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Biomedical subjects

R Zweiker

Publications and source records attributed to R Zweiker.

At least 37 records · Page 2Linked to original sources

Bradydysrhythmia-related presyncope secondary to pheochromocytoma.

Pheochromocytoma endures as a life-threatening disorder. In the absence of systemic hypertension, diagnosis may be difficult. We present a 46-year-old normotensive male with a history of presyncope. One of these episodes could be documented, and revealed symptomatic bradycardia suspicious of sinus node arrest. Due to hints of an elevated sympathetic tone (Schellong test, circadian blood pressure pattern without diurnal rhythm) 24-h urinary catecholamine concentrations were measured and found increased. MIBG-scintigraphy and abdominal-computed tomography indicated the location of the pheochromocytoma. After removal of the tumour, no further episodes of presyncopes or bradydysrhythmias were observed.

Adrenal Gland Neoplasms↗

Heart rate performance curve during incremental cycle ergometer exercise in healthy young male subjects.

In 1992 Conconi et al. (20) presented an indirect and noninvasive method for the determination of anaerobic threshold (AnT) in an incremental field test for runners. This noninvasive method for the determination of anaerobic threshold is dependent on the occurrence of a deflection of the heart rate performance curve (HRPC). The aim of our study was to evaluate the degree and direction of the deflection of the HRPC and the relationship of the heart rate threshold (HRT) to the lactate turn point in a group of 227 healthy young subjects (age: 23 +/- 4 yr). The subjects were divided into three groups by means of second degree polynomial fitting (GI: regular deflection, kHR > 0.1; G II: no deflection, 0 < kHR < 0.1; G II: inverse deflection, k < -0.1). No significant differences between the groups were found in the anthropometric data or in the power output and the blood lactate concentration at both the first (LTP1) and second (LTP2) lactate turn points and at maximum performance (Pmax). Using the method of Conconi et al. (20), 85.9% of the subjects showed a "regular" deflection, 6.2% showed no deflection at all, and 7.9% showed even an inverted deflection of the HRPC. An HRT could be obtained in both G I and G III, and power output at HRT was not significantly different in comparison to that at the LTP2. No HRT could be assessed in G II. The heart rate at HRT and the LTP2 were significantly lower in G III compared with G I. The phenomenon of heart rate break point may be attractive in training regulation, but its application is limited because a heart rate deflection cannot be found even in young subjects in some cases.

Exercise↗

Left ventricular function in response to the transition from aerobic to anaerobic metabolism.

The purpose of this investigation was to study myocardial function at rest, during three phases of energy supply, and during recovery. Radionuclide angiography was performed during the aerobic phase (phase I, rest-first lactate increase), the aerobic-anaerobic transition phase (phase II, first lactate increase-second lactate increase), the anaerobic phase (phase III, second lactate increase-maximal work performance (Pmax)), and during recovery. Thirty-eight male patients (59 +/- 7 d after myocardial infarction) were compared with 19 healthy control subjects and 21 sport students of comparable age. Left ventricular ejection fraction (LVEF) increased from rest to phase I and from phase I to phase II in sports students and control subjects. During phase III, LVEF did not change significantly in sports students, but it decreased significantly in control subjects. This is in contrast to the patients, who showed an increase of LVEF from resting values (47 +/- 3%) to phase I (50 +/- 1%), no change during phase II (51 +/- 2%), and a decrease to resting values (45 +/- 2) during phase III. All subjects showed an increase in stroke volume (SV) during phase I and II, reaching a maximum at phase II. This was evidenced by an improvement of the systolic function with a constant left ventricular end-diastolic volume (EDV) in control subjects and sports students. In contrast, an improved SV in patients was achieved through an increase in EDV and a less distinct increase in the left ventricular end-systolic volume (ESV). Maximal LVEF values were measured during the first 90 s of recovery in all subjects. Values during recovery are not representative of load dependent myocardial function. This increase in LVEF does not cause an increase in cardiac output but is a consequence of changes in the EDV and ESV, which decrease again immediately after the end of exercise performance.

