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Biomedical subjects

R Hambrecht

Publications and source records attributed to R Hambrecht.

53 records · Page 3Linked to original sources
PubMed1995

Impact of intensive physical exercise and low-fat diet on collateral vessel formation in stable angina pectoris and angiographically confirmed coronary artery disease.

This randomized study was performed to assess the effects of > 3 hours of physical exercise per week and low-fat diet on collateral formation in nonselected patients with coronary artery disease (intervention group, n = 56). Results were compared with those of patients in a control group (n = 57), who received usual care by their private physicians. Coronary lesions were assessed by quantitative coronary angiography at the beginning and after 1 year of study (n = 92). As previously reported, after 1 year there was a significant retardation of progression of coronary artery disease in the intervention group as compared with the control group. In this study, evaluation of collateral formation revealed no significant difference between both groups, and changes in hemodynamic and metabolic variables or leisure time physical activity were not related to changes in collateral formation. Although progression of the disease was significantly related to an increase in collateral formation, regression was significantly related to a decrease in collateral formation (p < 0.00001). Because patients in the intervention group exercised for > 3 hours/week, and patients with regression of coronary artery disease even dedicated 5 to 6 hours to leisure time physical activity per week, these findings question whether an exercise program within the safety tolerance of patients will be able to induce coronary collateralization in the presence of regression of coronary artery disease.

Activities of Daily Living↗
PubMed1995

Physical training in patients with stable chronic heart failure: effects on cardiorespiratory fitness and ultrastructural abnormalities of leg muscles.

OBJECTIVES: The present study was designed to evaluate the effect of an ambulatory training program on ultrastructural morphology and the oxidative capacity of skeletal muscle and its relation to central and peripheral hemodynamic variables in patients with chronic heart failure. BACKGROUND: Clinical evidence supports the hypothesis that exercise intolerance in patients with chronic heart failure is not only a consequence of low cardiac output, but is also a result of alterations in oxidative metabolism of skeletal muscle. METHODS: Twenty-two patients were prospectively randomized either to a training group (mean [+/-SD] ejection fraction 26 +/- 9%, n = 12) participating in an ambulatory training program or to a physically inactive control group (ejection fraction 27 +/- 10%, n = 10). At baseline and after 6 months, patients underwent symptom-limited bicycle exercise testing, and central and peripheral hemodynamic variables were measured. Percutaneous needle biopsy samples of the vastus lateralis muscle were obtained at baseline and after 6 months. The ultrastructure of skeletal muscle was analyzed by ultrastructural morphometry. RESULTS: After 6 months, patients in the training group achieved an increase in oxygen uptake at the ventilatory threshold of 23% (from 0.86 +/- 0.2 to 1.07 +/- 0.2 liters/min, p < 0.01 vs. control group) and at peak exercise of 31% (from 1.49 +/- 0.4 to 1.95 +/- 0.4 liters/min, p < 0.01 vs. control group). There was no significant change in oxygen uptake at the ventilatory threshold and at peak exercise in the control group. The total volume density of mitochondria and volume density of cytochrome c oxidase-positive mitochondria increased significantly by 19% (from 4.7 +/- 1.5 to 5.6 +/- 1.5 vol%, p < 0.05 vs. control group) and by 41% (from 2.2 +/- 1.0 to 3.1 +/- 1.0 vol%, p < 0.05 vs. control group) after 6 months of regular physical exercise. Cardiac output at rest and at submaximal exercise remained unchanged but increased during maximal symptom-limited exercise from 11.9 +/- 4.0 to 14.1 +/- 3.3 liters/min in the training group (p < 0.05 vs. baseline; p = NS vs. control group). Peak leg oxygen consumption increased significantly by 45% (from 510 +/- 172 to 740 +/- 254 ml/min, p < 0.01 vs. control group). Changes in cytochrome c oxidase-positive mitochondria were significantly related to changes in oxygen uptake at the ventilatory threshold (r = 0.82, p < 0.0001) and at peak exercise (r = 0.87, p < 0.0001). CONCLUSIONS: Regular physical training increases maximal exercise tolerance and delays anaerobic metabolism during submaximal exercise in patients with stable chronic heart failure. Improved functional capacity is closely linked to an exercise-induced increase in the oxidative capacity of skeletal muscle.

