[The significance of free radicals in cardiology].
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Coronary Disease↗
Biomedical subjects
D Modersohn
Publications and source records attributed to D Modersohn.
[Effect of an angiogenesis-promoting dipeptide on microcirculation in experimental chronic stomach ulcer in the rat].
The influence of an angiogenesis stimulating dipeptide (Lys-Pro-derivative) on the blood flow rate of the stomach was tested in rats suffering from ulcus ventriculi by microspheres technique. 21 days after operation (acetic acid model by Takagi) the ulcers in the group treated with the dipeptide were healed completely, but not in the control group. The higher blood flow in the ulcer area of the dipeptide group radiometrically gained, was not changed significantly (U-test by Man-Whitney). These results demonstrate, that the process of rapid wound healing promoted by the dipeptide cannot entirely be explained by a higher blood flow of the stomach.
Angiogenesis Inducing Agents↗
[Transfemoral balloon occlusion of the coronary sinus in patients with angina pectoris].
The aim of the study was to demonstrate the possibility of transfemoral balloon occlusion of the coronary sinus and to detect changes of the left ventricular function during this occlusion in patients with angina pectoris. In 9 of 18 patients a stable occlusion over 15 seconds was performed. There were found only short term negative effects on the left ventricular contraction and relaxation. The coronary sinus pressure increased to 53 +/- 11 mm Hg. Numerous venous anastomoses made it difficult to occlude completely the sinus. The retrograde perfusion of the myocardium reached 20-30% of the antegrade one.
Adult↗
[The effect of ionic and nonionic contrast media (amidotrizoate, iopromide) on cardiac function (contractility, relaxation, perfusion)].
In 30 patients the influence of ionic (Amidotrizoate) and non-ionic (Iopromide) contrast agents on the heart parameters contractility, relaxation, perfusion and the rate of extrasystoles was investigated. They were significantly less influenced by Iopromide than by Amidotrizoate. A negative inotropic action was detectable only for Amidotrizoate. It is concluded that non-ionic contrast media should be used especially for critical patients.
Coronary Circulation↗
[Acute changes in global and regional systolic heart function caused by pentoxifylline in patients with and without coronary sclerosis].
In 36 patients with angina pectoris during complex invasive diagnostic procedure the changes of global and regional systolic heart function by intravenous application of 200 mg pentoxifylline were examined. We observed a significant decrease of preload (reduction of LVEDP and MCS, LVEDV was not influenced) and an improvement of myocardial pump function, possibly combined with a favourable influence on alterated myocardial blood supply. In case of perfusion disturbances of the LV anterior wall the pentoxifylline injection was followed by signs of coronary-steal-mechanism in the LV posterior wall region. We did not found significant changes of afterload. Thus the acute hemodynamic effects of an intravenous application of pentoxifylline are comparable with those of nitrates and non-glycoside-cardiotonic substances with a predominant myocardial effect.
Coronary Artery Disease↗
[Effects of pentoxifylline on diastolic heart function in patients with angina pectoris and an increased left ventricular wall mass].
The combination of coronary heart disease (CHD) with increased left ventricular wall mass (LVWM) appears associated with prolonged isovolumetric relaxation (IVR) and consequently, alterations in the rapid filling phase. Methylxanthine-substances may improve relaxation through inhibition of phosphodiesterase activity. Accordingly we examined multiple indexes of left ventricular diastolic function before and after administration of 200 mg pentoxifylline (Trental) intravenously to 18 patients (51.3 +/- 9.0 years, 15 males, three females) with stable angina pectoris and positive exercise-ECG in NYHA class I or II and LVWM greater than 160 g (n = 9) and less than or equal to 160 g (n = 9). Left ventricular pressure (P) and volume (V) measurements were made with a high-fidelity-micromanometer before and twelve minutes after administration of pentoxifylline. The time constant of left ventricular isovolumic relaxation (T), usual global left ventricular volumes and derived indexes such as peak filling rate (PFR), time to peak filling rate (TPFR), segmental (relaxation and rapid filling phases) and total pressure-volume relationship before and after pentoxifylline were calculated. Significant differences between these two groups (greater than/less than or equal to 160 g LVWM) were found for end-diastolic volume (68.7 +/- 19.0 to 90.8 +/- 22.6 ml/sqm), end-systolic volume (21.7 +/- 16.0 to 36.1 +/- 14.7 ml/sqm), end-diastolic pressure (15.0 +/- 4.8 to 15.7 +/- 5.1 mm Hg), PFR (3.25 +/- 1.18 to 2.66 +/- 0.71 s-1), T (46.0 +/- 5.7 to 52.7 +/- 7.2 ms), the linear regression of lnP-V (lny = -0.117 x + 4.59 to lny = -0.091 x + 4.75) in the IVR-phase (dp/dtmin less than or equal to x less than or equal to 80 ms) (leftward shift in p-V-relationship when less than or equal to 160 g) and the complet p-V-areas. After pentoxifyl-line-administration there were significant decreases in T in patients with increased LVWM (52.7 +/- 7.2 to 47.7 +/- 5.9 ms) and the P-V-product over the time in the rapid filling phase in patients with LVWM less than or equal to 160 g. Total peripheral resistance and heart rate did not change. These changes in parameters of left ventricular diastolic function in combination with significant improvement of pump function especially in patients with LVWM greater than 160 g after administration of pentoxifylline suggest that improved diastolic function is the result of a direct myocardial effect of pentoxifylline.
