Search PubMed⌕ Search

Biomedical subjects

L Samek

Publications and source records attributed to L Samek.

At least 37 records · Page 2Linked to original sources
PubMed1984

Myocardial infarction at a young age (under 40 years).

Coronary morphology, risk factors, long-term prognosis, and progression of coronary arteriosclerosis were investigated in 679 (649 mean and 30 women) post-infarction patients under 40 years of age. These patients represented 80% of 844 MI patients under 40 who were referred to our hospital in the years 1973-1980; 20% had refused coronary angiography; 465 patients were followed up for 1-7 years (mean 3.5 years). In 164 patients, a second coronary angiography was performed 3.8 years after the first angiogram, which was done an average 3 months after the acute episode. The main results were as follows: 8.4% of the patients had zero-vessel disease and 3.7% had a normal coronary angiogram. The majority had single-vessel disease (57.3%). The prevalence of zero-vessel disease decreased with age while that of multivessel disease increased. With increasing vessel involvement, the prevalence of hypercholesterolemia, hypertriglyceridemia, and hypertension increased. A history of smoking was equally common in patients with zero-, single-, double-, and triple-vessel disease. In women the combination of smoking and the use of oral contraceptive drugs was frequently seen. In one-quarter of the zero-vessel disease patients, the infarction occurred during unusually intense physical exercise. The statistical analysis of the survival data using the proportional hazards model (univariate analysis) showed the variables heart volume/body wt., ventricular arrhythmias, PCP at rest, PCP max, work capacity, ventricular function, and number of diseased vessels to be of prognostic importance. Multivariate analysis using this model revealed the following independent variables to be relevant to prognosis: heart volume/body wt., ventricular arrhythmias, ventricular function, and number of diseased vessels. After an average of 3.8 years since the first coronary angiography, 28.6% of the patients showed a significant progression of coronary arteriosclerosis (at least two degrees of stenosis according to the AHA classification). In the subgroup of patients with multilocular disease in the first angiogram, progression was 10 times as frequent as in a group with initial unilocular disease (34.3% vs 3.6%). Patients with progression had continued to smoke significantly more often than patients without progression (38.4%) vs 14.5%). Regression of coronary angiographic findings was significantly more frequent in the group of patients with initial unilocular disease than in those with multilocular disease in the first angiogram (28.6% vs 10.6%). Regression might be explained as recanalization and organization of a thrombus.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1984

[Possibilities and limits of ambulatory coronary groups].

Physical exercise has become more and more popular as a treatment method in outpatients with coronary artery disease. The number of outpatient groups in the Federal Republic of Germany grew from 80 to 424 groups between 1978 and 1982. Exercise may have a favourable effect on various cardiovascular risk factors because it reduces bodyweight, blood pressure, LDL and VDL cholesterol and raises HDL cholesterol. It also improves work tolerance by raising the double product of heart rate and blood pressure at comparable workloads, as well as stroke volume and arteriovenous oxygen difference; the result is reduced myocardial oxygen demand. The favourable effect of exercise on the prognosis of patients after myocardial infarction has thus far only been demonstrated in one randomized study (14). That this has not been possible in other studies is mainly due to methodological problems such as sample size, drop-out, drop-in, and others. Nevertheless, it may be concluded that correctly conducted physical training in carefully selected patients with coronary artery disease improves cardiovascular function, quality of life and possibly even prognosis.

Coronary Disease↗
PubMed1984

[Prognostic significance of stress studies in patients with coronary 2-vessel disease--effect of stenosis of the proximal ramus intraventricularis anterior].

To determine whether exercise testing can provide additional prognostic information in patients with angiographically determined 2-vessel disease and normal or mildly impaired left ventricular function, we followed 316 medically treated patients (pts) for a mean of 4.5 years. The 5-year survival rate (5-YSR) was 89.7%. On the basis of the results of exercise testing (supine bicycle ergometry) pts were divided into 3 equally sized groups. Pts with an exercise tolerance (ET) of more than 110 W had a 5-YSR of 95% compared to 81% for pts with an ET of less than or equal to 90 W (p less than 0.003). The 5-YSR was 86% and 91% for pts with (n = 87) and without (n = 229) a proximal LAD stenosis (p = 0.12). Pts with a proximal LAD stenosis and an ET of more than greater than 80 W (the better half) had a 5-YSR of 97% in contrast to 76% in pts with an ET of less than or equal to 80 W (p less than 0.02). Pts without proximal LAD disease had a 5-YSR of 93% (ET greater than 80 W) and 87% (ET less than or equal to 80 W) (p = n.s.). Thus in pts with 2-vessel disease and good left ventricular function, exercise testing can differentiate patients with a good long-term prognosis from pts with a markedly reduced prognosis. Exercise testing appears particularly useful in patients with proximal LAD disease and can facilitate the decision-making process for aortocoronary bypass surgery.