Biopsy↗
PubMed1995

Treatment of coronary heart disease by diet and exercise.

Management of risk factors by diet and exercise in patients with coronary heart disease in two controlled studies, resulted in significant modification of atherogenic lipoproteins, myocardial perfusion, and physical work capacity. Moreover, within 1 year there were significantly more regression and less progression of coronary atherosclerosis in the study group compared to usual care control patients. Follow-up for 6 years showed erosion of dietary discipline, unfavorable changes in lipoprotein levels, and subsequent progression of coronary lesions in many patients. It is concluded that the course of coronary heart disease can be favorably modified by intensive dietary counseling and supervised exercise, but that maintenance of positive results remain a challenge for physicians and patients alike.

Arteriosclerosis↗
PubMed1994

Identification of patients at risk during swimming by Holter monitoring.

Cardiac arrest during swimming accounts for a considerable number of deaths during physical exercise in patients with coronary artery disease. A link between ST-segment depression and cardiac arrest has been observed in previous studies. In this study, exercise-induced myocardial ischemia was assessed in 23 patients with coronary artery disease by bipolar Holter monitoring during swimming, jogging, and treadmill testing. During treadmill testing, Holter monitoring and standard electrocardiograms were simultaneously recorded. Detection of ST-segment depression during swimming was standardized in a group of normal volunteers (n = 7). All patients with silent myocardial ischemia (n = 8) documented by thallium-201 scintigraphy had ST-segment depression during treadmill testing and swimming when recorded by Holter monitoring, whereas the standard electrocardiogram during treadmill testing was negative in 5 patients. Heart rate at 1 mm ST-segment depression was significantly lower during swimming (110 +/- 11 beats/min) than during treadmill testing (documented by standard electrocardiogram) (133 +/- 23 beats/min, p < 0.002) and jogging (125 +/- 21 beats/min, p < 0.03). However, there was no significant difference in heart rate at onset of angina pectoris in symptomatic patients, suggesting a delayed sensation of ischemic symptoms during swimming. The only clinical event in our group during 8 years of swimming occurred during this study. One patient with silent myocardial ischemia developed ST-segment depression during swimming that degenerated into ventricular fibrillation, requiring resuscitation. Therefore, Holter monitoring can be considered a valuable addition in identifying patients with silent myocardial ischemia during swimming, and thus identifying patients at risk for exertion-related life-threatening ventricular tachyarrhythmias.

Adult↗
PubMed1994

Association between lipoprotein(a) and progression of coronary artery disease in middle-aged men.

The association between lipoprotein(a) (Lp[a]) and progression of coronary artery disease (CAD) compared with other serum lipids was evaluated in 104 patients with angiographically proven coronary atherosclerosis. Patients were randomized to either an intervention or a control group. The 12-month intervention program consisted of a low-fat diet and daily physical exercise. Patients in the control group received "usual care" by their private physician. Eighty-three patients (36 in the intervention and 47 in the control group) underwent repeat angiography after 1 year. Angiographically documented net regression was seen in 13 patients (8 in the intervention and 5 in the control group), no change was seen in 40 patients (21 in the intervention and 19 in the control group) and progression was noted in 30 patients (7 in the intervention and 23 in the control group). No correlation could be shown between Lp(a) and angiographically documented progression of the disease. In a multivariate analysis including metabolic variables, group assignment, age and smoking habits, only assignment to the intervention group (p = 0.0075) and a decrease in total cholesterol (p = 0.0167) were independently associated with the course of the disease. Patients with or without previous myocardial infarction (70 vs 34) did not differ in Lp(a) levels (median 9.15 vs 14.25 mg/dl). Patients with Lp(a) > 25 mg/dl were younger than patients with Lp(a) < or = 25 mg/dl (52 vs 55 years; p < 0.03), indicating a connection between Lp(a) and the development of premature CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1994

[Low-fat diet and physical training in coronary heart disease. Long-term results of secondary prevention].