Adult↗

Intracoronary Stent Used in a Transplanted Heart.

The development of occlusive cardiac allograft vasculopathy is different from coronary artery disease in native vessels and treatment is still an unsettled problem. We describe a case of a 53-year-old male who underwent heart transplantation because of severe dilated cardiomyopathy. Based on myocardial ischemia, coronary angiography was performed six years later. Significant two-vessel coronary artery disease had developed and was treated by coronary angioplasty. Due to a suboptimal result, a Palmaz-Schatz stent was successfully implanted in the left anterior descending artery. The patency of the stent was demonstrated by ultrafast computed tomography and confirmed by control angiography three months later.

Journal Article↗

[Serum digoxin level in patients with dilated cardiomyopathy].

To investigate whether measuring levels of digoxin in patients with idiopathic dilated cardiomyopathy (IDC) is helpful in dose adjustment of digoxin we did the following study. In 77 patients (63 male, 14 female) with invasively verified IDC serum-digoxin levels were measured after a treatment period with beta-acetyldigoxin of at least 6 months. All patients received digoxin, 76 had ACE-inhibitors and 69 used diuretics. Mean serum-levels of digoxin were 0.96 ng/ml while using a mean daily dose of digoxin of 0.24 mg. Those who showed a serum level of digoxin within the recommended range took a slightly higher daily dose of digoxin when compared to those with low levels of digoxin (0.26 vs. 0.23 mg/day, p < 0.05). Therefore, we conclude that low serum-levels of digoxin are mainly caused by low intake of digoxin and it is justified to measure digoxin-levels in IDC-patients even if it increases costs.

Adult↗

[Current aspects of ACE inhibitor therapy from the cardiologic viewpoint].

From a cardiologist's view there are several established indications for the use of ACE-inhibitors like hypertension, heart failure and acute myocardial infarction. In other forms of coronary artery disease like stable and unstable angina and prevention of arteriosclerotic complications. ACE-inhibitors are under discussion. As antihypertensives ACE-inhibitors are about equally effective as calcium blockers, betablockers and diuretics without the negative effects on lipid metabolism and insulin sensitivity. Vascular and cardial remodelling are prevented with ACE-inhibitors at least to a certain degree. In heart failure ACE-inhibitors reduce morbidity and mortality, if left ventricular ejection fraction is reduced. In acute myocardial infarction ACE-inhibitors are indicated in overt heart failure, depressed left ventricular function and high-risk-patients. In silent ischaemia and secondary prevention ACE-inhibitors are under discussion.

Angiotensin-Converting Enzyme Inhibitors↗

[Smoking behavior and views on the smoking topic in the Styrian population--results of a survey at the Graz autumn convention].

Cigarette smoking has been identified as a major risk factor for cardiovascular diseases apart from hypercholesterolemia and arterial hypertension. Diseases of the respiratory system and several neoplasms as well as complications of pregnancy are considered to be "smoking-related", too. In order to survey the smoking habits and views on smoking in the Styrian population, a questionnaire was issued to 1034 visitors of the Graz Autumn Fair 1992. Pleasure proved to be the main motivation for smoking both in men and in women, habit, addiction, stress and boredom being further motivations. Not only non-smokers, but also smokers were assessed to be aware of smoking being a health hazard. Prohibition of tobacco advertising was accepted most widely as a mean of anti-smoking campaign. About half the non-smokers are exposed to environmental tobacco smoke, at place of work more frequently than at home. Percentage of smokers differs with age and job classes, however, no geographical variations were found. Further anti-smoking measures should be considered. Smoking restrictions at place of work and in public could prevent passive smoking. Ban on advertising seems to be the most effective anti-smoking campaign.

Adolescent↗

[Thrombosis of a prosthetic mitral valve in the anticardiolipin syndrome].

