steady increase in PCm was observed, whereas the Ei/Ai ratio was slightly decreased. Thus the observation at rest that an elevated PCm was associated with an elevated Ei/Ai was no longer valid during PTCA (Ei/Ai: r = 0.28; NS). A significant correlation was found between parameters of Doppler MF and PCm in patients with ischemic heart disease at rest. During PTCA this relationship was attenuated. Therefore noninvasive assessment of left ventricular filling pressures during acute ischemia by Doppler echocardiography does not seem feasible.

Adult↗
PubMed1990

Transfemoral placement of the left ventricular assist device "Hemopump" during mechanical resuscitation.

The Hemopump is a new left-ventricular assist device (21 F diameter), which provides up to 3.5 L/min output after placement in the left ventricle via the femoral artery. We describe the first case in which the device was inserted during resuscitation. The patient developed untreatable sustained ventricular tachycardias/fibrillation 40 hours after coronary artery bypass grafting. After prolonged mechanical resuscitation (about 3 hours) as a last resort the Hemopump was inserted and rhythm and hemodynamics stabilized. In the following hours a decrease in aortic pressure pulsatility indicated, effective left ventricular support when the Hemopump was running. For short periods the patient had nonpulsatile aortic pressure wave forms, implying complete pump dependence. In this situation cardiac output was about 3.0 L/min, mean aortic pressure reached nearly 50 mmHg using high dosage of catecholamines. The patient remained pump-dependent and died due to untreatable ventricular fibrillation. There was no significant hemolysis during the 20 hours the Hemopump was running. Autopsy revealed no signs of thrombembolism, but intimal lesions of the A. iliaca and of the abdominal aorta with subsequent thrombus formation were demonstrated. In view of the experimentally proven benefit in cardiogenic shock and problems and risks caused by the insertion, future indications for clinical use of this new device are discussed.

Femoral Artery↗
PubMed1990

Effect of acetylcholine on arterial and venous grafts and coronary arteries in patients with coronary artery disease.

Endothelium-dependent vasomotor responses differ in arteries and veins. The transfer of a given vessel from a different vascular bed into the coronary circulation by grafting may affect its endothelial function. In order to evaluate the differences in endothelial function of the internal mammary artery and aortocoronary venous grafts in patients with coronary artery disease, the response to acetylcholine (ach) was examined and compared with that of native coronary arteries. Eighteen patients were examined, including eight with internal mammary artery grafts (9 days to 48 months after surgery), and 10 with saphenous vein grafts (12-96 months after surgery). Ach (70-700 nmol min-1) was infused selectively into a graft on the left anterior descending coronary artery, and the effect on vessel diameters was assessed by quantitative arteriography. In both groups 84% and 83%, respectively, of the arterial segments distal to the bypass anastomosis were contracted by ach (greater than or equal to 70 nmol min-1). The segments of both groups did not show angiographic evidence of local atherosclerosis. A complete occlusion occurred in four cases. In contrast, internal mammary artery grafts were not contracted by ach; in four of 12 segments a dilatation was observed, whereas five of 20 aortocoronary venous graft segments showed a slight reduction in lumen diameter after the highest ach dose applied. The vasoconstricting effect of ach was reversed by intracoronary nitroglycerin. By using ach as an indicator of endothelial dysfunction it is concluded that the internal mammary artery grafts maintained an intact endothelial function after surgery, whereas the coronary artery segments showed an impaired endothelium-dependent vasodilatation. Some of the venous graft segments reacted as coronary arteries did with a less pronounced cholinergic vasoconstriction. This in vivo study supports the observation of a functional superiority of internal mammary artery over saphenous vein coronary grafts.

Acetylcholine↗
PubMed1990

Immunoscintigraphy with 111In antimyosin Fab.

