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Biomedical subjects

H D Schulte

Publications and source records attributed to H D Schulte.

At least 19 recordsLinked to original sources
PubMed2004

Intermittent aortic cross-clamping for coronary artery bypass grafting: a review of a safe, fast, simple, and successful technique.

Since the very beginning of coronary artery bypass grafting, the search for optimal myocardial protection has fascinated both clinicians and basic researchers. This retrospective review of a large patient cohort aims to display the advantages of one of the protective procedures, namely simple, intermittent aortic cross-clamping (IAC). Thus, this review aims to significantly contribute to daily bypass surgery. This review reports on coronary patients who were all operated on in international centers using IAC such that this review presents the state of the art on IAC. In addition, this review reports on the usage of IAC for more than 2 decades in the clinic of Dr. Bircks, Duesseldorf (DE) and the clinics of his former students. A meta-analysis of published data of international centers summarizes 7 837 operated patients with a total mortality of 123 (=1.6%). This excellent outcome compares well to the results of the Bircks'-related centers, where between 1978 and 2001, a total of 41 573 patients were revascularized with the help of IAC according to the original protocol. The total mortality was 778 (1.9%), with the lowest mortality rate (1.2%) in the largest center (Bad Oeynhausen, DE). According to the presented experience, IAC for coronary revascularization proves to be a highly effective method for myocardial protection; it has convincingly proven to be simple, safe and cost-efficient.

Aorta↗
PubMed2002

Elastase release following myocardial ischemia during extracorporeal circulation (ECC) -- marker of ongoing systemic inflammation?

BACKGROUND: 'Post-Perfusion Syndrome' (PPS) after cardiopulmonary bypass (CPB) is known to be evoked by inflammatory reactions. The hypothesis of a pathogenetic role for the neutrophil granulocytes in this inflammation would be strengthened if elevated concentrations of a neutrophil product such as elastase could be demonstrated, particularly in case of a PPS or a systemic inflammatory response syndrome (SIRS). METHODS: In a randomized prospective double-blind study, 40 patients undergoing aortocoronary bypass grafting (CABG) were divided into 4 groups of 10 patients each. One group served as the control group, one received prostacyclin (PGl 2 ), the third group was substituted with high-dosed aprotinin and the last group was treated with a combination of PGl 2 and aprotinin. 6 blood samples were taken from every patient perioperatively, and plasma elastase (PE), procalcitonin (PCT), C 1 -esterase inhibitor (CEI) and parameters of coagulation and fibrinolysis were determined. RESULTS: Levels of elastase increased significantly in all intra- and postoperative blood samples compared to the preoperative baseline values (< 30 microg/l, p < 0.05). The elastase release was even more pronounced in the control and aprotinin group (170 +/- 23 microg/l; 175 +/- 14 microg/l during ECC) compared to patients who received prostacyclin (142 = 21 microg/l, p < 0.05). Duration of myocardial ischemia could be directly correlated to elastase levels at the end of CPB. 10 of the 40 patients suffered postoperatively from a PPS or a SIRS; in these patients, elastase levels at the end of CPB were significantly higher (188 +/- 26 microg/l vs. 138 +/- 22 microg/l, p < 0.05). Immediately after the operation, these 10 patients also showed significant changes in the cascades of coagulation and fibrinolysis resulting in a hypercoagulatory state. Levels of PCT and CEI did not change significantly during and after ECC. CONCLUSIONS: Our results indicate that CPB initiates an elastase release that can be suppressed by prostacyclin. Increased intraoperative elastase levels in patients with PPS show that elastase may be an indicator of ongoing systemic inflammation, possibly causing complications due to a hypercoagulatory state. Myocardial ischemia seems to be one reason for this elastase release. It can be speculated that early PGl2-infusion could be a therapeutic option in inflammatory diseases caused by ECC.

Aprotinin↗
PubMed2002

Myocardial collagen type I and impaired left ventricular function under exercise in hypertrophic cardiomyopathy.

