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Biomedical subjects

M Schlepper

Publications and source records attributed to M Schlepper.

At least 91 records · Page 5Linked to original sources
PubMed1987

Long-term treatment of hypertrophic cardiomyopathy with verapamil or propranolol in matched pairs of patients: results of a multicenter study.

The effects of a 2-year treatment with high-dose propranolol (mean, 340 +/- 135 mg/day) and verapamil (mean, 493 +/- 136 mg/day) were compared in two groups of patients with hypertrophic cardiomyopathy. Both groups were broadly identical at the beginning of the trial and were formed of matched pairs. Out of 137 patients entering the study, 37 pairs completed the 2 year follow-up. The mean group symptomatology (NYHA-classification) improved significantly only following verapamil treatment. Individual improvement was seen more often following verapamil (V), but deterioration was almost exclusively seen during propranolol (P) treatment. Reduction of the Sokolow-index was significant in the V group only. Reduction in the resting heart rate and maximum gradient was more pronounced following P. No correlation could be found between the change in clinical symptoms and electrocardiographic, echocardiographic or hemodynamic data, nor to the dosage of V or P administered. From clinical and echocardiographic findings and in respect of side effects, V is advantageous over P in the treatment of hypertrophic cardiomyopathy, although a considerable number of patients improve after P. Objective data do not allow one to anticipate responders or non-responders to either treatment.

Cardiomyopathy, Hypertrophic↗
PubMed1987

[Determination of active components of amrinone by analysis of pressure-volume results; use of the conductance (volume) catheter technic and rapid load change by balloon occlusion of the inferior vena cava].

Endsystolic pressure-volume relationships (ESPVR) were determined using the conductance (volume) catheter-technique and the required rapid load changes by applying vasoactive drugs (nitroprusside = NP; phenylephrine = PE) or brief preload reduction by balloon occlusion of the vena cava inferior (BOVCI). With this load-independent index of contractility, we analyzed the hemodynamically active components of amrinone (AM) over a range of different LV-loading conditions. In 19 patients (study I) with still normal LV-function (LVF) in group A (dP/dtmax 1585 +/- 386 mmHg/s; n = 10) and impaired LVF in group B (dP/dtmax 1044 +/- 164 mmHg/s; n = 9) an infusion of AM, 1.5 mg/kg over 2 min, failed to induce changes in ESPVR (p greater than 0.05), but rather caused load changes, resembling like those seen with NP. During continuously paced heart rates (90/min) brief infusion phases with NP and PE provided the necessary load changes. In 11 patients (study II) with impaired LVF (dP/dtmax = 1177 +/- 163 mmHg/s) 2.5 mg/kg AM i.v. induced an increase in contractility, which was more pronounced after the additional application of dobutamine (DOB) at 10 micrograms/kg/min.; (1) Slope k rose from 0.52 to 0.80 mmHg/ml; (2) dP/dtmax increased by an average of 39% and 57% (p less than 0.01), respectively. The BOVCI provided the necessary load changes. Thus AM demonstrates its contractility-increasing effects in a dose-related fashion, probably (at least in part) via an increase in heart rate; inotropic effects further increased with the combination of AM and DOB. The use of the conductance technique for the assessment of ESPVR during acute decrease of preload by temporary BOVCI is innocuous to the patient, reproducible and can be carried out under the conditions of a routine cardiac catheter procedure. This technique seems to be useful in the assessment of relative inotropic effects of the newer cardiotonic drugs.

Amrinone↗
PubMed1987

[Dipyridamole thallium-201 myocardial scintigraphy in coronary diagnosis; a comparison of methods with thallium-201 myocardial scintigraphy after ergometer stress].