The long-term effect of a low-fat diet and physical training was investigated in 36 men (mean age 51 +/- 6 years) with coronary heart disease (one-vessel disease, n = 11; two vessel-disease: n = 18; three-vessel disease: n = 7). 18 patients (interventionist, group 1) undertook physical training within a coronary sport group (1 h twice weekly) and daily bicycle ergometry (30 min). They were held to a low-fat diet. In the remaining 18 patients (control, group 2), physical training and low-fat diet depended on own initiative after receiving advice. Over an observation period of 6 years total cholesterol concentration in the 17 patients of group 1 decreased significantly (243 +/- 33 vs. 219 +/- 28 mg/dl; P < 0.02). Physical performance in 12 patients (group 1) increased from 169 +/- 40 to 202 +/- 42 W in (P < 0.01). In contrast, total cholesterol increased slightly in group 2 (n = 16) from 245 +/- 31 at the beginning to 247 +/- 39 mg/dl (no significant change) at the end of the 6 years. Physical performance (n = 12) decreased slightly from 165 +/- 45 to 146 +/- 52 W (not significant). The difference between the two groups was significant after 6 years (P < 0.02 and P < 0.007, respectively). There seemed to be a tendency for progression of the coronary heart disease to be slower in the interventionist than the control group.

Body Mass Index↗
PubMed1993

[Successful lysis therapy in acute unilateral renal vein thrombosis].

A nephrotic syndrome developed in a 50-year-old man who, because of rheumatoid arthritis for the last three years, had been receiving gold therapy (30-50 mg sodium aurothiomalate weekly for 10 months). Treatment for the nephrotic syndrome was initiated with 100 mg prednisone daily. Ten days later he complained of severe pain in his right flank and haematuria was noted. Serum creatinine concentration increased from 1.0 to 1.8 mg/dl, while creatinine clearance fell to 62 ml/min. Computed tomography demonstrated significant enlargement of the right kidney and a thrombus in the right renal vein which extended cranial into the inferior vena cava. High dosage infusion of urokinase (4.5-7.5 mill. IU daily for nine days) achieved complete lysis of the thrombus. The creatinine concentration fell to 1.1 mg/dl, while creatinine clearance rose to 104 ml/min. On the 5th day the right kidney had 25% of total function, several days later 40%.--This case illustrates that, as long as there are no contraindications, adequately high doses of urokinase can be appropriate treatment of acute renal vein thrombosis associated with the nephrotic syndrome.

Acute Disease↗
PubMed1993

Various intensities of leisure time physical activity in patients with coronary artery disease: effects on cardiorespiratory fitness and progression of coronary atherosclerotic lesions.

OBJECTIVES: This study was designed to define the effect of different levels of leisure time physical activity on cardiorespiratory fitness and progression of coronary atherosclerotic lesions in unselected patients with coronary artery disease. BACKGROUND: It has been shown in various studies that regression of coronary atherosclerotic lesions can be achieved by means of lipid-lowering drugs, reduction of fat consumption and physical exercise. METHODS: Patients were prospectively randomized either to an intervention group (n = 29) participating in regular physical exercise or to a control group (n = 33) receiving usual care. Energy expenditure in leisure time physical activity was estimated from standardized questionnaires and from participation in group exercise sessions. After 12 months of participation, repeat coronary angiography was performed; coronary lesions were measured by digital image processing. RESULTS: After 1 year, patients in the intervention group achieved an increase in oxygen uptake at a ventilatory threshold of 7% (p < 0.001) and peak exercise of 14% (p < 0.05), whereas a significant decrease was observed in patients in the control group. To achieve significant improvement in cardiorespiratory fitness, approximately 1,400 kcal/week had to be expended in the form of leisure time physical activity (p < 0.001). The mean energy expended in such activity was 1,876 +/- 163 kcal/week in the intervention group and 1,187 +/- 97 kcal/week in the control group (p < 0.001). In the intervention group, regression of coronary artery disease was noted in 8 patients (28%), progression of disease in 3 (10%) and no change in coronary morphology in 18 (62%). In contrast, coronary artery disease progressed at a significantly faster rate in patients in the control group (progression in 45%, no change in 49% and regression in 6%) (p < 0.001 vs. intervention). When the two groups were combined, the lowest level of leisure time physical activity was noted in patients with progression of disease (1,022 +/- 142 kcal/week) as opposed to patients with no change (1,533 +/- 122 kcal/week) or regression of disease (2,204 +/- 237 kcal/week) (p < 0.005). CONCLUSIONS: Measurable improvement in cardiorespiratory fitness requires approximately 1,400 kcal/week of leisure time physical activity; higher work loads are necessary to halt progression of coronary atherosclerotic lesions (1,533 +/- 122 kcal/week), whereas regression of coronary lesions is observed only in patients expending an average of 2,200 kcal/week in leisure time physical activity, amounting to approximately 5 to 6 h/week of regular physical exercise.

