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Biomedical subjects

F Schwarz

Publications and source records attributed to F Schwarz.

At least 109 records · Page 6Linked to original sources
PubMed1984

Ventricular arrhythmias in idiopathic dilated cardiomyopathy.

Twenty four hour ambulatory electrocardiograms were recorded in 60 patients with idiopathic dilated cardiomyopathy. The diagnosis was based on clinical, laboratory, and cardiac catheterisation findings. All patients had a left ventricular ejection fraction less than 0.55; in 39 it was less than 0.40. Ventricular extrasystoles were evident in all patients: they were rare in 11 (18%), moderately frequent in 24 (40%), and frequent in 25 (42%). Multiform extrasystoles were recorded in 57 patients (95%), paired ventricular extrasystoles in 47 (78%), and non-sustained ventricular tachycardias consisting of three to 19 beats in 25 (42%) of the 60 patients studied. Eight patients had more than five episodes of ventricular tachycardia a day. Patients with atrial fibrillation had the same frequency and grade of ventricular arrhythmias as those with sinus rhythm. Patients with infrequent and frequent ventricular extrasystoles could not be differentiated on the basis of the clinical or haemodynamic findings. The mean values of NYHA functional class, cardiac index, left ventricular end diastolic pressure, and ejection fraction were, however, significantly different in patients with and without ventricular tachycardia. During follow up of 12 +/- 5 months seven patients died; all seven had an ejection fraction less than 0.40. In four patients who died of congestive heart failure, but in only one of the three patients who died a sudden cardiac death, ventricular tachycardia was recorded during ambulatory monitoring. High grade ventricular arrhythmias are often seen in patients with idiopathic dilated cardiomyopathy; patients with ventricular tachycardia have more impairment of left ventricular function than patients without ventricular tachycardia; and ambulatory monitoring may be of little help in identifying patients at increased risk of sudden cardiac death.

Adolescent↗
PubMed1984

Reduction of coronary reserve: a mechanism for angina pectoris in patients with arterial hypertension and normal coronary arteries.

The pathogenesis of angina pectoris in patients with left ventricular hypertrophy secondary to arterial hypertension and with normal coronary arteries remains uncertain. We measured coronary blood flow (argon method) in 12 control subjects and in 16 patients with arterial hypertension at rest and after intravenous administration of dipyridamole (0.5 mg/kg). In the patients with arterial hypertension, coronary blood flow response to dipyridamole was markedly reduced (p less than .001 as compared with control values). During coronary vasodilation there was a linear correlation between coronary resistance and left ventricular end-diastolic pressure (r = .67, p less than .001). Left ventricular catheter biopsy specimens did not reveal alterations in myocardial microvasculature. These findings suggest that reduction of coronary reserve may be an important contributor to the pathogenesis of angina pectoris in these patients.

Adult↗
PubMed1984

Determinants of survival in patients with congestive cardiomyopathy: quantitative morphologic findings and left ventricular hemodynamics.

We analyzed data from 68 consecutive patients with congestive cardiomyopathy to evaluate the prognostic significance of quantitative morphologic findings in left ventricular myocardium as compared with the prognostic significance of left ventricular hemodynamics. Left ventricular endomyocardial biopsy specimens were obtained from all patients during diagnostic heart catheterization. Myocardial fiber diameter, volume fraction of interstitial fibrosis, and intracellular volume fraction of myofibrils were determined by light-microscopic morphometry. All patients had normal coronary arteriograms, but reduced left ventricular ejection fractions. There were 23 deaths during a mean follow-up period of 1124 days. Multivariate regression analysis (Cox model) revealed that left ventricular ejection fraction (p less than .00001) and left ventricular systolic pressure (p less than .01), but not morphometric findings in biopsy specimens, were independent predictors of cardiac death. Thus, morphologic findings in the left ventricular myocardium do not contribute significantly to the prognostic evaluation in patients with congestive cardiomyopathy studied by hemodynamic and angiographic methods.

Adult↗
PubMed1984

Changes in plasma GH levels and clinical activity during bromocriptine therapy in acromegaly. The value of predictive tests.

