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Biomedical subjects

U Nielsen

Publications and source records attributed to U Nielsen.

11 recordsLinked to original sources
PubMed1995

Improving long-term survival of patients with acute myocardial infarction from 1977-1988 in a region of Denmark.

The aim of this investigation was to study secular trends in long-term survival following myocardial infarction (MI). Five thousand one hundred and fifty-seven consecutive cases of MI in 3942 patients were recorded in a well-defined region in the study period 1977-1988. The study period ended before thrombolytic therapy was introduced in the hospital. One and 5-year survival (+/- 95% confidence limits) was 61 +/- 2% and 42 +/- 2% in 1977-1980. These figures changed to 61 +/- 2% and 44 +/- 2% in 1981-1984, and to 64 +/- 2 and 46 +/- 2% in 1985-1988. The improvement with time was statistically significant (P < 0.001). In a Cox proportional hazard model, time of infarction was an independent predictor of survival. Patients were subdivided into a high risk group suffering from either congestive heart failure or cardiac arrest during hospitalization, and a low risk group without these complications. Year of infarction was without importance in the high risk group but highly significant in the low risk group. Long-term survival following MI gradually improved prior to the introduction of thrombolytic therapy. The improvement was confined to low risk patients without cardiac arrest or congestive heart failure.

Acute Disease↗
PubMed1991

[Acute surgery-requiring mitral valve insufficiency caused by rupture of the chordae tendineae].

The etiology of acute severe mitral incompetence resulting from rupture of the chordae is presented and is illustrated by four case reports. The condition was incorrectly diagnosed and treated primarily as pneumonia or obstructive pulmonary disease. The correct diagnosis was established primarily by echocardiography. Treatment was surgical with implantation of a mitral valvular prosthesis. In three out of four patients, myxomatously degenerated tissue and balooning of the edges of the cups, compatible with the diagnosis of the mitral prolapse syndrome were found. The pathogenesis appears to be primarily dysplasia of the chordae with a component of mechanical wear and tear with physical exertion as the factor precipitating the rupture. The diagnosis of severe mitral incompetence resulting from rupture of the chordae should be borne in mind in cases of acutely developing dyspnoea.

Acute Disease↗
PubMed1989

Opioid involvement in the perception of pain due to endurance exercise in trained man.

The purpose of this study was to evaluate the role of endogenous opiates in modulating physical performance during dynamic exercise in conscious man. The plasma concentration of beta-endorphin (BEP) and of adrenocorticotropic hormone (ACTH) along with muscle pain (McGuill Pain Questionnaire) were assessed in 17 trained, male runners before and after running the longest possible distance within 12 min (i.e., the Cooper test). Each runner participated twice in the test (double-blind cross-over design), with a 1-week interval--with or without an injection of the opiate antagonist naloxone (0.8 mg i.v.). The average (SEM) distance reached was 3,198 (45) m in the naloxone test and 3,240 (38) m in the placebo test. The BEP increased significantly during the tests by a factor of 4.1 on naloxone and by 2.8 on placebo (from the normal resting averages of 1.7 and 2.1 pmol/l, respectively). The ACTH also increased significantly by a factor of 2.0 on naloxone and 2.5 on placebo (from the normal resting averages of 19.3 and 16.8 pmol/l, respectively). There were no significant differences between the naloxone and the placebo test with respect to the increments of BEP or ACTH by exercise. However, the perception of muscle pain was enhanced with naloxone. The increased perception of pain did not decrease the athletes ability to perform in terms of the distance run. We conclude that endogenous opiates are involved in the perception of pain associated with exhaustive exercise and may subserve psychological rather than physiological functions during exercise.

Adrenocorticotropic Hormone↗
PubMed1986

beta-Blockade used in precision sports: effect on pistol shooting performance.

In a double-blind cross-over study of 33 marksmen (standard pistol, 25 m) the adrenergic beta 1-receptor blocker, metoprolol, was compared to placebo. Metoprolol obviously improved the pistol shooting performance compared with placebo. Shooting improved by 13.4% of possible improvement (i.e., 600 points minus actual points obtained) as an average (SE = 4%, 2P less than 0.002). The most skilled athletes demonstrated the clearest metoprolol improvement. We found no correlation between the shooting improvement and changes in the cardiovascular variables (i.e., changes of heart rate and systolic blood pressure) and no correlation to the estimated maximum O2 uptake. The shooting improvement is an effect of metoprolol on hand tremor. Emotional increase of heart rate and systolic blood pressure seem to be a beta 1-receptor phenomenon.

Adrenergic beta-Antagonists↗