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Biomedical subjects

P Bjerregaard

Publications and source records attributed to P Bjerregaard.

At least 19 recordsLinked to original sources
PubMed1992

Electrophysiologic and antiarrhythmic effects of magnesium in patients with inducible ventricular tachyarrhythmia.

Intravenous magnesium is reported to be effective in the treatment of ventricular arrhythmias associated with hypomagnesemia, digitalis toxicity, or prolongation of the QT interval. In most previous reports, magnesium was added to conventional antiarrhythmic drugs that had failed. There are few data on the antiarrhythmic efficacy of magnesium as monotherapy in patients without these associated abnormalities. Ten patients with life-threatening ventricular arrhythmia and inducible ventricular tachyarrhythmia by programmed electrophysiologic testing were treated with intravenous magnesium. Following magnesium infusion, all patients still had inducible ventricular tachyarrhythmia. Moreover, magnesium therapy was not associated with significant changes in ventricular refractory period or in the morphology, cycle length, or hemodynamic response to induced ventricular tachycardia. These data suggest that intravenous magnesium has no significant electrophysiologic or antiarrhythmic effects in patients with life-threatening ventricular arrhythmia and inducible ventricular tachyarrhythmia.

Aged↗
PubMed1992

Unusual Wenckebach upper rate response of an atrial-based DDD pacemaker.

We describe in this report an unusual form of Wenckebach upper rate response produced by a DDD pulse generator with atrial-based lower rate timing. The pacemaker maintained the programmed upper and lower rate intervals at the expense of a prolonged atrial paced-ventricular paced AV interval. This form of upper rate behavior eliminated the longer cycle (containing the unsensed P wave) that occurs at the end of the pacemaker Wenckebach sequence during traditional DDD pacing with ventricular-based lower rate timing.

Adult↗
PubMed1992

Fatal non-intentional injuries in Greenland.

Accidents are one of the main killers in Greenland, responsible for 16% of deaths but 34% of potential years of life lost (PYLL). During 1968-89, 1310 deaths from accidents were recorded, equivalent to a mortality rate of 118 per 100,000 person-years-more than six times higher than in Denmark. There was a decreasing secular trend but only for certain types of accidents. Mortality rates were considerably higher in indigenous Greenlanders than in Danes, higher in males than in females and higher in settlements than in towns. Most accidents were related to the Greenlandic life style with drowning and boat accidents responsible for 45% of all fatal accidents, and injuries due to fire, cold, firearms or bites of dogs responsible for 23%. In certain age groups and in particular in females, at least 60% of the fatal accidents were alcohol related.

Adolescent↗
PubMed1992

The thromboprophylactic effect of a low-molecular-weight heparin (Fragmin) in hip fracture surgery. A placebo-controlled study.

A prospective, randomized, double-blind trial concerning thromboprophylaxis in 82 patients in whom hip fracture surgery was performed was conducted to compare a new low-molecular-weight heparin (Fragmin) with placebo. Deep venous thrombosis (DVT) was detected by 125-I-fibrinogen uptake test followed by ascending phlebography when positive. Sixty-eight patients completed the study, and a 50% reduction in the incidence of DVT was demonstrated: nine of 30 patients in the treatment group (30%) and 22 of 38 patients in the placebo group (58%) developed DVT. This significant difference was achieved by one daily dose of 5000 IU Fragmin subcutaneously, commenced preoperatively and continued for six days. There were no differences in bleeding or other complications in the two groups. Fragmin given once daily offers an effective and safe thromboprophylaxis in hip fracture surgery.

Aged↗
PubMed1992

Severe measles outbreak in western Kenya.

During a measles outbreak investigation in Siaya district clustering of many measles cases were found to be an important determinant for measles mortality. A high proportion of cases were under one year of age. Case fatality rates were higher than previously reported from Kenya, particularly among infants. Vaccine efficacy was 18%. Alternative ways of protecting infants are discussed.

Child↗
PubMed1992

Infant mortality in Greenland: secular trend and regional variation.

Infant mortality and stillbirths were studied in the Inuit population of Greenland. Infant mortality rate decreased from 110 per 1000 live births in 1951 to 50 in 1970 and 20 in 1989. Statistically significant decrease was in particular seen for acute respiratory infections and certain perinatal conditions. Both perinatal and postperinatal mortality rates increased significantly with remoteness from the capital and were higher in settlements than in towns. The overall trend in Greenland is similar to the Danish pattern 30 years earlier, but there was pronounced regional variation. In towns, the infant mortality rate decreased continuously while in settlements an initial decrease was followed by a substantial increase during 1980-87 when the mortality rate doubled. The greater part of this increase could be attributed to an increased number of deaths in the postperinatal period countrywide during 1981-84 and an increased number of perinatal deaths in the settlements of one particular municipality during 1983-86.

Cause of Death↗
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↗