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Biomedical subjects

B Schwartzkopff

Publications and source records attributed to B Schwartzkopff.

At least 55 records · Page 3Linked to original sources
PubMed1996

[New aspects of differential therapy of arterial hypertension with beta-blockers].

The medical treatment of essential hypertension represents a long-term therapy that, besides a normalisation of blood pressure, should include a reparation of end organ damages, a beneficial influence on concomitant diseases, a better quality of life and an improved prognosis. Modern and differentiated therapy with betablockers improves and expands the spectrum of antihypertensive therapy.

Adrenergic beta-Antagonists↗
PubMed1995

[Hypertrophic obstructive cardiomyopathy: surgical treatment].

Hypertrophic obstructive cardiomyopathy (HOCM) is an autosomal, dominant inherited disease of the myocardium which leads slowly to increasing subvalvular, septal and left ventricular hypertrophy and deterioration of systolic and diastolic left ventricular compliance. Difficult molecular-genetic investigations localized genetic defects on different chromosomes. The disease is pathological-anatomically characterized by asymmetric subvalvular (aortic) septal hypertrophy and left ventricular outflow tract obstruction resulting in additional left ventricular hypertrophy and dysfunction. Histologically the myocytes are hypertrophied, exhibit atypical branching (disarray), and there is a high amount of interstitial connective tissue. In our biopsy material (from myectomies) dysplasia could be detected in more than 30% of dysplastic intramural arteries with partly extential media. These changes may indicate microcirculatory disturbances resulting in arrhythmias, syncopes, sudden death, and anginal pain on the basis of microcirculatory disturbances and scar development. Today the discussion of DDD-pacemaker therapy has resumed, but one must wait for definite results, especially in patients in whom surgical treatment seems to be the best choice. The indication for surgical treatment, which usually is transaortic subvalvular myectomy (Morrow) and modifications, is very restrictive. Only patients in clinical degree III (NYHA) after long-term medical treatment are candidates for surgery. In some mainly younger patients the indication in lower clinical degrees was accepted because of a family history with sudden death and personal experience of syncope, life-threatening tachycardia, or after resuscitation. In the period 1963 to 1994 466 patients were operated upon. The mean age was 44.9 years (range 3 months to 82 years). Total early mortality was 4.9% (n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Protection and "preconditioning" of the human heart during percutaneous transluminal coronary angioplasty (PTCA) by intracoronary dipyridamole administration].

BACKGROUND AND AIM: A brief episode of ischemia followed by reperfusion termed "ischemic preconditioning" has been identified as a mechanism rendering the myocardium more resistant to ischemia. Recently adenosine has been identified as an important mediator of ischemic preconditioning. Dipyridamole represents an important drug interfering with myocardial adenosine metabolism by inhibiting its degradation. The aim of this study was to investigate the effect of an intracoronary dipyridamole infusion on the extent and tolerance of myocardial ischemia during percutaneous transluminal coronary angioplasty (PTCA). PATIENTS AND METHODS: In the first study group 46 patients undergoing coronary angioplasty were randomised to receive dipyridamole or conventional treatment before PTCA. In the second study group 11 patients were investigated, receiving PTCA of restenosis following PTCA carried out 6 months earlier. RESULTS: In the first group as a striking result patients receiving pretreatment with dipyridamole tolerated longer times of balloon inflations (155.3 +/- 68.9 vs. 93.1 +/- 24.7 s), expressed lower severity of cardiac pain, demonstrated less pronounced ST-segment shifts on the surface ECG and showed a lower incidence of arrhythmias. In the second group the first dilatation had been performed conventionally, while pretreatment with dipyridamole had been performed prior to the dilatation of restenosis. Similar to the findings in the first patient group pretreatment with dipyridamole resulted in enhancement of balloon inflation times, regression in cardiac pain and lower extent of ST-segment shift and incidence of arrhythmias. In both study groups intracoronary application of dipyridamole showed no significant impact on heart rate and arterial blood pressure. CONCLUSION: Summarising our results indicate, that intracoronary application of dipyridamole renders the heart more resistant to ischemia.

Aged↗
PubMed1995

Hypertensive heart disease: cardioreparation by reversal of interstitial collagen in patients.

Impairment of coronary flow reserve in arterial hypertension and hypertrophy is caused by multiple mechanisms. Medial wall thickening of the small intramural arteries and rarification of capillarization are the major structural alterations in hypertensive hypertrophy. Since the small intramural resistance arteries contribute more to coronary resistance than capillaries, medial wall thickening of the intramyocardial arterioles has to be considered the most relevant mechanism for causing impaired coronary flow reserve in arterial hypertension. Additionally, qualitative changes in myocardial tissue composition and structure, such as reactive interstitial fibrosis, rather than the mere augmentation of the myocardial muscle mass, impair flow reserve extravascularly. Except for the structural vascular and myocardial changes, in some hypertensive patients an impaired endothelium-mediated vasodilation of the microvessels occurs. Preliminary clinical data indicate that myocardial interstitial collagen content can be regressed in some hypertensive patients by clinical antihypertensive therapy over a period of 9-12 months.