Twenty-seven patients with active acromegaly despite previous treatment by surgery and/or radiotherapy received bromocriptine in a dose of 10-20 mg daily for a period of 6-9 months. The results of chronic bromocriptine treatment were evaluated by measurement of plasma growth hormone (GH) levels during the day and by subjective and objective criteria of clinical activity. The results of chronic bromocriptine treatment were also compared with four biochemical criteria obtained before treatment e.g. basal plasma prolactin (Prl) levels and the plasma GH response to oral administration of 2.5 mg bromocriptine respectively iv administration of 200 micrograms TRH and 500 micrograms somatostatin. The main observations may be summarized as follows: 1) The mean pre-treatment GH levels during the day ranged from 6-207 mU/1. Hyperprolactinaemia was present in 6 patients. 2) During bromocriptine treatment mean plasma GH levels decreased to less than 50% in 11 patients (GH responders) whereas in 19 patients changes of mean plasma GH and of subjective criteria of clinical activity were concordant. 3) Glucose tolerance improved significantly (P less than 0.01) in 10 GH-responders and the urinary hydroxyproline/creatinine ratio decreased significantly (P less than 0.05) in 8 GH-responders. 4) Five out of 6 patients with hyperprolactinaemia belonged to the group of GH-responders. 5) A single dose of 2.5 mg bromocriptine induced a more than 50% decrease of plasma GH in 8 of 11 GH-responders and in 5 of 16 GH non-responders.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1984

Successful treatment with sodium valproate of a patient with Cushing's disease and gross enlargement of the pituitary.

Transfrontal hypophysectomy was performed in a patient with Cushing's disease and gross enlargement of the pituitary. Despite some reduction of cortisol production active Cushing's syndrome remained due to the presence of a tumour remnant. Medical treatment with the GABA-transaminase inhibitor sodium valproate induced hypocorticism necessitating corticosteroid substitution therapy. Nine months after sodium valproate withdrawal hypercorticism was documented. Re-institution of sodium valproate treatment induced hypocorticism again. As sodium valproate is known to induce a decrease of plasma ACTH in Nelson's syndrome, it is proposed that large tumours present at the time of diagnosis and those appearing after adrenalectomy may represent the spectrum of a single disorder. A prospective trial to study the effects of sodium valproate and other neurotransmitter modulating agents on the size and endocrine function of ACTH secreting macroadenomas is urgently needed.

17-Hydroxycorticosteroids↗
PubMed1984

[Left ventricular function and activity of vasoconstrictor systems in patients with chronic heart insufficiency].

An increased activity of vasoconstrictor mechanisms may play an important role in circulatory adjustments to heart failure. Thus, hemodynamic data and the plasma hormones epinephrine (E), norepinephrine (NE) and arginin vasopressin (AVP) as well as the plasma renin activity (PRA) were assessed in 50 patients undergoing coronary angiography and right heart catheterization. Patients were classified into three groups according to severity of left ventricular (LV) dysfunction as assessed by ejection fraction (LVEF): those with normal left ventricular function (group 1 (n = 12): LVEF greater than or equal to 55%, mean 70 +/- 3%) and those with moderate (group 2 (n = 16): LVEF 54-35%, mean 43 +/- 2%) or severe LV dysfunction (group 3 (n = 22): LVEF less than 35%, mean 22 +/- 1%). At rest plasma NE concentrations in patients with heart failure (group 2: 187 +/- 17 pg/ml; group 3: 299 +/- 27 pg/ml) did not differ significantly from control values (199 +/- 26 pg/ml). During exercise, NE concentrations increased in all patients (p less than 0.001). This increase in plasma NE was more pronounced in group 3 (753 +/- 71 pg/ml) than in group 1 (262 +/- 37) and group 2 (388 +/- 64). A significant inverse correlation was found between plasma NE and stroke index at rest (r = -0.592, p less than 0.001) as well as during exercise (r = -0.659, p less than 0.001). PRA was elevated at rest and during exercise in patients of group 3 but not of group 2 as compared with control patients (p less than 0.05). Plasma E and AVP were similar in all groups. Patients of group 3 were subdivided according to exercise capacity into patients who tolerated a maximum work load of 50 watts or more (group 3A) and those who did not tolerate a work load exceeding 25 watts (group 3B). At rest and during exercise, patients of group 3A had a higher stroke index than patients of group 3B. In contrast, there was no significant difference in LVEF between group 3A and 3B (22 +/- 2 vs 20 +/- 1%). During exercise patients with low exercise capacity (group 3B) had higher NE levels than patients with less impaired exercise capacity (group 3A) (948 +/- 86 vs 590 +/- 65 pg/ml, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗
PubMed1984

[Function of the right ventricle in mitral valve defects before and after surgical correction].

