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Biomedical subjects

O J Ohm

Publications and source records attributed to O J Ohm.

84 records · Page 5Linked to original sources
PubMed1977

Haemodynamic long-term effects of metoprolol at rest and during exercise in essential hypertension.

1 Twelve men with untreated essential hypertension in WHO stage I were studied on an outpatient basis to evaluate the haemodynamic long-term effect of a new beta-adrenoceptor blocker, metoprolol. 2 Oxygen consumption, heart rate, cardiac output (Cardiogreen) and intraarterial brachial pressure were recorded at rest in a supine and sitting position and during steady state work at 300, 600 and 900 kpm/min. 3 The subjects were treated with metoprolol (dose 50-250 mg/day) as the sole drug for 1 year and the haemodynamic study was repeated. 4 Mean arterial blood pressure was reduced about 12% at rest and 9% during exercise. The heart rate was decreased about 22% at rest and 20% during exercise. There was no significant compensatory increase in the stroke volume and consequently the cardiac index was reduced about 22% at rest sitting and about 17% during exercise. There was no decrease in total peripheral resistance. 5 No side-effects were seen. 6 The major haemodynamic long-term effects of metoprolol in mild and moderate essential hypertension resemble those seen by other beta-adrenoceptor blockers like alprenolol, atenolol and timolol. The study has not given support to the assumption that metoprolol should cause less depression in cardiac output than other beta-adrenoceptor blockers.

Adult↗
PubMed1976

Haemodynamic long-term effects of beta-receptor-blocking agents in hypertension: a comparison between alprenolol, atenolol, metoprolol and timolol.

1. Oxygen consumption and central haemodynamics were recorded at rest and during exercise in fifty-one men with essential hypertension (W.H.O. stage I) and repeated after 1 year on a single drug: alprenolol (n equals 10), atenolol (13) metoprolol (12) and timolol (16). 2. Mean arterial pressure was significantly reduced in all groups at rest (11-18%) and during exercise (5-11%). Heart rate was significantly reduced in all groups (20-28%) at rest and (17-26%) during exercise. Owing to increase in supine resting and exercise stroke volume in the alprenolol and atenolol group, cardiac index decreased less than heart rate---in contrast to the timolol group where cardiac index was decreased 26-32%. The calculated post-treatment total peripheral resistance was significantly increased at rest and during exercise in the timolol group. In the other groups the total peripheral resistance was significantly increased at rest when sitting, but not at rest when supine and during exercise. 3. It is concluded that the major haemodynamic changes induced in subjects with moderate and mild essential hypertension by these different beta-receptor blockers are the same, but that minor differences exist with respect to effect upon stroke volume and total peripheral resistance.

Adrenergic beta-Antagonists↗
PubMed1976

Complications with permanent endocardial electrode systems.

The different complications of endocardial electrode systems in 185 patients during the last seven years are discussed. The surgical technique for the now routinely used cephalic route is described. The choice of anaesthesia is discussed. In the last 39 implantations there have not been any displacements or retractions. Of the total number of patients only 3 required replacement of endocardial by myocardial electrodes. This was caused by unstable position and high stimulation threshold. Fracture of the electrode occurred in 4 cases. Stimulation of the diaphragm occurred in 10%, displacement and retraction of the electrodes in 6,5% and heart penetration or perforation in 3,8% of the patients. There was one death from cardiac tamponade due to electrode perforation of the right ventricle. One case had irreversible brain damage due to prolonged asystole during pulse generator replacement. Unimportant wound infections and haematomas occurred in 5 patients and phlebitis in 3 patients. More or less serious electrode complications have been seen in 56 of the 185 patients, 18 patients having more than one complication.

Electrodes, Implanted↗
PubMed1976

Interference with cardiac pacemaker function.

A survey is given of the factors affecting cardiac pacemaker function. Whereas it was earlier considered that external interference was a frequent cause of a pacemaker failure, more recent studies indicate that this is of minor importance. It would appear that failure of pacemaker function due to changes in the QRS-complex, i.e. voltage change, intraventricular conduction defects and frequency changes, intraventricular conduction defects and frequency changes, are more important. A lesser known cause of failure in demand function is the inhibition which arises from skeletal muscle postentials. This appears to be a major problem in some types of pacemaker. Manufacturing defects are unavoidable, and it can still be assumed that electronic component defects may develop in 1 of 1000 pulse generators. Cases with the problem of early run-away pacemaker are still being reported and two such cases are discussed. In one of the patients the run-away phenomenon was intermittent, and was accompanied by a variation in run-away frequency. This possibility should thus always be taken into consideration in a pacemaker patient presenting with snycope. In a patient with a QRS-inhibited pacemaker a double stimulation phenomanen has been observed.

Electrodes, Implanted↗