Monoclonal 111In antimyosin Fab is a marker for myocytes which have lost their membrane integrity. Because of the slow blood pool clearance of the radiopharmaceutical, imaging is usually started 24-48 h after intravenous injection of 74 MBq of the tracer. This long postinjection interval restricts its utilization in the primary diagnosis of acute myocardial infarction. However, antimyosin may help to differentiate between necrotic and viable myocardium in the subacute stage of incomplete myocardial infarction. Serial endomyocardial biopsy for early detection of transplant rejection after heart transplantation may be partially replaced or supplemented by antimyosin scintigraphy. The compound may facilitate the diagnosis of myocarditis. Other potential indications may be prognostic assessment of dilated cardiomyopathy, monitoring cardiotoxic side-effects of chemotherapeutics, recognition of cardiac contusion as well as diagnosis of rhabdo- and leiomyosarcoma. In specific clinical situations 111In antimyosin Fab immunoscintigraphy may provide valuable diagnostic information.

Antibodies, Monoclonal↗
PubMed1990

Hemodynamic effects of nebivolol at rest and on exertion in patients with heart failure.

Nebivolol is a novel B-1-adrenoceptor-blocking drug with an unusual hemodynamic profile unlike classical B-blockers. In dogs and in healthy volunteers it decreases blood pressure and heart rate but improves left ventricular function. The authors studied 10 male patients with coronary artery disease and heart failure (ejection fraction mean = 46%). A Swan-Ganz catheter was placed into the pulmonary artery, and the mean blood pressure, the heart rate, the pulmonary artery pressure, the pulmonary wedge pressure, the right atrial pressure, the cardiac output, and the stroke volume were measured at rest and on exertion before and after seven days' treatment with oral nebivolol (5 mg/day). While the blood pressure and the heart rate decreased significantly, the pulmonary artery and wedge pressures, as well as the right atrial pressure and the cardiac output, did not change during treatment. The stroke volume increased significantly. The maintained cardiac output cannot be explained by any changes in preload or afterload; instead a positive inotropic mechanism must be assumed. Unlike other B-blockers it seems to be possible to treat patients with heart failure with nebivolol without causing the hemodynamic situation to deteriorate.

Adrenergic beta-Antagonists↗
PubMed1990

Effect of serotonergic antagonism on local responses to an acute and selective endothelial trauma in vivo.

Serotonin is liberated during platelet release reaction. It is concluded from in vitro experiments that serotonin influences both platelet activation and thrombus-induced vasoconstriction. The subject of the present study was to assess the impact of the serotonin2 antagonist naftidrofuryl on both thrombogenesis and thrombus-induced vasoconstriction in vivo. In a hamster cheek pouch, vessels form a rich meshwork, allowing repetitive experiments to obtain intraindividual control measurements. With a contactless photochemical process, endothelial cells can be damaged in vivo. Regularly platelets and the coagulation system are activated and thrombi are formed. In larger arterial vessels local vasoconstriction occurs. Thrombogenesis was induced in arterioles with an inner diameter between 17 and 20 microns. It was monitored by the continuous measurement of blood cell velocity to assess initial hemodynamics and the interval elapsing until perfusion stops. Solvent alone had no effect. Naftidrofuryl was given in clinically relevant dosages of 1, 5, and 20 mg/kg intra-arterially. Even 1 mg/kg showed a significant antithrombotic effect. Efficacy increased in a dose-related manner as well as during the time interval of observation (i.e., 2 h after application). As an established antithrombotic standard, acetylsalicylic acid was applied in dosages of 10 and 100 mg/kg. Both dosages were found to be antithrombotic, but not more effective than comparable dosages of naftidrofuryl. Larger arterioles with an inner diameter of about 50 microns have smooth muscle cells. They constrict during thrombogenesis as a local response to substances released by the thrombus. Topical application of papaverine abolished vasoconstriction. A thromboxane antagonist (EP092) was also effective. Naftidrofuryl reduced the vasoconstriction whereas its solvent was without effect.

Acute Disease↗