[Aortic stenosis].
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Aortic Valve Stenosis↗
Biomedical subjects
H J Schäfers
Publications and source records attributed to H J Schäfers.
Development of ulcerative colitis after heart transplantation during immunosuppressive therapy.
BACKGROUND: Cardiac transplantation has become an accepted treatment modality for end-stage heart failure. Immunosuppressive agents, which are used after transplantation, are considered as therapeutic options for inflammatory bowel disease. CASE REPORT: We report on a 53-year-old patient who was treated for 2 years with cyclosporine A, azathioprine and prednisolone after heart transplantation. He developed a distal colitis with all features of ulcerative colitis. An infectious or ischemic etiology was carefully excluded. In spite of high-dose treatment with prednisolone the patient's abdominal symptoms worsened and he developed a progression of the inflammation in the entire colon and a colectomy with ileostomy was necessary. The histology was consistent with ulcerative colitis. After colectomy he recovered and remained in a good state of health. CONCLUSIONS: This report supports the concept that new onset inflammatory bowel disease can develop in a heart transplantation recipient in spite of immunosuppression.
Biopsy↗
Recent progress in heart valve surgery: innovation or evolution?
Although heart valve surgery continues to evolve in a dynamic fashion, there is still no optimal solution for all patients. Minimally invasive surgery currently receives considerable attention but its value still needs to be determined. Progress has been made in valve repair, which now allows reconstruction in most patients with mitral valve disease. Reconstruction of the aortic valve is now also possible with results that are now comparable to those of mitral repair. In the future a wider application of repair procedures and further improvements of biologic valves can be anticipated not only to influence long-term results, but also the decision making process for conservative or surgical treatment.
Aortic Valve↗
Influence of inhaled iloprost on transpulmonary gradient of big endothelin in patients with pulmonary hypertension.
BACKGROUND: The pulmonary circulation is an important site for the production and clearance of endothelin (ET)-1, a potent vasoactive and mitogenic peptide. In healthy individuals, 40% to 50% of circulating ET-1 is removed on each passage through the lungs resulting in an arteriovenous ratio of <1, whereas many patients with pulmonary arterial hypertension (PAH) have ratios >1, indicating reduced clearance or increased release of endothelin. The influence of inhaled prostanoids on endothelin clearance is unknown. METHODS AND RESULTS: In a prospective investigation, plasma concentrations of big endothelin-1 (big ET-1, Elisa) were measured in 15 patients with pulmonary hypertension undergoing right heart catheterization with iloprost inhalation (4 m, 11 f, aged 35 to 75 years, mean pulmonary arterial pressure (PAPm) 54+/-2.3 mm Hg, pulmonary vascular resistance (PVR) 1061+/-141 dyn x sec x cm(-5)). There was a significant transpulmonary gradient for big ET-1 with 31% +/-11% higher concentrations in the radial artery than in the pulmonary artery (P<0.001). After inhalation of iloprost a significant decrease in the AV-ratio from 1.31+/-0.11 to 0.92+/-0.06 (P<0.007) was observed. The pulmonary net release of 3.10+/-0.65 pmol/min big ET-1 at baseline decreased to -1.24+/-1.32 pmol/min (P=0.013) within 15 minutes indicating a restored balance. Patients under long-term treatment with iloprost (n=7) tended to have a lower net release and AV-ratio for big ET-1 than patients without pretreatment. CONCLUSION: An increase in pulmonary clearance of big-ET could be a mechanism contributing to the beneficial effects of inhaled prostanoids in the treatment of PAH.
Administration, Inhalation↗
[Daily activities and circadian variation of ventricular tachyarrhythmias in patients with implanted defibrillator].