Coronary Angiography↗
PubMed1993

[Slowing the progression and regression of the basic arteriosclerotic process].

UNLABELLED: If patients with coronary artery disease are followed by "usual care" nearly half of them will experience significant progression of their disease within five years. Therefore, it is justified to develop interventions in order to retard the rate of progression and reduce the number of clinical events. In relevant studies published up to this date two different strategies were applied, first, reduction of risk factors by low fat diet, physical exercise, lipid lowering agents or partial ileal bypass; second, inhibition of atherogenesis by application of calcium blocking agents. The effect on progression of coronary artery disease was assessed by digital angiography in the majority of studies; without exception a positive effect was noted in all of them. In the calcium blocker studies this effect, however, was limited to new or minimal lesions. The magnitude of morphological difference between intervention and control groups ranged below 0.5 mm and thus approached the long term variability of quantitative coronary angiography. The frequency of clinical events was reduced in only two studies, whereas they were increased in four intervention groups. CONCLUSIONS: Reduction of risk factors or application of calcium blockers are capable of retarding progression of coronary artery disease; predominant regression, however, seems to be unattainable. The frequency of clinical events is determined by additional factors other than morphologic changes.

Calcium Channel Blockers↗
PubMed1992

Myocardial perfusion and regression of coronary artery disease in patients on a regimen of intensive physical exercise and low fat diet.

This intervention program tested the applicability and effects of intensive physical exercise and a low fat diet on progression of coronary atherosclerotic lesions and stress-induced myocardial ischemia in patients with stable angina pectoris. Eighteen patients participated in this program for 1 year; they consumed a low fat, low cholesterol diet (less than 20 energy % fat, cholesterol less than 200 mg/day) and exercised for greater than 3 h/week. Change in coronary morphology was assessed by angiography and digital image processing; stress-induced myocardial ischemia was measured by thallium-201 scintigraphy. Results were compared with those in patients receiving "usual care." In the intervention group, significant regression of coronary atherosclerotic lesions was noted in 7 of the 18 patients; no change or progression was present in 11 patients. In patients receiving usual care, regression was detected in only 1, with no change or progression in 11 patients (different from intervention, p less than 0.05). There was a significant reduction in stress-induced myocardial ischemia, which was not limited to patients with regression of coronary atherosclerotic lesions. Thus, regular physical exercise and a low fat diet may retard progression of coronary artery disease; however, improvement of myocardial perfusion may be achieved independently from regression of stenotic lesions.

Angiography, Digital Subtraction↗
PubMed1992

Regular physical exercise and low-fat diet. Effects on progression of coronary artery disease.