BACKGROUND: Transaortic subvalvular myectomy (TSM) reduces left ventricular outflow tract gradient and improves symptoms and working capacity in patients with hypertrophic obstructive cardiomyopathy (HOCM). Nevertheless, TSM does not completely restore normal ventricular function, and some patients complain of symptoms despite optimal surgical results. Abnormal myocardial collagen structure in hypertrophic cardiomyopathy might be an indicator of impaired cardiac function. METHODS: Nine patients with HOCM were investigated. Myocytic diameter, collagen volume fraction and light absorbance of immunohistochemically stained collagen subtype I and its product (Coll I(prod)) were measured quantitatively in myectomy specimens. Patients underwent symptom-limited bicycle exercise testing with equilibrium radionuclide angiocardiography to determine ejection fraction (EF). Right heart catheterization was performed simultaneously in order to measure pulmonary capillary wedge pressure (PCWP) as a parameter of global ventricular diastolic filling and cardiac index (CI) as a parameter of functional capacity. RESULTS: Postoperatively, CI increased from 3.1 +/- 0.4 to 5.7 +/- 1.3 l/min/m(2) under exercise. EF was normal at rest (64 +/- 9 %) but did not increase significantly under exercise (66 +/- 14 %). Coll I(prod) (13.62 +/- 7.35 Vv%(prod)) correlated inversely with EF under exercise (r = -0.64; p = 0.05). PCWP increased under exercise from 8 +/- 2 mmHg at rest to 22 +/- 9 mmHg (p = 0.01). Coll I(prod) correlated with PCWP under exercise (r = 0.90; p = 0.001). CONCLUSIONS: Increased collagen subtype I is a predictor of diastolic as well as systolic dysfunction under exercise in patients with HCM after successful TSM.

Adolescent↗
PubMed2002

Repair of critical aortic coarctation in neonatal age.

BACKGROUND: The data of 111 (male: 64; female: 47) in the period of 1967 until 12/93 consecutive operated neonatals (<1 month) were studied retrospectively (mean weight 3270 g, mean age at operation 14 days). METHODS: Preductal anatomy was present in 96 patients. The coarctation was isolated in 30 patients (group I), 34 patients had additional large ventricular septal defects (group II) and 47 had complex heart disease (group III). The preoperative heart catheterization revealed a gradient of <20 mmHg in 35%, >20 mmHg in 51.4% and >50 mmHg in 12.9%. The indication for repair was conservatively untreatable heart insufficiency. In the vast majority (n=97) of patients resection and end-to-end anastomosis were performed, in 31 cases using an absorbable suture, in 18 of these using a continuous suture line. In 4 patients a subclavian flap angioplasty (SFA) was done, in 4 a patch enlargement, 4 times a repair was described as not possible and in 2 patients there was no gradient after division of the ductus. RESULTS: Early lethality was 3.3% (n=1) in group I, 24.2% (n=8) died in group II and 39.1% (n=18) in group III; after introducing Prostaglandin E1 0% in group I, 15% in II and 25% in III. Relevant recoarctation (Gradient >20 mmHg) developed in 9 (among them 4 with hypoplastic arch, 2 after SFA) of the 77 long-term survivors; 6 of these were reoperated on, 5 without residual gradient, 1 with a gradient of 25 mmHg without clinical symptoms (after 4 years). In the last 3 patients a balloon dilation was carried out without residual gradient. Mean follow-up time was 6 (0-24) years. No patient needs antihypertensive treatment. The cumulative survival rate is 96.7% (+6.6%) for group I, 77.4% (+15.0%) for II and 51.9% (+16.6%) for III. CONCLUSIONS: Resection and end-to-end anastomosis using a continuous absorbable suture is the method of choice at theoretical considerations and in our experiences. The number of recoarctations in neonatal age is relatively high; reinterventions (operation respectively dilation) can be done safely and successfully.

Age Factors↗
PubMed2001

Myocardial revascularization in patients with end-stage renal disease: comparison of percutaneous transluminal coronary angioplasty and coronary artery bypass grafting.