BACKGROUND AND STUDY AIM: Acute cardiovascular events may be triggered by physical and mental stress. Does also the typical circadian variation of arrhythmia recurrence (morning peak of events) in patients with implanted cardioverter-defibrillator correlate with the individual circadian variation of physical and mental daily activities? PATIENTS AND METHODS: In 29 consecutive patients with a minimum of three documented ventricular tachyarrhythmias after defibrillator implantation the circadian variation of habitual daily activities was determined in a standardized interview and compared to the individual circadian variation of arrhythmic events saved in the defibrillator event memory during long-term follow-up. RESULTS: The habitually highest physical and mental activity was determined during the time period with most arrhythmic events in 55 % and 23 % of patients, respectively. A comparison of the level of activity during the time period with the highest event frequency to the mean activity level during the rest of the day (without sleeping time) revealed significantly higher physical activity during the time of day with the highest arrhythmia recurrence. There was a positive correlation between circadian variation of arrhythmic events and the sum of all activities (r = 0.34, p < 0.05) and physical activities alone (r = 0.25, p = 0.056) while a relationship to mental activities alone could not be shown (r = 0.02, p = 0.84) CONCLUSION: The circadian variation of acute cardiovascular events may be discussed as an essential factor influencing the circadian variation of habitual daily activities in patients with cardiac disease.
Activities of Daily Living↗
Effects of hematocrit on cerebral microcirculation and tissue oxygenation during deep hypothermic bypass.
BACKGROUND: One rationale for hemodilution during hypothermic cardiopulmonary bypass (CPB) has been improved microcirculation. However, the optimal degree of hemodilution remains unclear. We therefore studied cerebral microcirculation and tissue oxygenation in a new intravital microscopic model at 3 different hematocrit (Hct) values. METHODS AND RESULTS: Three groups of 5 piglets with a cranial window over the parietal cortex underwent cooling at Hct of 10%, 20%, or 30%, followed by 1-hour deep hypothermic circulatory arrest (DHCA) and rewarming on CPB. For assessment of functional capillary density (FCD), plasma was labeled with fluorescein-isothiocyanate-dextran. Rhodamine-stained leukocytes were observed in postcapillary venules with analysis for adhesion and rolling. NADH, a natural intracellular fluorophore that increases during ischemia, was measured densitometrically during bypass and DHCA. FCD did not significantly differ from baseline during cooling in any group. However, during early reperfusion (5 minutes) after DHCA, the FCD was significantly higher in the Hct 30% group than in the Hct 10% group. Leukocyte adherence decreased in all groups during CPB and was only moderately increased at the end of the experiment. However, severe hemodilution (Hct 10%) was associated with a significantly greater number of rolling leukocytes relative to Hct 30%. CONCLUSIONS: Higher Hct does not impair cerebral microcirculation and reduces white cell/endothelial activation after deep hypothermic bypass and circulatory arrest. Severe hemodilution (Hct 10%) results in evidence of inadequate cerebral tissue oxygenation during the cooling phase of CPB. This study suggests that Hct of 30% is preferable relative to lower Hct values during hypothermic CPB, particularly if DHCA is used.
Animals↗
Microvascularization and ventricular function after local alginate-encapsulated angiogenic growth factor treatment in a rat cryothermia-induced myocardial infarction model.
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Alginates↗
[Pharmacotherapeutical approaches to insomnia patients with cardiac diseases and after heart transplantation].
Insomnia in patients with heart transplantation and cardiac disease is a common problem. Organic factors, immunodepressant medication (e.g. ciclosporine and steroids) and psychological factors may account for this symptom. The article reviews different hypnotic drugs and their value in the treatment of insomnia. For short-time treatment, medication with benzodiazepine hypnotics may be useful. If the problems of drug dependence and rebound insomnia are taken into consideration, treatment with non-benzodiazepine hypnotics offers more safety and comfort. If insomnia is part of a depressive syndrome, pharmacotherapeutical intervention with antidepressive sedative medication is required. With regard to cardiac disease, treatment with mirtazapine, nefazodone or trazodone should be preferred because of the chinidine-like effect of tricyclic antidepressants (TCA). Sedative neuroleptic medication (e.g. melperone) is commonly given to geriatric patients; nevertheless, patients with chronic insomnia may also benefit from this medication. The risks and benefits of hypnotic drugs are discussed especially in relation to pharmacological interaction (cytochrome system) and cardiac disease.