A 40-year-old woman in whom the mitral valve had to be replaced with a prosthetic one (St. Jude's) had to be reoperated 8 months later because of endocarditis on the second prosthetic valve (Carbo-Medics). Four months later her general condition deteriorated progressively with cough and dyspnoea, requiring hospitalization. Auscultation revealed moist rales over both lung bases; heart sounds were distant but otherwise normal. The "international normalized ratio" was 2.5, while erythrocyte sedimentation rate, white cell count and C-reactive protein were normal. Transthoracic echocardiography demonstrated a hardly moving mitral valve prosthesis with an opening area of 0.8 cm. Subsequently this decreased further and measurement of the anticardiolipin antibody titre revealed an IgG fraction of 37.9 U/ml (normal up to 12 U/ml). Within 48 hours thrombolysis with streptokinase had increased the valve's opening area to 1.8 cm. The patient made an uneventful recovery under strict anticoagulation. This case illustrates that the anticardiolipin syndrome can be a cause of an otherwise unclear genesis.

Adult↗

Transient reduction of autoantibodies against oxidized LDL in patients with acute myocardial infarction.

Fifteen consecutive patients (mean age 66 +/- 14, range 31-82) with an acute myocardial infarction (MI) suitable for thrombolytic therapy were included in this study. Autoantibodies against oxidized low-density lipoprotein (LDL) were determined by enzyme-linked immunosorbent assay (ELISA). Patients (n = 10) with marked elevation of the MB isoenzyme of creatinine kinase (CK-MB)-mass had significant decreases of oLDL-Ab during the acute phase, with a minimum after 8 h following the onset of thrombolytic therapy (within-group significance: p < .001; between groups: p = .01). Patients (n = 5) with CK-MB-mass values less than 70 ng/ml did not show this phenomenon. Furthermore, significant correlations existed between CK-MB-mass and oLDL-Ab after 6 and 8 h (n = 15; r = .72; p = .003) and the time of the highest CK-MB-mass values (after 12 h) and the time of the maximal decrease of oLDL-Ab (after 8 h) (r = .74; p = .003). Our observations provide further evidence for the release of free radicals and for increased lipid peroxidation during reperfusion after prolonged ischemia. The decrease of oLDL-Ab appears to be a marker for the severity of MI.

Adult↗

[Coronary aneurysm in a 69-year-old patient. Transthoracic echocardiography].

This case report is on a 69-year old male patient treated with cephalosporins because of suspected myocarditis due to borreliosis. Using transthoracic echocardiography a big aneurysm of the proximal part of the left coronary artery was detected. Coronary angiography revealed an aneurysm 1.2 cm in diameter at the origin of the left anterior descending branch and confirmed the initial diagnosis. In addition, coronary three-vessel disease with reduced left ventricular function was found. Coronaritis due to Lyme borreliosis could not be ruled out with certainty. The patient was relatively asymptomatic, and hence conservative therapy was recommended. The case described here serves as a basis for a discussion on the aetiology, clinical manifestation, diagnosis and therapeutic management of coronary aneurysms.

Aged↗

Changes in thyroid hormone parameters after acute myocardial infarction.

Abnormalities in circulating thyroid hormone levels are very common in systemic nonthyroidal illnesses, such as acute myocardial infarction. In this study, thyroid parameters were determined in a series of 16 consecutive infarction patients treated by thrombolysis. Blood samples were taken before therapy as well as 2, 4, 6, 8, 12 and 72 h following admission. Total and free serum thyroxin and triiodothyronine decreased and reverse T3 increased significantly showing no major variations up to 72 h, whereas thyroid-stimulating hormone values remained almost unchanged during the observation period. Subjects with CK-MB levels of more than 150 ng/ml (n = 10) revealed similar changes in thyroid parameters in comparison to those with lower values (n = 6; NS). Thus, although hormone modifications very often occur following acute infarction, thyroid status may not serve as a marker for the extent of left ventricular dysfunction in the early phase of myocardial infarction.

