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Biomedical subjects

J Thormann

Publications and source records attributed to J Thormann.

161 records · Page 9Linked to original sources
PubMedDate not supplied

[Effects of practolol on A-V conduction during atrial stimulation in 50 patients with and without coronary heart disease].

Practolol was injected intravenously at 3 dose levels (5, 15 and 25 mg total dose) in patients with ischemic heart disease and in non-cardiac cases. The influence of practolol on the P-Q interval at rest and at paced rates (atrial stimulation) of 110, 125 and 140 beats/min was studied: only the 15 mg dose produced a significant prolongation of the P-Q interval of normal patients at rest and at paced rates. No significant P-Q changes were found in patients with ischemic heart disease at all dose levels. It is concluded that practolol has no measurable direct effect on A-V conduction and that patients with ischemic heart disease are not more sensitive as regards A-V conduction.

Adolescent↗
PubMedDate not supplied

Pacing-induced myocardial ischemia in spite of nitroglycerin. Correlations regarding the extent of coronary artery disease.

In 10 patients without and 20 patients with various degrees of angiographically proven CAD 93 pacing runs were studied. Changes of PAm, of ECG, and of anginal pain serving as parameters of myocardial ischemia were correlated to the rate-pressure-product. In patients without CAD no correlations could be ascertained. In each patient with CAD determination of ischemia was achieved reproducibly. Ischemia threshold is represented by a sharp increase of PAm. Ischemia threshold seems a parameter to be preferred as compared to pain threshold. The extent of CAD (angiographically estimated) correlates well with the pacing test especially when collaterals are taken into account. After NG no substantial improvement of ischemia can be detected: Ischemia threshold before and after NG was reached at same rate pressure in each case. We conclude the atrial pacing test to be an excellent test for the provocation of myocardial ischemia. The test is also useful for estimation of the extent of CAD.

Adolescent↗
PubMedDate not supplied

AR-L 115 in coronary artery disease: positive inotropic effects and increase of left-ventricular pump function without inducing angina.

1. AR-L 115 improves pump function in patients with advanced and fully treated congestive cardiomyopathy. Since, in spite of such beneficial responses, the energy cost involved might be detrimental when used in advanced coronary artery disease, we monitored clinical haemodynamic and ECG responses to AR-L 115 (2 mg/kg body weight, bolus) in ten patients with coronary artery disease who had developed angina pectoris and/or pathological increases in left ventricular-end diastolic pressure (LVEDP) at the end of a 1 min pacing stress test. 2. When subjected to these stress conditions again (but this time during the peak effect of AR-L 115), there was no longer evidence of ischaemic myocardial impairment, neither clinically by ECG or haemodynamically. 3. There were (average) increase of 43% in cardiac index, 16% in heart rate, 27% in stroke index, 20% in ejection fraction, 31% in VCF and 39% in dp/dt max, while LVEDP decreased to normal values as if at resting conditions. All changes were significant (P less than 0.05). 4. LV-systolic pressure and end diastolic volume (P greater than 0.05) remained the same. Thus the AR-L 115-induced improved LV-pump function was accomplished under stress conditions in the absence of evidence for myocardial ischaemia.

Adult↗
PubMedDate not supplied

Comparative efficacy of the new cardiotonic agent DPI 201-106 versus dobutamine in dilated cardiomyopathy: analysis by serial pressure/volume relations and "on-line" MVO2 assessment.

DPI 201-106 (DPI) as a positive inotropic drug might be useful in treating dilated cardiomyopathy (DCM). In seven DCM patients with normal (group A) and eight DCM patients with abnormal (group B) left ventricular (LV) function, we analyzed serially (computer-assisted) pressure/volume (P/V) effects as P/V loops (microtip catheter/99mTc scintigraphy) using DPI (30 micrograms/kg X min i.v.) and dobutamine (DOB) (10 micrograms/kg X min i.v.) for quantitative comparison of hemodynamic effects. Contractility (dP/dtmax) improvement was greater with DPI (group A, +23%; group B, +47%) than with DOB (group A, +21%; group B, +32%), as was the simultaneous LV end-diastolic pressure decrease--DPI (group A, -39%; group B, -42%) versus DOB (group A, -21%; group B, -18%). LV efficiency increased with DPI (group A, +22%; group B, +55%), but myocardial oxygen consumption (MVO2) did not change significantly. Five of 15 patients showed an increase in dP/dtmax with DPI only; with DPI there were fewer "nonresponders" than with DOB. Thus, DPI increases contractility in DCM hearts while reducing preload rather than causing higher metabolic costs. Such beneficial hemodynamic effects appear to be stronger in the more impaired myocardium (group B patients) and quantitatively superior to those induced by DOB. This might indicate that residual myocardial reserves are more readily accessible to the influences of DPI than to those of DOB. Serial P/V loops and MVO2 assessment aided the demonstration of DPI's efficacy in a more complex way.

Adult↗
PubMedDate not supplied

Comparison of Björk-Shiley ABP and St. Jude Medical Prostheses in a newly developed pulse duplicator.

Pre-clinical and clinical testing of artificial heart-valves has not been standardized. Therefore different centers have been using individual procedures. As a consequence, the results from different laboratories on different valves can be compared only after certain assumptions. In order to compare different valves under identical conditions, a pulse duplicator was developed and the Björk-Shiley and St. Jude Medical valves were studied in the aortic position under pulsatile flow, at stroke volumes ranging from 40 to 90 ml and frequencies from 40 to 130 cpm. Linear relationships were observed between the gradients as measured across the artificial valves and both, stroke volume and frequency. Loss of pressure divided by stroke volume, expressed as a function of frequency, was found to be a simple parameter to describe the fluid mechanical properties of an artificial valve under pulsatile flow and to compare different types of devices. The comparison of BS ABP and SJM aortic prostheses of equal diameter revealed the fluid mechanical properties of the SJM valve to be superior to those of the BS prosthesis under identical testing conditions.

Heart Valve Prosthesis↗