Angina Pectoris↗
PubMed1983

Serial exercise testing up to 6 years after coronary bypass surgery: behavior of exercise parameters in groups with different degrees of revascularization determined by postoperative angiography.

To evaluate the behavior of exercise parameters in patients with different angiographically defined degrees of revascularization, serial exercise tests were analyzed in 435 patients 1 to 6 years after coronary artery bypass grafting (CABG). All patients had undergone postoperative angiography 2 to 12 months after CABG to determine the degree of revascularization achieved. Revascularization was complete in 182 patients (all significantly stenosed arteries had patent grafts), sufficient in 176 patients (at least the dominant artery supplying the left ventricle had a patent graft) and incomplete in 57 patients (the dominant artery supplying the left ventricle had a closed graft). Twenty patients had all grafts occluded. Exercise tolerance, angina-free exercise tolerance (angina threshold), maximal double product, prevalence of greater than or equal to 0.1 mV exercise-induced S-T segment depression, and the prevalence of the combination of S-T segment depression plus angina pectoris were determined in serial exercise tests (average of 3.0 postoperative exercise tests per patient for a mean follow up of 3.5 years). Patients with complete, sufficient, and incomplete revascularization showed improvement of all exercise parameters for 6, 4, and 1 year after CABG, respectively. Patients with all grafts occluded had improvement of only some exercise parameters. Five years after CABG, exercise tolerance was improved by 24 W (p less than 0.0005) and 21 W (p less than 0.005) in patients with complete and sufficient revascularization, respectively, and not improved in patients with incomplete revascularization or with all grafts occluded. The angiographically determined completeness of revascularization correlates with the extent and the duration of improvement of exercise parameters after CABG.

Angina Pectoris↗
PubMed1983

Does exercise testing with invasive measurements of cardiac output and pressure really contribute?

Quantification of heart failure is possible with hemodynamic parameters such as cardiac output and filling pressure at rest and during exercise. These parameters can easily but invasively be achieved by floating catheter measurements. In our experience, the risk of this method is low but existent. In greater than 20 000 patients with chronic diseases no death occurred in connection with the procedure; 26 patients developed ventricular fibrillation or ventricular tachycardias which made defibrillation necessary in 10 of these patients. In three patients asystolia demanded resuscitation. Hemoptysis did not occur. In the acute stage of a disease, e.g. in the acute myocardial infarction, the risk may be higher, especially if the catheter remains in the circulation for longer periods. The possibilities and limitations of the method will be discussed for the following patient groups: (1) Patients with acute myocardial infarction, (2) Postinfarction patients, (3) Patients with cardiomyopathies, (4) Patients with valvular heart disease.

Aortic Valve Insufficiency↗
PubMed1983

Exercise testing provides additional prognostic information in angiographically defined subgroups of patients with coronary artery disease.

We examined whether exercise testing with measurement of cardiac output during maximal exercise can provide additional prognostic information for medically treated patients in whom left ventricular function and extent of coronary artery disease are known. We followed 1034 patients with normal or mildly impaired left ventricular function; 410 of these patients (group 1) had single-vessel disease, 316 had double-vessel disease (group 2), and 308 had triple-vessel disease (group 3). In addition, 204 patients with double- or triple-vessel disease and moderately impaired left ventricular function (group 4) were followed. Mean follow-up in these 1238 patients was 4.5 years. End point of follow-up was death. Groups 1, 2, and 3 were divided into terciles according to the maximally achieved values of the following exercise variables: exercise tolerance, angina-free exercise tolerance, maximal heart rate, and cardiac output during maximal exercise. Group 4 was divided into halves accordingly. Survival curves (according to the method of Cutler and Ederer) for group 2 showed a 15% difference in 5 year survival rate between the highest and lowest terciles (p less than .005) by use of the noninvasive variables exercise tolerance, angina-free exercise tolerance, and maximal heart rate (95% vs 80%). The separation into terciles according to cardiac output during maximal exercise resulted in a significant difference in survival rates between the highest and lowest terciles (halves) in all groups of patients. The differences in 5 year survival rates were 9% (p less than .05), 16% (p less than .05), and 19% (p less than .005) for groups 1, 2, and 3, respectively, and 22% for group 4 (p less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1983

[Condition following myocardial infarct: which studies at what time and with what patients?].