BACKGROUND: Significant regression of coronary and femoral atherosclerotic lesions has been documented by angiographic studies using aggressive lipid-lowering treatment. This study tested the applicability and effects of intensive physical exercise and low-fat diet on coronary morphology and myocardial perfusion in nonselected patients with stable angina pectoris. METHODS AND RESULTS: Patients were recruited after routine coronary angiography for stable angina pectoris; they were randomized to an intervention group (n = 56) and a control group on "usual care" (n = 57). Treatment comprised intensive physical exercise in group training sessions (minimum, 2 hr/wk), daily home exercise periods (20 min/d), and low-fat, low-cholesterol diet (American Heart Association recommendation, phase 3). No lipid-lowering agents were prescribed. After 12 months of participation, repeat coronary angiography was performed; relative and minimal diameter reductions of coronary lesions were measured by digital image processing. Change in myocardial perfusion was assessed by 201Tl scintigraphy. In patients participating in the intervention group, body weight decreased by 5% (p less than 0.001), total cholesterol by 10% (p less than 0.001), and triglycerides by 24% (p less than 0.001); high density lipoproteins increased by 3% (p = NS). Physical work capacity improved by 23% (p less than 0.0001), and myocardial oxygen consumption, as estimated from maximal rate-pressure product, by 10% (p less than 0.05). Stress-induced myocardial ischemia decreased concurrently, indicating improvement of myocardial perfusion. Based on minimal lesion diameter, progression of coronary lesions was noted in nine patients (23%), no change in 18 patients (45%), and regression in 13 patients (32%). In the control group, metabolic and hemodynamic variables remained essentially unchanged, whereas progression of coronary lesions was noted in 25 patients (48%), no change in 18 patients (35%), and regression in nine patients (17%). These changes were significantly different from the intervention group (p less than 0.05). CONCLUSIONS: In patients participating in regular physical exercise and low-fat diet, coronary artery disease progresses at a slower pace compared with a control group on usual care.

Adult↗
PubMed1991

[Type III hyperlipoproteinemia in monoclonal IgM gammopathy].

A 42-year-old woman, found to have increased blood-lipid levels, developed hand-line xanthomas 3 months later. She also had an increased erythrocyte-sedimentation rate and a type lambda monoclonal IgM abnormality. In the course of the following 4 years the IgM concentration rose (from 5.8 to 12.3 g/l) steadily and synchronously with those of the triglycerides (from 147 to 391 mg/dl) and cholesterol (from 212 to 380 mg/dl). During the entire period of observation the ratio of VLDL cholesterol and triglyceride concentrations was elevated (greater than 0.4; normal: less than 0.3). Division of the lipoprotein fractions pointed to a type III hyperlipoproteinaemia. She also had an abnormality of lipid metabolism on the basis of a genetic defect (apolipoprotein-E2 homozygotism), which only manifested itself when an additional factor, IgM paraproteinaemia, was present. Paraproteins thus apparently interfered with the breakdown of the lipoproteins. Neither bezafibrate in increasing doses (200-800 mg daily) with low-fat diet nor administration of lovastatin (20 mg twice daily) together with nicotinic acid (500 mg twice daily) were adequate treatment for this form of auto-immune hyperlipidaemia.

Adult↗
PubMed1991

[Modification of risk factors through physical training and low-fat diet].

This intervention program investigated the applicability and the effects of intensive physical exercise and low-fat diet on the progression of coronary atherosclerotic lesions and stress induced myocardial ischemia in patients with stable angina pectoris. Patients participating in this study were recruited following routine coronary angiography for angina pectoris. Inclusion criteria were male sex, stable symptoms, a willingness to participate in the study for at least twelve months, and coronary artery stenoses well documented by angiography. Exclusion criteria were unstable angina pectoris, left main coronary artery stenosis greater than 25% luminal diameter reduction, severely depressed left ventricular ejection fraction (less than 35%), significant valvular heart disease, insulin-dependent diabetes mellitus, primary hypercholesterolemia (type II hyperlipoproteinemia, low-density lipoprotein greater than 210 mg/dl), and conditions precluding regular physical exercise. 18 patients participated in this program for one year; they consumed a low-fat, low-cholesterol diet (less than 20 energy % fat, cholesterol less than 200 mg/day) and exercised for more than 3 h/week. Myocardial oxygen consumption was estimated from maximum rate-pressure product at peak exercise; it was correlated to stress induced myocardial ischemia, as measured by 201Tl-scintigraphy. Results were compared with those of 18 matched patients on "usual care". In the intervention group, physical work capacity (161 +/- 34 W vs. 194 +/- 42 W) and maximum rate pressure product (25.0 +/- 6.3 x 10(3) vs. 27.2 +/- 5.3 x 10(3)) increased significantly (p less than 0.01). Patients willing to devote time and effort to intensive physical exercise and to comply with a low-fat diet may benefit from this form of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Disease↗
PubMed1991

[Different rates of progression of heart valve defects].

