Search PubMed⌕ Search

Biomedical subjects

M Schlepper

Publications and source records attributed to M Schlepper.

At least 109 records · Page 6Linked to original sources
PubMed1984

[Mechanically-induced intraventricular block caused by a right-heart floating catheter--frequency and electrophysiologic findings].

During the course of 2,434 right heart catheterizations with 2,019 floating 3F Grandjean catheters and 415 5F Swan-Ganz catheters we observed 7 patients (0.3%) with catheter-induced infranodal conduction impairment: right bundle branch block (RBBB) in 3 patients, left anterior fascicular block (LAFB) and subsequent RBBB in 1 patient, and complete heart block in 3 patients with pre-existing left bundle branch block (LBBB). There was no apparent difference regarding the incidence of blocks between the two types of catheters. Three patients (one with LAFB + RBBB and two with LBBB) underwent electrophysiologic studies. All three patients exhibited a prolongation of the HV-interval due to coexisting pathologic changes of the right bundle. LBBB patterns disappeared during distal His bundle pacing in two patients, indicating a proximal site of block and suggesting incomplete involvement of the right bundle. Additional mechanical trauma, probably in this region, produced the blocks. Thus, use of balloon tipped or flexible catheters does not provide complete protection against transient lesions of the conduction system.

Adult↗
PubMed1984

[Comparison of T1201 stress scintigraphy and rest and stress ventriculography with respect to the degree of stenosis and collateral findings].

The influence of coronary obstructions and collaterals on the results of T1 201 myocardial scans and regional wall motion on ventriculography at rest and after pacing was examined with digital observer-independent methods, whereby criteria for positive and negative findings were defined in advance. The results indicate the high accuracy of 201-thallium scans in the detection of coronary artery disease in symptomatic single vessel disease, when the lesions obstruct greater than 60% of the vascular diameter. Cineventriculography at rest is inefficient as a test for this purpose. Ventriculography after pacing produced regional dysfunction in most of the patients and was comparable in its accuracy to T1 201 scans. A correlation of severity of stenoses and regional wall motion was not possible in the presented population. Collateral function is able to provide O2 supplies for normal myocardial function at rest and becomes insufficient during exercise and pacing. These results of T1201 stress scintigraphy correspond with results of stress ventriculography.

Adult↗
PubMed1984

[Effects of the new cardiotonic agent TA-064: serial computer-assisted analyses of pressure-volume relations and online myocardial 02 consumption].

UNLABELLED: According to investigations conducted in Japan, TA-064 is a new cardiotonic agent, which is also effective orally. We analyzed computer-assisted alterations of pressure-volume relations serially and of MVO2 online (Bretschneider) during TA-064 influence in 16 patients with congestive cardiomyopathy: LV-function of 7 patients was only moderately decreased (group A) and in 9 patients massively (group B). RESULTS: 1) TA-064, 8 micrograms/kg/min, i.v. had positive inotropic effects in both groups and induced mean maximal delta% changes at about the 5th minute of infusion as follows: LVSWI + 65% and 47%; DP/DTmax + 61% and 59%; LV-efficiency + 62% and 53%; MVO2 + 31% and + 11% (p less than 0.05). 2) TA-064, 20 mg p.o. induced serum levels (A: 23.8 +/- 12 and B: 26.4 +/- 20 ng/ml) corresponding to the effects with the dosages 1-2 micrograms/kg/min, i.v. (p greater than 0.05), thus implying that significant changes in LV-function require higher p.o. dosages. 3) TA-064 i.v. on the 6th day of exposure to the medication produced less LV-function improvement than on day 1 (p greater than 0.05). CONCLUSIONS: In both groups A and B TA-064 improves LV-function primarily via increased contractility, without toxic side effects. For a more complex definition of the efficiency and mechanism of cardiotonic agents, the validity and importance of using on-line MVO2 assessment and analysis of serial pressure-volume relations is stressed.

Adult↗
PubMed1984

[Hemodynamic significance of the coordination of atrial and ventricular systole in tachycardia].

