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Biomedical subjects

K Arnman

Publications and source records attributed to K Arnman.

15 recordsLinked to original sources
PubMed1989

Intravenous infusion of enprofylline with an exponentially decreasing drug concentration in acute asthma.

Nine patients (3 women), aged 29-78 years, with acute asthma were treated with the antiasthma xanthine, enprofylline, in an open-design study without a reference drug. Enprofylline was administered intravenously (i.v.) over 2 h with an exponentially decreasing concentration. This alternative infusion system was found to be simple to handle. All patients but one reached a therapeutic plasma concentration of enprofylline within 20 min, but with a lower peak plasma, concentration as compared to what previously has been found with a conventional i.v. injection of the same amount of drug. The plasma concentration of enprofylline remained on a stable and therapeutic level over the 2-h observation period. The effect on lung function was comparable to that found in other controlled trials with enprofylline. A system for i.v. administration of drugs with an exponentially decreasing concentration as an alternative to manually given i.v. injections should be further evaluated.

Adult↗
PubMed1985

The haemodynamic importance of atrioventricular synchrony and rate increase at rest and during exercise.

To compare the added haemodynamic importance of atrioventricular synchrony to rate increase, we studied 10 patients, healthy except for atrioventricular block, treated with atrioventricular synchronous pacemakers. Haemodynamic data were obtained by brachial and pulmonary arterial catheterisation. Recordings were made at rest and during upright bicycle ergometry at two submaximal work loads (50% and 80% of maximal aerobic exercise tolerance). The investigation was first performed in the atrioventricular synchronous mode of pacing (VDD) and later repeated during fixed-rate ventricular pacing (VVI) at ventricular rates adjusted to the levels achieved during atrioventricular synchronous pacing. At rest (mean rate 74 bpm), preserved atrioventricular synchrony increased cardiac output (5.0 +/- 0.7 l min-1; mean +/- SD) compared with asynchrony (4.5 +/- 1.0; P less than 0.05), owing to a higher stroke volume (70 +/- 19 versus 64 +/- 22 ml; P less than 0.05), illustrating the importance of the atrial contribution to ventricular filling. During exercise at 50% (mean rate 122 bpm) and 80% (mean rate 146 bpm) of maximal aerobic tolerance, there were no significant differences in cardiac output (50%: VVI 10.1 +/- 2.5, VDD 10.5 +/- 1.6 NS; 80%: VVI 12.8 +/- 4.1, VDD 12.3 +/- 3.5, NS) or in stroke volume (50%: VVI 83 +/- 23, VDD 88 +/- 17, NS; 80%: VVI 89 +/- 32, VDD 85 +/- 27, NS). We conclude that the capacity for rate increase is of major importance while preserved atrioventricular synchrony seems to be much less important for the ability of the individual to increase cardiac output during exercise, at least in patients without myocardial disease.

Aged↗
PubMed1985

Physiological versus single-rate ventricular pacing: a double-blind cross-over study.

Previous comparisons of physiological and single-rate ventricular pacing are mostly based on open studies. The present investigation was designed to control possible biases of such a study design with the aim to investigate effects of the two pacing modes on maximal and submaximal exercise tolerance and the subjective feeling of well-being of the patients. Forty-four patients treated with atrioventricular synchronous pacemakers for more than 12 months participated in the study. Their pacemakers were randomly programmed to one 3-week long period of ventricular inhibited and a similar period of atrioventricular synchronous ventricular inhibited pacing. Thereafter, they went through echocardiography, symptom-limited maximal exercise test and answered a questionnaire on subjective symptoms. The study was blind since neither the patients nor the physician conducting the exercise tests were informed of pacing mode. The mean maximal exercise tolerance increased 14% (p less than 0.01) on atrioventricular synchronous pacing. Arterial lactate, respiratory rates and perceived exertion ratings during submaximal levels of exercise were higher on ventricular inhibited pacing, as well as symptoms scored during the two 3-week periods. A majority of patients improved their functional class during atrioventricular synchronous pacing and preferred the physiological pacing mode.

Adolescent↗
PubMed1984

Felodipine in primary pulmonary hypertension. Report of two cases.

Two women with primary pulmonary hypertension were treated with felodipine, a vasodilating agent. A marked reduction in pulmonary artery pressure was noted in one, whereas the other showed no reduction in pressure but an increase in blood flow and a decrease in pulmonary vascular resistance.

Adult↗
PubMed1983

A double-blind trial of metoprolol in acute myocardial infarction. Effects on ventricular tachyarrhythmias.

