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Biomedical subjects

T Gundersen

Publications and source records attributed to T Gundersen.

At least 37 records · Page 2Linked to original sources

The role of exercise testing in heart failure.

The objectives of exercise testing in congestive heart failure (CHF) may be summarized as follows: (a) detect impaired cardiac performance, (b) grade severity of cardiac failure and classify functional capability, and (c) assess effects of interventions. Several different methods are available to make these assessments, and we have to ask ourselves how well exercise testing achieves these objectives. It has to be kept in mind that the power generated by the exercising muscles is dependent on the oxygen delivery to the skeletal muscles. Oxygen uptake is the result of an integrated performance of the lungs, heart, and peripheral circulation. In patients, as well as in normal subjects, oxygen uptake is related to hemodynamic indices such as cardiac output, stroke volume, or exercise duration when a stepwise regulated maximal exercise protocol is used. However, there are major differences in the concept of a true maximum in normal subjects versus heart failure patients. Fit-normal subjects will achieve a real maximal oxygen uptake, whereas patients may stop testing before a maximum is reached because of symptoms such as dyspnea or leg fatigue. Therefore, it is better if the actual oxygen uptake can be measured. "Peak" rather than true maximal oxygen uptake has been suggested for the classification of the severity of heart failure. Peripheral factors modify the cardiac output through such factors as vascular resistance, organ function, and hormonal release. Maximal exercise will stress the cardiovascular system to a point where the weakest chain will impose a limiting effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

[Protein C deficiency and the P pill].

A 18-year old woman was hospitalized because of vena cava inferior thrombosis, renal vein thrombosis and pulmonary embolism due to inherited protein C deficiency and three months of contraceptive treatment with oestrogen hormones. Protein deficiency was detected in 12 other members of the family. The father had had a pulmonary embolism 12 years earlier, and two other members may have died of thromboembolism.

Adolescent↗

[Idiopathic long QT syndrome. An underdiagnosed disease].

Two eleven-year old boys were referred to the medical department, division of cardiology, Aust-Agder Central Hospital, because of reported attacks of syncope during physical exercise. Idiopathic prolongation of the QT-interval was diagnosed and their families were examined. A total of 25 patients with long QT-syndrome were identified. Eight patients had attacks of syncope, six patients had dizzy spells and five persons were asymptomatic. Nine cases of sudden and unexpected death were assumed retrospectively to be due to QT-prolongation. All patients with syncopes of unknown cause should be examined for QT-prolongation, and the study confirms the importance of examining all family members of patients with idiopathic long QT-syndrome.

Adolescent↗

[Hypothyroid cardiomyopathy--an underdiagnosed cause of heart failure].

20 patients with hypothyroid cardiomyopathy were evaluated by M-mode echocardiography. The mean interventricular septum (IVSd) thickness was 1.94 cm before treatment and was reduced to 1.21 cm after 4-6 months of thyroxin therapy. The mean left ventricular posterior wall (LVPWd) thickness was 1.14 cm before and 1.05 cm after treatment. The IVS/LVPW ratio decreased from 1.7 to 1.15 within 4-6 months. Pericardial effusion was demonstrated in 15 of the patients, but disappeared during thyroxin therapy. The study confirms the importance of examining for hypothyreoidism in the case of patients with symptoms of heart failure of unknown cause, and of patients with echocardiographic evidence of asymmetric septal hypertrophy (ASH) and idiopathic hypertrophic subaortic stenosis (IHSS).

Aged↗

[Allopurinol hypersensitivity syndrome].

Two patients developed severe hypersensitivity reactions to allopurinol. Both patients required long-term corticosteroid therapy to control their symptoms. We make recommendations on the use of allopurinol.

Aged↗

Effect of metoprolol on early exercise-induced ST-segment changes and ventricular arrhythmias in patients with suspected acute myocardial infarction.

One-hundred and ninety-seven consecutive patients admitted for suspected acute myocardial infarction were randomized to double-blind treatment with intravenous followed by oral metoprolol or matching placebo within 24 hours (mean 6.9 hours) after onset of symptoms. A symptom-limited exercise test was performed 15 days after admission in 132 patients (70 patients receiving metoprolol; 62 placebo). Patients treated with metoprolol had a lower observed frequency of exercise-induced ST-segment elevation (11.4% vs. 22.6%; P less than 0.05) and less ventricular arrhythmias (7.1% vs. 19.4%; P less than 0.05) on the predischarge exercise test compared to placebo-treated patients; however, ST-segment depressions were equally distributed to the two treatment groups. Mean exercise capacity was the same in the two groups. Early administration of metoprolol to patients with suspected acute myocardial infarction reduces early exercise-induced parameters related to a bad prognosis and may therefore improve the long-term prognosis without reducing physical performance.

Arrhythmias, Cardiac↗

The antianginal efficacy and tolerability of controlled-release metoprolol once daily: a comparison with conventional metoprolol tablets twice daily.