BACKGROUND: Ischemic heart disease is the major cause of death in patients with end-stage renal disease. The high prevalence of coronary artery disease results in a rising number of dialysis patients requiring myocardial revascularisation. OBJECTIVE: The objective of this study was to compare the outcomes of recurrent angina, myocardial infarction, rate of reinterventions and cardiovascular death following percutaneous coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) in patients with end-stage renal disease. PATIENTS AND METHODS: In a retrospective investigation 40 patients with chronic renal failure undergoing primarily PTCA and 65 patients undergoing CABG were included. Both groups were comparable for gender, duration on dialysis and the number of cardiovascular risk factors per patient. Patients undergoing PTCA were younger (53 +/- 12 years vs. 57 + 8 years; p < 0.05) and more often diabetics (30% vs. 14%; p < 0.05). RESULTS: Most patients in both groups had a multi-vessel disease (95% in the CABG group vs. 74% in the PTCA group), in the CABG group there were significantly more patients with a triple-vessel disease (62% with vs. 40% in the PTCA group; p < 0.01), PTCA was primarily successful in 95% of the patients while complete revascularization was achieved in 88% of patients undergoing CABG. The perioperative mortality after CABG was 4.8% as compared to none after interventional revascularisation. The cumulative freedom of angina after 6, 12 and 24 months after intervention was significantly lower after PTCA (54%, 40%, 29%) than after bypass grafting (97%, 94%, 90%, p < 0.001). The frequency of reinterventions following PTCA was significantly higher compared to patients following CABG (p < 0.001). After PTCA 15 patients needed further revascularisations, 8 of them underwent CABG, whereas after CABG only two patients required additional myocardial revascularisation. There was no significant difference in the overall mortality between both groups; the survival rate after 12 and 24 months was 95% and 82% after PTCA and 93% and 86% after CABG, respectively. CONDITION: Although patients receiving CABG had a more severe coronary artery disease the overall mortality was comparable and clinical and functional outcome was improved compared to patients after coronary angioplasty.

Adult↗
PubMed2001

Long-term results after repair of total anomalous pulmonary venous connection.

BACKGROUND: Operative strategies and early results concerning repair of Total Anomalous Pulmonary Venous Connection (TAPVC) are relatively well known. Less well defined data are available to evaluate the long-term outcome. We would therefore like to contribute our long-term data in this presentation. PATIENTS AND METHODS: Between 1958 and 1992 52 consecutive patients aged two days to 42 years (15 neonates, 16 infants, 9 children and 12 adults) with TAPVC were operated on. The data were collected retrospectively from the records. In 24 patients, a current follow-up study was performed, including clinical evaluation, echocardiography, and a twenty-four-hour ambulatory ECG. RESULTS: Early mortality was 34.6% (n = 18). The postoperative follow-up period ranged from 4 months to 28 years (mean 10.7 years). There were 4 late deaths, yielding an overall long-term mortality of 7.7% (4/52). Causes of death were severe hypoplasia of central pulmonary veins in 1, ventricular fibrillation (2) and non-cardiac in one case. 80% of the operative survivors were available for assessment. Preoperatively, 11 of these patients were in NYHA functional class II, six in class III and seven in class IV. After treatment, 22 patients were in class I and two in class II. Ventricular function was evaluated by echocardiography and invasive catheterization. Only two of 24 patients (8%) showed an abnormal IVS-motion and enlargement of the right ventricle. Cardiac catheterization revealed a mean PA pressure of 26 mmHg, the peak systolic pressure in the RV was 34 mmHg. All 24 long-term survivors underwent assessment of cardiac rhythm by 24 h electrocardiogramm (ECG) monitoring. Significant arrhythmias were recorded in 11 of 24 cases (46%), including sinus node dysfunction in 3 patients. Multiform ventricular ectopic beats were evaluated in 9 cases. According to the Lown classification, 7 patients were class I while 2 cases were considered to be class IV. CONCLUSIONS: A normal hemodynamic state can be achieved in most cases. Significant arrhythmias may exist in asymptomatic patients late after surgical correction of TAPVC, and therefore, long-term follow-up of these patients, including 24 h ECG monitoring, is recommended, even if they are asymptomatic.

