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Biomedical subjects

P Bjerregaard

Publications and source records attributed to P Bjerregaard.

At least 109 records · Page 6Linked to original sources
PubMed1991

Circadian variation and influence of risk factors on heart rate variability in healthy subjects.

Quantification of variations in instantaneous heart rate (HR) can be used to evaluate cardiac autonomic function. A 24-hour standard deviation of all normal RR intervals less than 50 ms in survivors of myocardial infarction has been shown to be an independent marker of adverse prognosis. Twenty-four-hour HR variability in 140 healthy subjects aged 40 to 77 years was determined as (1) standard deviation, and (2) percentage of successive RR interval differences greater than 6%--an index of parasympathetic activity. The 24-hour standard deviation varied between 68 and 261 ms (median 139). Range for index of parasympathetic activity was 0.1 to 29.6% (median 4.4). Twenty percent of the interindividual variation in HR variability was explained by impact of risk factors. Standard deviation was uninfluenced by age, whereas parasympathetic activity decreased by increasing age. High physical training level was independently associated with significantly higher standard deviation (and parasympathetic activity) values during both day and night. Hourly figures of standard deviation decreased during the night, whereas parasympathetic activity increased and peaked early morning. Standard deviation values as low as those reported in high-risk patients were not observed, but comparable low values for, and lack of diurnal variation in, parasympathetic activity were seen in healthy subjects also. In conclusion, risk factors and, in particular, the physical training level have impact on 24-hour HR variability in healthy subjects. This may prove valuable for modification of cardiac autonomic activity in patients.

Adult↗
PubMed1991

Attenuated 24-h heart rate variability in apparently healthy subjects, subsequently suffering sudden cardiac death.

Attenuated cardiac parasympathetic activity appear to be an important risk factor contributing to sudden cardiac death in subjects with overt coronary disease but its predictive value in otherwise healthy normal subjects is not known. We have for 8 years followed 260 apparently healthy adult subjects who underwent Holter monitoring. Twelve died, 14 developed ischaemic heart disease and four suffered sudden cardiac death. A healthy control subject was matched, along with other risk factors, for each case. In each subject 24-h heart rate variability was calculated as the deviation of all normal R-R intervals from mean R-R (SD) and the percentage of successive R-R interval differences exceeding 6% (%DIF6%)--this was used as an index of cardiac parasympathetic activity. There were no significant differences in heart rate variability between the cases developing problems and controls. In the sudden cardiac death victims, however, there was a clear trend towards lower heart rate variability. In them waketime mean SD was 73 ms versus 85 ms for cases and controls respectively (p = 0.08), and for sleeptime 61 ms versus 76 ms (p = 0.07). Compared to normal limits for heart rate variability obtained in 140 subjects that remained healthy for 8 years, figures for both SD and %DIF6% in sudden cardiac death subjects were at or below 95% confidence limits. The results indicate that altered autonomic balance may contribute to sudden cardiac death even in apparently healthy subjects. Subjects with a low 24-h heart rate variability on Holter monitoring may be predicted at an early stage of being at greater risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Predictive value of ventricular premature beats for subsequent ischaemic heart disease in apparently healthy subjects.

From 1978 to 1980, 260 healthy subjects, 40-79 years of age, underwent 24 h ambulatory electrocardiography in order to determine the prevalence and complexity of ventricular premature beats (VPBs) in adults without apparent heart disease. The number of types of VPBs seem in 5% or less were considered 'abnormal' and the present follow-up study undertaken in order to assess the significance of such 'abnormal' VPBs as predictors of subsequent ischaemic heart disease (IHD). Information concerning cardiac events within the follow-up period was available in 237 subjects. Nine were lost to follow-up and 24 refused clinical examination. IHD was documented in 13 (eight myocardial infarction, five angina pectoris). 'Abnormal' VPBs occurred in six out of 13 (46%) who later developed IHD compared to only 24 out of 213 (11%) without IHD (P less than 0.001). The presence of either more than 900 VPBs 24 h-1 or ventricular tachycardia of more than three beats, identified five out of 13 patients with IHD (sensitivity 38%), whereas 210 out of 213 with no evidence of IHD at follow-up were identified (specificity 98%). Four out of seven who initially had more than 900 VPBs 24 h-1 had IHD on follow-up. Our results have demonstrated a strong positive association between 'abnormal' VPBs observed in a random 24-h electrocardiographic recording of apparently healthy subjects 40-79 years of age and subsequent IHD. They also suggest that a 24-h ECG may be useful for the assessment of coronary risk even in asymptomatic subjects.

Adult↗
PubMed1991

Thromboprophylaxis by low-molecular-weight heparin in elective hip surgery. A placebo controlled study.