In 15 patients, aged 55.6 +/- 3.7 years with normal LV-function, the comparison of hemodynamic results as induced by ventricular pacing (VP) (at 110, 140 and 170 bpm) versus atrio-ventricular pacing (AVP) (AV-sequences: 30, 130 and 230 msec) revealed the following: VP with increasing rates inversely proportionally compromised AO-pressure by an average of -7, - 19 and -28% respectively, and cardiac output (CO) by an average of -2, -12 and -26% respectively. However, AVP with an AV-sequence of 130 msec, at the same 3 basic rates, clearly proved hemodynamically superior in comparison, in that AO-pressure dropped significantly (by an average of -13%) only at 170 bpm, an CO even showed tendencies to increase at 110 and 140 bpm (by an average of +17 and +7% respectively), finally decreasing by a mere -11% at 170 bpm only. Pacing, when using AV-sequences of 30 and 230 msec, resulted in an impairment of AO-pressure and CO of the same range as during VP at equal rates. Thus, beneficial hemodynamic results, AVP versus VP, have been proven also for rapid-rate pacing in normal ventricles, provided the AV-sequence is optimal (130 msec for the present patient group) but not in any incoordinate range of AV-sequences (as for instance 30 and 230 msec), with which beneficial atrial transport function cannot be achieved.

Blood Pressure↗
PubMed1984

[Regularization of ventricular intervals in atrial fibrillation--electrophysiologic findings on the underlying mechanism].

In 13 patients with chronic atrial fibrillation, programmed right ventricular pacing was performed before and after intravenous administration of 4 mg gallopamil. Application of the Ca-antagonist resulted in a marked decrease in the ventricular response in all and in a regularization of the ventricular response (variation coefficient of the ventricular cycle length: less than 10%) in 7 of 13 cases, while atrial fibrillation persisted. During regularization right ventricular extrastimulus testing showed a constancy of the postextrasystolic interval irrespective of the changes in the coupling interval of the extrasystole. The postextrasystolic cycle was slightly longer than the basic cycle; the difference amounts to a mean value of 107 +/- 22 ms. During the control period the postextrasystolic cycle showed the same irregularity as the basic cycle. The same random distribution was observed if the first 10 cycles of the spontaneous rhythm were analyzed after a short period of ventricular overdrive pacing. After regularization the first 2-3 postpacing cycles were markedly prolonged, and during the following cycles a gradual adjustment to the length of the basic cycles before overdrive pacing was seen, resembling the warming up of a pacemaker. It is concluded that regularization is most probably due to atrioventricular nodal depression and the occurrence of a junctional escape pacemaker.

Adult↗
PubMed1984

Influence of fluid removal rate during hemodialysis on left ventricular performance and exercise tolerance in patients with coronary artery disease.

The effect of hemodialysis (HD) on left ventricular (LV) function and exercise tolerance were measured at rest and during exercise using gated equilibrium radionuclide ventriculography in seven patients with confirmed coronary artery disease (CAD). To separate the effects of fluid removal rate on LV function in CAD, we investigated the same patients with identical overall volume loss of 4 liters during two different treatment times (4 hr and 2 hr). HD significantly increased resting LV ejection fraction (EF) from 55.7 +/- 8% to 64.7 +/- 8% (P less than 0.01) during the 4 hr HD and from 58.1 +/- 9 to 68.1 +/- 10 (P less than 0.05) during the 2 hr HD. Indicating ischemia, EF decreased at pre- and postdialysis peak exercise without differences between both treatments. HD also resulted in an improved segmental wall motion score. Exercise duration as well as S-T segment depression and angina score improved during HD, whereas heart rate, blood pressure and double product remained unchanged. We conclude that HD improves global and regional resting LV function and exercise tolerance in patients with CAD. The degree of interdialytic hydration and not the degree of fluid removal per time affects LV performance in CAD. Since LV function is the major prognostic factor in CAD, those patients require volume restriction and/or shorter interdialytic phases.

Adult↗
PubMed1983

[Complete revascularization surgery in patients with coronary disease with severely reduced left ventricular function. Discrepancies in the evaluation of results].

