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Biomedical subjects

L Samek

Publications and source records attributed to L Samek.

15 recordsLinked to original sources
PubMed1992

Exercise tolerance and working capacity after valve replacement.

Between 1978 and 1987, 1270 patients who survived single aortic or mitral valve replacement at the Rehabilitation Center in Bad Krozingen, Germany, underwent a comprehensive rehabilitation program. The preoperative diagnosis was isolated aortic stenosis in 425, isolated aortic regurgitation in 159, mixed aortic lesion in 211, isolated mitral stenosis in 208, isolated mitral insufficiency in 137 and mixed mitral lesion in 130 cases. Follow up examinations were carried out one and six months after surgery, and at yearly intervals thereafter. Exercise testing was performed with an electrically braked bicycle ergometer in the supine position, and the load was increased by 25 or 50 watts every two minutes until fatigue, severe angina, more than 0.3 mV ST-segment depression, or 80% of the age predicted maximum heart rate was achieved. Patients after aortic valve replacement had a better exercise performance one month after operation than did those after mitral valve replacement. Those with mitral stenosis showed more severe impairment of exercise tolerance than did the mitral insufficiency group. There was a steady increase in exercise tolerance between one and six months postoperatively, both in patients with aortic and those with mitral valve replacement, but the difference in performance between the two groups was still present (72% versus 57% of normal). The results of univariate and multivariate analyses showed that the preoperative employment status was the most important factor for postoperative return to work, followed by gender (male > female), exercise tolerance and valualar lesion (aortic > mitral).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1992

[Interval resistance exercise in comparison with bicycle ergometry stress. Studies with resistance endurance training in coronary patients].

UNLABELLED: In the rehabilitation of coronary patients there is an increased interest in using complementary resistance exercise training. Therefore, we studied nine patients (males; age: 51 +/- 7 years) with chronic stable coronary heart disease during extensive resistance exercise (ex RE) (legpress, abduction, adduction) (60-s work: 60-s rest; contraction intensity: 65% of 1 RM) and during intensive resistance exercise (int. RE) (legpress) (30-s work: 45-s rest) with 85% of 1 RM. Non-invasive continuously measured blood pressure, heart rate, norepinephrine, epinephrine, lactic acid, and glucose were compared with values from maximal bicycle ergometry (3-min steps, each 25 w; max. performance: mean 156 w; range 125-200 w). RESULTS: 1) Comparing ex RE and int RE with bicycle ergometry there were no differences in blood pressure (systolic: 206 and 204 vs. 210 mm Hg; ns; diastolic: 98 and 104 vs. 92 mm Hg; ns). Heart rates (104 and 103 vs. 125/min; p < .01), norepinephrine (3.8 and 3.3 vs. 8.8 nmol/l; p < .01) and epinephrine (0.7 and 0.6 vs. 1.4 nmol/l; p < .01) were considerably lower. 2) The most significant increase and decrease of blood pressure and heart rate occurred within 15-30 s after the beginning and end, respectively, of isometric exercise. CONCLUSIONS: 1) ex RE is suitable for patients with stable CHD and cardiac exercise tolerances of 1.5-2 W/kg = 125-150 watts. 2) Blood pressure monitoring by the cuff method (RR) immediately after RE did not reflect blood pressure during RE. 3) Controlling RE by the training heart rate prescribed for endurance exercise is not possible.

Adult↗
PubMed1990

Recreational swimming in CHD patients and healthy control subjects in relation to left heart function.

We examined the influence on heart rate, blood pressure, lactate, glucose, and catecholamine levels of moderate recreational swimming at a mean time of 5.2 to 9 minutes with mean speed of 0.33 to 0.49 m/s in 25 CHD patients and 8 healthy control subjects. During swimming, changes in these exercise-related parameters were observed such as were only found in seated ergometry trials at levels above 100 to 175 W. We consider these changes tolerable for patients with mild left heart damage (n = 13; ejection fraction 54 +/- 7%; exercise capacity 2.1 +/- 0.4 W/kg). They may indicate overexertion in patients with marked damage to the left heart (n = 12; ejection fraction 44 +/- 5%; exercise capacity 1.3 +/- 0.4 W/kg). Six of the 12 patients with marked left heart damage stopped swimming before the planned time had elapsed for subjective (overexertion) or objective (arrhythmia) reasons.