In a double-blind, randomised study of thromboprophylaxis in patients undergoing total hip replacement, we compared a low-molecular-weight heparin with a placebo. Of the 120 patients enrolled, 112 completed the trial; 58 in the treatment group and 54 in the placebo group. Nine (16%) patients in the treatment group and 19 (35%) in the placebo group developed deep venous thrombosis, diagnosed by the 125I-fibrinogen uptake test (p < 0.02). Verification was obtained by phlebography in 86% of the patients. Prolonged surgery increased the risk of thrombosis in the placebo group but not in the treatment group (p < 0.05). There were significantly more cases of deep venous thrombosis in the placebo group during the first four postoperative days (p < 0.02). The groups did not differ with respect to peroperative and postoperative bleeding. Low-molecular-weight heparin offers safe and easily administered thromboprophylaxis in total hip replacement.

Adult↗
PubMed1991

Economic analysis of immunization programmes.

Two economic analyses of immunization programmes, one from Denmark and one from Kenya, are described with emphasis on practical problems in relation to the collection of data. The Danish study was performed by a study group with participation of experts within health economics and epidemiology and a specifically designed computer programme was developed. The Kenyan study was performed by the management unit of the Kenyan immunization programme using standard computer software developed by WHO (EPICost) and without external assistance. Both studies yielded results of significant relevance for the dialogue with the administration and politicians.

Child↗
PubMed1991

Disease pattern in Greenland: studies on morbidity in Upernavik 1979-1980 and mortality in Greenland 1968-1985.

The disease pattern is described for the population of Upernavik, which is the administrative centre of a very large, sparsely populated municipality in North Western Greenland. The number of medical contacts per person was by and large similar in Upernavik and Denmark despite different health care systems, but the distribution of diagnoses was different. Persons with poor socioeconomic status (housing conditions and social group) were admitted to hospital more often than those with high status. Mortality in Greenland was studied using a computerized register of causes of death covering all deaths in residents of Greenland during 1968-1985. Age standardized mortality rate was twice as high in Inuit of Greenland as in the population of Denmark but five times higher in children. Mortality due to infectious diseases, ischaemic heart disease and certain accidents decreased during the period studied while mortality due to lung cancer, suicide and homicide increased. Regional differences in mortality were pronounced with high infant mortality and high mortality from acute infections and accidents in the socioeconomically poor settlements and remote districts. The suicide and homicide rates were highest in the capital and in the remote East Greenland. Compared with Denmark, mortality rates were higher in Greenland from most causes with ischaemic heart disease as an exception, being significantly less common in Greenland in both males and females. A comprehensive literature review describes the disease pattern in Greenland with special emphasis on the period after 1970. It is concluded that epidemiology can contribute to future health planning in Greenland and that research and development must be given high priority. Some major health problems facing the Greenlandic community are the high mortality from suicides and homicides, the prevalence of violence often triggered by alcohol, the many accidents, the high infant and child mortality and the high mortality from preventable cancers (lung and cervix).

Cause of Death↗
PubMed1990

[Lowest heart rate and pauses in adults with healthy hearts].

The lowest heart rate measured in a one minute period (HRmin) and prevalence of pauses, was determined with eight years interval, in two 24 hour Holter Monitorings, in 183 persistently healthy adults aged 40 to 85 years. For the individual, HRmin is a stable parameter, but the level depends on sex, smoking and physical activity habits. Independently of age, HRmin less than 40 beats per minute and pauses greater than or equal to 2.0 seconds are rare events, and should be considered abnormal.

Adult↗
PubMed1990

The concentration of the Na,K-pump in skeletal and heart muscle in congestive heart failure.

Na,K-ATPase (or the Na,K-pump) is essential for excitability and contractility of muscle tissue. Previous studies have shown a decrease in the concentration of this pump in endomyocardial biopsies from patients with dilated cardiomyopathy. The effect of congestive heart failure on the concentration of Na,K-ATPase in skeletal muscle was assessed in 16 patients by measurement of binding of 3H-ouabain to biopsies of the vastus lateralis muscle. Ten patients had impaired left ventricular function with an ejection fraction of 0.32 +/- 0.03 and a concentration of the Na,K-pump of 229 +/- 15 pmol/g wet weight in the skeletal muscle, whereas 6 patients had an ejection fraction of 0.66 +/- 0.05 (P less than 0.001) and a concentration of 307 +/- 17 pmol/g wet weight (P less than 0.01). In endomyocardial biopsies, the concentration of Na,K-ATPase was 340 +/- 37 and 500 +/- 39 pmol/g wet weight (P less than 0.025) in patients with impaired and normal ventricular function, respectively. There was a significant correlation between the concentration of the Na,K-pump in the biopsies of the skeletal muscle and ejection fraction, as well as between its concentration in the endomyocardial and skeletal muscular biopsies (r = 0.56, P less than 0.025 and r = 0.72, P less than 0.005, respectively). The decrease in concentration of the pump in skeletal muscle may contribute to the limitation of exercise capacity in congestive heart failure.

Adult↗
PubMed1990

Avoidable deaths in Greenland 1968-1985: variations by region and period.