Aged↗

[Hypertension and hemorheology].

A number of epidemiologic studies have provided evidence for an increased blood viscosity in hypertensive patients. Increased viscosity could result either from hemoconcentration, thus constituting a secondary phenomenon, or, alternatively, result directly from increased intracellular calcium concentrations in erythrocytes. The latter would augment the aggregating potential of these cellular blood compounds. This currently hypothetic view remains to be elucidated. Enhanced viscosity, however, may result in increased peripheral resistance and lead to hypertensive complications. The evaluation of antihypertensive therapy should therefore take possible effects upon blood viscosity into account.

Antihypertensive Agents↗

[What are the therapeutic consequences of evaluating hypertensive patients with 24-hour blood pressure monitors and blood pressure self-measurement?].

Arterial hypertension is an important risk factor for excessive cardiovascular morbidity and mortality due to its high prevalence of about 20% in the adult population. Causal readings, which have been obtained for diagnosis and control of treatment in hypertension are of limited value. They are not reproducable due to physiologic variability of blood pressure, which causes a rise of blood pressure, if a straining situation (e.g. in doctor's office) occurs (white-coat-hypertension). Furthermore, no correlation between causal readings and signs of endorgan-damage (EOD) such as left ventricular hypertrophy (LVH) can be observed. Especially the development of LVH comprises an independent risk factor and worsens prognosis. Results of ambulatory monitoring and self-measurement of blood pressure are reproducable and show an excellent correlation to EOD. Both methods are able to exclude white-coat-hypertension. Furthermore, ambulatory blood pressure monitoring allows to obtain blood pressure values during sleep, which may give further information concerning secondary hypertension, EOD and prognosis. Self measurement of blood pressure reinforces compliance of the patient and gives the possibility of self-titration and long-term control of antihypertensive drug treatment. The non-consensus concerning normal values is one limitation of both methods, but the cut-off level of office blood pressure recordings appears arbitrary, too. For optimal concomittance of hypertensives both methods have to reach more importance for diagnosis, evaluation of prognosis as well as treatment control.

Adult↗

[Thrombolytic therapy of acute myocardial infarct in advanced age (based on 2 case reports)].

The introduction of thrombolysis has reduced the mortality of acute myocardial infarction (MI) by 25%. Large-scale studies have revealed that especially patients over 65 benefit from this therapy. Nevertheless, many centers apply an age limit for thrombolytic therapy due to the higher risk of stroke or bleeding in elderly patients. In 1993 181 patients suffering from acute MI were admitted to the intensive care unit of the University Clinic of Internal Medicine, Graz, and 54 (29.4%) of them were treated with fibrinolytic drugs. In this paper we report on the successful thrombolytic management of acute MI in two male patients (87 and 88 years old) who were treated with 100 mg recombinant tissue-type plasminogen activator complex. As a sign of successful reperfusion a rapid increase in plasma creatinine kinase levels and fast amelioration of the ischemia-related ECG changes were observed. In the follow-up examination after four months the first patients showed only minimal exertional dyspnea and was otherwise well. The second patient died one month after MI following a laparotomy for ileus. We draw the conclusion that patients of advanced age also benefit from thrombolytic treatment of acute myocardial infarction, but the indications and contraindications have to be carefully observed.

Aged↗

[Dilated cardiomyopathy--diagnosis and conservative therapy].

Diagnosis of dilated cardiomyopathy (IDC) is a diagnosis of exclusion. Physical examination of the patient, non-invasive tests and invasive tests have to be done to exclude secondary dilated cardiomyopathies. Treatment can be divided into baseline therapy, established treatment, e.g. ACE-inhibitors, digitalis and diuretics and optional treatment including betablocker, anticoagulation and an natural course of IDC for an individual patient is not clear although there are several prognostic parameters for this disease.

Angiotensin-Converting Enzyme Inhibitors↗