Two scintigraphic methods, resting dipyridamole and exercise thallium-201 myocardial perfusion imaging, to detect and localize coronary artery stenosis were compared in 32 patients suffering from coronary artery disease. The sensitivity of detecting a greater than 50% coronary stenosis was 94% for exercise thallium-201 perfusion imaging and 88% for dipyridamole thallium-201 perfusion imaging. The overall sensitivity and specificity of localizing a greater than 50% coronary stenosis by the two methods were also not significantly different. The results of the two scintigraphic methods were independent of the severity of coronary artery disease. Dipyridamole thallium-201 myocardial perfusion imaging provides a useful and safe alternative test for detecting and localizing coronary artery stenosis in patients unable to perform maximal exercise.

Coronary Disease↗
PubMed1987

Effects of forskolin on left ventricular function in dilated cardiomyopathy.

The adenylate cyclase activator 17 beta-acetoxy-8, 13-epoxy-1 alpha,6 beta,9 alpha-trihydroxylabd-14-en-11-one (forskolin) was studied for its beneficial effect as therapeutic agent for the treatment of dilated cardiomyopathy (DCM). In 7 DCM-patients with normal (group A) and 8 DCM-patients with pathological dP/dtmax-values (group B), we analyzed serially (computer-assisted) the pressure/volume (P/V) effects as P/V-loops (microtip catheter/Tc-99m scintigraphy) and on-line MV02 (indirectly: Bretschneider equation) under dobutamine, 10 micrograms/kg/min i.v., and forskolin, 3 micrograms/kg/min i.v. For the total group (A + B) there was no change of contractility during forskolin (p greater than 0.05); with dobutamine, however, it rose by an average of +25%. The preload decline was more pronounced with forskolin (LVEDP by -27%) as compared to dobutamine (by-19%); while left ventricular (LV-)function improved moderately only with forskolin (by +9%) and significantly (by +34%) with dobutamine. Thus, forskolin improved LV-function primarily via reduction of preload in DCM-hearts and without rising metabolic costs. Beneficial hemodynamic effects with forskolin are quantitatively less as compared to those with dobutamine (accompanied by higher MVO2-costs). It is concluded that residual myocardial reserves in DCM are mobilized by dobutamine rather than forskolin. Serial P/V-loop and on-line MVO2 registration aided in the demonstration of forskolin efficacy as compared to dobutamine.

Angiography↗
PubMed1986

Electrophysiologic effects of an acute beta-blockade induced by bisoprolol in patients with supraventricular tachycardia as assessed by His-bundle electrograms.

The acute electrophysiologic effects of 10 mg bisoprolol (B, given intravenously) were evaluated during an electrophysiological study in 10 patients with a history of paroxysmal tachycardia. Drug administration resulted in a significant decrease of sinus rate (Control [C]; 70.8/min; B: 59.4), and in an increase in sinus node recovery time (+20%). AV-nodal depression was marked at high heart rates during incremental atrial pacing. A second-degree AV-block occurred at a pacing cycle length (CL) of 329 ms (182/min) before and at a CL of 378 ms (158/min) after drug administration. Depression of AV-nodal conduction was negligible at low heart rates; the AH-interval at sinus rhythm was not affected (C: 84 ms, B: 86 ms); and functional and effective refractory periods of the AV-node were only slightly prolonged. Conduction intervals and refractory periods on atrial and ventricular level did not change. In 5 of 6 patients with accessory AV-pathways, circus movement tachycardia (CMT) could be elicited prior to as well as after B. Due to AV-nodal delay, CMT CL was slightly prolonged after B. Echozone and refractoriness of accessory pathways were not affected. In 1 of 2 patients with ectopic atrial tachycardia, B prevented the induction of paroxysms. In one patient with paroxysmal atrial fibrillation, the ventricular response decreased from 128/min to 94/min. The findings suggest that the electrophysiologic effects of B are due to a selective beta-adrenergic antagonism. Therapeutic efficacy is only to be expected if an increased adrenergic drive is a prerequisite for induction and continuation of a tachycardia.

Adrenergic beta-Antagonists↗
PubMed1986

[Effects of the autonomic nervous system in supraventricular arrhythmia].

