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Biomedical subjects

G Rettig

Publications and source records attributed to G Rettig.

At least 37 records · Page 2Linked to original sources
PubMed1984

Sudden cardiac death during ambulatory Holter monitoring. Report on 3 documented cases.

Three cases are presented who died suddenly while being continuously monitored on ambulatory Holter ECG. Two patients with coronary artery disease and severe left ventricular dysfunction after multiple myocardial infarctions died instantly from ventricular fibrillation; this was preceded by a rapid uniform ventricular tachycardia in one patient with normal Q-T interval and by polymorphous ventricular tachycardia in the other whose Q-T was prolonged on combined antiarrhythmic therapy with propafenone and mexiletine. The third patient died from rapidly progressive circulatory failure and acute pulmonary edema due to secondary cardiomyopathy. Despite its occurrence within 30 min after the onset of symptoms, death was not primarily arrhythmic in origin.

Ambulatory Care↗
PubMed1984

[Mechanism of action of oxyfedrine as a partial beta receptor agonist].

To investigate a possible dual action of oxyfedrine on beta-adrenergic receptors, hemodynamics and systolic time intervals were studied in 12 healthy volunteers during intravenous infusion of isoprenaline. The dose was titrated to a mean target heart rate of 113 bpm corresponding to an average dose of 6.16 micrograms/min. After return to baseline hemodynamics, oxyfedrine was administered as an intravenous bolus of 8 mg and the protocol was repeated. Compared to baseline, the percentage changes induced by isoprenaline at doses of 2.73 and 6.16 micrograms/min before and after (in parentheses) oxyfedrine were: heart rate: +33/+83% (+19/+62%); cardiac output: +90/153% (+30/+71%); systolic blood pressure: +16/+20% (+6/+7%); stroke volume: +42/+38% (+10/+6%); peripheral vascular resistance: -50/-63% (-31/-50%); cardiac work: +86/+148% (+19/+54%); pre-ejection period: -40/-56% (-27/-45%); isovolumic contraction time: -56/-79% (-29/-63%); systolic ejection rate: +67/+103% (+27/+52%); tension time index: +32/+50% (+7/+20%). Thus, the dose-dependent hemodynamic effects of isoprenaline were significantly attenuated by oxyfedrine pre-treatment with a shift of the dose-response curve to the right; this was attributed to a beta-antagonistic property of oxyfedrine. The results indicate that, in view of its well-known beta-stimulating effects, oxyfedrine exerts a dual action on adrenergic beta-receptors consistent with partial agonistic activity. Thereby, the different profiles of hemodynamic and metabolic actions of oxyfedrine compared to those of pure beta-agonistic agents can be explained as well as its beneficial therapeutic effects in patients with coronary heart disease.

Adolescent↗
PubMed1983

[Acute and long-term effects of gallopamil (D 600) in stable angina pectoris--a randomized double-blind study].

The effects of the calcium-channel-blocking agent Gallopamil (D 600) were assessed in 20 patients with stable exertional angina pectoris in a randomized placebo-controlled double-blind protocol using serial exercise tests. Both after a single oral dose and during long-term treatment over 3 weeks, Gallopamil caused a dose-dependent increase in exercise duration and a reduction in ischemic ST segment depression that became clinically relevant using single doses of 50 mg. Since the rate-pressure product was not significantly affected by Gallopamil, its anti-anginal action cannot adequately be explained by a reduction in myocardial oxygen consumption as a result of this mechanism. The only side effects observed were asymptomatic second-degree sinoatrial block in one and first-degree atrioventricular block in another patient, each on 150 mg gallopamil daily. It thus seems justifiable to study the effectiveness of higher doses.

Adult↗
PubMed1983

[Incidence and significance of angina pectoris in aortic valve disease].

To determine the incidence and significance of angina pectoris in aortic valve disease, clinical, haemodynamic, and angiographic data concerning 111 consecutive patients aged 27-68 years (mean 52) were retrospectively analysed. 14.4% (group A) had significant, 85.6% (group B) had no coronary heart disease. There was a significant difference between the groups regarding the incidence of typical angina pectoris (62.5% vs 31.6%, p less than 0.01) and freedom from chest pain (12.5% vs 32.6%, p less than 0.05). No difference, however, could be found concerning the incidence of atypical chest pain (25% vs 35.8%). Of 12 patients aged over 50 years with coronary artery disease, no patient was free of angina pectoris. 83% had typical, 17% had atypical angina pectoris. Of 4 patients below 45 years with coronary artery disease, however, none had typical angina pectoris, 2 patients had atypical angina, and 2 patients had none. These results demonstrate that typical angina pectoris in patients with aortic valve disease is not a specific indicator of concomitant significant coronary artery disease. On the other hand, absence of chest pain does not predict absence of coronary artery disease, especially in younger patients. We therefore suggest that coronary angiography be carried out in all adult patients in whom aortic valve surgery is being considered.

Adult↗
PubMed1982

Afferent visual projections in three species of lungless salamanders (family Plethodontidae).