To ascertain whether surgical correction of mitral valve lesions can lead to postoperative improvement of right ventricular function, investigations were carried out in 17 patients with mitral valve disease, clinical severity grade III and IV, before and at an average of 18 months postoperatively. Six subjects without heart disease served as controls. Preoperatively, all patients underwent catheterization and cineangiographic evaluation of both the right and left ventricles. The right ventricular ejection fraction (RV-EF) was also determined from the radionuclide ventriculogram before and after the surgical intervention (closed mitral commissurotomy in five patients and mitral valve replacement in twelve). The patients were studied at rest and during bicycle ergometry in the supine position. As compared with control subjects, before surgery at rest, patients with mitral valve disease had significantly higher values for mean left atrial pressure (22 +/- 7 vs 8 +/- 2 mm Hg), mean pulmonary artery pressure (39 +/- 17 vs 17 +/- 5 mmHg), pulmonary arteriolar resistance (361 +/- 260, increased 5-fold, vs 69 +/- 27 dyn . s . cm-5) and right ventricular systolic pressure (55 +/- 20 vs 24 +/- 6 mmHg) while the values for right ventricular end-diastolic pressure, mean right atrial pressure, left ventricular end-diastolic pressure and left ventricular systolic pressure did not differ (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1984

[Significance of morphological findings in congestive cardiomyopathy].

In 48 consecutive patients with myocardial disease, left ventricular biopsies were taken during diagnostic heart catheterization. Morphometric quantification of ultrastructural alterations of the heart muscle was performed. The patients were subdivided into 3 groups by means of clinical criteria: Group A: 18 surviving patients with pathological ECG, normal left ventricular ejection fraction, and normal coronary arteries. The mean follow-up in this group was 22 months. Group B: 23 surviving patients with congestive cardiomyopathy, i.e., normal coronary arteries and depressed left ventricular ejection fraction. The mean follow-up in this group was 23 months. Group C: 7 patients with congestive cardiomyopathy, who died during the study period from cardiac complications. The mean survival time of these patients after heart catheterization was 23 months. Myocardial fiber diameter, volume fraction of interstitial fibrosis, intracellular volume fraction of myofibrils, and the total myofibrillar mass per 100 g heart muscle were determined by light microscopic morphometry. In a pilot study comprising 26 patients the reproducibility of the morphological results were assessed by investigation of two different biopsy specimens taken from different areas of the left ventricular wall of each patient. The study revealed a coefficient of variation of 6% for myocardial fiber diameter, 28% for myocardial fibrosis, and 4% for myofibrillar volume fraction. Since there are only poor results from morphological investigations of the diseased myocardium, it was the purpose of the follow-up study presented in this paper: To quantify ultrastructural alterations of the heart in congestive cardiomyopathy by morphometric techniques. To correlate the quantitative morphometric data with the contractile state of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Thrombolysis in acute transmural heart infarction: length of ischemia as a determinant of late results after 15 months].

In 28 patients the effect of coronary artery reperfusion in acute transmural myocardial infarction was evaluated by the clinical and hemodynamic results obtained after 15 months. Patients with successful reperfusion within 4 hours after onset of symptoms were assembled in group A1 (n = 11), patients with successful reperfusion after more than 4 hours in group A2 (n = 7). Group B consists of 10 patients with unsuccessful reperfusion. Left ventricular ejection fraction (radionuclide ventriculography) and the perfusion defect (thallium-201 scintigraphy) were measured acutely and after 15 months (at rest and during exercise). The coronary anatomy and the regional ejection fraction of infarct area were determined acutely and after 4 weeks by cineangiography. Serum creatine kinase activity was measured serially during the acute phase of the infarction. Before the acute intervention, the patients of the 3 groups were comparable with regard to killip class, location of infarction, number of previous infarctions, coronary anatomy, left ventricular ejection fraction, thallium-201 perfusion defect and base-line serum creatine kinase activity. During acute infarction peak creatine kinase activity tended to be lower in group A1 (1296 U/l) than in group A2 (2100 U/l, NS) and in group B (2240 U/l, NS). After 4 weeks regional ejection fraction of infarct area was higher in group A1 (36%) than in groups A2 (24%, NS) and B (20%, p less than 0.05). After 15 months the thallium-201 perfusion defect was smaller in group A1 (7%) than in groups A2 (28%, p less than 0.05) and B (34%, p less than 0.01). At the same time left ventricular ejection fraction was higher in group A1 (52%) than in groups A2 (34%, p less than 0.05) and B (35%, p less than 0.05). Fifteen months after acute infarction patients in group A1 tended to reach a higher workload during exercise (118 watts) compared with patients of groups A2 (82 watts, NS) and B (86 watts, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1984