Capillaries↗
PubMed1995

Remodelling of intramyocardial arterioles and extracellular matrix in patients with arterial hypertension and impaired coronary reserve.

The heart in pressure overload is threatened by the development of diastolic and systolic dysfunction even in the absence of coronary heart disease. In pressure overload, systolic wall stress leads to an increase in left ventricular mass through hypertrophy of myocytes. An activation of myocytic as well as non-myocytic cells is present. An increase in interstitial collagen accompanies hypertrophy of the myocytes. Thus, myocytic hypertrophy and fibrosis cause diastolic dysfunction early on, even when systolic function is still well preserved. In hypertensive heart disease, the coronary microcirculation is remodelled by thickening of the walls of intramyocardial arterioles in relation to their lumen and by an increase in periarteriolar fibrosis. This remodelling of the intramyocardial vasculature is combined with a reduction in coronary vasodilator reserve that may lead to malnutrition and malperfusion of the hypertrophied myocytes. The combined processes of myocytic hypertrophy, vascular remodelling and increased fibrosis may be important in the process of ventricular dilatation and failure in hypertensive heart disease.

Adult↗
PubMed1995

Evaluation of cardiac damage in hypertension.

Functional and structural alterations of the coronary microcirculation and left ventricular hypertrophy represent the two key cardiac manifestations of arterial hypertension. In addition, qualitative changes in myocardial tissue composition and structure, such as reactive interstitial fibrosis, are frequently present. The extent of the impairment of coronary flow reserve can be measured using Doppler, argon gas chromatography or thermodilution techniques. Impaired flow reserve can be detected non-invasively using positron emission tomography. The combination of both a normal coronary angiogram and a positive exercise tolerance test (electrocardiogram or thallium) strongly indicates the presence of a hypertension-related disorder of the coronary microcirculation. Left ventricular hypertrophy can easily be quantified using echocardiography (Penn formula). Diastolic function can be assessed by measuring mitral inflow using pulsed-wave Doppler echocardiography (E/A ratio). Non-invasive assessment of myocardial structural alternations may be possible in the future using backscatter echocardiography.

Coronary Circulation↗
PubMed1995

[Pharmacologic myocardial protection during percutaneous transluminal coronary angioplasty (PTCA) by intracoronary dipyridamole: hemodynamic, contractile and dynamic ventricular consequences].

Percutaneous transluminal coronary angioplasty (PTCA) represents a suitable model to establish myocardial ischemia in man. Balloon inflation usually is accompanied by a significant deterioration in left ventricular systolic and diastolic properties. A brief episode of ischemia followed by reperfusion termed preconditioning has been identified as a mechanism rendering the myocardium more resistant to ischemia. Adenosine is considered as important mediator of preconditioning. Dipyridamole represents an important drug interfering with myocardial adenosine metabolism by inhibiting its cellular reuptake. The aim of this study was to investigate if an intracoronary infusion of dipyridamole represents a suitable tool in preventing the deterioration of left ventricular performance and hemodynamics during PTCA. In 20 patients undergoing elective coronary angioplasty of a major vessel assessment of angiographic left ventricular performance and left ventricular hemodynamics was performed before, during and after coronary angioplasty. Patients were randomly allocated to study group 1 receiving an intracoronary infusion of dipyridamole prior to PTCA and study group 2 where conventional pretreatment was performed. In study group 3 intracoronary dipyridamole infusion was performed in 10 patients with coronary artery disease during coronary angiography in order to evaluate its effect on baseline hemodynamics and left ventricular performance. Dipyridamole-pretreatment resulted in a significant preservation of systolic and diastolic left ventricular performance during PTCA, as documented by an uneffected global ejection fraction (in comparison to a deterioration of 29.2% in study group 2) and an increment in diastolic stiffness of only 12.7% (in comparison to an increment of 57.3% in study group 2). Furthermore, a significant prolongation of achievable balloon-inflation times of 48.4% could be obtained in study group 1. In addition, incidence of arrhythmias seemed to be reduced in study group 1. Apart from two cases of coronary steal phenomenon no significant side effects of dipyridamole infusion could be detected. Finally, in study group 3 dipyridamole-pretreatment per se induced a significant amelioration of angiographically assessed left ventricular systolic performance.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine↗
PubMed1993

[Improvement of coronary reserve following regression of hypertrophy resulting from blood pressure lowering therapy with a beta-receptor blocker].