Clinical data, function and compliance of left ventricle as well as regional wall motion were analysed in 17 patients with preoperatively limited left-ventricular function and signs of myocardial ischaemia after complete revascularisation surgery. Recatheterisation after 5.2 months on average after surgery showed improvement by one NYHA class, an increase of mean left-ventricular enddiastolic pressure, which was interpreted as "improved status of ischaemia", a decrease of left-ventricular compliance by 30%, of enddiastolic volume by 14% and of endsystolic volume by 20% (P less than 0.05). Loss of function occurred in 3 out of 92 bypasses. Up to the time of reporting, 22.4 months postoperatively, all patients have survived in a relatively satisfactory clinical state. All parameters of left-ventricular function as well as regional wall motion showed a tendency for improvement after surgery in the majority of patients. However, pre- and postoperative mean values were not significantly different (P greater than 0.05). Thus, despite clearcut improvement of clinical state and "ischaemia index", improvement of left-ventricular function and regional wall motion are not consistently demonstrable. The reasons of this discrepancy cannot be ascertained by this investigation. The quality of the surgical intervention and the sensitivity of parameter assessment cannot be held responsible.

Blood Pressure↗
PubMed1983

Diurnal changes and reproducibility of corrected sinus node recovery time.

Corrected sinus node recovery time (CSRT) has been found unreliable in identifying all cases of sick sinus syndrome. Since other factors than sinus node dysfunction might add to the pathologic significance of the CSRT, we assessed it in 15 patients (nine group I patients with "prolonged" CSRT max = 3,196 + 2,740 msec and six group II patients with "short" CSRT max = 367 + 79 msec) at 0800, 1100, 1400, 1700, 2000, and 2300 hours with atrial overdrive stimulation rates (AST) of 90, 110, 140, 170, and 200 bpm on three consecutive days using a loop-mounted stable atrial electrode. Only with AST greater than or equal to 140 beats per minute (bpm) did all CSRTI values prove prolonged (greater than or equal to 560 msec). CSRTI values at corresponding time intervals were reproducible with AST greater than or equal to 140 bpm (day 1 vs 2 vs 3, P greater than .05), but not at AST 90 bpm and 110 bpm (P less than .05); CSRTII results, however, varied from day to day (less than .05) due to less scatter of single results. CSRTI results increased progressively with AST 90, 110, and 140 bpm from 301 + 256 msec by 60% for each pacing rate up to 785 + 848 msec. With AST greater than or equal to 140 bpm, the pattern of CSRT changes was inconsistent; this was also reflected by the distribution of the mean maxima of CSRTI: For 0800 hours at AST 140 bpm = 822 + 937 msec; for 1100 hours at AST 200 bpm = 824 + 1446 msec; for 1400 hours at AST 140 bpm = 780 + 814 msec; for 1700 hours at AST 170 bpm = 1,099 + 1,008 msec; for 2000 hours at AST 200 bpm = 1,156 + 1,280 msec; and for 2300 hours at AST 170 bpm = 1,021 + 1,102 msec. We conclude therefore that the optimal diagnostic yield for sick sinus syndrome testing is influenced by the time of the day and the AST used for CSRT testing.

Adult↗
PubMed1983

Thrombotic complications with pacemakers.

To analyze thrombotic complications, we performed brachial phlebographies in 100 consecutive patients (group 1), about 44 months after permanent pacemakers had been installed. Thirty-nine patients showed thrombotic lesions in the veins used to pass the stimulation electrode into the right ventricle. In 10 patients the medical history and in 12 patients clinical symptoms and signs indicated an impairment of venous flow. Fifteen of the 39 patients showed complete occlusion of one venous segment; collateral vessel formation was found dependent on the site and the extent of the occlusion. In the remaining 24 patients only partial occlusion without collateralization was demonstrated. Group 2 comprised 12 patients in whom the pacing lead originally inserted via right-sided veins had been severed and the free distal end left unsecured intraluminally when the second electrode was inserted via the left-sided cephalic vein. In all these patients phlebography about 19 months later revealed thrombotic complications, while 11 presented with clinical symptoms and signs. The incidence of thrombotic complications including segmental occlusion after the application of permanent pacer leads is only one-third of patients with segmental occlusion symptoms. However, since severed leads produce severe symptomatic complications in almost all cases their removal is mandatory.

Adult↗
PubMed1983

Effects of AR-L 115 BS (Sulmazol), a new cardiotonic agent, in coronary artery disease: improved ventricular wall motion, increased pump function and abolition of pacing-induced ischemia.