[Is the quotient: systolic peak pressure/end-systolic volume a useful parameter in the assessment of left ventricular function?].

The quotient: peak systolic pressure/end-systolic volume (SP/ESVI) has been proposed as a parameter of LV function and as a substitute for the slope k of the end-systolic pressure-volume relation (P-Ves), because SP/ESVI is much easier to obtain. Therefore, the relation between SP/ESVI and k and the relation between SP/ESVI and ejection fraction (EF) were investigated. In 18 patients P-Ves was obtained after vegetative blockade (1.5 mg atropine and 0.15 mg/kg propranolol) from three LV angiograms at three different afterloads (control, isosorbide dinitrate, methoxamine). - SP/ESVI and slope k showed a moderate correlation: SP/ESVI = 0.50k + 2.35; r = 0.76. SP/ESVI and EF were correlated best in an exponential way: SP/ESVI = 0.267 X e0. 045EF ; r = 0.82.- An essential disadvantage of the quotient SP/ESVI resides in the fact, that the P-Ves line has varying intercepts on the abscissa. Secondly, any quotient may belong to several P-Ves lines. The quotient SP/ESVI may be used only with caution and under specific conditions as a substitute of the slope k of the P-Ves.

Blood Pressure↗
PubMed1983

Intracoronary thrombolysis in acute myocardial infarction: an attempt to quantitate its effect by comparison of enzymatic estimate of myocardial necrosis with left ventricular ejection fraction.

The quantity of myocardium was estimated that can be salvaged by reperfusion of acute transmural myocardial infarction (MI). Serial analysis of serum creatine kinase (CK) activity was carried out in 41 consecutive patients with acute MI who underwent intracoronary thrombolysis. Enzymatic estimate of MI size was calculated using an average (method A) and an individually determined elimination constant (method B). Left ventricular ejection fraction 4 weeks after successful thrombolysis (cineangiogram) correlated inversely with MI size (method A: r = -0.85, method B: r = -0.76; both p less than 0.001). Patients with recanalization within 4 hours after the onset of symptoms were assembled in group A1 (n = 13, early reperfusion), and patients with successful recanalization after 4 hours in group A2 (n = 16, late reperfusion). Group B consisted of 12 patients without reperfusion. MI size in group A1 was 21 CK-g-Eq (method A) and 23 CK-g-Eq (method B), in group A2 50 CK-g-Eq (method A) and 54 CK-g-Eq (method B), and in group B 73 CK-g-Eq (method A) and 63 CK-g-Eq (method B). Mean values in group A1 were lower than in group A2 and group B (p less than 0.05). It is concluded that MI size was significantly reduced to about one third after early reperfusion as compared with no reperfusion. In contrast, MI size was not significantly reduced after late reperfusion.

Adult↗
PubMed1983

Coronary dilatory capacity in idiopathic dilated cardiomyopathy: analysis of 16 patients.

Hemodynamic function and overall coronary blood flow (argon technique) were measured in 16 patients with idiopathic dilated cardiomyopathy (IDC) and in 12 patients without detectable heart disease (control subjects) referred for precordial pain. In patients with IDC, coronary blood flow was normal at rest (78 +/- 17 ml/100 g-min versus 78 +/- 9 in control subjects). During maximal inducible coronary vasodilation (dipyridamole, 0.5 mg/kg), coronary blood flow was significantly reduced (142 +/- 38 ml/100 g.min versus 301 +/- 64 in control subjects; p less than 0.001). Consequently, obtainable minimal coronary resistance was increased in IDC (0.54 +/- 0.20 mm Hg/ml/100 g.min versus 0.23 +/- 0.04 in control subjects; p less than 0.001). In patients with IDC, left ventricular (LV) end-diastolic pressure was significantly increased (19 +/- 11 mm Hg versus 6 +/- 3 in control subjects; p less than 0.005), and the LV ejection fraction was diminished (36 +/- 11% versus 72 +/- 3% in control subjects; p less than 0.001). In patients with IDC, LV end-diastolic pressure correlated significantly with the obtained minimal coronary resistance after application of dipyridamole (r = 0.85; p less than 0.001). LV catheter biopsy specimens revealed no alterations in myocardial microvasculature. Thus, coronary dilatory capacity is impaired in patients with IDC, due partially to an increase in extravascular component of coronary resistance.

