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Biomedical subjects

F Burkart

Publications and source records attributed to F Burkart.

At least 55 records · Page 3Linked to original sources
PubMed1990

Prevalence and extent of right ventricular dysfunction after myocardial infarction--relation to location and extent of infarction and left ventricular function.

In view of today's efforts to preserve myocardial function in acute myocardial infarction, the prevalence and extent of persistent right ventricular dysfunction was analysed in a prospective study of 127 patients admitted with a first myocardial infarction without thrombolysis. Right ventricular ejection fraction measured at hospital discharge by radionuclide angiocardiography was related to the location of infarction as judged electrocardiographically, its size as estimated enzymatically, and by the simultaneously measured left ventricular ejection fraction. Two opposite patterns of right and left ventricular function were observed in relation to the location of infarction: the right ventricular ejection fraction was significantly depressed in inferior, but not in anterior, infarction and the reverse was true for left ventricular ejection fraction (P less than 0.001 between infarct locations for both right ventricular ejection fraction and left ventricular ejection fraction). There were significant correlations between peak levels of creatine kinase and left ventricular ejection fraction for anterior (r = 0.76, P less than 0.001) and inferior (r = 0.57, P less than 0.001) infarction, while peak levels of creatine kinase and right ventricular ejection fraction correlated only in inferior infarction (r = 0.45, P less than 0.01). There was no overall correlation for left ventricular ejection fraction and right ventricular ejection fraction (r = 0.28, P NS), despite the fact that right ventricular ejection fraction was lower in patients with severely reduced left ventricular ejection fraction than in those with normal left ventricular function (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Effect of antiarrhythmic therapy on mortality in survivors of myocardial infarction with asymptomatic complex ventricular arrhythmias: Basel Antiarrhythmic Study of Infarct Survival (BASIS)

In view of the high risk of sudden cardiac death and the prognostic importance of complex ventricular ectopic activity, the effects of prophylactic antiarrhythmic treatment were investigated prospectively in patients with persisting asymptomatic complex arrhythmias after myocardial infarction. End points were total mortality and arrhythmic events (sudden death, sustained ventricular tachycardia and ventricular fibrillation). Of 1,220 consecutively screened survivors of myocardial infarction, 312 had Lown class 3 or 4b arrhythmia on 24 h electrocardiographic recordings before hospital discharge and consented to the study. They were randomized to individualized antiarrhythmic treatment (Group 1, n = 100), treatment with low dose amiodarone, 200 mg/day (Group 2, n = 98) or no antiarrhythmic therapy (Group 3 [control group], n = 114). During the 1 year follow-up period, 10 patients in Group 1 died, as did 5 in Group 2 and 15 in Group 3. On the basis of an intention to treat analysis, the probability of survival of patients given amiodarone was significantly greater than that of control patients (p less than 0.05). In addition, arrhythmic events were significantly reduced by amiodarone (p less than 0.01). These effects were less marked and not significant for individually treated patients (Group 1). These findings suggest that low dose amiodarone decreases mortality in the 1st year after myocardial infarction in patients at high risk of sudden death.

Amiodarone↗
PubMed1990

Cardiac evaluation of candidates for kidney transplantation: value of exercise radionuclide angiocardiography.

In view of the high incidence and mortality of coronary artery disease (CAD) in patients with kidney transplantation, a systematic cardiac evaluation was prospectively performed in 103 uraemic patients eligible for transplantation. After clinical examination, 28 patients with symptoms of CAD or diabetes mellitus were referred directly for coronary angiography, whereas the remaining 75 patients had rest and exercise radionuclide angiocardiography for evaluation of possible asymptomatic CAD. Among them, left ventricular ejection fraction was below 40% at rest or fell during exercise by at least 5 EF% in 12 patients; coronary angiography in nine showed CAD in four and hypertensive heart disease in five. In the remaining 63 (of 75) patients without severe resting left ventricular dysfunction or exercise ischaemia, the follow-up of 28 +/- 7 months revealed no clinical manifestation of CAD. Overall incidence of CAD in symptomatic and asymptomatic patients during a follow-up of 27 months after cardiac evaluation was 20 and 25% in nondiabetic and diabetic candidates for kidney transplantation, respectively (P = n.s.). Thus, clinical examination combined with exercise radionuclide angiocardiography in patients without signs or symptoms of heart disease had a high predictive accuracy for presence or absence of late manifestations of CAD. Exercise radionuclide angiocardiography is therefore a useful method for screening kidney transplantation candidates for asymptomatic CAD.

