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Biomedical subjects

C J Schuster

Publications and source records attributed to C J Schuster.

At least 19 recordsLinked to original sources
PubMed1997

Cardiac risks in total hip replacement.

During total hip replacement, identifiable myocardial ischemia occurs intraoperatively, indicating myocardial strain. Coronary heart disease (CHD) patients are at risk during this type of surgery. Perioperatively, CHD patients had significantly longer ST depressions than patients not suffering from CHD (3348 min vs 454 min). The number of depression episodes was also significantly higher for CHD patients (160 vs 36). Comparing the perioperative with the postoperative stage demonstrated that CHD patients experienced a highly significant shift towards shorter periods of ST-segment depression postoperatively.

Aged↗
PubMed1992

Bilocular atrial malignant mesenchymoma causing mitral and localized pulmonary vein flow obstruction: diagnosis by transoesophageal echocardiography.

Cardiac malignant mesenchymoma is an extremely rare malignancy with poor prognosis. We report a patient presenting with a history and clinical findings typical of mitral stenosis. Transthoracic echocardiography showed a mass on the thickened posterior mitral leaflet. Transoesophageal echocardiography revealed two tumoural masses: one on the atrial side of the posterior mitral leaflet causing mitral obstruction, the other arising in the region of the right lower pulmonary vein orifice and obstructing inflow through this vein.

Constriction, Pathologic↗
PubMed1988

Combination of calcium channel blocker and thrombolytic therapy in acute myocardial infarction.

To evaluate the protective effect of nifedipine on ischemic myocardium, in addition to thrombolytic therapy, a total of 149 patients with acute myocardial infarction were included in a double-blind controlled study in which they received 20 mg sublingual nifedipine (74 patients in group 1) or placebo (75 patients in group 2) in the emergency ward, either intracoronary nifedipine, 0.2 mg before and 0.2 mg after reperfusion of the infarct-related vessel and 20 mg three times/day during the hospital stay, or placebo. Combined intravenous and intracoronary thrombolytic therapy was initiated by means of mechanical recanalization in nonreperfused vessels. There were no differences between group 1 and 2 with regard to age, sex, body weight, or location of infarct. Evolution of CK-MB release and cumulative CK-MB was higher in group 1 than in group 2. Changes with regard to regional and global left ventricular function and coronary anatomy were not significantly different (NS) between the two groups. Reocclusion occurred in 15 of 74 (20%) and 10 of 75 (13%) patients in groups 1 and 2, respectively. During the reperfusion period, second- and third-degree atrioventricular block occurred in 5.4% and 6.7% (NS), ventricular couplets in 17.6% and 24% (NS), ventricular tachycardia in 2.7% and 9.3%, and ventricular fibrillation in 2.7% and 8% of the patients, respectively. Mortality rates were 13% and 8%. The study demonstrates that even very early administration of nifedipine combined with intracoronary administration does not enhance the salvage of ischemic myocardium achieved by reperfusion.

Adult↗
PubMed1988

[Results of PTCA following thrombolysis in acute myocardial infarct].

The mortality in acute transmural myocardial infarction can be reduced by thrombolytic therapy administered within 6 hours after onset of symptoms. In patients with coronary angiography proven stenosis of less than 70% conservative therapy is recommended. In patients with one vessel disease PTCA in patients with suitable lesions should be used. Further studies have to elucidate, if the angioplasty has to be performed in the acute stage or on an elective basis. PTCA is recommended in patients with occluded coronary vessels and in patients with high grade stenosis and limited coronary blood flow. In patients with multi vessel disease aortocoronary bypass surgery is recommended to reduce high mortality. Long-term results demonstrate, that patients in whom PTCA or coronary bypass surgery was performed demonstrated the highest survival rate.

Angioplasty, Balloon↗
PubMed1987

[Local fibrinolytic therapy of vascular occlusions in the pelvic-leg area and the upper extremity].

Seventy-three patients with vascular occlusions in the pelvis or lower limbs and three patients with upper limb lesions were treated by local low dose fibrinolysin, with strict control of any possible bleeding tendencies. Adequate recanalisation was obtained in 56 patients (73.6%). In ten patients, the occlusion recurred while the patient was still in hospital. After four to six months, 37 of the 56 (67%) of the vessels were still patent. In 18 patients, peripheral emboli resulted in some deterioration, but in 15 of these cases this could be treated successfully by operation. The methods and indications of local fibrinolysis therapy and the problems associated with it are discussed.