Afferent visual projections were demonstrated in three species of plethodontid salamanders by means of anterograde transport of horseradish peroxidase. On the contralateral side three optic tracts and seven neuropil areas can easily be distinguished, which are similar among the three species examined as well as in European salamandrids. On the ipsilateral side the marginal optic tract shows great diversity. The retinal projections of the latter range from weakly labeled terminal fields restricted to the thalamus to heavily labeled fields covering the entire tectum opticum.

Animals↗
PubMed1982

[Effects of oxyfedrine on sinus nodal function and AV-conduction (author's transl)].

In 20 patients the electrophysiologic effects of oxyfedrine at doses of 0.3 mg/kg/hr and 0.6 mg/kg/hr were studied. At the low dose, oxyfedrine caused a significant shortening of the absolute and rate-corrected sinus node recovery time by 16 and 27 percent, respectively. Sinus cycle length decreased slightly by 9 percent. Estimated sinoatrial conduction time tended to shorten, but not significantly so. AV-nodal conduction was slightly accelerated at sinus rhythm as well as during atrial stimulation; correspondingly paced cycle length at which Wenckebach AH-conduction occurred decreased. HV-interval remained unchanged. Increasing the dose of oxyfedrine had no additional effect on electrophysiologic parameters compared to the first dose used. The results demonstrate a moderate stimulatory action of oxyfedrine on sinus nodal automaticity and a slight acceleration of AV-nodal conduction. Whether the drug might be useful in the clinical setting for medical management of sinus nodal dysfunction or AV-conduction disturbances, remains to be elucidated on long-term studies; more pronounced effects of oxyfedrine than found in this investigation, however, are expected to be limited by its autoinhibitory action at higher dose levels.

Adult↗
PubMed1981

Development of retinofugal neuropil areas in the brain of the alpine newt, Triturus alpestris.

The development of the retinofugal projection areas of the brain has been studied in larvae of Triturus alpestris by means of anterograde transported horseradish peroxidase. The optic tract establishes contacts with the optic tectum prior to the onset of robust terminal formation in the diencephalon. The tectum becomes covered by the retinofugal projection in a rostro-caudal direction. The basal optic neuropil develops synchronously with the oculomotor neurons. Their dendrites extend into this neuropil area. A small amount of uncrossed label occurs long before metamorphosis. Around metamorphotic climax this ipsilateral label increases but does not attain the adult pattern even three monts postmetamorphosis. The data are compared with the onset of visual induced behaviour.

Animals↗
PubMed1979

Complications with retained transvenous pacemaker electrodes.

Out of a series of 1,734 pacemaker patients, the clinical course of 46 patients was reviewed in whom a functionless endocardial electrode was retained. Non-infected electrodes (25 patients) were generally well tolerated without complications, except in one patient who experienced fatal catheter embolism into the pulmonary artery. In cases of infected electrodes (21 patients) a mortality rate of 25% was encountered due to septic complications. Catheter migration was fatal in two out of three patients. It is concluded that entrapped electrode catheters should be removed by thoracotomy if persisting infection is present or if catheter migration has occurred.

Adult↗
PubMed1979

Hemodynamic effects of pentazocine in acute myocardial infarction.

In 12 patients with acute myocardial infarction the hemodynamic effects of a single intravenous injection of 30 mg of pentazocine were investigated. The administration of pentazocine resulted in no significant hemodynamic changes. In particular, there was no increase in peripheral vascular resistance and no evidence of decreased left ventricular function or respiratory depression. In the occasional patients who demonstrated an elevation of pulmonary arterial pressure, it was probably due to a direct effect of the drug on the pulmonary vasculature.

Aged↗
PubMed1979

Influence of perfusion and mechanical activity of ornithine decarboxylase activity in the isolated rat heart.

A small, but not significant, decrease in ornithine decarboxylase activity occurred in isolated hearts during one hour of recirculating perfusion with Krebs-Henseleit solution. A significantly greater decrease occurred with a non-recirculating system. Ornithine decarboxylase activity was the same in the working heart preparation as in the non-working preparation. It is concluded that a substance, necessary for the maintenance of ornithine decarboxylase, is removed during perfusion. The nature of the mechanical activity of the heart did not appear to be a determining factor.

Animals↗
PubMed1978

[The effects of oxyfedrine on the hemodynamics of patients with acute myocardial infarction].

In 16 patients with acute transmural myocardial infarction the effect of 8 mg of intravenous oxyfedrine followed by an infusion of 0.3 mg/kg body weight per hour on haemodynamics of the pulmonary and systemic circulation and dynamic cardiac indices was investigated. Cardiac rate, systemic arterial blood pressure, minute volume, cardiac output, and tension-time index remained unchanged on the whole. On the other hand oxyfedrine produced a persistant significant decrease of the mean and diastolic pulmonary artery pressure, pulmonary capillary pressure, and of the contraction and pressure-increase time. These effects were also demonstrable in patients previously treated with digitalis. No cardiac arrhythmias were observed. The positive inotropic effect of oxyfedrine is suggested as reason for these changes.

Aged↗