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Biomedical subjects

F Pedersen

Publications and source records attributed to F Pedersen.

At least 55 records · Page 3Linked to original sources
PubMed1989

Elevated pain threshold in patients with effort-induced angina pectoris and asymptomatic myocardial ischemia during exercise test.

The purpose of the present study was to analyze the prevalence of asymptomatic (silent) myocardial ischemia during exercise testing among patients with effort-induced angina pectoris, and further, to compare the pain threshold of patients with symptomatic and asymptomatic myocardial ischemia. A group of 26 patients comprised the study. In half of the patients myocardial ischemia during the exercise testing was silent and in one half it was symptomatic. Asymptomatic myocardial ischemia was defined as an asymptomatic ST-segment depression greater than or equal to 0.1 mV, lasting longer than 60 s during an exercise test. In patients with asymptomatic ischemia the pain thresholds both on toe and finger were significantly higher than in patients with symptomatic ischemia: mean values were 10.1 versus 4.9 mA on the toes, p less than 0.025, and 8.4 versus 2.5 mA on the fingers, p less than 0.01. We conclude that asymptomatic myocardial ischemia during exercise test is seen often in patients with angina pectoris and that this may be due to an increased pain threshold.

Aged↗
PubMed1989

Echocardiography and cerebral computed tomography in chronic atrial fibrillation.

Chronic atrial fibrillation (CAF) may be complicated by asymptomatic small silent cerebral infarctions as well as by stroke. The echocardiographic findings in 29 patients with CAF and 29 controls in sinus rhythm are presented. The cerebral computed tomography (CT) findings in these patients were previously published and significantly more small low-density lesions, probably reflecting previous infarctions, were found in patients with CAF than in controls. The aim of the present study was to evaluate if patients with such cerebral lesions had characteristic echocardiographic abnormalities with special reference to patients with CAF. No significant differences could be detected between the groups with and without cerebral lesions regarding the occurrence of valvular heart disease, left ventricular dysfunction, end-diastolic diameter of the left ventricle, left atrial dimension and left ventricular fractional shortening. Only seven patients with CAF (24%) compared with 21 in sinus rhythm (72%) had normal echocardiograms (P less than 0.001). In conclusion, echocardiography gave no guidance to why some patients developed cerebral low-density areas on CT.

Aged↗
PubMed1989

Cerebral computed tomography in paroxysmal atrial fibrillation.

Atrial fibrillation (AF) is associated with an increased risk of stroke. In patients with chronic AF, without clinically known cerebrovascular disease, computed tomography (CT) has revealed a high frequency of abnormal low-density areas suggesting old asymptomatic infarcts. To investigate the frequency of such lesions in paroxysmal AF, 30 patients with paroxysmal AF and 30 controls matched in sinus rhythm, without history of cerebrovascular disease, were CT scanned. Four patients with paroxysmal AF (13%) and 3 controls (10%) had abnormal CT scans with areas of low density with sharp demarcation from surrounding tissue. The abnormal areas probably reflected small, clinically silent infarcts. There were no differences between paroxysmal AF and controls in number and size of abnormal areas with apparent tissue loss. In contrast to chronic AF, the risk of such lesions in paroxysmal AF does not seem to be increased compared with matched sinus rhythm controls. This is in agreement with the clinical experience of a low risk of stroke in paroxysmal AF.

Adult↗
PubMed1988

Serum magnesium, calcium, phosphate and PTH following long-term beta-blockade in ischaemic heart disease.

In 40 patients with ischaemic heart disease the serum levels of magnesium, parathyroid hormone (PTH), phosphate, calcium, and ionized calcium remained unchanged and within normal limits following treatment for 12 months with alprenolol (n = 20) or placebo (n = 20). No changes occurred during a 2 week withdrawal period. The clinical implication is that the non-cardioselective betablocker alprenolol can be given to patients with ischaemic heart disease without the risk of inducing potentially cardiotoxic disturbances in serum magnesium and serum calcium levels. Whether this applies to cardioselective beta-blockers remains to be established.

Adrenergic beta-Antagonists↗
PubMed1988

Transcutaneous pacing: experience with the Zoll noninvasive temporary pacemaker.