AR-L 115 BS (Sulmazol) is a new noncatechol, nonglycosidic cardiotonic agent. In 17 patients with significant coronary artery disease, the influence of AR-L 115 BS on hemodynamics and regional wall motion was investigated under the following conditions: 1) control, 2) the immediate postpacing period without medication, and 3) the postpacing period under the peak influence of AR-L 115 BS, 2 mg/kg intravenously. During the postpacing phase without medication, all patients developed ischemia (angina, ST segment alterations, increase of mean left ventricular end-diastolic pressure from 13 to 30 mm Hg), left ventricular pump function diminished and overall regional wall motion showed a tendency to decrease (p greater than 0.05). However, during the postpacing period with AR-L 115 BS medication, ischemia was abolished (no angina; mean left ventricular end-diastolic pressure decreased to 13 mm Hg; hemodynamic variables returned to control levels and left ventricular pump function showed some improvement while overall regional wall motion showed tendencies to improve. A comparison of alterations of hemodynamics and regional wall motion during the postpacing phase without medication with those under the influence of AR-L 115 BS shows that overall left ventricular pump function and regional wall motion improved while angina and an increase in left ventricular end-diastolic pressure were prevented. It is concluded that AR-L 115 BS improves left ventricular pump function and regional wall motion in coronary artery disease without inducing ischemia, probably by means of a reduction in extravascular resistance.

Angina Pectoris↗
PubMed1983

Effects of flecainide on electrophysiological properties of accessory pathways in the Wolff-Parkinson-White syndrome.

The effect of flecainide in 12 patients with the Wolff-Parkinson-White syndrome was analyzed with respect to the anterograde and retrograde conduction properties of the accessory pathway, the modes of initiation and termination of circus movement tachycardias, and the ventricular response during induced atrial fibrillation. The principal effect of this drug was to depress both anterograde and retrograde conduction of the accessory pathway. In 8/9 cases circus movement tachycardia was terminated by prolongation of the retrograde effective refractory period of the accessory pathway. Flecainide increased the shortest and the mean cycle length during induced atrial fibrillation. It is concluded that the drug may be of potential benefit in patients with paroxysmal supraventricular tachycardias in patients with the Wolff-Parkinson-White syndrome.

Adult↗
PubMed1983

[Modification of hemodynamics in tachycardiac atrial fibrillation by metoprolol and verapamil].

Hemodynamic effects of the beta-receptor-blocking agent metoprolol (100 mg orally) and the calcium antagonist verapamil (160 mg orally) were analyzed in 24 patients with atrial fibrillation of different etiology (idiopathic atrial fibrillation, 6 cases; congestive cardiomyopathy, 6 cases; mitral stenosis, 5 cases; mitral regurgitation, 6 cases). 2 h after the administration of either metoprolol or verapamil heart rate was reduced significantly both at rest and during exercise. Cardiac output during exercise was significantly diminished under metoprolol in all groups of patients, whereas no effects were noted under verapamil. Peripheral vascular resistance was significantly decreased by verapamil both at rest and during exercise. No change in total peripheral resistance was noted after metoprolol at rest, but an increase occurred during exercise. Different effects on peripheral circulation may explain the different patterns of cardiac performance observed after heart rate reduction in atrial fibrillation by a calcium antagonist and a beta-blocking agent.

Atrial Fibrillation↗
PubMed1983

Myocardial perfusion and left ventricular performance during long and short haemodialysis in patients with coronary heart disease.

In seven patients with confirmed coronary heart disease and stable blood pressure control acetate haemodialysis improved left ventricular performance and exercise tolerance. Similar positive effects were obtained by a four hour dialysis (one litre fluid removal/hour) and a two hour dialysis (two litre fluid removal/hour). In this group of patients weight gain and overhydration between dialyses appears to be the major risk for myocardial perfusion and rapid weight reduction by acetate dialysis appears adequate therapy. One practical consequence from our study is to minimise fluid overload in coronary heart disease and we try to avoid iatrogenic induction of thirst by decreasing dialysate sodium from 140 mmol/litre to 125-135 mmol/litre. As far as myocardial risk factors are concerned it appears that it is more important to focus on interdialysis weight gains than on acute dialysis therapy.

Adult↗
PubMed1983

Quantitative angiographic assessment of coronary stenoses: problems and pitfalls.