Adult↗
PubMed1990

[The long-term management of heart transplant patients].

The long-term care of patients following heart transplantation is characterized by the problems associated with long-term immunosuppression. In addition, a specific form of coronary atherosclerosis develops within years in many patients requiring coronary angiography on a yearly basis. The examination of patients after heart transplantation does not reveal characteristic findings, as long as the transplanted heart functions properly and a normally functioning graft allows a functionally almost normal life. The dependence on a specialized center, which may be more or less depending on the clinical course, and the ever present knowledge of the potentially lethal consequences of a graft failure present a severe psychic stress to the patient. This stress is handled more or less well and requires special attention by the treating physicians and, ideally, an intact social environment. The care of patients in a center close to their place of living is less time consuming for the patient and relieves the burden of the transplanting center.

Follow-Up Studies↗
PubMed1990

Relations between sympathetic activation and plasma atrial natriuretic factor in man.

To study the relationship between sympathetic activation and cardiac release of atrial natriuretic factor in man, plasma concentrations of norepinephrine, epinephrine and atrial natriuretic factor were measured in 20 patients before and after dynamic exercise (16 subjects) or the application of venous occlusion cuffs to the thighs (4 subjects). Plasma concentrations of norepinephrine, epinephrine and atrial natriuretic factor all increased during exercise, whereas venous occlusion produced a fall in plasma atrial natriuretic factor. There was no relation between basal plasma concentrations of atrial natriuretic factor and either norepinephrine or epinephrine. However, there was a linear relation between the changes in plasma atrial natriuretic factor induced by exercise or thigh cuffs and both plasma norepinephrine (r = 0.829, p less than 0.0001) and epinephrine (r = 0.733, p less than 0.001). We conclude that, in man, acute changes in sympathetic activity and release of atrial natriuretic factor are closely related. Further studies are required to determine whether this association is due wholly to the hemodynamic effects of sympathetic activation, or whether the latter has a direct effect on the release of atrial natriuretic factor.

Atrial Natriuretic Factor↗
PubMed1989

[Dyspnea of cardial origin].

The cardiac cause of dyspnea is left ventricular failure, usually secondary to coronary or hypertensive heart disease and occasionally due to valvular lesions or cardiomyopathy. The grading of this symptom is discussed, with the various tests, their feasibility and normal values. Invasive and noninvasive methods for further evaluation of these patients are described. Finally, the high correlation between dyspnea and measured physical work capacity, and the poor correlation between this symptom and ejection fraction or prognosis, are documented.

Cardiac Catheterization↗
PubMed1989

[How long should antithrombotic therapy be continued following aortocoronary bypass surgery?].

In a prospective randomized trial the effect of prolonged antithrombotic treatment with anticoagulants or antiplatelet drugs (50 mg aspirin + 400 mg dipyridamole daily) on late bypass-graft occlusion was studied. After 3 months active treatment was replaced by placebo in half of the patients. Between the angiographic checkups 2 weeks and 12 months postoperatively, 28/330 (8%) new graft occlusions had occurred on continued therapy, versus 44/319 (14%) on placebo (p = 0.03). This difference was most pronounced in individual grafts (6% vs 12%, p = 0.01), so that fewer patients with 12 months' active therapy had at least one occluded graft (22% versus 32%, p = 0.08). These findings suggest that antithrombotic treatment should not be halted 3 months after CABG surgery but should be continued for at least one year and possibly longer.

4-Hydroxycoumarins↗
PubMed1989

[Emergency coronary dilatation in acute myocardial infarct with contraindications to thrombolytic therapy: salvage of the myocardium by early intervention].