The concept of avoidable deaths suggests that certain deaths ought not occur in a given society because it is possible to prevent or treat the disease or condition. A list of avoidable deaths is time and community specific as it reflects the socioeconomic conditions, professional medical capacity and political will of the society. A list of avoidable deaths is proposed for Greenland which includes, inter alia, meningitis, lung cancer, acute respiratory infections, suicides, boat accidents and alcohol related diseases and accidents. All were considerably more common in Greenland than in Denmark and several showed an increasing time trend. The regional patterns were particularly clear for infectious diseases and accidents, which showed low mortality rates in the capital and other towns and high mortality rates in settlements and in the remote East Greenland, while mortality rates from suicides and alcohol related diseases were high in the capital and East Greenland and low in West Greenlandic settlements. It is concluded that further studies on preventable diseases and causes of death, in particular certain infectious diseases, accidents and suicides, are needed.

Cause of Death↗
PubMed1990

Fatal accidents in Greenland.

The occurrence of fatal accidents in Greenland was studied for 1968-1985 with emphasis on the native Inuit population. 1004 deaths were recorded, 43% of which were drowning and boat accidents. The mortality rates from all fatal accidents together were 202 and 72 per 100,000 person-years in males and females, respectively, and fatal accidents made up 16% of all deaths. 23% of the accidents were alcohol related, considerably more in certain age groups and in females. Most accident types, including alcohol related accidents, showed a decreasing mortality trend during the period of study but boat accidents not related to alcohol increased significantly. The mortality rates were higher in East Greenland than in West Greenland for most accident types and, in West Greenland, the mortality rates from drowning, boat accidents, fire and accidental shots increased with remoteness from the capital. Many accidents can be prevented but certain accidents are natural consequences of traditional activities which hold compensating benefits.

Accidents↗
PubMed1990

Geographic variation of mortality in Greenland. Economic and demographic correlations.

Geographic variation of mortality in the native (Inuit) Greenlandic population was studied and compared at community level with income, population change and community size. Six well defined geographic regions were identified. Mortality rates from infectious diseases and accidents were lowest in West Greenlandic towns and highest in settlements and in East Greenland; they showed a significant negative correlation with income. Mortality rate from ischaemic heart disease was highest in West Greenlandic towns excluding the capital (Nuuk) while no clear geographic pattern was observed for cerebrovascular disease. The suicide rate was very high in the capital and in East Greenland while it was low, at the Danish level, in West Greenlandic settlements. The study has demonstrated an internal variation in the Greenlandic mortality pattern which must be taken into account in the planning of both scientific studies and practical health interventions.

Cause of Death↗
PubMed1989

[Vaccination of children in Kenya].

Since 1980, Danida has supported Kenya Expanded Programme on Immunization (KEPI) financially and with technical advisers. Before the introduction of KEPI, 43% of Kenyan children were fully immunized and the measles vaccine efficacy (VE) was 50%. A national survey in 1987 showed that vaccination coverage had increased to 51% and VE to 70%, but there are still pronounced geographical and social differences. The number of immunizing clinics has been doubled to 1,250, and it is regarded as more important to create a programme, which provides the majority of Kenyan children with continuous and reliable immunization services, than to increase coverage rapidly. The total cost of the programme was about 7 million US $ in 1987, equivalent to 12.39 $ per fully immunized child; 62% of this consisted of local salaries, 21% of vaccines, 11% of annualized capital costs and 6% of other running costs. KEPI will face significant challenges in the near future and continued technical and financial support from foreign donors will be required.

Child↗
PubMed1989

[Percutaneous pulmonary balloon valvuloplasty in Denmark].

Percutaneous balloon valvuloplasty of valvular pulmonary stenosis (PPB) was carried out for the first time in 1982 and is now regarded as the primary method of treatment of this condition. The results of the first PPB treatments in Denmark are presented here. PPB was planned in 28 patients and was carried out in 25 (22 children and 3 adults). PPB was carried out on two occasions in one patient. Twenty-three patients had isolated valvular pulmonary stenosis and two patients had Fallot's anomaly. No complications of significance occurred after the treatments. The average gradient for all dilatations was 77 +/- 24 mm Hg prior to and 36 +/- 23 (p less than 0.0001) immediately after PPB. The gradient was reduced by more than 50% in 68% of the patients. In 14 patients, the gradients over the pulmonary valve was measured by Doppler technique or by cardiac catheterization greater than 6 months after PPB. In these patients, the average gradient was 69 +/- 21 mm Hg prior to PPB, 29 +/- 12 mm Hg (p less than 0.0001) immediately after PPB and 27 +/- 9 mm Hg (p less than 0.0001) at the most recent control examination, on an average 12 months (range 6-24 months) after PPB. In the same patient group, significant reduction of the electrocardiographic right-sided hypertrophy was found at the most recent control examination. It is concluded that PPB is an effective and safe treatment of valvular pulmonary stenosis.

Adolescent↗