Adult↗
Flow wire measurements after complete arterial coronary revascularization with T-grafts.
BACKGROUND: The T-graft procedure achieves complete arterial revascularization in coronary three-vessel disease. In this technique, all bypass anastomoses are supplied by the left internal mammary artery (IMA). This prospective study explores the question of whether the quantitative flow in such grafts is influenced by the pathology in the native coronary arteries. METHODS: Eighty-two patients with coronary three-vessel disease were studied after complete arterial coronary revascularization with T-grafts. Quantitative flow and coronary flow reserve were measured in the proximal IMA with a Doppler guide wire. Three groups were compared: group 1, all native coronary arteries were stenosed but patent (n = 31); group 2, one occluded native coronary vessel (n = 33); group 3, two or more occluded native coronary arteries (n = 18). RESULTS: Quantitative flow was significantly higher in group 3 than in group 2 at 1 week (93.9 +/- 39.5 vs 75.8 +/- 27.3 mL/min, p < 0.05) and 6 months postoperatively (86.0 +/- 40.1 vs. 69.1 +/- 35.5 mL/min, p < 0.05). Flow in group 2 was significantly (p < 0.05) higher than in group 1 (1 week: 58.0 +/- 28.4 mL/min, 6 months: 55.2 +/- 29.2 mL/min) in both examinations. There were no significant differences in coronary flow reserve between the three groups (1: 2.88 +/- 0.97, 2: 2.84 +/- 0.96, 3: 2.74 +/- 0.94). CONCLUSIONS: After complete arterial revascularization with T-grafts, the quantitative flow in the IMA is influenced by the status of the native coronary arteries. As a result of competitive flow phenomena, blood flow in the bypasses is significantly lower when the coronary arteries are affected only by stenosis.
Coronary Circulation↗
Left ventricular-right atrial fistula complicating redo mitral valve replacement.
We describe the case of a 58-year-old female patient who underwent redo mitral valve replacement and remained in heart failure. The diagnosis of a left ventricular-right atrial fistula was made. The fistula was closed surgically with a patch of autologous pericardium. The patient improved immediately after the operation and has been asymptomatic since.
Female↗
Impaired flow in left internal mammary artery grafts due to subclavian artery stenosis.
We report two cases of patients with left internal mammary artery (LIMA) grafts impaired by proximal stenosis of the subclavian artery. The functional impact of the subclavian lesions was investigated using flow-wire. The hemodynamic relevance of the lesions could be documented with the functional flow measurements in both instances. The relevance of preoperative evaluation of the subclavian artery is emphasized when it is planned to use the LIMA as coronary bypass. Moreover, the case reports indicate that percutaneous intervention of the subclavian artery is an effective treatment modality to restore adequate flow in the LIMA.
Aged↗
Heparin and the nonanticoagulant N-acetyl heparin attenuate capillary no-reflow after normothermic ischemia of the lung.
BACKGROUND: Ischemia-reperfusion injury of the lung frequently occurs after cardiopulmonary bypass, after pulmonary thromboendarterectomy, and especially after lung transplantation. Heparin is known to be protective in ischemia-reperfusion injury, but the risk for bleeding disorders may restrict its use in a variety of diseased conditions. Therefore, we tested the efficiency of nonanticoagulant N-acetyl (NA) heparin to protect from postischemic reperfusion injury of the lung. METHODS: Pentobarbital-anesthetized, mechanically ventilated Lewis rats were heparinized (100 IU/kg) before insertion of catheters. Additionally, animals received either heparin (200 IU/kg; n = 7), NA heparin (1.1 mg/kg; n = 7), or saline (control, n = 7) before ischemia. After normothermic ischemia for 50 minutes, the left lung was reperfused for 120 minutes, or until the death of the animal. The nonischemic right lung was excluded after 10 minutes of reperfusion. RESULTS: Survival rate at 120 minutes of reperfusion was 7 of 7 and 6 of 7 in the heparin and the NA-heparin group, but 0 in 7 in the control group (p < 0.01). At 30 minutes of reperfusion, PaO2, blood flow through the ascending aorta and mean systemic blood pressure were also significantly higher in the heparin and the NA-heparin group when compared with the control group (p < 0.05). Pulmonary vascular resistance was significantly lower in the heparin and the NA-heparin groups, and histologic examination of the lungs from these groups confirmed reperfusion of nutritive alveolar capillaries by the presence of red blood cells. Lack of red blood cells in the alveolar capillaries of lung specimens from the control group indicated failure of capillary reperfusion. CONCLUSIONS: Heparin and NA heparin exert similar protection against capillary no-reflow after normothermic ischemia of the lung. This implies that the protective effect of heparin is mediated by properties different from its anticoagulant activity. Thus the nonanticoagulant N-acetyl heparin may pose a safe new therapeutic approach in lung ischemia-reperfusion injury without increasing the risk of hemorrhagic complications.
