Biomedical subjects

S Michelsen

Publications and source records attributed to S Michelsen.

24 records · Page 2Linked to original sources

PubMed1990

Long-term follow-up in isolated ventricular septal defect considered too small to warrant operation.

An isolated ventricular septal defect (VSD) was diagnosed in 70 patients (39 men and 31 women, mean age 29 years, range 10-64 years). Surgery was judged unnecessary. The follow-up period was at least 10 years, or until death or 31 December 1988, comprising a mean duration of 21 (range 6-29) years. The mortality was 11/69 (one lost to follow-up), and was not significantly higher than in a matched 'normal' group. Six deaths were cardiac, four of which could probably be related to the VSD. The follow-up study revealed that: (1) 14 (22%) subjects had major, VSD-related complications, and cardiac surgery was indicated in eight patients; (2) six (10%) had minor complications. By the end of 1988, 24% of subjects had significant dyspnoea, 22% had chest pain and 19% used cardioactive drugs. Only 33% were receiving regular cardiac control in a hospital. Thus unoperated adults with a small VSD should be monitored closely, since this condition is far from benign.

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PubMed1990

Reproducibility of cumulative work, heart rate and blood pressure response during stepwise versus continuous load increment during a maximal bicycle ergometer test.

The reproducibility of physical capacity expressed as cumulative work (CW) and work pulse (WP) as well as haemodynamic response to maximal exercise was evaluated by two different principles for increasing work load during a maximal bicycle ergometer exercise test: (i) stepwise increment (SI) of 50 Watts (W) every fourth minute; (ii) continuous increment (CI) of 10 W at the end of every minute, both with a starting load of 50 W. Forty apparently healthy men aged 29-69 (mean 47) years performed two tests with a mean interval of 17 (3-43) days. Group A: 10 men who did SI twice; group B: 10 who repeated CI; group C: 10 men who performed SI and CI alternatively; group D: 10 men who did SI in the morning vs afternoon. Error % (percentage of the absolute difference of the mean of two values) was 3.9 for CW in group A vs 7.8 in group B (p less than 0.05). The error % of heart rates at submaximal work levels were lower with SI than CI. Mean CW in group C was 182.3 +/- 65.1 kJ for CI and 154.8 +/- 48.8 kJ for SI (p less than 0.01), whereas the mean exercise time was 1206 +/- 297 s and 1089 +/- 197 s respectively (p less than 0.01). Group D subjects achieved 142.7 +/- 49.4 kJ in the morning and 134.4 +/- 48.8 kJ in the afternoon (p less than 0.05). No significant differences were noted for WP in groups A-D. A better reproducibility for CW was found for SI, whereas both tests had similar reproducibility for heart rate and blood pressure response during maximal exercise.

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PubMed1989

[Serum cholesterol in a selected group of healthy individuals aged 20-70 years. Influence of age and sex].

Several epidemiological studies world-wide have shown that serum (s)-cholesterol is a major risk factor for development of atherosclerosis. The risk of coronary heart disease increases with increasing s-cholesterol, and the relationship is continuous and curvilinear, with an increase with s-cholesterol levels greater than or equal to 5.2 mmol/l (200 mg/dl). Therefore, the recommended s-cholesterol is below 5.2 mmol/l. The purpose of this study was to investigate the level of s-cholesterol in a group of apparently healthy Norwegians aged 20-70 years in 1987. 94 men and 93 women were examined. We found, as others have shown before, that s-cholesterol increases significantly with age both among men and among women. The intersexual differences are not statistically significant. 69% of the total group had s-cholesterol greater than or equal to 5.2 mmol/l. These findings should have consequences for dietary policy in Norway.

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PubMed1989

M-mode echocardiographic findings in apparently healthy, non-athletic Norwegians aged 20-70 years. Influence of age, sex and body surface area.

In order to assess M-mode echocardiographic recordings in a normal Norwegian population, 190 apparently healthy subjects (95 women and 95 men) aged 21-69 years were examined with an Irex Meridian system. Measurements were performed according to criteria recommended by the American Society of Echocardiography. Absolute values for all parameters except for left ventricular (LV) shortening fraction (SF) were greater in men (P less than 0.001). When corrected for body surface area (BSA), the differences between the two genders were far less pronounced. Women had greater left atrium (LA) (P less than 0.01) and LV end-diastolic diameter (EDD) (P less than 0.001), whereas the interventricular septum in end-diastole (IVS-ED) (P less than 0.05) and LV posterior wall (PW) in ED (P less than 0.001) were thicker in men. Only weak correlations between age and the various echocardiographic parameters with r-values less than or equal to 0.30 were observed. It is recommended that BSA corrected values should be preferred since the differences between men and women are negligible. When absolute values are used, different normal ranges for both sexes should be applied.

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PubMed1989

Influence of age on physical performance, heart rate and systolic blood pressure response during exercise in apparently healthy women.

In order to assess normal physical performance in women, a near-maximal ergometer bicycle test was performed in 95 healthy non-athletic women aged 24-65 years (mean 44 years). The starting load was 50 W and the load was increased by 50 W every 4 min until exhaustion. Physical performance was expressed as cumulative work in Watts (W). All subjects had normal two-dimensional, M-Mode and Doppler echocardiographic findings. Physical performance was similar in the age groups 24-29, 30-39 and 40-49 years. Mean cumulative work among subjects less than 50 years was 1208 (600-1800) W vs. 947 (500-1600) W (p less than 0.001) in those greater than or equal to 50 years. Physical performance was similar in the age groups 50-59 and 60-65 years (NS). An inverse correlation between maximal heart rate and age was found (r = 0.64, p less than 0.001). Systolic blood pressure increased more during exercise in the subjects greater than or equal to 50 years (p less than 0.001 vs. those aged less than 50 years). M-Mode echocardiographic measurements at rest were similar in all age groups. These findings may be related to reduction in beta-sympathetic stimulation during exercise in women greater than or equal to 50 years of age.

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PubMed1988

Prevalence of tricuspid and pulmonary regurgitation diagnosed by Doppler in apparently healthy women. Possible influence on their physical performance?

Ninety-five apparently healthy, non-athletic women aged 24-65 (mean 44) years were screened by Doppler echocardiography for the presence of tricuspid and pulmonary regurgitation (TR and PR). An Irex Meridian system was used. TR was diagnosed in the presence of a pansystolic regurgitant jet into the right atrium with a maximal velocity of greater than 1.5 m s-1. Regurgitant flow throughout diastole was diagnostic for PR. Right-sided regurgitation was found in 43 women (Group 1), 22 with TR, 12 with PR, and nine with combined TR and PR. The remaining 52 women were studied as a control group (Group 2). Group 1 had a significantly larger heart size on X-ray (P less than 0.025) and left ventricular end systolic diameter assessed from M-mode echocardiography (P less than 0.05) than did Group 2. The possible clinical significance of the valvular regurgitation was assessed by using a standardized symptom-limited exercise test on an ergometer bicycle. In Group 1, the mean cumulative work achieved was 7008 (+/- 1630) kpm, and in Group 2 6363 (+/- 1633) kpm (P less than 0.05). TR and PR occurring in otherwise healthy women does not seem to impair physical exercise performance.

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