During a double-blind trial in which patients with suspected myocardial infarction received metoprolol or placebo, we analyzed the occurrence of ventricular tachyarrhythmias. Metoprolol (15 mg intravenously) was given as soon as possible after admission, and thereafter 200 mg was given daily for three months. Antiarrhythmic drugs were given only for ventricular fibrillation and sustained ventricular tachycardia (greater than 60 beats per second). Definite acute myocardial infarction developed in 809 of the 1395 participants, and probable infarction in 162. Metoprolol did not influence the occurrence of premature ventricular contractions or short bursts of ventricular tachycardia. However, there were 17 cases of ventricular fibrillation in the placebo group (697 patients) and only 6 in the metoprolol group (698 patients, P less than 0.05). During the hospital stay significantly fewer patients receiving metoprolol (16) than placebo (38) (P less than 0.01) required lidocaine. In a separate analysis of 145 patients, metoprolol did not influence the occurrence of premature ventricular contractions or short bursts of ventricular tachycardia during the first 24 hours of treatment. Despite a lack of effect on less serious ventricular tachyarrhythmias, metoprolol had a prophylactic effect against ventricular fibrillation in acute myocardial infarction.

Double-Blind Method↗
PubMed1983

Plasma concentration of disopyramide given as capsules and controlled release tablets.

Steady state plasma levels and clinical effects of disopyramide have been compared following administration of standard capsules and controlled release (CR) tablets. Nineteen patients (29-70 years) with atrial or ventricular arrhythmias were treated for two weeks with disopyramide capsules 200 mg t.i.d. and then with CR tablets 300 mg b.i.d. for 14 weeks. After treatment either with capsules or CR tablets, plasma concentrations of disopyramide and its metabolite N-deisopropyldisopyramide were similar within 1 dosage interval. Maximum and minimum concentrations of the parent drug were 10.1 +/- 0.9 mumol/l (mean +/- SEM) and 5.7 +/- 0.5 mumol/l with CR tablets, and 10.2 +/- 0.5 mumol/l and 5.6 +/- 0.5 mumol/l with standard capsules. The bioavailability of disopyramide was the same after capsules and CR tablets. Disopyramide, independent of the formulation, produced good antiarrhythmic effects. The side-effects reported on questioning were mainly of the anti-cholinergic type and there was no significant difference between the formulations with respect to their incidence, type or severity. Of 16 patients who stated a preference for one of the dosage forms, 11 prefered the CR tablets. The study confirms the good antiarrhythmic effect of disopyramide and shows that the CR preparation permits twice daily administration of disopyramide.

Adult↗
PubMed1983

Atrial synchronous ventricular pacing in ischaemic heart disease.

Atrial synchronous pacing has been considered contraindicated in patients with a high degree of atrioventricular block and concomitant ischaemic heart disease. The rationale for this view was a fear of provoking angina pectoris by a rate-dependent increase in myocardial oxygen consumption. As possible problems with atrial synchronous pacing in patients with ischaemic heart disease have not been extensively studied we have examined whether these patients could benefit from this more physiological method of pacing. Thirteen patients with ischaemic heart disease and a high degree of atrioventricular block were supplied with pacemakers, programmable both in reference to the pacing mode (ventricular inhibited (VVI) or atrial synchronous ventricular inhibited (VDD)) and for maximal synchronous rate. The patients were examined with the pacemaker programmed in the VVI and VDD modes. Maximal exercise capacity was determined by means of bicycle ergometry. There was a statistically significant increase in exercise capacity when comparing VVI (67 + 24) with VDD (79 + 25, P less than 0.001) pacing with suitable programming of maximal synchronous rate. No patient experienced increased anginal pain on VDD pacing and all preferred VDD compared to VVI pacing. In conclusion, VDD pacing should not be considered contraindicated in patients with ischaemic heart disease and a high degree of atrioventricular block, and may, on the contrary, contribute to further clinical improvement.

Aged↗
PubMed1982

Comparison of metoprolol and verapamil in the treatment of angina pectoris.

The cardioselective beta adrenoceptor blocking agent metoprolol was compared with the calcium antagonist verapamil in relation to effects on angina pectoris. Twenty patients with stable, exercise-induced angina pectoris took part in a 14 week study that began with a 4 week single blind placebo period. In the succeeding 4 weeks, verapamil in a daily dose of 360 mg or metoprolol, 200 mg twice daily, was administered in double-blind fashion. After 2 weeks the patients were transferred to a second 4 week period of treatment with the other drug. The number of anginal attacks and the consumption of nitroglycerin tablets were reported. At the end of each treatment period a symptom-limited maximal exercise test was performed. The mean daily rate of anginal attacks and nitroglycerin consumption decreased significantly (p less than 0.01) and to a similar extent with both drugs. Exercise capacity increased from 103 +/- 7 to 113 +/- 7 watts (p less than 0.01) with metoprolol and to 119 +/- 6 watts (p less than 0.01) with verapamil. The increase with verapamil was significantly higher (p less than 0.05) than with metoprolol. Metoprolol caused a substantial reduction in the rate-pressure product both at rest and during exercise (p less than 0.001); this variable was not influenced by verapamil. Adverse effects were only mild to moderate and did not cause the cessation of treatment in any case. In conclusion, metoprolol and verapamil are two effective drugs for treatment of stable exercise-induced angina pectoris. Which drug is preferable as a first choice may depend on possible contraindications to one of these agents rather than on the belief that one is much more effective than the other.