In a randomized, double-blind, cross-over study treatment with a new controlled-release (CR) preparation of metoprolol, given once daily, was compared with treatment with conventional metoprolol tablets, given twice daily, in 115 patients with stable effort angina pectoris. The patients were treated with 100 mg/day or 200 mg/day, depending on their previous beta-blocker dose. Antianginal efficacy was estimated by counting the number of anginal attacks, by noting the consumption of nitroglycerin tablets, and by exercise tolerance testing. Adverse effects were recorded by a standardized questionnaire. When all patients were analysed together there were no differences in antianginal efficacy between the two treatment regimens. However, when the group taking 200 mg daily was analysed separately better exercise tolerance was found during metoprolol CR therapy, as measured by onset of chest pain and ST-segment change, compared with conventional metoprolol therapy. The two formulations were well tolerated. When given once daily in a total daily dose of 100 mg, the CR preparation induced less adverse effects than the conventional tablets, 50 mg twice daily. It was concluded that the new metoprolol CR preparation, given once daily, possesses the same antianginal efficacy as conventional metoprolol tablets, given twice daily, and may be better tolerated in patients susceptible to side-effects. The antianginal effect of metoprolol CR, 200 mg/day, may be greater over 24 h than that produced by conventional metoprolol tablets, 100 mg twice daily.

Adult↗

Rapid diagnosis of genital herpes simplex infection by an indirect ELISA method.

Herpes simplex virus (HSV) detection was performed by a rapid ELISA antigen detection method in a small field trial, and the results were compared to the results of ordinary cell culture isolation. Swabs from 54 patients, suffering from clinically suspected genital HSV infection, were examined by both methods. In 49 samples the results were identical. Three samples were negative by ELISA, but HSV was isolated by culture, while two samples were positive by ELISA, but negative by culture. Compared to the culture results, the ELISA method had 87.5% sensitivity and 93.3% specificity. Most culture positive samples were identified within two (54%) or three (75%) days, and all within six days after inoculation. The ELISA method turned out as a good and easy method for rapid detection of genital HSV infections.

Enzyme-Linked Immunosorbent Assay↗

Tolerability and antiarrhythmic efficacy of disopyramide compared to lignocaine in selected patients with suspected acute myocardial infarction.

In a randomized open study with intravenous lignocaine and disopyramide in patients with suspected acute myocardial infarction and ventricular premature contractions the occurrence of cardiac events, adverse reactions, withdrawals and arrhythmias were compared. Of the total 68 patients included in the study, 33 were randomized to disopyramide and 35 to lignocaine treatment. The treatment was given for 24 hours or until withdrawal due to occurrence of serious cardiac events or side-effects possibly related to the drugs. Sustained ventricular tachycardia occurred in one patient in each treatment group. 15 per cent of the patients treated with disopyramide and 14 per cent of the patients treated with lignocaine were withdrawn because of adverse reactions. Withdrawals due to depressed left ventricular function and sinoatrial and atrioventricular conduction disturbances were not different in the two treatment groups. However, more patients treated with lignocaine had supraventricular arrhythmias compared to disopyramide. Significantly more patients treated with disopyramide obtained complete abolition of premature ventricular contractions on Holter recordings compared to lignocaine treatment (P less than 0.001). The results indicate that disopyramide and lignocaine can be used alternatively in the treatment of ventricular arrhythmias in patients with suspected acute myocardial infarction.

Adrenergic beta-Antagonists↗

Effect of timolol on mortality and reinfarction after acute myocardial infarction: prognostic importance of heart rate at rest.

Long-term timolol treatment after acute myocardial infarction is associated with a significant reduction in mortality and nonfatal reinfarction. To evaluate whether the reduction in mortality and morbidity is exclusively or partly dependent on a reduction in heart rate (HR), cardiac events in the Norwegian Timolol Multicenter Study were analyzed according to resting HR at baseline and at 1 month of follow-up Resting HR at baseline was a significant predictor of total death and all events (total death plus nonfatal reinfarction) both in placebo- and in timolol-treated patients. In the placebo group the median resting HR was unchanged from baseline to 1 month control (72 beats/min), but was reduced from 72 beats/min to 56 beats/min in the timolol group. Resting HR during follow-up remained a significant predictor of total death. Further, mortality at a given HR during treatment was not markedly different whether the HR was spontaneous or caused by timolol. Timolol treatment was related to a significant reduction in mortality, and this study suggests that the major effect of timolol treatment on mortality after acute myocardial infarction may be attributed to the reduction in HR. Timolol treatment was also associated with an overall reduction in nonfatal reinfarction. However, nonfatal reinfarction was inversely related to resting HR during follow-up, indicating that although coronary artery occlusion in low-risk patients may cause nonfatal reinfarction, the outcome in high-risk patients is more likely to be death. When analyzing mortality and nonfatal reinfarction combined, timolol treatment was related to a reduction in cardiac events at any given HR, suggesting that factors in addition to HR reduction are important in the protective effects of timolol.

Clinical Trials as Topic↗