Analysis of Variance↗
PubMed1990

Catecholamine metabolism in heart failure patients and healthy control subjects.

Parameter of catecholamine metabolism were examined in patients (Groups II to V) in chronic, stable stages of coronary heart disease (n = 45), dilated cardiomyopathy (n = 17) and healthy control subjects (Group I). Plasma and urinary catecholamine patterns, catecholamine plasma half-life and catecholamine metabolism following administration of levodopa were determined. In cases of slight (Group II, ejection fraction (EF) 54 +/- 7%) to marked left-heart damage (Group III, EF 44 +/- 5%), the findings indicate elevated catecholamine excretion and a beginning reduction of plasma clearance as the cause of excessive, circulating and renally excreted catecholamines (applies to noradrenaline, less to adrenaline). The renal 24-h dopamine elimination is already slightly reduced in these patients. In cases of severe left-heart damage, the findings are not uniform. In some cases, noradrenaline at rest and at comparable exercise levels are elevated (Group IV, EF 20 +/- 11%), in some cases they are normal (Group V, EF 16 +/- 4%). The 24-h dopamine elimination is reduced in both groups to 34-41% of normal. Noradrenaline and adrenaline elimination is normal, or reduced (Group V, adrenaline). The exercise-induced, maximum plasma noradrenaline concentrations in Group IV and V are much lower (33-40% of normal) than in the healthy control individuals and patients in Groups II and III. Oral administration of 2-4 g levodopa per day result in a 20- to 40-fold dopamine increase in patients with heart failure (Group IV) and healthy control persons (Group I) (free and conjugated plasma dopamine, as well as free urinary dopamine).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

[Coronary angiographic findings in 308 patients with the clinical diagnosis of intramural myocardial infarction (author's transl)].

308 patients with the clinical diagnosis of intramural myocardial infarction made elsewhere were re-investigated more than eight weeks after the acute event. ECGs and pulmonary "wedge" pressures were recorded at rest and during exercise and coronary angiography performed (Sones' or Judkin's technique). In the first group (1973/74) of 77 patients, 35 (45.5%) had a normal coronary angiogram, compared with 0.7% in a control group with transmural myocardial infarction. A normal coronary angiogram was found in 85% of the 40 patients who had no angina during exercise. In a second group (1974/77) of 231 patients, there was a steady decrease in the number of patients without angina pectoris during exercise, in parallel with a decrease in the number of those with normal coronary angiograms. This change in pattern was apparently due to improved diagnosis in the referring hospitals. Of the 37 patients (first group) with angina during exercise, all but one were subsequently found to have significant coronary arteriosclerosis. It is suggested that most patients with a normal coronary angiogram had sustained a myocarditis and (or) pericarditis which produced the symptoms and the altered ECGs, leading to the misinterpretation of "intramural myocardial infarction".

Adult↗
PubMed1977

[Relationship between coronary angiographic findings and exercise Ecg in patients without transmural myocardial infarction (author's transl)].