The coronary microcirculation was investigated by the argon gas method in ten patients (eight men, two women; mean age 56 [44-63] years) before and after an average of 12.9 (9-18) months of treatment with the cardioselective beta-receptor blocker bisoprolol. Left ventricular muscle mass was measured echocardiographically, before and after the treatment. All these patients were known to have hypertension, with exercise-related angina and ischaemic signs in the resting ECG, but normal coronary angiograms. After the treatment period both maximal coronary perfusion and coronary reserve had increased by 22%. At the same time, left ventricular muscle mass had decreased from 161 +/- 18 to 146 +/- 21 g/m2. These results demonstrate that blood pressure reducing treatment can bring about not only a regression of left ventricular hypertrophy, but also an improvement in coronary reserve.

Adult↗
PubMed1993

Hemodynamic findings in patients with left bundle branch block after myectomy in hypertrophic obstructive cardiomyopathy (HOCM)

To determine the hemodynamic effects of postoperative left bundle branch block (LBBB) in patients with hypertrophic obstructive cardiomyopathy (HOCM), we investigated 28 patients using Swan-Ganz pulmonary artery catheterization at rest and on exercise. Fourteen patients had postoperative LBBB (group A) and 14 had undisturbed intraventricular conduction (group B). All patients were examined by clinical investigation, electrocardiogram and bicycle ergometer exercise preoperatively and postoperatively (mean 6 months). Pulmonary artery pressure and pulmonary capillary wedge pressure were continuously measured, stroke volume index and cardiac index were obtained by the thermodilution method. All patients showed an improvement of their clinical symptoms (NYHA class: 2.8 +/- 0.45 before and 1.7 +/- 0.22 after operation) (P < 0.05). The postoperative exercise capacity (Watt) increased significantly (P < 0.05) in group A by 38% and in group B by 30%. The maximum mean pulmonary artery pressure on physical exercise decreased in group A from 40.7 +/- 9.1 to 32.5 +/- 8.7 mmHg and in group B from 42.8 +/- 12.4 to 32.4 +/- 9.2 mmHg (P < 0.05). The maximal stroke volume index and cardiac index improved significantly in 9 of 14 patients in each group. Thus, patients with HOCM and LBBB after myectomy have a marked improvement in postoperative hemodynamics, the results equaling those of patients with undisturbed intraventricular conduction.

Adolescent↗
PubMed1993

Structural and functional alterations of the intramyocardial coronary arterioles in patients with arterial hypertension.

BACKGROUND: In hypertensive patients with angina pectoris, the coronary vasodilator reserve is frequently impaired despite a normal coronary angiogram. Experimental data indicate that structural alterations of the intramyocardial coronary vasculature contribute to an increased minimal coronary resistance and a diminished coronary flow reserve. METHODS AND RESULTS: In 14 patients (10 men and 4 women) with arterial hypertension and 8 normotensive subjects, minimal coronary resistance and vasodilator reserve (dipyridamole: 0.5 mg/kg body wt, gas chromatographic argon method) were determined after the angiographic exclusion of relevant coronary artery disease. Coronary reserve was depressed in hypertensive patients (2.7 +/- 2.3 vs 4.6 +/- 1.3, P < or = .05) due to increased minimal coronary resistance (0.64 +/- 30 vs 0.24 +/- 0.055 mm Hg.min.100 g.mL-1, p < or = 0.002). In right septal biopsies, mean external arteriolar diameter (21.6 +/- 2.3 vs 17.2 +/- 2.5 microns, P < or = .001), mean arteriolar wall area (271 +/- 61 vs 172 +/- 62 microns 2, P < or = .01), percent medial wall area (69.9 +/- 4.0 vs 66.0 +/- 3.2%W, P < or = .05), mean periarteriolar fibrosis area (216 +/- 122 vs 104 +/- 68 microns 2, P < or = .05), and volume density of total interstitial fibrosis (3.6 +/- 1.8 vs 1.9 +/- 0.5Vv% fibrosis, P < or = .05) were increased in hypertensive patients compared with normotensive subjects. Minimal coronary resistance correlated with %W (r = .6, P < or = .003) and Vv% fibrosis (r = .62, P < or = .002). Left ventricular mass index (111 +/- 21 vs 97 +/- 17 g/m2, P = NS) and left ventricular end-diastolic pressure (12 +/- 6 vs 8 +/- 3 mm Hg, P = NS) did not correlate significantly with minimal coronary resistance. In multivariate analysis, both %W and Vv% fibrosis explained half of the variability of minimal coronary resistance (r2 = .5, P < or = .002). CONCLUSIONS: Structural remodeling of the intramyocardial coronary arterioles and the accumulation of fibrillar collagen are decisive factors for a reduced coronary dilatory capacity in patients with arterial hypertension and angina pectoris in the absence of relevant coronary artery stenoses.