This review discusses the stepwise approach to postinfarction patients. For some patients only a few basic steps are needed, for others the whole diagnostic spectrum becomes necessary. The baseline diagnostic workup at the time of discharge from the hospital includes: history, clinical examination and risk factor analysis, ECG at rest; x-ray examination of the heart; Holter-ECG recording and exercise testing. The results of this routine diagnostic program determine whether additional and invasive methods are necessary, e.g. echocardiography, myocardial perfusion scintigraphy, radionuclide angiography and coronary angiography. The indication for coronary angiography should be adjusted to the indications for aortocoronary bypass surgery and aneurysmectomy. In young postinfarction patients and those in specific jobs, coronary angiography is also indicated to improve the evaluation of prognosis.

Adult↗
PubMed1982

[Improved angina-free work tolerance up to 6 years following bypass operation according to degree of revascularization].

Bypass surgery improves exercise performance in a high percentage of patients with effort angina. The influence of the degree of revascularization on the extent and duration of improvement of exercise parameters was evaluated in 415 patients with angiographically determined degrees of revascularization (REV) by serial exercise testing 1-6 years after bypass surgery. Patients with three different degrees of REV are compared. REV I: All vessels up to 50% stenosed have a patent graft. REV II: The main vessel supplying the left ventricle (LV) has a patent graft. REV III: The main vessel supplying the LV has not a patent graft but at least one additional graft is patent. Angina-free exercise tolerance in watts, the maximum double product (HR X BP), and the percentage of patients with angina pectoris and ST-segment depression during exercise were recorded. In patients with REV I and II the angina-free exercise tolerance was improved up to 6 years after bypass surgery but in patients with REV III only 2 years afterwards. Patients with REV I, REV II, and REV III showed improvement of all three parameters for 6 years, 4 years and 1 year respectively. The completeness of revascularization is an important determinant in the longterm improvement of postoperative exercise parameters up to 6 years after surgery.

Angina Pectoris↗
PubMed1982

Pindolol postmyocardial infarction study: evaluation of the drug's antiarrhythmic and antianginal activity.

The study was designed to assess the antiarrhythmic and antianginal properties of pindolol as well as the tolerance to the drug by patients who had experienced a myocardial infarction 5 to 6 months previously. Exercise tests were performed in 521 postinfarct patients before and after a single oral 5 mg dose of pindolol. Depending on the physical condition of the patient, the initial work load was 25 or 50 watts, which was increased by 25 watts every 5 minutes. In patients with an initial heart rate (HR) of more than 68 bpm on the average, HR at rest was reduced with pindolol. This reduction was more pronounced the higher the initial HR. If the initial HR was below 68 bpm, HR increased slightly with pindolol, reflecting the drug's intrinsic activity. The frequency-regulating effect of pindolol dependent on the level of exercise that produced the tachycardia: tachycardia at rest responded more markedly to pindolol than exercise-induced tachycardia; tachycardia due to low-level exercise responded better than that due to higher level exercise. Of the 88 patients who developed typical effort angina and/or ischemic ST-segment depression, 62 became symptom free during exercise when taking pindolol. The patient sample included 66 patients with effort-related premature ventricular contractions (PVCs), 44 of whom responded well to pindolol. Of the 453 patients with a stable HR, 15 exhibited PVCs during exercise for the first time while receiving pindolol. Overall, pindolol exerted a statistically highly significant antiarrhythmic effect. Tolerance to pindolol was good; no side effects were observed.

Adult↗
PubMed1981

Results of exercise tests and prognosis in postinfarction patients below age 40.

In a follow-up study (mean = 3.6 years) of 555 men under 40 years of age (mean = 35.7 years) who had recently suffered transmural myocardial infarction, 44 patients (7.9%) suffered cardiac death with an annual rate of 2.2%. In a bivariate analysis a significant correlation was found between cardiac death and work capacity (p less than 0.02), vessel involvement (greater than 50% stenosis), left ventricular impairment as evaluated by ventriculography (p less than 0.001) and heart volume enlargement (p less than 0.01). There was no significant correlation between the degree of ST-segment depression and ventricular premature depolarisation (during exercise test). Complex results from non-invasive approaches can identify groups with good and bad prognosis as effectively as invasive techniques.

Adult↗
PubMed1980

[Pindolol in myocardial infarction patients: (author's transl)].

Exercise tests were performed in 521 post-infarction patients to consider the acute effect of 5 mg pindolol orally. The main results are: In patients with an initial heart rate(HR) of more than 68 beats/min the HR at rest was reduced. This reduction was more pronounced the higher the initial HR. With HR below 68 beats/min there was a slight increase due to the intrinsic sympathomimetic activity of pindolol. In exercise testing the decrease in HR also correlated positively with the initial values. During the first test run (i. e. without pindolol) angina pectoris was observed in 88 patients. 70% of these patients showed an improvement or total disappearance of angina when pretreated with pindolol. Without medication, 66 patients showed ventricular extrasystoles which diminished or disappeared in 40 after pindolol.

Cardiac Complexes, Premature↗