Influences of the autonomic nervous system may cause modifications of the initiation, continuation and discontinuation of supraventricular rhythm disturbances. Whether or not clinically relevant bradycardia syndromes (such as the hypersensitive carotid sinus syndrome and the sick sinus syndrome) also may exist primarily on a functional basis, remains to be proven. Organic pathology, whether it is clinically apparent or not, probably provides the basis for the activation of influences on the autonomic nervous system. In atrial fibrillation and atrial flutter the influence of the autonomic nervous system is apparent in a form of the vagotonically and sympathotonically evoked paroxysms. In the case of persistent atrial fibrillation vagal and sympathotonically transmitted changes in the AV-dromotropy determine the mode of heart rate. Junctional re-entry tachycardias and re-entry tachycardias under the influence of accessory pathways, are potentially triggered by mechanisms, as transmitted by the autonomic nervous system. Furthermore, such autonomic influences are responsible for changes in the conducting velocity and the refractory properties, as produced by parallel conducting pathways. Hemodynamic changes themselves, which are induced at the very beginning of the tachycardia, may activate other electrophysiological mechanisms and thereby cause a modification in the type of tachycardia in question.

Arrhythmias, Cardiac↗
PubMed1986

Incidence and pathogenesis of late aneurysms after patch graft aortoplasty for coarctation.

From 1957 to 1984 direct and indirect isthmoplasty as described by Vossschulte has been the method of choice for surgical therapy of coarctation of the aorta in our hospital. A total of 317 patients have been so treated, 54 of whom were less than 12 months old at operation. The hospital mortality in this group was 15% and the mortality in patients older than 1 year was 3%. The early results were encouraging, but during follow-up an increasing number of postoperative aneurysms have been detected. During reinvestigation an aneurysm was diagnosed in 18 cases. Therefore, we have studied the cause of these aneurysms. To this point reoperation has been performed in 15 patients having late aneurysms. Extensive resection of a fibrous membrane of the aortic isthmus at the first intervention seems to be an essential predisposing factor for development of aneurysms. Microscopic examination of the aneurysmal wall revealed degeneration of the media in more than half of the patients. From our experience we conclude that the posterior fibrous ridge should no longer be excised and the Vossschulte operative technique should be viewed more critically.

Adolescent↗
PubMed1985

Analysis of the efficacy of the new cardiotonic agent TA-064.

TA-064 is a new cardiotonic agent which is also effective orally, according to investigations conducted in Japan. We analyzed computer-assisted alterations of pressure-volume relationships serially and of indirect myocardial oxygen consumption (MVO2) estimations on line during TA-064 influence in 16 patients with congestive cardiomyopathy: left ventricular function was moderately decreased in seven patients (group A) and drastically decreased in nine (group B). Results showed that TA-064, 8 micrograms/kg/min intravenously, exerted positive inotropic effects in both groups and induced mean maximal delta percentage changes at about 5 minutes of infusion as follows: left ventricular stroke work index +65% and +47%; dP/dtmax +61% and 59%; left ventricular efficiency +62% and 53%; MVO2 +31% and +11% (p less than 0.05). TA-064, 20 mg by mouth induced serum levels (group A = 23.8 +/- 12ng/ml and group B = 26.4 +/- 20 ng/ml) corresponding to the effects with dosages of 1 to 2 ng/kg/min intravenously (p greater than 0.05), thus implying that significant changes in left ventricular function require higher oral dosages. We conclude that TA-064 improves left ventricular function, primarily via a contractility increase, also in group B patients without toxic side effects. On-line indirect MVO2 assessment and analysis of serial pressure-volume relationships helped to provide a more complex definition of the mechanism and efficiency of the cardiotonic agent under study.

Administration, Oral↗
PubMed1985

Combined therapy of re-coarctation of the aorta and coronary heart disease.