Adult↗
PubMed1986

Percutaneous transluminal coronary angioplasty after thrombolytic therapy: a prospective controlled randomized trial.

In 162 patients with acute transmural myocardial infarction, combined intravenous and intracoronary thrombolytic therapy with streptokinase was initiated. In vessels that remained occluded, mechanical recanalization was performed with a 3F recanalization catheter (group I, n = 79) or a 4F Grüntzig balloon catheter (group II, n = 83). After reperfusion, intracoronary streptokinase was administered superselectively. After termination of streptokinase infusion, angioplasty was performed only in patients in group II. There was no difference between the groups in relation to sex, age, infarct location, creatine kinase levels and time between onset of symptoms and start of treatment. Initial coronary angiography showed an open vessel in 27 (34%) of 79 patients in group I and 21 (25%) of 83 patients in group II. The final reperfusion rate was 90% (71 of 79) in group I and 86% (71 of 83) in group II. Angioplasty was attempted in 69 of the 71 patients in group II with a success rate of 65% and an occlusion rate of 3%. During the hospital stay, reocclusion occurred in 14 (20%) of 71 patients in group I. After thrombolytic therapy, coronary luminal narrowing in group I was 75 +/- 17% in patients without and 87 +/- 6% in patients with reocclusion (p less than 0.05). In group II, reocclusion was found in 10 (14%) of 71 patients. After angioplasty, the degree of coronary stenosis in group II was reduced from 82 +/- 12 to 51 +/- 30% (p less than 0.001). Reocclusion was found in 3 (7%) of the 45 patients with successful angioplasty and in 7 (32%) of the 22 patients with unsuccessful angioplasty (p less than 0.01). Improvement in regional left ventricular function was observed only in patients from group II with anterior myocardial infarction. In conclusion, by combined medical and mechanical recanalization, the rate of coronary reperfusion can be increased and infarct time shortened, providing the possibility of full revascularization by angioplasty, with improvement of regional wall motion and reduction of the rate of reocclusion.

Adult↗
PubMed1986

Balloon coronary angioplasty in patients with acute myocardial infarction.

After successful thrombolysis, approximately 75% of all patients will have significant coronary stenosis, which can be dilated by means of percutaneous transluminal balloon angioplasty (PTCA). In a randomized control study, 95 of our patients (Group I) had thrombolysis alone, whereas 95 others (Group II) had thrombolysis and PTCA. Both groups were comparable with respect to age, sex, infarct location, and maximal creatine kinase (CK) value. The clinical outcome during the hospital phase was better in Group II, which had a reocclusion rate of 13%, a reinfarction rate of 5%, a lethal reinfarction rate of 2%, and a cardiac death rate of 7%, compared with respective rates of 20%, 13%, 7%, and 13% in Group I. Furthermore, in Group I, residual coronary stenosis immediately after thrombolysis (75% +/- 20%) did not improve significantly until the end of the hospital phase, when it decreased to 69% +/- 21%. In Group II, stenosis (78% +/- 16%) was improved by PTCA to 33% +/- 21%, and this improvement remained constant during the hospital phase (30% +/- 26%). In Group-II patients who had an unsuccessful PTCA, stenosis was approximately the same before dilatation (83% +/- 12%), after dilatation (80% +/- 17%), and at the control study (83% +/- 17%). The end-diastolic, end-systolic, and stroke volume indices, as well as the ejection fraction, also remained unchanged. In Group I, the number of pathologic wall segments (12.2 +/- 5.0) did not improve during the hospital phase (12.2 +/- 7.9), but in Group II, the improvement was significant (14.0 +/- 5.7 vs. 10.9 +/- 8.2) (p < 0.05). PTCA seems to improve the clinical outcome, reduce the infarction and mortality rates, and enhance myocardial perfusion and performance.

Journal Article↗
PubMed1986

[Combined use of thrombolysis and PTCA in myocardial infarct. Effect on global and regional ventricular function].