Adolescent↗
PubMed2001

Does the time of resternotomy for bleeding have any influence on the incidence of sternal infections, septic courses or further complications?

BACKGROUND: Former studies on sternal wound infections indicate predisposing factors like diabetes, obesity, use of bilateral internal mammary grafts, impaired renal function and reoperation. We wanted to evaluate whether the time of resternotomy for postoperative bleeding has any influence on the development of a sternal wound infection and other complications. METHODS: In our department, 12,315 patients underwent median sternotomy for cardiac surgery between 1987 and 1998. We analyzed the clinical data of all patients which were reoperated on for postoperative bleeding, especially patients with subsequent operations caused by sternal wound infections. All data were compared by T-test respectively chi2-test, and p<0.05 was regarded as significant. RESULTS: 406 of the 12,315 patients were re-explored because of postoperative bleeding (3.3%). 57 (14%) of these patients died in the postoperative period of non-infectious complications. The remaining patients were divided into two groups: Group A (286 patients) (70.4%) did not suffer from any sternal wound complications, where as group B patients (n = 63) (15.6%) needed subsequent surgery due to sternal infection. There were no significant differences in either concerning age, clinical data and first operation. All patients had an average blood loss of 223 ml/hr. The time before re-operation for bleeding was 5.3+/-1.7 hours in group A compared to 11.1+/-4.2 hours in group B (p<0.05). A significant delay of reoperation for bleeding could also be found for patients with postoperative septic complications (ø: 5.2+/-1.9 hours, +: 12.9+/-5.2 hours), renal failure, mechanical ventilation >48 hours and a stay in hospital >20 days. CONCLUSIONS: Early reoperation for postoperative bleeding decreases the number of subsequent complications, e.g. sternal wound infections, septic complications and prolonged mechanical ventilation.

Cardiac Surgical Procedures↗
PubMed2001

Blood product use during routine open heart surgery: the impact of the centrifugal pump.

A prospective randomized study was done including 1,000 patients undergoing routine open heart surgery. Patients were randomly assigned to either a roller pump or a BioMedicus centrifugal pump with identical extracorporeal circuits. There were no significant differences between study groups. Actual blood products transfused and predicted transfusion requirements (using Cardiac RiskMaster) were examined as was chest tube drainage (CTD). The predicted transfusion requirement was 885 of 1,000 patients. Transfusions were required by 472 of 1,000. Risk factors as significant predictors of increased CTD and use of blood products were emergency surgery status, increased cross-clamp time, and higher predicted risk of mortality. The only significant predictor of decreased CTD was the use of a centrifugal pump. Predictors of increased length of stay were myocardial infarction, preoperative urea, age, and massive transfusion. Data provide evidence that use of the centrifugal pump improves patient outcomes by decreasing CTD and decreasing the requirements for transfusion, which results in a shorter hospital stay.

Blood Transfusion↗
PubMed2001

Stroke is not a contraindication for urgent valve replacement in acute infective endocarditis.

BACKGROUND AND AIM OF THE STUDY: A treatment dilemma arises when endocarditis is complicated by cerebral embolism. Secondary cerebral hemorrhagic complications may arise following suppression of coagulation during extracorporeal circulation. Extensive valvular vegetation is regarded as an indicator for urgent surgery. The study aim was to determine the relative risk of thromboembolic complications, and to analyze the prognostic influence of different treatment strategies following onset of these complications, in particular, secondary cerebral hemorrhagic events after urgent surgery. METHODS: Between 1978 and 1993, endocarditis was diagnosed in 288 consecutive patients. Patients treated before 1982 (6.9%) were analyzed retrospectively. The remaining patients (93.1%) were followed prospectively (mean 4.3+/-1.7 years). RESULTS: In 50 patients (17.4%), the clinical course was complicated by one embolism, and in 58 patients (20.2%) by recurrent embolisms. In total, 71% of all embolisms were cerebral events. The operated patients were categorized with regard to the time between recurrent thromboembolic events and cardiac surgery (<72 h, 3-8 days, and >8 days). The prognosis for patients operated within 72 h was significantly more favorable (p <0.0001) than for those treated medically. Patients undergoing cardiac surgery more than eight days after stroke, and those treated conservatively, had poor prognoses. CONCLUSION: When endocarditis is complicated by stroke, it is recommended that cardiac surgery be performed within 72 h of the cerebral embolism, when the risk of secondary cerebral hemorrhage appears to be low. Cranial computed tomography is obligatory immediately before surgery in order to identify patients with early reperfusion hemorrhages due to spontaneous fragmentation of the thrombus. In these patients, cardiac surgery must be postponed because of the high risk of severe cerebral bleeding during extensive perioperative anticoagulation, and is only justified in the case of an otherwise unfavorable prognosis.