We investigated the effectiveness of noninvasive transcutaneous pacing in 35 patients. Pacing was achieved in 33 of 35 patients (94%). In 24 patients the indications were: acute sinoatrial block, atrioventricular block, or asystole with unconsciousness due to acute myocardial infarction in eight; sick sinus node syndrome in 12; and other indications in four patients. These patients were paced for 2 minutes to 14 hours; the median length of pacing was 15 minutes. The pacing thresholds varied from 30 to 110 mA; pacing was achieved in 22 patients without serious side effects. Nine patients needed sedation and six were unconscious; 12 later had a temporary or permanent transvenous pacemaker implanted. In 11 patients noninvasive transcutaneous pacing was performed prior to implantation of a permanent pacing catheter: in eight pacing was done just prior to catheter insertion, and in three the threshold was determined before a weekend on which the patient had to wait for implantation. Pacing thresholds were from 45 to 90 mA; the median was 55 mA. Seven of these eight patients felt chest pain. No serious side effects were seen. We conclude that transcutaneous pacing is effective and safe and can be used instead of inserting a transvenous catheter if this is impossible or until one can be inserted.

Adolescent↗
PubMed1988

Normal myocardial enzymes and normal echocardiographic findings during noninvasive transcutaneous pacing.

Noninvasive transcutaneous pacing was performed for 30 minutes in 10 healthy volunteers. The pace rate was from 85 to 115 min-1, and the threshold for pacing was from 38 to 70 mA, median 59 mA. Echocardiography before and during pacing showed no changes in left ventricular end-diastolic diameter, in fractional shortening nor in contraction pattern. Also, blood pressure remained unchanged. Blood samples for determination of myoglobin, creatine phosphokinase, creatine kinase MB and lactate dehydrogenase were drawn prior to pacing and 1,2,3,4,6,8 and 24 hours after pacing. The serum concentrations were the same before and after pacing for all enzymes and myoglobin. We conclude that non-invasive transcutaneous pacing for 30 minutes causes no muscular or myocardial injury and that the left ventricular function remains normal.

Adult↗
PubMed1988

In-the-ear hearing aids. The use and benefit in the elderly hearing-impaired.

Preliminary clinical experiences with in-the-ear hearing aids (ITE-HAs) have been promising, and a beneficial effect has been demonstrated in younger hearing-impaired subjects. However, the subjects applying for audiological examination and rehabilitation are predominantly elderly people (i.e. greater than or equal to 70 years). The present questionnaire examination was performed in order to evaluate the use and benefit of ITE-HAs also in the elderly hearing-impaired, and compare with the effect in younger subjects. An extensive questionnaire was sent 6 months after hearing aid fitting to all patients fitted with ITE-HAs. A total number of 693 subjects corresponding to 80% responded to the questionnaire. 70% of the patients are greater than or equal to 70 years and 23% are above the age of 80 years. The results demonstrate that the elderly hearing-impaired use the hearing aids predominantly in situations when listening to television and in small groups; 64% use their hearing aids the whole day and only 6% never use the aids; with increasing age were indicated increasing handling problems, both concerning change of battery, handling of volume control, and insertion of the aid into the ear canal. Only 8% of the patients were dissatisfied with the cosmetic appearance of the hearing aids, the dissatisfaction being more frequent in the young age group below 70 years (16%) than above the age of 70 years (9%). It is concluded that also the elderly hearing-impaired use and benefit from ITE-HAs.

Adolescent↗
PubMed1988

Silent myocardial ischaemia and life threatening ventricular arrhythmias.

In a retrospective study of four patients with paroxysmal ventricular tachycardia (VT) induced by silent ischaemia (SI) one case was related to transmural SI secondary to coronary artery spasm and the other cases to subendocardial SI related to non-dynamic coronary artery stenosis. In one patient it was possible simultaneously to document the presence of myocardial ischaemia preceding VT using two independent markers: ECG and thallium scintigraphy. The common feature was attacks of fast polymorphic VT with fainting and intermediate cardiac arrest as the sole clinical manifestation. Attacks at rest occurred in both types of patients, whereas exercise induced attacks were an inconstant feature of SI-VT in non-dynamic coronary artery stenosis. VT suppression was accomplished by anti-ischaemic intervention in three patients: by calcium antagonist medication in the patient with coronary artery spasm, by coronary artery surgery in two cases of non-dynamic artery stenosis. The risk of underdiagnosing SI-VT is discussed. Screening of patients with the aborted cardiac arrest syndrome by ambulatory ECG-monitoring and repeated symptom-limited exercise-ECG is recommended.