The study was performed to evaluate the combined effect of thrombolysis therapy and percutaneous coronary transluminal angioplasty (PTCA) on global and regional left ventricular function. In 127 patients with acute transmural myocardial infarction combined intravenous (250 000 U) and intracoronary (50 000 U) streptokinase therapy was started. When the infarct related vessel was occluded mechanical recanalization was performed with recanalization by Gruentzig balloon catheters. Patients were randomized in two groups, group I, n = 64, thrombolysis without PTCA; group II, n = 63, thrombolysis with PTCA. Both groups demonstrated no difference in relation to sex, age, infarct location, as well as CPK levels and time between onset of symptoms and start of treatment. First coronary angiography showed an open vessel in 23/64 patients (36%) of group I and in 12/63 patients (19%) of group II (p less than 0.001). Mechanical recanalization with 3 F catheters could be achieved in 27/41 patients (66%) of group I and with 4 F catheters in 26/51 patients (51%) of group II. In 9/41 patients (22%) of group I and in 18/51 patients (35%) in group II reperfusion took place before mechanical recanalization could be performed or occurred during superselective thrombolysis therapy, when mechanical recanalization failed. Thus, reperfusion rate in group I was 59/64 patients (92%) and in group II 56/63 patients (89%). PTCA was attempted in 55/56 patients in group II with a success rate of 65% and reocclusion rate of 4%. During hospital stay, reocclusion occurred in 10/59 patients in group I (17%) and in group II in 9/55 patients (16%). The patients were divided in those with and without successful angioplasty. Reocclusion was found in 3/36 patients (8%) and 6/17 patients (35%), respectively. Improvement with PTCA of regional and global left ventricular function was observed in patients with anterior myocardial infarction. With combined medical-mechanical recanalization, reperfusion rate can be increased and infarct time shortened, thus, providing the possibility of full revascularization by PTCA, improving coronary blood flow as well as improving global and regional left ventricular function.

Angioplasty, Balloon↗
PubMed1986

[PTCA and intracoronary lysis in acute myocardial infarct].

In 76% of all patients in whom thrombolysis was successful a residual stenosis exceeding 75% luminal diameter was found. Some patients suffered from single, others from multi-vessel disease. In single vessel diseases immediate intracoronary balloon dilatation of the residual stenosis is feasible. In multi-vessel diseases an aortocoronary bypass operation may follow. In a non-randomized study of 411 patients treated successfully with thrombolysis the best prognosis during the hospital phase and the subsequent 12 months was found in those who had had bypass surgery; patients treated with PTCA had the next best prognosis, and those treated with medical therapy had the worst. In a randomized study 95 patients were treated with thrombolysis alone and another 95 patients with thrombolysis plus immediate PTCA. PTCA diminished the degree of stenosis significantly (78 +/- 16% vs. 33 +/- 21%; p less than 0.001). This value remained constant during the following four weeks (30 +/- 26%). The clinical course, segmental wall motion and myocardial perfusion were more favourable in the PTCA group. No differences were found regarding spontaneous and inducible ventricular electrical vulnerability. Immediate PTCA without prior thrombolysis was performed in 27 patients with overt cardiogenic shock. The clinical mortality was significantly lower than in comparative studies. Recanalisation was successful in 24 of 27 patients. PTCA is complementary to successful thrombolysis in acute myocardial infarction to improve the prognosis and myocardial perfusion.

Aged↗
PubMed1986

The serum selenium concentration of patients with acute myocardial infarction.

Serum selenium concentration was determined in 49 patients with acute myocardial infarction within 4 hours after the beginning of the symptoms. The mean serum selenium concentration of the patients was significantly lower than that of healthy controls (55 +/- 15 micrograms/l vs. 78 +/- 11 micrograms/l). Among the 49 patients with acute myocardial infarction 20 (41%) had serum selenium concentration below the 95% percentile of the healthy control group. It is concluded that the low serum selenium concentration was present in these patients before the acute event and was not a consequence of the myocardial infarction. No relationship was found in this study between the serum selenium concentration and the severity of myocardial infarction if the number of coronary vessels occluded is taken as the criterion of severity. Serum selenium concentration was similar in patients with 1 or more coronary vessels occluded. Patients with anterior or posterior myocardial infarction had similar serum selenium concentrations. A positive correlation was observed between serum selenium concentration and total serum creatine kinase (CK) activity and serum myoglobin (MB). The serum selenium concentration correlated negatively with the ratio CK-MB/total CK activity, which can be interpreted as minor injury of mitochondria during infarction in patients with normal serum selenium concentration.

Aged↗
PubMed1984

Supernormal conduction in the right bundle branch: lack of influence of autonomic blockade.

A programmed atrial stimulation at a driving rate of 100/min was performed in a 47-year-old woman with left bundle branch block. Supernormal conduction lasting 40 ms was revealed within the right bundle branch. After autonomic blockade (0.2 mg propranolol/kg body weight and 0.04 mg atropine/kg body weight) the position and duration of the supernormal conduction did not change. This suggests that the autonomic nervous system has no influence on the supernormal phase of conduction in the human intraventricular conduction system.