Animals↗
Pulmonary thromboendarterectomy--risk factors for early survival and hemodynamic improvement.
OBJECTIVE: Pulmonary thromboendarterectomy (PTE) for chronic thromboembolic pulmonary hypertension is a challenging procedure with a considerable mortality. The aim of this investigation was to identify risk factors influencing mortality and operative results. METHODS: Between October 1995 and August 2000, 69 patients (age 54 years; 34 women; mean New York Heart Association (NYHA) stage 3.4) underwent PTE. The preoperative pulmonary vascular resistance (PVR) was 988+/-554 dynes x s x cm(-5), mean pulmonary artery pressure 50+/-12 mmHg, right atrial pressure (RAP) 11.5+/-4 mmHg. Hospital mortality was 10.1% (n=7/69). Mean postoperative PVR on the 2nd day was 324+/-188 dynes x s x cm(-5). Pulmonary angiography was reviewed for number of involved segments (mean 9.3+/-2) and bronchial arteries diameter (BAD; mean 4.6+/-1.6 mm). A univariate and multivariate analysis was performed to determine preoperative risk factors for hospital death and inadequate hemodynamic improvement. RESULTS: By univariate analysis, mortality was influenced by age (P=0.04), right atrial pressure (P=0.009), NYHA (P=0.02) and the number of angiographically involved segments (P=0.02). Sex, left ventricular function, presence of coronary artery disease and bronchial artery diameter did not show correlation with mortality. Inadequate hemodynamic improvement in a dichotomized analysis (PVR > or =500 dynes x s x cm(-5), n=11, and PVR < 500 dynes x s x cm(-5), n=58), assessed by univariate analysis, was significantly influenced by age (P=0.02), preoperative PVR (P=0.01), NYHA (P=0.002), RAP (P=0.02) and female sex (P=0.02). Multivariate analysis identified age (P=0.1), RAP (P=0.002) and female sex (P=0.007) as risk factors for inferior hemodynamic improvement. CONCLUSIONS: Preoperative parameters can be utilized to assess postoperative mortality and hemodynamic improvement after pulmonary thromboendarterectomy. Patient age and clinical deterioration of pulmonary hypertension are considerable preoperative factors influencing hospital mortality. Inadequate postoperative hemodynamic improvement is affected by severity of disease and female sex.
Adolescent↗
Vasoreactivity of arterial grafts in the patient with diabetes mellitus: investigations on internal thoracic artery and radial artery conduits.