We report on an uncommon case of recoarctation of the aorta 36 years after resection and end-to-end anastomosis associated with coronary heart disease. Since a two-staged surgical therapy implies an increased risk of life for the patient, we decided to perform a combined surgical procedure. Exposing the heart by a median sternotomy we implanted a 16 mm synthetic graft from the ascending to the descending thoracic aorta and performed a prosthesio-coronary bypass in one session. The patient had an uneventful recovery. In our opinion this procedure is the method of choice for similar cases.

Adult↗
PubMed1985

Malignant ventricular tachyarrhythmias in association with propafenone treatment.

During treatment with the class Ic antiarrhythmic agent propafenone, the drug appeared to cause malignant ventricular tachyarrhythmias in five patients. Sudden cardiac death occurred in two of them. Three patients exhibited a transition from non-self-terminating ventricular tachycardia to ventricular fibrillation. In the other two patients electrocardiography during syncope revealed ventricular fibrillation. The observed malignant arrhythmias occurred within the first three days of treatment for chronic complex ventricular ectopic activity. Two of the five patients had markedly impaired left ventricular function. All patients received digoxin and low dose diuretic therapy. In contrast to drug induced arrhythmias encountered with other type I antiarrhythmic agents, the proarrhythmic effects of propafenone were not associated with marked QT prolongation. QRS duration was only slightly affected.

Adult↗
PubMed1985

[Double nuclide myocardial scintigraphy with thallium 201 and iodine 123-heptadecanoic acid--the possibilities in cardiological diagnosis].

UNLABELLED: We studied in 11 patients the individual variable pattern of coronary blood supply after the end of diagnostic coronary catheterisation by intracoronary injection of T1201 into the left and J 123-heptadeconic acid into the right coronary artery. In 4 static views computer aided quantitative analysis of circumferential profiles was performed. Based on Schlesinger's criteria three types of coronary arterial patterns were defined (right, left preponderant, balanced) after the presentation in the angiographic projections. CONCLUSIONS: Sharp boders between different perfusion areas could be detected by the gamma camera. If patients with right preponderant circulation are compared with balanced circulation, the perfusion areas of the left coronary artery are greater in all cases with balanced circulation than expected. More important for the indication of coronary artery surgery is that a considerable area of the left ventricular myocardium is perfused by the right coronary artery independent of the anatomical perfusion pattern with the exception of the left preponderant type.

Coronary Disease↗
PubMed1985

[Comparative echocardiographic volume determinations using a dynamic heart model].

Using a dynamic and symmetrical cardiac phantom different echocardiographic mathematical models (Simpson 7 slices, area-length method, Simpson 2 slices and method according to Teichholz) were compared. 9 different end-diastolic (EDV) and end-systolic (ESV) volumes, 9 different stroke volumes (SV) and ejection fractions (EF) were used. EDV and ESV varied between 39-298 ml; SV between 29-100 ml and EF between 14-46%. In addition 10 fixed volumes of the same shape were evaluated using the same echocardiographic mathematical models. While symmetrical fixed volumes can be assessed correctly (r = 0.97-0.98), apart from the formula according to Teichholz (r = 0.89, significant underestimation of volumes), the correlation coefficients decrease using a dynamic cardiac phantom. In the modification of Simpson with 7 slices the best correlation was found for all parameters (EDV: r = 0.93; ESV: r = 0.94; EF: r = 0.87; SV: r = 0.81). The biplane area-length method has no advantages over Simpson's rule with 2 slices in the short axis; for symmetrical models both methods are comparable, both having high correlation coefficients (for volumes r = 0.85 and r = 0.88; for EF 0.78 and 0.84). Using the method according to Teichholz symmetrical volumes can be well assessed (r = 0.90), for the determination of EF the correlation coefficient decreases to r = 0.65 and for stroke volume to 0.33, reflecting no significant correlation to the actual SV. Possible causes for a poorer correlation are discussed for moving objects as opposed to the fixed volumes.

Cardiac Output↗