Acute Disease↗
PubMed2000

The human beta-myosin heavy chain gene: sequence diversity and functional characteristics of the protein.

The beta-myosin heavy chain gene (MYH7) encodes the motor protein that drives myocardial contraction. It has been proven to be a disease gene for hypertrophic cardiomyopathy (HCM). We analyzed the DNA sequence variation of MYH7 (about 16 kb) of eight individuals: six patients with HCM and two healthy controls. The overall DNA sequence identity was up to 97.2% compared to Jaenicke and coworkers (Jaenicke et al. [1990] Genomics 8:194-206), while the corresponding amino acid sequences revealed 100% identity. In HCM patients, eleven nucleotide substitutions were identified but no causative disease mutation was found: six were detected in coding, four in intronic, and one in 5' regulatory regions. The average nucleotide diversity across this locus was 0.015% with an average of 0.02% in the coding and 0.012% in the noncoding sequence. Analysis of the kinetic behaviour of beta-MHC in the intact contractile structure of normal individuals and HCM patients revealed apparent rate constants of tension development ranging between 1.58 s(-1) and 1.48 s(-1).

Base Sequence↗
PubMed2000

[Is the estimation of the progression of valvular aortic stenosis possible?].

BACKGROUND AND OBJECTIVE: It is of great importance to assess progression of aortic valvar stenosis (AVS) when cardiac surgery is planned for other indications when established criteria for aortic valve replacement are not fulfilled at that moment. These considerations have often been ignored in prospective planning of treatment, necessitating a second cardiac surgical intervention just a few years later. The aim of this study was to establish criteria for estimating the rate of progression of AVS. PATIENTS AND METHODS: Clinical, echocardiographic and haemodynamic data were analysed for 169 patients with aortic valvar stenosis (169 men, 88 women; mean age at first cardiac catheterization [CC] 55.2 +/- 15.7 years, at second CC 63.4 +/- 15.6 years. RESULTS: The degree of AVS increases exponentially in relation to the extent of calcification (graded 0-3) and the fall in transaortic gradient (TG), from a TG > 0.6 mmHg/ml stroke volume and can be sufficiently predictable for clinical purposes. But neither age, sex nor the aetiology/pathology of the valvar defect have a sustained influence on the progression of AVS. CONCLUSIONS: These data indicate that knowing the current reduction in TG and the degree of calcification makes it possible to assess the likely progression of previously asymptomatic AVS and thus greatly facilitate the decision of whether or not to combine aortic valve replacement with another indicated cardiac operation.

Adolescent↗
PubMed2000

Procalcitonin (PCT) in cardiac surgery: diagnostic value in systemic inflammatory response syndrome (SIRS), sepsis and after heart transplantation (HTX).