In 311 patients (269 men and 42 woman, 20 to 65 years old) without transmural myocardial infarction the results of exercise tests in supine position were compared with the results of coronary angiography. 1. Patients having ischemic ST-segment depression (greater than or equal to 0.1 mV) and angina pectoris during exercise (n = 108) showed a greater than or equal to 50% stenosis of at least one vessel in 86.1%. In men the number of a greater than or equal to 50% stenosis was significantly higher than in women (91.3 vs. 56.2%). In patients without digitalis agreement with coronary angiographic findings is higher than in patients with digitalis (92.7 vs. 79.2%). After excluding women, patients under digitalis and those with an intramural myocardial infarction, agreement was 96.8%. 2. In patients having ischemic ST-segment depression agreement was 30% and in those with angina pectoris 36.8%. 3. In patients having neither ischemic ST-segment depression nor angina pectoris during exercise up to a heart rate of 80% of the age-dependent heart rate limit a coronary angiogram without a greater than or equal to 50% stenosis was found in 87.6%. After excluding patients with an intramural myocardial infarction, women and patients under digitalis, agreement increased to 97.9%. 4. In patients having both ischemic ST-segment depression and angina pectoris during exercise a 2- or 3-vessel disease was more often found than in patients having either ischemic ST-segment depression or angina pectoris, or in those having neither ischemic ST-segment depression nor angina pectoris respectively (57.5% vs. 16.6, 8.9 and 1.9%). 5. The number of positive coronary angiograms, especially of 2- and 3-vessel disease, increases with the degree of an ischemic ST-segment depression and the reduction of exercise tolerance.

Adult↗
PubMed1977

[Can predictability of coronary angiographic findings be improved by additional measurement of pulmonary wedge pressure during exercise? (author's transl)].

The correlation between the three ischemia indicators angina pectoris (AP), ST-segment depression (ST) and excessive pulmonary wedge pressure rise (PCP) during exercise, and the coronary angiographic findings, were analysed in 293 patients without previous transmural myocardial infarction. This patient material consisted of 253 men and 40 women between the age of 20 and 65 years, the mean age being 48. The exercise tests were performed on a bicycle ergometer in supine position and in relatively steady state conditions. Pulmonary wedge pressure was measured by means of a Swan-Ganz floating catheter. The essential findings were: 1. If all three ischemia indicators were positive, the incidence of a positive angiographic finding i.e. a greater than or equal to 50% stenoses in at least one main coronary artery was 96.3%. 2. If only the two classic ischemia indicators were evaluated and positive, the incidence of a positive angiographic finding was only 86.1% (24). This difference is mainly due to false positive results of AP and ST in women. 3. If all three ischemia indicators were negative, the incidence of a negative angiographic finding was 89.2%. 4. If only the two classic ischemia indicators were evaluated and negative the incidence of a negative angiographic finding was as high (87,6% [24]). This lack of difference is due to the fact that patients with a previous intramural infarcion can be free not only of AP and ST but also of PCP during exercise. 5. The combination of AP and PCP, or ST and PCP, is equally reliable in predicting coronary morphology as the classic combination of AP and ST. It follows that PCP measurement is recommended, if one of the classic ischemia indicators cannot be properly evaluated.

Adult↗
PubMed1975

[Stress tests and coronary angiography in chronic myocardial infarct].

In patients with myocardial infarction (MI) the presence or absence of lesions in vessels other than the one which perfuses the infarcted area, has implications regarding coronary bypass surgery, long term anticoagulant therapy, work capacity and prognosis. We investigated whether involvement of a 2nd or 3rd vessels as demonstrated by coronary angiography can be predicted on the basis of angina pectoris and/or ischemic ST-segment depression during exercise. Inferior myocardial infarction (IMI, n = 146) Severe lesions (greater than or equal to 75%) of a 2nd or 3rd vessel were found in 61.7% of patients with IMI, who developed angina pectoris and ischemic ST-segment depression, in 18.6% of patients with ST-segment depression only, in 9.1% of patients with angina pectoris only and in 3.4% with neither angina pectoris nor ST-segment depression. Anteroseptal infarction (ASI, n = 116) Severe lesions (greater than or equal to 75%) of a 2nd or 3rd vessel were found in 30.2% of patients with ASI, who developed Angina pectoris and ischemic ST-segment depression; in 26.6% of patients with ST-segment depression only, in 20.0% of patients with angina pectoris only and in 3.0% of the patients with neither angina pectoris nor ST-segment depression. The clinical implications of the results are discussed.

Angina Pectoris↗