Coronary Disease↗
PubMed1987

Prediction of cardiac risk in non-cardiac surgery.

This prospective study was carried out to develop a model for the prediction of cardiac risk in non-cardiac surgery. Detailed data were collected concerning the preoperative status of 2609 consecutive patients, who were followed closely during the postoperative course. Fatal or life-threatening cardiac complications occurred in 68 patients (2.6%). By utilizing logistic regression, a model for prediction of cardiac risk was developed. The model contained six significant preoperative predictor variables: Congestive heart failure (with 3 degrees of severity); ischaemic heart disease (with 2 degrees of severity); diabetes mellitus; serum creatinine above 0.13 mmol l-1; emergency operation; and the type of operation (two categories). With this model it seems possible to discriminate between patients with very different levels of cardiac risk.

Adult↗
PubMed1986

Acupuncture in severe, stable angina pectoris: a randomized trial.

Twenty-six patients with stable angina pectoris, resistant to medical treatment, were randomized to either active or sham acupuncture in a single-blind design. Sham acupuncture was defined as the insertion of needles in a point within the same spinal segments as the active acupuncture, but outside the Chinese meridian system. The effect was evaluated from anginal attack rate, nitroglycerin consumption and exercise tests. Compared to patients receiving sham acupuncture the patients receiving active acupuncture increased cardiac work capacity significantly, expressed as dPRP (difference in pressure-rate-product between rest and maximum exercise) and maximal PRP during exercise (p less than 0.001). None of the other variables showed any significant difference between the two groups. Concerning exercise tolerance the median difference was 138 Wmin (95% confidence limits - 12.5 to 325 Wmin), concerning anginal attack rate the median difference was 29.5% (95% confidence limits 55% to -11%) and with regard to nitroglycerin consumption the median difference was 5% (95% confidence limits +67% to -44%). No significant effect of sham treatment was observed, no adverse effect was observed. We suggest that acupuncture may improve cardiac work capacity in patients with angina pectoris, refractory to medical treatment.

Acupuncture Therapy↗
PubMed1984

"Low T3-syndrome" in acute myocardial infarction--relationship to beta-adrenergic blockade and clinical course.

Serum levels of T4, T3 rT3 and resin T3 uptake were followed for 5 days in 40 patients with acute myocardial infarction (AMI) allocated to early treatment either with alprenolol or placebo. There was a significant fall in T3 (P less than 0.05) and an increase in rT3 (P less than 0.05) without any significant difference between the alprenolol - (n = 19) and placebo - (n = 21) treated groups. The risk of missing a further 20% change in se-T3 and se-rT3 after alprenolol compared to placebo treatment (beta) was less than 0.10 and less than 0.50, respectively. In patients with a severe clinical course, the fall in T3 and increase in rT3 was significantly greater than in patients without complications. No change in T4 was observed either with respect to the clinical course nor following alprenolol. The data suggest that alprenolol can be given in the acute phase of myocardial infarction without causing any additional disturbance in the serum levels of T3 and T4.

Adrenergic beta-Antagonists↗
PubMed1984

Long-term alprenolol treatment affects serum T4, T3 and rT3 in euthyroid patients with ischaemic heart disease.

After treatment with alprenolol for 1 year, serum 3,3',5'-triiodothyronine (rT3) was significantly increased (P less than 0.01) in a group (n = 20) of euthyroid subjects compared to a control group (n = 20) given placebo. All subjects had definite or suspected myocardial infarction one year previously. Serum thyroxine (T4), free T3 index (FT4I), serum 3,5,3'-triiodothyronine, (T3) and free T3 index (FT3I) were not significantly different in the two groups. Alprenolol and placebo were gradually withdrawn over 14 days. On the first day after withdrawal a significant decrease in serum rT3 in the alprenolol treated group was the only change observed. Fourteen days after withdrawal a significant fall in serum T4, FT4I, rT3 and a rise in serum T3 and FT3I was found in the alprenolol treated group. Six months after withdrawal the only further change observed in the alprenolol treated group was an increase in T3 and FT3I. No changes occurred in the placebo treated group in any of the hormones studied. The results are consistent with a direct effect of long-term alprenolol treatment on the peripheral levels of serum T4, T3 and rT3 in euthyroid subjects. The changes in the thyroid hormones after withdrawal further indicate withdrawal of a permanent inhibition of 5'deiodinase during long-term treatment with alprenolol in euthyroid subjects.

Adult↗