Atropine↗
PubMed1984

Blood volume following diuresis induced by furosemide.

Changes in blood volume were investigated following intravenous injection of a single dose of furosemide in 21 patients with pulmonary edema. In a subset of 10 patients in whom the blood urea nitrogen level was 11.4 +/- 2.2 mg/dl and the serum creatinine level was 1.3 +/- 0.1 mg/dl and in whom total urine output exceeded 1 liter over a four- to six-hour interval ("diuretic" group), no significant change in plasma or total blood volume was observed, nor were there any significant changes in hematocrit. In a "nondiuretic" group of 11 patients who had moderately decreased renal function (blood urea nitrogen level 59.3 +/- 13.0 mg/dl and serum creatinine level 2.3 +/- 0.3 mg/dl) and in whom total urine output was less than 1 liter over the four- to six-hour interval, there was a significant increase in blood volume with a concomitant decrease in hematocrit and hemoglobin levels. Furosemide-induced diuresis therefore did not deplete intravascular volume. To the contrary, actions of furosemide that were independent of its diuretic action were associated with an expansion of plasma volume in the absence of diuresis. This may be related to the venous capacitance effects of furosemide with lowering of venous resistance and, therefore, lowering of the capillary hydrostatic pressure. In addition, there was an increase in colloid osmotic pressure. Both mechanisms increase the effective oncotic pressure gradient, which favors reabsorption of extravascular (edema) fluid. It is concluded that intravascular volume was therefore replenished at a rate equal to or in excess of the volume removed by diuresis.

Adult↗
PubMed1984

Application of impedance cardiography in critical care medicine.

In spite of good correlations between cardiac output measurements by impedance and established invasive procedures (dye- and thermo-dilution) reported by numerous authors it is doubtful uptil now whether calculations of stroke volume according to the formula of Kubicek et al. (1974) can provide absolutely reliable results. The origin of the dz/dt curve and influencing factors of impedance wave have to be cleared up prior to the total acception of impedance cardiography as a reliable method for determining non-invasive stroke volume. This is true in spite of the agreement of all authors we know, that the reproducibility of the impedance cardiography values is as good as in dye or thermo-dilution measurements. However, for patient monitoring it is sometimes more important to assess the relative changes in stroke volume than to measure its absolute value. For long-term non-invasive monitoring of myocardial contractility in critically ill patients or after pharmacological interventions impedance cardiography may be recommended. Besides systolic time intervals, such as pre-ejection time and ventricular ejection time, three more reliable parameters can be derived from the first derivate of impedance wave. Impedance plethysmography has been shown as a reliable method to diagnose deep vein thrombosis and good correlations between impedance and strain-gauge plethysmography and phlebographic findings are reported. In addition fluid volume changes in the leg, venous capacity, venous outflow and arterial inflow may be determined by impedance plethysmography in a simple way. There is no doubt that alterations in the fluid content of biological tissue may measured by impedance technique. However, correlations between changes in the transthoracic impedance and fluid content of the thorax can be quantified only in a single subject which serves as its own control. Overall standardization is not possible. The reason for interindividual differences in the thoracic impedance at a given reduction of body water are due to anatomical differences, intrapulmonary air volume and pressure, location of the electrodes, electrical conductivity of the tissue and, above all, due to the position of the body. Therefore if transthoracic impedance is determined sequentially measurements must be performed with special attention to the position of the body to get reproducible results. Rapid infusion of colloids or blood transfusion may decrease transthoracic impedance due to intravascular volume expansion even at a net fluid lost during forced furosemide-induced diuresis or extracorporal hemodialysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Cardiac Output↗
PubMed1984

[Successful transvenous electric ablation of the AV conduction system in therapy-refractory atrial flutter].

The technique of closed-chest ablation of the atrioventricular (AV) conduction system was used in 3 patients (53-62 years of age) with atrial flutter not responding to medical management. A persistent third-degree AV block was induced in all patients. Moderate increases in CK and CKMB enzymes but not in Tc-pyrophosphate uptake were observed in these patients. 5 days after the procedure a permanent pacemaker was implanted in each case. We conclude that closed-chest ablation of the AV conduction system is a safe and efficient procedure in selected patients with drug-resistant supraventricular arrhythmias.

Adult↗
PubMed1983

[Effect of nifedipine on sinus node and atrioventricular node function following autonomic blockade in the human].

