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Biomedical subjects

H Scheld

Publications and source records attributed to H Scheld.

At least 19 recordsLinked to original sources
PubMed1996

The clinical impact of thallium-201 reinjection for the detection of myocardial hibernation.

Thallium-201 reinjection improves detection of hibernating myocardium in about 30%-50% of persisting defects. The main goal of cardiac revascularization techniques is amelioration of clinical symptoms such as angina and dyspnoea; however, improvement in regional and global pump function is an additional and important target. The aim of this study was to investigate whether fill-in in the reinjection study is correlated with improved contractile function after treatment (percutaneous transluminal coronary angioplasty/aortocoronary bypass surgery). We studied 32 patients with coronary heart disease and impaired regional wall motion (RWM). RWM and ejection fraction (EF) were assessed by analysing ventriculographic images using the centreline method (values in standard deviations from mean values found in a healthy control group). Three 201Tl single-photon emission tomographic studies (stress, redistribution and reinjection) were performed prior to revascularization and analysed using a bull s-eye scheme. Patients were divided into two groups (group FI-=no fill-in, n=16; group FI+=fill-in, n=16). Fifty-six percent of all patients showed persisting defects, and 56% of these defects showed fill-in after reinjection. Fill-in in our patient group was independent of the size of the persisting defects. After revascularization RWM increased significantly in group FI+ (from -1.9 to 0.0 SD, P<0.001) whereas group FI- showed no significant change (from -1.6 to -1.8 SD). EF increased from -4.3 preoperatively to -2.1 SD postoperatively in group FI+ and did not change significantly in group FI- (-2.5 to -3.2 SD). The predictive value of reinjection for improvement of RWM was 88%. It is concluded that fill-in in the 201Tl reinjection image can predict recovery of RWM and EF after revascularization and should be used in all patients with impaired RWM and persisting defects independent of their extent.

Adult↗
PubMed1996

Implantable cardioverter-defibrillator: present and future indications.

Indications for of automatic cardioverter-defibrillators of automatic in patients with ventricular tachyarrhythmias have changed since the publications of first guidelines in 1991. Less invasive surgical approaches reduced the perioperative mortality. Tiered therapy devices improved the quality of life by reducing appropriate and inappropriate shocks. A low annual incidence of sudden death with implantable cardioverter defibrillators and frustrating results with antiarrhythmic drugs caused an extension of implantable cardioverter-defibrillator indications. Despite the absence of prospective studies implantable cardioverter-defibrillators have become a first line treatment for patients with ventricular tachyarrhythmias which are not due to acute myocardial infarction. In cardiac arrest survivors implantable cardioverter-defibrillator therapy has become the gold standard due to the low annual incidence of sudden death seen in implantable cardioverter-defibrillator patients. The results of ongoing prospective studies comparing implantable cardioverter-defibrillator therapy to antiarrhythmic drugs have to be awaited and will influence tomorrow's indications for implantable cardioverter-defibrillator therapy in patients with documented ventricular tachyarrhythmias. Additionally, studies evaluating prophylactic implantable cardioverter-defibrillator implantations in patients at high risk for ventricular tachyarrhythmias might expand indications for implantable cardioverter-defibrillator therapy.

Cardiac Pacing, Artificial↗
PubMed1993

Chondromyxoid fibroma of the sternum. Case report.

We report the second case of chondromyxoid fibroma (CMF) of the sternum, documented in the literature. In this case, only histology of the biopsy was useful in diagnosing CMF before definitive surgery. A wide subtotal resection of the sternum and reconstruction with a Gore-Tex soft tissue patch was performed.

Adult↗
PubMed1993

201Tl reinjection predicts improvement of left ventricular function following revascularization.

The aim of this study was to evaluate the correlation between improved Tl uptake in reinjection imaging with improvements in regional wall motion and global ejection fraction following PTCA or aorto-coronary bypass surgery. 19 patients with CHD were investigated and divided into two groups according to their thallium uptake in the reinjection studies. Group I showed additional uptake on reinjection imaging compared to the redistribution image, whereas group II showed no additional uptake. Both groups had a similar number and distribution of affected vessels and location of the leading stenosis. Stress, redistribution and reinjection images were obtained prior to revascularization and evaluated semiquantitatively from a bulls eye scheme. There was a postoperative increase in regional wall motion in group 1 from 5.3 to 8.8% whereas group II did not show a relevant change (6.3 vs 6.0%). The ejection fraction increased II from 55.0 to 66.7% in group I and dit not increase in group II (59.8 vs 58.7%). The overall predictive value of the reinjection image for improvement in wall motion (> 10%) was 91% and for the redistribution image 58%. Increased uptake in reinjection imaging predicts improved ventricular function following revascularization and indeed indicates viable myocardium with reversible functional impairment.

Aged↗
PubMed1989

Blood conservation in cardiac operations. Cell separation versus hemofiltration.