Adult↗
PubMed1983

Quantitative morphologic findings of the myocardium in idiopathic dilated cardiomyopathy.

This study assesses the relation between quantitative morphologic findings and left ventricular contractile function in patients with idiopathic dilated cardiomyopathy. Left ventricular endomyocardial catheter biopsy specimens were obtained from 73 patients during diagnostic heart catheterization. All patients had normal coronary arteriograms but abnormal electrocardiograms. Twenty-six patients had normal left ventricular function (ejection fraction greater than or equal to 55%), whereas 47 patients had contractile dysfunction (ejection fraction less than or equal to 54%). Myocardial fiber diameter, volume fraction of interstitial fibrosis, and intracellular volume fraction of myofibrils were determined by light microscopic morphometry. Results of light microscopic morphometry were confirmed by electron microscopic morphometry in 12 patients. The coefficient of variation (analysis of several biopsies from the same patient) was 6% for determination of fiber diameter, 43% for interstitial fibrosis, and 3% for volume fraction of myofibrils. Fiber diameter (r = -0.32, p less than 0.01) and fibrosis (r = -0.47, p less than 0.001) showed a negative correlation, the volume fraction of myofibrils (r = 0.55, p less than 0.001) and calculated myofibrillar mass per 100 g of myocardium (r = 0.64, p less than 0.001) a positive correlation with the ejection fraction. Thus, (1) sampling error is low for determination of fiber diameter and myofibrils but high for evaluation of fibrosis, and (2) a reduction in the volume fraction of myofibrils and an increase in fibrosis are morphologic correlates of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy.

Adult↗
PubMed1983

No acute effect of pimozide on the plasma GH levels in acromegaly.

In 34 acromegalic patients either untreated or inadequately treated by surgery and/or radiotherapy the plasma GH levels and plasma Prl levels were determined during 8 h after the acute administration of the dopamine agonist bromocriptine and during 150 min after the administration of the dopamine antagonist pimozide. A 50% or more suppression of the basal GH levels was arbitrarily defined as a positive response. Seventeen patients displayed a positive response to bromocriptine, 17 patients displayed a negative response to bromocriptine. Plasma Prl levels were elevated in 6 of 17 bromocriptine responders and in 2 of 17 bromocriptine nonresponders. There was no difference in the plasma GH response to pimozide administration in the patients with a positive or a negative GH response to bromocriptine. With one exception there was in no patient a positive GH response to pimozide. In further experiments the plasma GH response to pimozide was measured during 11 h in 6 bromocriptine sensitive and 6 bromocriptine insensitive patients. Again no difference was found between bromocriptine responders and non-responders. There was also no difference in the Prl response to bromocriptine or pimozide between GH responders and GH non-responders. The Prl response to pimozide was blunted in comparison to a control group. The present study does not not lend support to the idea that there is a fundamental difference in the degree of hypothalamic dopaminergic control of GH or Prl secretion between bromocriptine sensitive and bromocriptine insensitive patients with acromegaly.

Acromegaly↗
PubMed1983

Sodium valproate and cyproheptadine may independently induce a remission in the same patient with Cushing's disease.

A patient with Cushing's disease was unsuccessfully treated by pituitary surgery and external pituitary irradiation. One year later sodium valproate treatment induced a remission and finally hypocorticism developed. After drug withdrawal hypercoticism recurred. Treatment with cyproheptadine again induced hypocorticism necessitating corticosteroid substitution therapy. Biochemical characteristics of this patient included responsiveness to bromocriptine and cyproheptadine in acute tests. The study demonstrates that sodium valproate and cyproheptadine may both be effective independently in the treatment of the same patient with Cushing's disease. It is proposed that the disease is due to an ACTH producing tumour of pituitary intermediate lobe origin.

Adrenocorticotropic Hormone↗