In 1986/87, emergency-PTCA in acute myocardial infarction was performed in 13 patients in whom thrombolysis was contraindicated. All infarct-related arteries could be opened with PTCA. Patency rate after one week was 94%. Reopening of the vessel resulted in immediate cessation of ischemic chest pain and in stable cardiac rhythm and hemodynamics. Prior cardiopulmonary resuscitation and/or cardiogenic shock did not influence short- or longterm outcome. In nine of eleven patients an improvement of left ventricular function was found after four to six months as compared to one to four weeks after PTCA. The functional result proved to be better if PTCA was performed early; PTCA within 90 minutes was associated with normal left ventricular function. Thus, PTCA is feasible as an emergency procedure in patients with acute myocardial infarction and contraindications to thrombolysis. It can salvage myocardium and improve or prevent severe infarct complications when performed early after onset of pain. Rapid hospital admission through the primary care physician importantly influences the outcome for these patients.

Adult↗
PubMed1989

Trial of low-dose aspirin plus dipyridamole versus anticoagulants for prevention of aortocoronary vein graft occlusion.

In a prospective randomised trial, 249 patients who had aortocoronary vein bypass surgery were assigned either to a platelet inhibitory drug regimen or to standard anticoagulant therapy. Treatment was replaced by placebo in half of the patients in each group after 3 months. The platelet inhibitory drug regimen--very low-dose aspirin combined with dipyridamole--was as effective as standard anticoagulant therapy to prevent early and late graft occlusion. Death, myocardial infarction, and severe bleeding occurred significantly more often in patients receiving anticoagulants, whereas mild drug-related gastrointestinal and cerebral side-effects were more common in patients taking platelet inhibitory drugs. Antithrombotic treatment should be continued for at least 1 year after coronary artery bypass graft surgery.

4-Hydroxycoumarins↗
PubMed1989

[The diagnosis of cardiomyopathies using magnetic resonance].

Magnetic resonance imaging (MRI), a relatively new, noninvasive technique, provides comprehensive information on the myocardial anatomy through its excellent contrast resolution, high spatial resolution and intrinsic high contrast between the blood pool and the surrounding soft tissues. Cine MRI possesses an adequately high time resolution for the analysis of the global and regional function of the left ventricle. 31phosphorus magnetic resonance spectroscopy (MRS) is a unique tool for the assessment of alterations of the myocardial high energy phosphate metabolism in the intact, working heart. On the basis of personal data and an overview of the literature, the current relevance and future perspectives of MRI and MRS in the diagnosis of cardiomyopathies are presented.

Cardiomyopathies↗
PubMed1989

[A new beta 1-receptor blocker in the therapy of essential hypertension and angina pectoris].

In 242 patients with hypertension and/or angina pectoris, a new cardioselective betablocker without ISA, bisoprolol (Concor), was tested. The average mean value of 168/102 mm Hg was lowered in the 174 hypertensive patients by a systolic value of 17 and a diastolic value of 11 mm Hg. A normal diastolic pressure of 95 mm Hg or below was attained within 4 weeks in 73% of patients. Angina pectoris improved from 7 attacks per week before treatment to 3 attacks after 2 weeks; patients with additional hypertension showed a further improvement after another two weeks to an average of 1.7 attacks per week. Side effects were most frequently dizziness, headache and fatigue and also a few patients with gastrointestinal symptoms, an unusual side effect with this treatment. The results show the effective antihypertensive and antianginal action of bisoprolol in a large group of outpatients.

Adrenergic beta-Antagonists↗
PubMed1989

Circulatory counter-regulations induced by continuous administration of nitroglycerin.