Adult↗
PubMed1982

A comparison of the acute and long-term hemodynamic effects of ventricular inhibited and atrial synchronous ventricular inhibited pacing.

Sixteen patients treated with a noninvasively programmable pacemaker were examined after a prolonged period of ventricular inhibited (VVI) and atrial synchronous ventricular inhibited (VDD) pacing. Maximal working capacity was determined by bicycle ergometry. Atrial and ventricular rates, brachial artery cuff pressure and breathing rate were determined at rest and during exercise. There was a mean increase in working capacity of 24% with VDD compared with VVI pacing (p less than 0.001). Thirteen of the patients were catheterized. During VDD pacing, cardiac output was significantly higher, particularly during exercise (+/- 32%) due to the capability of heart rate increase and despite a substantial compensatory stroke volume increase during VVI pacing. Arteriovenous oxygen difference was much higher during VVI pacing, reaching 164 +/- 14 ml/l during the highest work load, while the corresponding level during VDD pacing was 140 +/- 14 ml/l (p less than 0.001). During exercise, arterial blood lactate was significantly higher during VVI than during VDD pacing. Heart size was significantly smaller, 568 +/- 98 vs 530 +/- 96 ml/m2 BSA (p less than 0.05), during VDD pacing a questionnaire was completed by the patients to evaluate subjective symptoms and pacemaker preference. This part of the study favored the VDD mode of pacing. The conclusion of this study is that VDD pacing is superior to VVI pacing.

Aged↗
PubMed1980

Prophylaxis of ventricular tachyarrhythmias with intravenous and oral tocainide in patients with and recovering from acute myocardial infarction.

In a double-blind placebo controlled study, tocainide, 750 mg i.v. during a 15-minute period directly followed by 800 mg orally and later 400 mg t.i.d., was administered to patients wiht acute myocardial infarction (AMI). Treatment was started as soon as possible following onset of symptoms; the follow-up period was 6 months. The patient groups consisted of 56 tocainide and 56 placebo patients. There was no significant effect on the incidence of ventricular fibrillation or symptomatic ventricular tachycardia. The mortality rates were similar and low in both groups. Tocainide suppressed ventricular arrhythmias, including ventricular tachycardia, both in the acute stage of AMI and during convalescence. Tocainide also suppressed exercies-induced ventricular arrhythmias. Side effects were in general mild or moderate.

Administration, Oral↗
PubMed1979

Syncope caused by lithium treatment. Report on two cases and a prospective investigation of the prevalence of lithium-induced sinus node dysfunction.

Lithium salts have been widely used for several years in the treatment of manic-depressive psychosis. Various side-effects of lithium salts have been described. The present case report present two patients in whom sinus node dysfunction leading to syncope was caused by lithium. One of the cases showed signs of depressed sinus node function even when not on lithium, but no symptoms arose until lithium treatment was commenced. The second case showed no signs of depressed sinus node function when lithium was withdrawn. To study the prevalence of sinus node dysfunction in patients on lithium therapy, 97 consecutive patients on lithium were examined. The examination included case history, ECG and carotid massage. In two patients lithium could not be ruled out as being responsible for sinus node depression and in one patient the same was true for the atrioventricular node. None of these patients had any symptoms. It is concluded that lithium treatment may result in sinus node dysfunction. This side-effect is, however, not common. Lithium treatment can obviously be instituted in all patients without a history suggesting sinus node dysfunction. Patients with a history of dizziness and/or syncope should not be given lithium until thorough cardiological examination has been carried out. Likewise, a cardiological examination should be performed if patients on lithium develop symptoms of this type.

Aged↗
PubMed1975

The effect of norepinephrine and theophylline on blood glucose, plasms FFA, plasma glycerol and plasma insulin in normal subjects.

The plasma concentrations of free fatty acids (FFA), glycerol and insulin as well as the blood glucose concentration have been followed in two groups of subjects after infusions of theophyllamine. Each individual was examined twice. The 5 subjects in group 2 were given an infusion of norepinephrine before the theophyllamine at one of the examinations and saline at the other. The 6 subjects in group II were given an infusion of norephinephrine at both examinations, followed by theophyllamine on one occasion and by saline on the other. Thus, the subjects in both groups served as their own controls. It was found that theophyllamine caused lipid mobilization, as measured by the plasma FFA and plasma glycerol concentrations, both when given as the only active drug and when given after norepinephrine. The blood glucose concentration rose slightly after norepinephrine and the plasma insulin level increased concomittantly. When theophylline was given as the only active drug, there was no increase in the blood glucose but the plasma insulin concentration rose slightly.

Adult↗