The effects of hemoconcentration performed during and after extracorporeal circulation by either centrifugation (cell separation group, n = 20) or hemofiltration (n = 20) were investigated in 40 patients undergoing elective aorta-coronary bypass grafting. Interest was focused on the quality of the blood concentrated from the blood remaining in the extracorporeal circuit and on the reaction of the patients after retransfusion of the concentrated products. Hemofiltration was easy to perform and produced whole blood quicker than the cell separation technique. Coagulation studies revealed no significant differences in heparin concentration, levels of fibrinogen and antithrombin III, or platelet counts. Various coagulation parameters tended to normalize completely and more quickly after hemofiltration than after centrifugation. None of the patients had severe bleeding postoperatively. Free hemoglobin levels were not affected by hemofiltration; elastase concentration was higher only immediately after retransfusion of the concentrated blood, with no effect on organ function. We conclude that both methods were effective means of hemoconcentration during extracorporeal circulation and in salvaging the diluted pump blood after extracorporeal circulation. Loss of plasma fraction is an important disadvantage in the centrifugation technique, which can be avoided by hemofiltration; derangement in colloid osmotic pressure and coagulation parameters was less pronounced after hemofiltration. Costs were lower, as well. Therefore, when a high volume of cardioplegic solution and two-stage cannulation are used, hemofiltration seems to be the method of choice for blood conservation during cardiac operations.

Aged↗
PubMed1989

[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 prosthesis-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↗
PubMed1988

Influence of acute normovolemic hemodilution on extravascular lung water in cardiac surgery.

Preoperative hemodilution (HD) is an established blood-saving method. With HD, however, a concomitant increase in extracellular and interstitial water has been reported. This randomized study was undertaken to compare the effects of acute normovolemic HD (10 ml/kg; n = 15) using hydroxyethyl starch solution (HES) on extravascular lung water (EVLW) with those of an untreated control group (n = 15) of cardiac surgery patients submitted to extracorporeal circulation (ECC). A thermal-dye technique was used to measure EVLW. There was no significant change in EVLW due to preoperative HD (5.55 +/- 0.51 vs. 5.71 +/- 0.59 ml/kg). After ECC, a transient increase in both groups could be demonstrated because of a possible change in pulmonary capillary permeability (maximal increase in the HD group: +1.30 ml/kg and in the nonHD group: +1.02 ml/kg). Five hours after ECC, no differences could be seen between the groups. Pulmonary gas exchange was not significantly affected (PaO2 in the HD group: -20 torr). Hemodynamic and laboratory variables indicated the typical changes during HD (cardiac index increases while albumin concentration decreases); circulatory stability was maintained during the entire study. We conclude that preoperative normovolemic HD did not increase lung water content significantly nor compromise pulmonary function even in cardiac surgery patients. Although ECC provides an additional HD (crystalloid priming of the heart-lung bypass machine) and possibly damage of capillary integrity, the two groups did not differ.

Body Water↗
PubMed1988

RETRACTED: Influence of PEEP ventilation immediately after cardiopulmonary bypass on right ventricular function.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the request of the editor. In 2018, CHEST published a notice1 that all articles authored by Joachim Boldt be read with caution due to expressions of concern about falsified data. In 2020, CHEST received additional evidence of research misconduct and breaches of scientific integrity that were discovered following an investigation by the author's former institution, the University of Giessen2. In light of this new evidence, this article has been retracted by CHEST. 1. Irwin, R.S., MD, Master FCCP. Notice From the Editor in Chief. CHEST 153(3), p. 767. 2. Mukherjee, J. Statement on the scientific credibility of articles published by Joachim Boldt, formerly professor at Justus Liebig University (JLU), Giessen, Germany. https://ars.els-cdn.com/content/image/1-s2.0-S000709122030163X-mmc3.pdf.

Cardiac Output↗
PubMed1987

Effects of hypothermia on somatosensory evoked responses in man.

Somatosensory evoked responses after median nerve stimulation were recorded in 21 patients during hypothermic cardiopulmonary bypass. During hypothermia a significant linear correlation (P less than 0.001) was found between evoked potential latency and temperature. Correlation was best for tympanic membrane temperature during cooling and for perfusate temperature (arterial, venous) during rewarming. The increase in latency was more pronounced for middle latency components (N2, N3) and for the early cortical N1 than for the cervical N0 and central conduction time. In all patients N1 was detectable at 26 degrees C, with slightly reduced amplitude. In the rewarming period the changes occurred in the reverse order and pre-bypass values were achieved at normothermia. The slopes of the regression lines were different during cooling and rewarming, when latencies were related to patient (tympanic, nasopharyngeal, rectal) temperature, but identical when arterial or venous blood temperature was used as the reference. No correlation was found between latency and perfusion pressure. We conclude that sophisticated temperature measurement is required to aid the interpretation of evoked responses used during hypothermia.

Aged↗
PubMed1985

The effects of retrograde perfusion of cardioplegic solution in cardiac operations.