PURPOSE: Since it is of great importance to distinguish between a systemic inflammatory response syndrome (SIRS) and an infection caused by microbes especially after heart transplantation (HTX), we examined patients following heart surgery by determining procalcitonin (PCT), because PCT is said to be secreted only in patients with microbial infections. METHODS: Sixty patients undergoing coronary artery bypass grafting (CABG) and 14 patients after heart transplantation were included in this prospective study. In the CABG group we had 30 patients without any postoperative complications (group A). Furthermore we took samples of 30 patients who suffered postoperatively from a sepsis (group B, n=15) or a systemic inflammatory response syndrome (C, n=15). In addition we measured the PCT-levels in 65 blood samples of 14 patients after heart transplantation (Group I: rejection > IIa, II: viral infection (CMV), III: bacterial/fungal infection, IV: controls). RESULTS: In all patients of group A the pre- and intraoperative PCT-values and the measurement at arrival on intensive care unit (ICU) were less than 0.2 ng/ml. On the second postoperative day the PCT-value was 0.33+/-0.15 ng/ml in the control group. At the same time it was 19.6+/-6.2 ng/ml in sepsis and 0.7+/-0.4 ng/ml in systemic inflammatory response syndrome patients (P<0.05). In transplanted patients we could find the following PCT-values: Gr.I: 0.18+/-0.06 II: 0.30+/-0.09 III: 1.63+/-1.16 IV: 0.21+/-0.09 ng/ml (P<0.05 comparing group III with I, II and IV). CONCLUSIONS: These results show that extracorporeal circulation (ECC) and systemic inflammatory response syndrome do not initiate a PCT-secretion. Septic conditions cause a significant increase of PCT. In addition, PCT is a reliable indicator concerning the essential differentiation of bacterial or fungal--not viral--infection and rejection after heart transplantation.

Aged↗
PubMed1999

Remodeling of the hypertrophied human myocardium by cardiac bHLH transcription factors.

The basic helix-loop-helix transcription factors eHAND and dHAND are involved in developmental cardiac growth and differentiation. We investigated HAND gene expression in the normal and in the hypertrophied right and left ventricle of patients with tetralogy of Fallot (ToF) and hypertrophic obstructive cardiomyopathy (HOCM). HAND mRNA was constitutively expressed in the hypertrophied heart and increased in the hypertrophic tissue of both patient groups. HAND genes had a complementary left-right cardiac asymmetry of expression with dHAND predominantly in the right and eHAND in the left ventricle. The two cardiac bHLH factors have the ability to form heterodimers with the ubiquitous bHLH protein E12, subsequently recognizing E-boxes in the promoter region of target genes like ALC-1. We found a highly significant positive correlation between HAND and ALC-1 mRNA. The total ALC-1 protein level in ToF was smaller than in HOCM, although ALC-1 mRNA as well as HAND mRNA levels were significantly higher. ToF patients expressed around four times more ALC-1 mRNA for similar amounts of ALC-1 than HOCM patients. Suggesting disturbed ALC-1 translation in ToF, we found ALC-1 antisense mRNA expression in the hypertrophied, but not in the normal, ventricles. The higher the antisense/sense ALC-1 mRNA ratio, the lower ALC-1 protein was expressed.

Base Sequence↗
PubMed1999

Expression of atrial myosin light chains but not alpha-myosin heavy chains is correlated in vivo with increased ventricular function in patients with hypertrophic obstructive cardiomyopathy.

The adult rodent heart adapts to increased work load by reexpression of its fetal genes, for example, beta-myosin heavy chain (MHC), in order to improve contractile function. However, the human ventricle regulates contractility by expression of atrial essential myosin light chain (ALC-1) rather than beta-MHC. We evaluated the impact of both mechanisms in patients with hypertrophic cardiomyopathy. MHC isoform expression was quantified at the mRNA and protein levels by reverse transcriptase polymerase chain reaction and immunoblotting, respectively. Although alpha-MHC mRNA was detected in control and hypertrophied human ventricular tissue, alpha-MHC protein was not observed. Similarly, we investigated the expression of ALC-1 by two-dimensional polyacrylamide gel electrophoresis and the clinical and hemodynamic parameters of the patients with hypertrophic cardiomyopathy. We found a significant positive correlation between ALC-1 protein expression and dP/dtmax in the hypertrophied human ventricle in vivo. Correlations between dP/dtmax and expression of protein for the ryanodine receptor and L-type Ca2+ channel were excluded. Our data suggest that reexpression of ALC-1 improves the contractile state of the adult human heart. We propose that two evolutionarily divergent compensatory mechanisms for increased work demand exist in the mammalian heart: MHC regulation in rodents and essential MLC regulation, of cardiac contractility, in humans.

Adult↗