In order to determine the rate of progression in valvular heart disease, the records of patients with simple valve lesions and two cardiac catheterizations performed prior to surgery were examined retrospectively. In 53 patients (mitral regurgitation n = 16, aortic regurgitation n = 13, mitral stenosis n = 13, aortic stenosis n = 11) complete data were available. The time interval between the two studies averaged 47 +/- 24 months. In patients with mitral regurgitation left ventricular ejection fraction deteriorated significantly faster than in the other groups; the rate of left ventricular volume gain and rise in pulmonary pressure also tended to be higher in this group. The transvalvular gradient in aortic stenosis showed a highly significant increase during the observation period (56 +/- 26 mm Hg vs 78 +/- 29 mm Hg; p less than 0.01), however, left ventricular ejection fraction remained within normal limits. These data indicate that patients with mitral regurgitation should be followed closely prior to valve replacement.

Adult↗
PubMed1989

[Peracute constrictive, idiopathic pericarditis--a case report of an acute life-threatening disease picture].

Generally, idiopathic pericarditis is considered a benign, self-limiting disease. Frequently, the exsudative phase of the disease is followed by a mild form of transitory constriction of the pericardium. The case reported here shows an unusual course of the disease. Shortly after the symptoms of exsudative pericarditis subsided a life-threatening form of pericardial constriction developed within weeks. In case of chronic pericardial constriction perioperative mortality for partial pericardiectomy is not insignificant. This is a result of myocardial damage that is difficult to assess prior to surgery. For that reason a partial pericardiectomy should be attempted as early as possible, even in cases with acute pericardial constriction.

Acute Disease↗
PubMedDate not supplied

Five years of physical exercise and low fat diet: effects on progression of coronary artery disease.

PURPOSE: This study was designed to assess the long-term effects of low-fat diet and intensive physical exercise. METHODS: Long-term efficacy of exercise and diet was assessed in 18 nonselected, fully employed patients with symptomatic coronary artery disease. Results were compared to 18 patients on usual care. RESULTS: In the intervention group at 1 year, serum lipoproteins were brought to ideal levels, exercise-induced myocardial ischemia was significantly reduced, and progression in coronary atherosclerosis was retarded. After more than 5 years, patients in the intervention group showed a significant reduction in lipoprotein levels (total cholesterol, 248 [179-299] vs 214 [173-272] mg/dL, P < .01; low density lipoprotein, 146 [83-216], vs 152 [121-197] mg/dL, P < .005 vs control; triglycerides; 151 [80-303] mg/dl, vs 98 [46-182] mg/dL; P < .005) and body mass index (26 +/- 2.9 vs 25.4 +/- 3.3 kg/m2; P < .05). Exercise induced myocardial ischemia, measured by 201thallium scintigraphy, decreased by 29% (41 degrees +/- 36 degrees vs 29 degrees +/- 29 degrees, P = NS) and coronary atherosclerosis, assessed by angiography and digital image processing, progressed at a slower pace in light of a 21% increase in physical work capacity (169 +/- 40 vs 205 +/- 50, P < .01) and a 28% increase in maximal rate pressure product (25 +/- 6 vs 32 +/- 4, P < .004). In contrast, patients in the control group showed only poorly controlled coronary risk factors (total cholesterol, 243 [179-306] vs 26 [178-304] mg/dL, P = NS; low density lipoprotein, 151 [79-229] vs 196 [107-238] mg/dL, P < .0005 vs intervention; body mass index 25.7 +/- 2.5 vs 27.5 +/- 3.5 kg/m2, P < .01), whereas their physical work capacity tended to deteriorate (165 +/- 45 vs 142 +/- 62 Watts, P = not significant). CONCLUSIONS: These data demonstrate that current usual care is insufficient in controlling risk factors of coronary artery disease. However, intensive physical exercise and low-fat diet remain an effective form of treatment after more than 5 years.

Constriction, Pathologic↗