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Biomedical subjects

H Schieffer

Publications and source records attributed to H Schieffer.

At least 109 records · Page 6Linked to original sources

[Incidence of ventricular arrhythmia relative to the QT interval in spontaneous intracranial hemorrhages].

A prospective study was done in 54 patients with acute spontaneous intracranial haemorrhage, 27 of them with subarachnoid bleeding and 27 with primary intracerebral haemorrhage. The frequency of ventricular arrhythmias was registered by continuous long-term ECG and the incidence of QT prolongation by daily standard ECG registration. Prolongation of frequency-corrected QT-interval (QTc) developed in 9 patients with subarachnoid haemorrhage and in 10 with intracerebral haemorrhage. For assessment of time-relation between QT-interval and ventricular arrhythmias the results of corresponding long-term ECG and standard ECG were used and two groups were defined: group A (149 tapes) = QTc less than or equal to 450 ms, group B (43 tapes) = QTc greater than 450 ms. In group B singular frequent ventricular extrasystoles, couplets and non-persistent ventricular tachycardias occurred more frequently though not significantly so. Persistent ventricular tachycardias occurred significantly more frequently in group B (14% vs. 1%, P less than 0.01). In three tapes of group B, all of them with QTc prolongation of more than 550 ms persistent ventricular tachycardias with typical "torsade de pointes " morphology were seen. The results show that QTc prolongation of more than 450 ms occurs in a third and significant ventricular arrhythmia in nearly half of patients with spontaneous intracranial haemorrhage. Persistent ventricular tachycardias occur almost only in cases of QTc-prolongation. Pronounced QTc prolongation of more than 550 ms is rare. However, it can give rise to torsade de pointes and ventricular fibrillation.

Adult↗

[Long-term therapy of angina pectoris. Evaluation of the effectiveness and tolerance of oxyfedrine in ambulatory patients].

In an open multicentre trial, the clinical efficacy and tolerance of Oxyfedrine, (Ildamen forte) was evaluated in 123 patients with angina pectoris. After three months of treatment the frequency of anginal attacks and nitroglycerin consumption were markedly reduced in 80 percent, after 12 months in 88% of patients; 37 percent were totally angina-free and 50% were without need for sublingual nitroglycerin. Side-effects were reported by 23.6% of patients during the first months of treatment with a total of eight symptoms being reported in 40 instances; after one year, the incidence of side-effects was substantially reduced to 8 instances in 6 percent of patients. Laboratory investigation were not significantly affected: in 11 patients minor deviations from the reference range were noted without clinical relevance. Dropouts due do drug intolerance were not observed.

Adult↗

Sustained atrial flutter after cardiac surgery: successful termination by rapid atrial pacing.

For termination of sustained atrial flutter, 28 rapid atrial stimulations were performed in 26 patients undergoing cardiac surgery, including coronary bypass surgery, and valvular heart surgery as well as surgery for primum and secundum atrial septal defect and anomalous connection of the pulmonary veins. In 18 patients rapid atrial pacing was successful in directly converting a flutter to a sinus rhythm, in 5 patients after a short period of transient atrial fibrillation. Atrial flutter could be changed to atrial fibrillation in a further 3 patients who remained in permanent atrial fibrillation and subsequently underwent DC cardioversion. Our results demonstrate that rapid atrial pacing is very effective in the treatment of sustained atrial flutter in patients following cardiac surgery and may be used alternatively to DC countershock.

Adolescent↗

[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↗

[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↗

[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↗

[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↗

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↗

[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↗

[Effects of oxyfedrine on haemodynamics in patients with acute myocardial infarction (author's transl)].

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↗

[Coincidence of malformations of the cardiovascular system as well as of the kidneys and of the efferent urinary tract (author's transl)].

Excretion urograms were prepared subsequent to angiocardiograph in a total of 115 cardiac catheter examinations. 104 of these examinations were evaluated. In 17 cases (16.3%), malformation of the kidney or the ureter was found. In consideration of the fact that such fundings are often directly linked to therapeutic consequences (plastic operations), the additional preparation of an excretion urogram is indicated during cardiac catheter examinations.

Angiocardiography↗

[Effect of cardiac catheter investigations and angiocardiography on enzyme activity in serum (author's transl)].

The serum activities of LDH, alpha-HBDH, CK, GOT and GPT wer investigated in 124 patients who had undergone cardiac catheterization with angiocardiography or coronary angiography. The determinations were made before and 2, 16 and 40 hours after the investigation. There was no significant influence on the enzyme activities. Lengthy intracardial catheter manipulation, trans-septal puncture and ventriculography may cause transient clinically unimportant increases in activity, especially of CK within normal limits. Distinctly pathological enzyme values were only measured in individual cases of intramyocardial contrast media depots after ventriculogram.

Adult↗