In a placebo-controlled, double-blind, cross-over study in seven healthy volunteers, continuous transdermal administration of nitroglycerin over 48 h by means of Nitroderm TTS 10 evoked counter-regulations that interfered with the nitrate effects. These counter-regulations comprised an increase in sympathico-adrenal activity, manifested in elevated plasma levels of adrenaline and noradrenaline, and an internal hemodilution, readily perceptible from the decrease in the hematocrit readings. As a result, several of the circulatory effects of nitroglycerin were no longer in evidence, or much weaker on the second day of the study. The effects concerned were the reduction of systolic and diastolic blood pressure, the increase in heart rate, the prolongation of PEPc, and shortening of LVETc, and the change in digital-pulse morphology (increase in the a/b quotient). On the other hand, the increase in venous distensibility and the decrease in hematocrit were unaltered throughout the observation period. The attenuation of the action of nitroglycerin noticeable 24 h after application of the patches is, therefore, not indicative of any loss of effect of the substance per se, but due to the circulatory counter-regulations, which were largely confined to the arterial side of the circulation and scarcely affected the venous system. One or two hours after removal of the patches, counter-regulations had practically ceased.

Administration, Topical↗
PubMed1988

[Study of the long-term effects of amiodarone on thyroid function using ultrasensitive TSH measurements. Preliminary report].

The results of a prospective study of basal ultrasensitive TSH concentrations in patients during long-term treatment over 12 months with amiodarone are reported. 2 patients (3%) developed hypothyroidism, whereas no case of hyperthyroidism was observed. A significant increase in FT4 with a simultaneous decrease in T3 was demonstrated at every periodic investigation during amiodarone therapy. In most patients ultrasensitive TSH values stayed within the normal range and showed no significant alteration during treatment. A slow decline in TSH during therapy was observed in a subgroup of patients with completely euthyroid initial TSH concentrations. This TSH decrease reached statistical significance after 12 months' therapy. FT4 showed pathological results in 35% of all determinations at any time during the study, T3 in 27%, and TSH in only 17%. In conclusion, a new steady-state of thyroid tests is attained during treatment with amiodarone and most patients maintain a euthyroid function state. Assessment of ultrasensitive TSH can be recommended as a primary screening test for evaluation of thyroid function in patients under amiodarone therapy.

Amiodarone↗
PubMed1988

[Acute myocardial infarct in patients under 30 years old].

Between 1980 and 1985 nine patients under the age of 30 were admitted to our hospital with acute myocardial infarction. They represented 4% of all patients with acute myocardial infarction. Coronary angiography was performed in 8 patients and in a high proportion (5 patients) no stenotic lesion was found. In these patients, vasospasm seems to be the most likely pathogenesis. In one patient no angiography was performed; he had stopped anticoagulation therapy after aortic valve replacement and therefore coronary embolism was the obvious reason for the infarct. After a median of 5 years (2-7) no patient had died or had suffered a new coronary event. The 5 patients with angiographically normal coronary arteries had ceased taking medication and were all back to work full time. Psychological evaluation showed impaired ability to express aggression in all 9 patients.

Acute Disease↗
PubMed1988

[Thrombolysis in acute myocardial infarct. Initial experiences in a Swiss university hospital].

Preliminary experience with thrombolytic therapy in patients with acute myocardial infarction and its practicability in a CCU of a Swiss university hospital are presented. Out of 674 patients with a transmural or non-transmural infarction, 72 (11%) have been treated with thrombolytic agents since March 1986. 53 of these patients were included in the "European Cooperative Study Group" multicenter trial and treated with recombinant tissue plasminogen activator (rt-PA) or placebo; the other 19 patients received streptokinase i.v. with the same inclusion/exclusion criteria. The results corresponded to the well known effects of early thrombolysis with improvement in infarct size reduction, cardiac performance and early mortality.--The importance of the time factor and the implications regarding information of potential patients and practitioners and organization of rapid hospitalization are outlined. Follow-up (after a mean of 14 months) of our 72 thrombolysis patients revealed a high percentage of patients still dependent on medical care, reduced physical capacity in almost half of the patients and (a favourable result) a large number of patients who stopped smoking after the infarction. --In view of the slight additional stress caused by this therapy for patients, physicians and nursing staff, the use of thrombolytic agents in acute myocardial infarction should (with strict inclusion/exclusion criteria) be rapidly generalized in the hospitals of Switzerland.

Clinical Trials as Topic↗