Adult↗
[Significance of the diastole in the clinical evaluation of heart function].
The diastole is frequently neglected in the assessment of the heart function, though for a long while has been known that in the diastole active, energy-requiring processes take place. After a description of the various definitions and fundaments of the diastolic function of the ventricle the essential criteria and the methodological possibilities are mentioned. The most exact informations are to be obtained from simultaneous analyses of pressure dimensions (and volumes, respectively) with regional differentiation. In this case we are particularly interested in the early (isovolumetric) relaxation phase, since here the essential energetic processes take place, which may early be changed and which also first to all may be influenced medicamentously. By means of a listing of parameters of the diastolic ventricular function depending upon the methodological possibilities impulses shall be given to take into consideration the diastole more for diagnosis, prognosis and above all for therapy.
Cardiac Volume↗
[The cardiovascular effect of Cordemcura on various animal models in vivo].
The cardiotonic activity of Cordemcura was investigated in anesthetized pigs, cats, and rats. Hemodynamic measurements were made under normal conditions and under drug-induced heart failure (hexobarbital, isoproterenol). Cordemcura caused significant positive inotropic effects with rapid onset and relatively short duration of action (0.2-3.2 mg/kg i. v.). In the pig dp/dtmax was increased by 31.4% (p less than 0.02) at 1.6 mg/kg, in the cat by 34.2% (p less than 0.05) at 0.5 mg/kg, and in the rat by 14.4% (ns) at 0.5 mg/kg. The inotropic response was associated with a significant reduction of total peripheral resistance (TPR) (pig: -21.4%, p less than 0.02; cat: -13.7), and relatively small changes in heart rate, cardiac output, and blood pressure. Under drug-induced heart failure there was no further increase in the cardiotonic activity of Cordemcura. The hemodynamic effects of Cordemcura were compared with the effects of dopamine (5-100 micrograms/kg i. v.) and ouabain (10-40 micrograms/kg i. v.).
Aminopyridines↗
Absolute and relative myocardial ischemia by isoproterenol overdosage.
Administration of greater than or equal to 10 mg/kg isoproterenol in rats absolutely diminished local myocardial blood flow within 0.5 min continuing up to 45 min. The blood flow reduction was followed by an increased lactate content and a decrease of both the intracellular redox potential and the content of high energy phosphates in the myocardium. The graduation of the initial lactate accumulation in different myocardial regions corresponds to the myocardial distribution of the infarct-like necroses occurring 24 h later. The very early alterations are comparable with an absolute (blood flow reduction), irreversible, and acute ischemia. In the dose range from 0.05 to 1 mg/kg of isoproterenol, an acceleration of the local myocardial blood flow was caused which, however, was accompanied by ischemia-like disturbances, too. Therefore, this condition is considered as a relative ischemia, an increased but insufficient blood supply.
Animals↗
[The use of sodium nitroprusside (Nipruton) in ischemia-related acute heart insufficiency].
By controlled vasodilation with nitroprusside sodium we succeed in improving the negative haemodynamic effects of the pumping insufficiency in myocardial ischamia. Increased filling pressures decrease, volumes of output increase in clearly decreased oxygen consumption of the myocardium. The influence on the time volume of the heart depends on the height and reaction of the filling pressure on nitroprusside sodium. In normal LVEDP the time volume of the heart decreases by nitroprusside sodium. The local function of the heart may clearly be improved under nitroprusside sodium in ischaemia. Altogether the hitherto got results in man are not homogeneously interpreted. Problems result from in form of therapy necessary frequent controls of the filling pressures and volumes of output as well as from the possible decrease of the time volume of the heart and the critical reduction of the perfusion pressure. According to own results of experiments on animals the sequelae of ischaemia may be reduced under the infusion of nitroprusside sodium. The restricted regional function of the heart is particularly improved. An obligatory judgment concerning the temporarily restricted use of nitroprusside sodium in the pumping insufficiency conditioned by ischaemia is not yet possible. A complicating effect have the individually different dose-effect-relations as well as not foreseeable haemodynamic results as a sequel of the basic disease in the complicated myocardiac infarction which is to be regarded as indication.
Animals↗
[Therapeutic principles of drug-induced cardiac debit with vasodilators].