Angina Pectoris↗
PubMed1993

Prognosis of patients with hypertrophic obstructive cardiomyopathy after transaortic myectomy. Late results up to twenty-five years.

A complete clinical study was performed for 364 patients with hypertrophic obstructive cardiomyopathy who were operated on in the years 1963 to 1991 (217 male, 146 female, mean age 40 years, range 5 months to 76 years). Transaortic subvalvular myectomy was performed in 272 patients (hospital mortality 2.9%), and 92 patients needed additional cardiac procedures simultaneously (hospital mortality 10.9%). A complete follow-up study (100%) included 346 patients who survived the operation. The shortest follow-up time was 2 months and the longest 25.2 years (mean 8.2 years). Most of the patients improved clinically by one to three classes (New York Heart Association). During the observation period 38 patients (10.4%) died. The death of 17 patients was closely related to the original disease (4.9%). Other causes, unrelated to hypertrophic obstructive cardiomyopathy, were responsible for the death of 21 patients (5.8%). In consideration of these data, the yearly total death rate was 2.2%; in close relation to hypertrophic obstructive cardiomyopathy it was about 0.6%. The cumulative survivals were 88% after 10 years and 72% after 20 years. In our long-term clinical experience it is increasingly evident, despite the restrictions of a retrospective study, that patients with symptomatic hypertrophic obstructive cardiomyopathy and failing medical therapy benefit from transthoracic subvalvular myectomy.

Adolescent↗
PubMed1993

Heart failure on the basis of hypertension.

Arterial hypertension leads to left ventricular hypertrophy. In proportion to increased left ventricular systolic pressure, left ventricular hypertrophy is considered to be of adaptive nature from the point of view of wall stress regulation. In the beginning, left ventricular function is normal, whereas diastolic filling is already compromised by the process of hypertrophy and altered ventricular geometry. In case of ventricular dilation and wall thinning, wall stress increases and leads to an increment in myocardial oxygen demand and a decrease of left ventricular ejection fraction. This is followed by a further decline in intrinsic myocardial contractility and a decrease in the elastic material properties of the myocardium. The structure of the myocardium is characterized by myocyte hypertrophy, a process of reactive and reparative fibrosis and alterations of the coronary microcirculation. Coronary vasodilator reserve is markedly impaired and is likely to initiate a process of malperfusion and malnutrition under increased metabolic demands. Particularly, the combined involvement of myocytes, interstitium, and intramyocardial vasculature appears to predispose to late heart failure after prolonged exposure to chronic pressure overload in arterial hypertension.

Animals↗
PubMed1992

Doppler echocardiographic assessment of the pressure gradient during bicycle ergometry in hypertrophic cardiomyopathy.

To assess the behavior of the subvalvular pressure gradient under physical exercise, 13 patients with obstructive hypertrophic cardiomyopathy were examined during upright bicycle ergometry by means of Doppler echocardiography. Additionally, right-sided cardiac catheterization was performed within 7 days. In 10 patients adequate Doppler tracings could be obtained during exercise. The Doppler-derived systolic pressure gradient increased from 75 +/- 24 to 140 +/- 42 mm Hg (p less than 0.0005). This was associated with an increase in the duration of the systolic mitral-septal contact from 59 +/- 21 to 136 +/- 28 ms (p less than 0.0005). Correlation between the pressure gradient and the duration of mitral-septal contact at rest and during exercise was good (r = 0.86), whereas correlation between the resting and exercise pressure gradient (r = 0.34) did not reach statistical significance. The increase in stroke volume during exercise, from 90 +/- 18 to 95 +/- 24 ml, was significant (p less than 0.05) but minimal. Therefore, only a moderate increase in systolic flow, from 205 +/- 54 to 268 +/- 78 ml/s (p less than 0.0005), was observed. Outflow tract resistance, defined as the ratio of the pressure gradient to systolic flow, increased from 0.38 +/- 0.11 to 0.57 +/- 0.24 mm Hg.s/ml (p less than 0.01). Thus, in a selected group of patients with hypertrophic cardiomyopathy a substantial increase in the maximal pressure gradient during upright bicycle ergometry was demonstrated in most patients. Exercise Doppler echocardiography may be valuable to assess the hemodynamic significance of obstruction in individual patients in a physiologic setting and has a potential to monitor the effect of therapeutic interventions.

Adult↗