The effect of intravenously administered nifedipine (7.5 micrograms/kg) on sinus node and atrioventricular (AV) node function was evaluated in 17 patients, 9 of whom had sinus node disease after autonomic blockade (propranolol 0.2 mg/kg and atropine 0.04 mg/kg i.v.). The patients' ages ranged from 18 to 77 years. After nifedipine there was a nonsignificant increase in the median values for sinus cycle length from 750 ms to 760 ms, for sinus node recovery time from 1150 ms to 1240 ms, for corrected sinus node recovery time from 440 ms to 460 ms, and for sinoatrial conduction time from 63 ms to 75 ms. Nevertheless, nifedipine produced a significant increase in the AV node refractory periods (median values): the effective refractory period lengthened from 300 ms to 305 ms (rate 100/min) and from 290 ms to 300 ms (rate 120/min) respectively. The functional refractory period increased from 380 ms to 400 ms (rate 100/min) and from 385 ms to 410 ms (rate 120/min) respectively. The Wenckebach period was significantly prolonged from 370 ms to 390 ms. We conclude, therefore, that in the absence of autonomic control intravenous administration of nifedipine exerts a mild depressive effect on AV node but not on sinus node function.

Adolescent↗
PubMed1982

Two automated methods for plasma antithrombin III compared, and the clinical significance of the results.

Antithrombin III (AT III) activity was determined with two different new chromogenic substances--Chromozym-TH (Tos-Gly-Arg-p-nitroanilide; Boehringer Mannheim) and alpha-N-carbobenzyl-oxy-L-lysine-thiobenzyl ester (Du Pont)--with both a discrete (aca) and a centrifugal analyzer (COBAS BIO). The correlation between the Chromozym-TH/centrifugal analyzer and Du Pont ester/aca methods was good (r = 0.9890). Precision within and between runs was similar to that for typical enzymic determinations. AT III in plasma of 226 healthy men and women ranged from 76.6 to 141.1% (100% = "normal"). We found no significant differences ascribable to oral contraceptives. AT III activity was decreased in 27% of patients with acute thromboembolic diseases (n = 62), in 48% of patients the first day after abdominal operations without complications (n = 78), and in 100% of patients with reversible or irreversible shock (n = 58). In patients receiving continuous therapy with heparin (1500 USP units/h) we saw no decrease in AT III within 96 h of beginning treatment. Plasma from 14 of 16 patients with disseminated intravascular coagulopathy showed a decrease in AT III of from 17 to 51% of normal before and during heparin therapy. We then treated all 16 patients with AT III concentrate. During such treatment, AT III in plasma must be monitored over short intervals to assure that sufficiently high proportions of AT III (greater than 70% of normal) are reached.

Adolescent↗
PubMed1981

Significance of hyperlactatemia in acute hypnotic drug poisoning.

Lactate concentration, fibrinogen and fibrin(ogen) -- degradation-products in central venous blood were analysed in 35 unconscious patient with acute hypnotic drug poisoning (HDP) and compared with the results in 13 healthy control persons undergoing the same degree of forced diuresis via central venous catheters. Blood samples were taken on admission and at 12 h intervals up to 36 h after admission. Patients with HDP were attributed to the categories of moderate intoxications (n = 17) and severe intoxications (n = 18) according to their clinical condition. On admission, blood lactate was significantly higher in severe intoxication (3.90 +/- 2.94 mmol/l) as compared to the control group (1.25 +/- 0.17 mmol/l). Blood lactate was less elevated in moderate poisoning (2.74 +/- 1.22 mmol/l). Thirty-six hours after admission blood lactate was completely normalised in patients with moderate intoxication (1.19 +/- 0.69 mmol/l) but still significantly elevated in severely poisoned patients (2.26 +/- 1.48 mmol/l). Lactate concentration was above normal in 15 out of 17 patients with moderate and in 17 out of 18 patients with severe poisoning. A statistically significant linear correlation existed between the duration of unconsciousness and the maximal lactate concentration within 12 hrs after admission. For fibrinogen concentrations statistically significant differences were observed neither between groups nor across time. Titers of FDP were elevated in 9 out of 11 patients with moderate and to a higher degree in all patients with severe poisoning, indicating low rate DIC. Hyperlactatemia is a frequent finding in acute hypnotic drug poisoning. Blood lactate estimations may improve the evaluation of the severity of poisoning and the efficacy of therapeutic interventions.

Adult↗