For the haemodynamically controlled preload reduction (LVEDP and ZDV) as well as the afterload reduction (arterial blood pressure) with volume of output taken into consideration in the first place glycerol trinitrate, nitroprusside sodium, alpha-blockers, hydralazine, prazosine and nitrates are used. The medication is given in acute and chronic pumping insufficiency. The distance between therapeutic effect wanted and unfavourable influences due to critically reduced preload and coronary perfusion as well as reduced volume of output is close. The haemodynamic analysis of actual situation of the disease as well as regular controls are necessary. The effects of the long-term therapy in chronic pumping insufficiency with peroral effective vasodilators are still unsatisfactory.
Adrenergic alpha-Antagonists↗
[Evaluation of regional heart function by means of local changes in pressure and direction in the vector cardiogram].
Regional function parameters under myocardial ischemia are frequently clearly changed when the parameters as the stroke volume, cardiac output, ejection fraction and the like are still unchanged by a compensation mechanism. Length changes can be measured regionally and phasically by means of a mercury wire strain gauge. The active shortening during the ejection time in relation to the total length change in this region is a possibility for the registration of the relative systolic shortening (delta LS%). Changes will be quantified still clearer and earlier if in the x-y display a vector representation of the regional displacements with the pressure in the left ventricle takes place. The plane of this vector decreased already a few seconds after the coronary occlusion. This is therefore a special early change in ischemia. The important for the estimation of therapeutic measures and other indirect measuring methods is accentuated.
Animals↗
[Importance of microcirculation in myocardial circulatory disorders].
The importance of microcirculation for disturbances of the blood perfusion of the myocardium is demonstrated by experimental results obtained by the isoproterenol model of rats and the occlusion model of mini pigs. Hypoxia in this region causes very quickly an increase of the extracapillary space and a swelling of the capillary endothelial cells of different degrees. These changes are accompanied by an increase of the ST-region of the epicardial ECG, by a decrease of the myocardial contractility and the coronar-venous oxygen pressure, by an increase of the lactate and pyruvate level in the tissue and a decrease of the creatine-phosphate level in the myocardium. The relation between the wet weight and the dry weight increased in hypoxia, too. The morphological and physiological parameters can be influenced contrarily by infusions with hypertonic mannitol solution. The importance of these changes, especially in the early period of myocardial hypoxia is discussed by the application of the model of Krogh. The necessity of an early influence of these disturbances by pharmacotherapy during the starting period of a myocardial hypoxia is emphasized.
Animals↗
[Beta-receptor blockers in ischemic heart disease: the pathophysiological and clinical aspects].
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Adrenergic beta-Antagonists↗
[The effect of early appearing extrasystoles on systemic and coronary circulation].
In 10 anaesthesized dwarf pigs with an open thorax the effects of extrasystoles on systemic and coronary circulation were investigated. The actual effect of an extrasystole depends on the time of its onset. Early extrasystoles hamper the cardiac blood perfusion, with decreases in the stroke volume, mean arterial pressure, coronary blood flow, and elevation of coronary resistance. Extrasystoles setting on later are of minor haemodynamic and coronarodynamic importance. The effects of bigeminy and 2:1 extrasystolia are more adverse than the consequences of extrasystoles with later onset. With cumulation of several consecutive extrasystoles also adverse the haemodynamic coronarodynamic sequelae increase, in dependence on the magnitude of the quotient coupling time /extrasystolic excitation period [ greater than 1.1], or of the quotient: duration of pre- and postextrasystolic intervals/ normal interval of heart action [ greater than 1.5]. The authors point out the importance of haemodynamic findings during early extrasystoles in ischaemic heart disease.
Animals↗
[Cardiovascular effects of sodium pentacyanonitrosylferrate(III) (sodium nitroprusside) in experimental coronary occlusion in the minipig].
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Animals↗
[The prevention of accidents in dental local anesthesia].
The relatively rare complications developing under local anaesthesia may be due to various causes. The possibilities of the development of accidents under local anaesthesia are outlined; and prophylactic and therapeutic measures are deduced. A schematic premedication cannot prevent the development of complications with a sufficient degree of certainty; for instance, in certain cases the administration of atropine alone will still worsen the course of a complication. On the contrary, an individual premedication should be aimed at, especially in risk patients; the dosage must take into consideration all important factors. Consequently, atropine is of less importance than, for example, psychopharmaca and beta-receptor blockers.
Adrenergic beta-Antagonists↗
[Importance of continuous recording of vascular resistance].
The behaviour of resistance in the periphery of the circulation and in the organic regions underlies different influences. Depending on the function of the organs, on the situation of heart and circulation and on the therapeutic influences the vascular resistance changes. To the study of the dynamics of the behaviour of resistance particularly the continuous electronic recognition is suitable. The gain of time and information is great. Especially for the determination of the coronary perfusion in different functions of heart and circulation the continuous registration of the vascular resistance is necessary. Its importance was as an example demonstrated for the left-ventricular ejection resistance and for the left- and right-coronary influx resistance.
Animals↗