OBJECTIVE: Arterial revascularization with either internal thoracic artery (ITA) or radial artery (RA) appears to be particularly attractive in diabetic patients. Previous investigations have shown that endothelial dysfunction and artherosclerosis are seen more often in these patients. The aim of this study was to compare the vasoreactive properties of ITA and RA grafts in diabetic and non-diabetic patients. METHODS: Arterial rings were harvested from 57 patients who underwent complete arterial revascularization. The patients were divided into a non-diabetic group (I: n = 30) and patients with diabetes mellitus (II: n = 27). Arterial rings of the ITA (I: n = 30; II: n = 27) and RA (I: n = 28; II: n = 19) were mounted on a strain gauge in oxygenated, normothermic Krebs's--Henseleit solution at optimal resting tension. With KCL (80 mM) serving as the control, assessment of force of contraction (norepinephrine), endothelium-dependent relaxation (acetylcholine) and smooth muscle-dependent relaxation (glyceroltrinitrate) were obtained. RESULTS: After KCL, the RA showed a trend to lower maximum contraction forces in diabetics (I: 76 +/- 25 mN; II: 69 +/- 29 mN), which was pronounced in patients with diabetes of more than 10 years duration (55 +/- 23 mN; P = 0.1). Maximum contraction force of the ITA was similar in both groups (I: 41 +/- 20 mN; II: 34 +/- 19 mN) and not influenced by the duration of diabetes. The two groups showed no significant differences of the relative vasoconstriction after norepinephrine in RA (I: 53 +/- 18%; II: 61 +/- 19%) and ITA rings (I: 70 +/- 23%; II: 69 +/- 25%). Also, endothelium-dependent relaxation with acetylcholine in RA (I: 53 +/- 14%; II: 57 +/- 16%) and ITA rings (I: 42 +/- 17%; II: 44 +/- 20%), and smooth muscle relaxation with glyceroltrinitrate of RA (I: 72 +/- 8%; II: 73 +/- 12%) and ITA rings (I: 64 +/- 12%; II: 58 +/- 20%) was comparable in both groups. No influence of duration of the diabetic disease was noted. CONCLUSIONS: Although RA rings of patients with a long duration of diabetes have decreased maximum contraction forces, their relative vasoconstriction after norepinephrine, endothelium-dependent relaxation and smooth muscle relaxation was similar to non-diabetic patients. We thus conclude that the RA is an adequate arterial conduit in the patient with diabetes mellitus.
Aged↗
Treatment of a case of acute right heart failure by inhalation of iloprost, a long-acting prostacyclin analogue.
Perioperative acute right heart failure after orthotopic heart transplantation contributes significantly to morbidity and mortality. Vasodilators administered intravenously may decrease pulmonary vascular resistance, but also affect systemic circulation. A decrease of mean arterial pressure will result in reduced right coronary blood flow and deterioration of right ventricular performance. Vasodilators administered by inhalation, i.e. nitric oxide and prostacyclin, are attractive due to a more selective effect on the pulmonary circulation. This is the first report on the use of aerosolized iloprost, a long-acting prostacyclin analogue, applied for treatment of postoperative right heart failure in cardiac transplantation. After uneventful surgery, a heart transplant recipient was extubated on the first postoperative day and exhibited right heart failure on the following day. Standard treatment did not resolve this clinical problem sufficiently. A trial with inhalation of iloprost (16 microg per inhalation cycle, applied six times per day) was initiated. Iloprost inhalation resulted in a sufficient decrease of pulmonary vascular resistance (-23.5%), while cardiac index (+24.0%) and mixed venous saturation (+9.0%) increased. No profound effect on the systemic vascular resistance was observed (-2.8%). Iloprost inhalation may be an effective alternative to nitric oxide in the intensive care management of acute right heart failure after orthotopic heart transplantation. Due to the prolonged effect on the pulmonary vascular resistance, iloprost is especially useful for extubated patients.
Administration, Inhalation↗
Do changes in blood flow in the subclavian artery affect flow volume in IMA grafts after complete arterial revascularization with the T-graft technique?