The effects of continuous retrograde coronary perfusion of a cardioplegic solution were investigated in 42 patients. From each patient, a needle biopsy was taken on the anterior left ventricular free wall during cardiac operations and investigated by electron microscopy. With the use of our well-standardized ultrastructural criteria of ischemic injury, we found that the retrograde perfusion technique provides cardiac protection of a quality superior to that of antegrade perfusion. This finding applied to the state of the myocardial cells. The cardiac microvessels, on the other hand, were more severely injured by retrograde perfusion, and extracellular edema occurred more frequently. It is concluded, therefore, that the retrograde perfusion of a crystalline cardioplegic solution during cardiac operation has beneficial effects on the preservation of myocardial cells in comparison to the antegrade application. Unfortunately, we also conclude that the occurrence of extracellular edema and of microvascular damage represents a serious drawback in the clinical use of this method. This technique, therefore, needs to be improved before it may routinely be applied in patients undergoing cardiac operations.

Glucose↗
PubMed1983

[Hemodynamic effects of mexiletine and lidocaine in coronary surgery patients].

In two groups of 10 coronary bypass patients during the postoperative phase a comparison was carried out of the haemodynamic effects of mexiletine and lidocaine in order to evaluate mexiletine's applicability as an antiarrhythmic in intensive care patients. With mexiletine cardiac effort (CE) fell by 6%, total peripheral resistance (TPR) fell by 11%, while CO increased by 8%. With lidocaine CE and TPR remained unchanged, CO dropped by 4%. Mexiletine seems to be applicable in intensive care without hazards to circulation.

Cardiac Surgical Procedures↗
PubMed1982

The effects of global ischemia and reperfusion on human myocardium: quantitative evaluation by electron microscopic morphometry.

During open-heart operation, myocardial biopsies were taken from 31 patients undergoing aortic valve replacement during total cardiopulmonary bypass. The first needle biopsy was taken before induction of cardiac arrest (Kirsch cardioplegia), the second at the end of global ischemia, and the third during the reperfusion period. Teh tissue was investigated by electron microscopy, in both a qualitative and a quantitative manner (morphometry). Ultrastructural morphometry revealed cellular and especially mitochondrial swelling that occurred during the reperfusion phase, but not after ischemia alone. On the basis of morphological measurements, this study shows the occurrence of postischemic cellular and mitochondrial edema that possibly might be avoided by the use of improved techniques of myocardial protection during operation.

Aortic Valve↗
PubMed1982

[Antidiuretic hormone in peridural anesthesia with 0.5% bupivacaine. The effect of severe blood loss on ADH release].

14 patients scheduled for peripheral vascular surgery received epidural anaesthesia with bupivacaine 0.5%. Blood samples were obtained preoperatively (twice), intraoperatively (9 times) and postoperatively (3 times) for analysing the following parameters: 1. antidiuretic hormone (ADH, arginine-vasopressin) 2. serum electrolytes (potassium, sodium) 3. plasma osmolality In three patients unexpected sudden blood loss occurred, accompanied by typical haemodynamic changes. Pre- and intraoperative ADH-levels were normal with a slight increase at the end of the operative procedure. Electrolytes and osmolality in serum/plasma stayed within the normal range during the whole investigation period. In three patients suffering from shock due to unexpected blood loss ADH-levels rose excessively. The data demonstrate the well-known stress-attenuation under EDA as well as an increase of ADH-secretion in haemodynamic alteration.

Anesthesia, Epidural↗
PubMed1982

[Bicycle ergometric examinations and pulmonary function analyses after patch aortoplasty of coarctation of the aorta in children (author's transl)].

The blood pressure of patients who underwent surgical correction of coarctation of the aorta are usually controlled at rest in the upper and lower extremities. The assessment of the success of the operation is then based on these blood-pressure readings. It is, however, more important to control the blood pressure during standardized exercise so that assessment of the capacity for work in daily life could be made. This is best realized with the bicycle ergometric examination with simultaneous blood-pressure readings 40 patients who had undergone surgical correction of the coarctation of the aorta, using the Vossschulte indirect patch aortoplasty method, were examined. The examination results were compared with those of 35 healthy children. The bicycle-ergometric exercise was carried out in stepwise increasing loads of up to 2 Watt/kg body weight. The blood-pressure, were compared based on the age of the patient at the time of the operation, in relation to the time between the operation and the ergometric examination and the age of the patient at the time of the operation. The W170 (Physical working capacity at a heart rate of 170) and the maximum oxygen intake of the subjects were also used as parameters for comparison. It could be seen that the initial blood pressure at rest was, on the average, relatively higher than those of the control subjects. This tendency was also observed during the bicycle-ergometric examination. In some subjects, the blood pressure rose to dangerously high values particularly at 2 Watt/kg body weight. The blood pressures of the patients remained on the average higher than those of the control subjects during the resting phase after the exercise (control after 1' and 5') and normalized relatively slowly. 45% of the patients showed pathological blood-pressure values. The W170 of the patients, a parameter for precise assessment of the cardiorespiratory fitness, was measured. The findings in the patients showed only very slight difference compared to those of normal subjects in all the assessment parameters. This applies also to the maximum oxygen supply, particularly when one considers the standard deviation. It is advisable to consider limitation of activities, for example sport, in the special cases where there are dangerously high blood-pressure rises during exercise even though no subjective complaints are made by the patients and the blood pressures at rest are normal. It is, on the whole, interesting to note that the operated patients compare very favourably with the control subjects in the W170 and the maximum oxygen-intake values.

Adolescent↗