A precondition for quantitative angiography is strict standardization of all geometric parameters, i.e., position of the patient and radiation-source-object-image geometry. Correction for respiratory and cardiac cycles is equally important. When all these variables are controlled, the absolute size of a vessel can be a major source of error, since border recognition becomes progressively difficult with decreasing vascular diameter. Finally, contrast density, independent of vascular geometry, will induce errors by virtual magnification of minimal diameters. The results in this paper show the influences of image intensifier position, angulation of the imaging device, and contrast concentration on the geometry of model coronary stenoses when evaluated with computer-assisted quantitative methods. Increase of object-image intensifier distance led to an underestimation of size which increased with decreasing vascular diameter. Decrease in contrast concentration led to a significant overestimation of actual size, up to 20% (p less than 0.05). This effect could be confirmed in human coronary arteriograms (n = 11, p less than 0.05). In conclusion, realistic contrast-perfused calibration devices will have to be developed to replace wire or plaster models in order to control systemic errors that may impede the measurement of absolute vascular size.

Contrast Media↗
PubMed1982

Hemodynamic and myocardial energetic changes induced by the new cardiotonic agent, AR-L 115, in patients with coronary artery disease.

AR-L 115 has been shown to improve left ventricular (LV) pump function in patients with advanced congestive cardiomyopathy by the intravenous and oral routes. Since AR-L 115 effects on myocardial oxygen consumption (MVO2) and coronary blood flow (CSF) are unknown, the hemodynamic, myocardial metabolic, and ECG responses to AR-L 115 (2 mg/kg bolus) were monitored at 9-, 14-, and 9-minute intervals in seven patients with coronary disease, exhibiting ischemia during pacing stress only. Maximal responses occurred at the fourteenth minute after AR-L 115. There were (average) increases in cardiac index by 30%, heart rate by 19%, CSF by 39%, MVO2 by 34%, and LV dp/dt max by 27%. There were (average) decreases in peak LV systolic pressure by 13%, LV end-diastolic pressure by 42%, systemic vascular resistance by 34%, and in coronary vascular resistance by 37%. All changes were significant (p less than 0.05). Myocardial lactate extraction, stroke work index, and stroke index remained unchanged (p greater than 0.05). The modest increase in MVO2 is possibly explained by the increase in contractility being partially offset by reductions in LV preload and afterload. AR-L 115-improved LV pump function was accompanied by moderate increases in MVO2 and CSF but without evidence of myocardial ischemia.

Cardiotonic Agents↗
PubMed1982

Alterations in aortic pressure and coronary blood flow: their time sequences with induced paroxysms of ventricular tachycardia in normal and impaired myocardium.

In an attempt to define more clearly the hemodynamic effects of paroxysmal tachycardia in their time sequence not only for the normal heart, we monitored coronary sinus flow (CSF), aortic mean pressure (AOMP), and coronary vascular resistance in 42 patients. They underwent stress testing of left ventricular function by paced ventricular tachycardia (VT 170/min); 13 patients had no heart disease (controls), 10 patients left ventricular hypertrophy, and 19 patients coronary artery disease (CAD). Up to the 6th s after the sudden start of VT, CSF was maintained during a 50% decrease in AOMP, while controls and hypertrophy patients with less pressure reduction (of 33 and 42%, respectively) showed a tendency to increase CSF. From the 12th to the 26th s of VT, a slight recovery of the low AOMP values took place, while CSF remained at or slightly below baseline levels. The steady state VT was characterized by further improved pressures and a CSF slightly above baseline even in CAD. Up to the 12th s after sudden stop of VT, aortic systolic pressure showed a steep increase (by 17, 13, and 8% for the three groups, respectively), while CSF dropped temporarily and after an upswing between the 12th and 26th s reached baseline levels together with AOMP. We conclude: (1) The rapidity of coronary response and its initial lag after changes of perfusion pressure are similar for normal and impaired myocardium; slight differences exist in quantity. (2) While with VT initiation perfusion pressure drops precipitously, CSF is maintained at baseline levels or slightly below even in CAD. (3) The quality of coronary hemodynamic adaptation to tachycardiac paroxysms in the impaired myocardium warrants the presence of additional operative mechanisms other than a reduced reduction in coronary vascular reserve capacity known in CAD and left ventricular hypertrophy.

Adult↗