BACKGROUND: The T-graft procedure achieves complete arterial coronary revascularization with only two conduits. In this technique, all the bypass anastomoses are supplied by the left internal mammary artery (IMA). Changes in flow conditions or flow redistribution in the subclavian artery may thus sigificantly influence coronary perfusion. The objective of this study was to determine whether changes in blood flow in the subclavian artery affect the flow in IMA grafts in patients who have undergone complete arterial revascularization with T-grafts. METHODS: Quantitative flow volume and flow profiles in the IMA graft and the proximal subclavian artery were measured with a flow-wire in 20 patients one week postoperatively. Following baseline measurements, brachial artery constriction was achieved by applying a blood pressure measurement cuff to the patient's left upper arm. After 5 minutes, quantitative flow in the IMA and in the proximal subclavian artery was assessed. The cuff was then released and the measurements repeated. RESULTS: Flow in the subclavian artery changed significantly (p < 0.01) from baseline (355.4 +/- 95.2 ml/ min) to constriction (171.2 +/- 61.3 ml/min) and hyperemia (679.3 +/- 195.1 ml/min). Flow in the IMA graft remained constant irrespective of subclavian artery flow (75.4 +/- 26.2 ml/min vs. 78.0 +/- 28.9 ml/min vs. 75.5 +/- 29.3 ml/min, respectively). The flow profile in the IMA was similarily unchanged. CONCLUSION: In patients in whom the coronary bypass blood flow is dependent on the left IMA, neither the quantitative flow volume nor the flow profile are altered by changes in blood flow of the subclavian artery.
Aged↗
Aortic valve replacement with a stentless bioprosthesis using the full-root technique.
BACKGROUND: In aortic valve replacement stentless bioprostheses results in improved hemodynamic function compared to stented valves. Using the root replacement technique even larger prostheses are implantable. We present our experience with stentless bioprostheses implanted in the "full-root" technique. PATIENTS AND METHODS: Between 01/1997 and 12/2000, 149 patients underwent root replacement with a stentless xenograft (age 70 +/- 9y, women 52 %, ejection-fraction 58 +/- 15 %). Isolated stenosis was present in 34 %, incompetence in 24 %, and mixed disease in 42 % of patients. Bacterial endocarditis was found in 16 %, and 3 patients suffered from acute aortic dissection. RESULTS: Mean bypass time was 118 +/- 45 min, ischemic time 83 +/- 26 min and operating time 201 +/- 62 min. Concomitant procedures were CABG (32 %), replacement of ascending aorta (22 %) and aortic arch (13 %), mitral valve repair (6.7 %), and carotid thrombendarterectomy (1.3 %). Total in-hospital mortality was 6.7 %, with a 1.8 % mortality rate for patients with isolated aortic valve disease. CONCLUSION: Aortic valve replacement using stentless bioprostheses in the root replacement technique is a safe surgical option. In patients with small aortic roots or ring abscesses it guarantees remodelling of the aortic annulus.
Aged↗
Complete arterial coronary artery bypass grafting versus conventional revascularization--early results.
BACKGROUND: Complete arterial coronary artery bypass grafting (CABG) offers the potential to improve long-term results. However, an increased perioperative risk has been controversially discussed. New operative techniques (skeletonization of the ITA/ T-grafts/utilization of the radial artery (RA)) may decrease perioperative risk. We compared the outcome after conventional with that after complete arterial CABG. MATERIAL AND METHODS: Three consecutive groups of patients were analyzed. In group I (n = 50), CABG was performed using left ITA and vein grafts. The other two groups received complete arterial CABG with either both ITA's (group II; n = 52) or left ITA and RA (group III; n = 52). RESULTS: A mean of 3.9+/-0.8 (I) versus 4.2+/-0.8 (II) and 3.9+/-0.9 (III) anastomoses were performed per patient (ns). Mean operating time was significantly prolonged in group II (II: 252+/-54; p<0.0001; vs. I: 191+/-36; III: 203+/-33). Mean ischemic time was significantly prolonged in group II and III (II:65+/-20; p<0.0001; III: 68+/-16; p<0.0001; vs. I: 51+/-15). Mean bypass time (I: 83+/-23; II: 95+/-41; III: 91+/-21), the rate of postoperative complications and in-hospital mortality (I: n = 0; II: n = 2; III: n = 0; ns) showed no significant differences. CONCLUSIONS: Complete arterial CABG using modern surgical techniques is as safe as the conventional surgical approach using left ITA and vein graft.
Analysis of Variance↗