23rd Bethesda conference: access to cardiovascular care. Task Force 5: Access to cardiovascular care: an international comparison.
Explore the source record for details and available documents.
Australia↗
Biomedical subjects
H A Huysmans
Publications and source records attributed to H A Huysmans.
Strut fracture with Björk-Shiley 70 degrees convexo-concave valve. An international multi-institutional follow-up study.
Between 1980 and 1983, 831 Björk-Shiley 70 degrees convexo-concave prosthetic heart valves were implanted at five institutions in Sweden, Germany. The Netherlands, and Canada. As of January 1991, there were 34 outlet strut fractures occurring from 0.2 to 10.1 years (median = 4.6 years) after implantation. In addition, there were 28 sudden, unexplained deaths. The mortality after strut fracture was 84%. The mortality after emergency valve replacement for strut fracture was 50%. The 10-year actuarial fracture rate (standard error) was 10.5 (2.4)% for large (29-33 mm) valves vs. 3.3 (1.2)% for 21-27 mm valves (P less than 0.001). Within valve size groups, fracture rates for aortic and mitral valves were similar. Cox regression analysis found only valve size to be significantly associated with strut fracture. There is a further subgrouping of the valves according to the manufacturer: group I are the earlier large 29-33 mm) valves; group II are the later large valves; group III are the small size (21-27 mm) valves. The risk of strut fracture was highest in group I (12.3% at 10 years) with an approximatively constant hazard (1.4% per year). A comparison was made with a statistical model incorporating all cases reported to the manufacturer. This model estimates fracture rates approximately 63%-73% of those found in the present study. These findings lead us to recommend that group I patients should be considered for elective reoperation on an individual basis, giving careful attention to risk factors and contraindications.
Adolescent↗
Steps into the future.
Explore the source record for details and available documents.
Cardiac Surgical Procedures↗
Pulmonary metastasectomy in patients with osteosarcoma.
Between 1980 and 1990, 70 patients with high malignant osteosarcoma of the extremities were treated according to the European Osteosarcoma Intergroup trials. Of the 31 patients with metachronous metastases (group I), 17 underwent pulmonary metastasectomy. Six of the 17 survived 8 months to 4 years after metastasectomy without evidence of recurrent metastatic disease. The type of orthopedic surgical treatment had no influence on the disease free interval (DFI), nor on the overall survival. The DFI was significantly longer (P less than 0.003) in patients with resectable pulmonary metastases. Overall survival was not influenced by the length of the DFI. Six of 11 patients with synchronous metastases (group II) underwent pulmonary metastasectomy, 1 survived longer than 7 months. Nevertheless, overall survival is not significantly different between group I and group II (P = 0.2): 28 patients without pulmonary metastases (group III) had a 95% survival at 5 years. In patients with metachronous metastases, metastasectomy independently had a positive effect on survival (P less than 0.001), but did not cure the patients. Strict patient selection and additional therapy to prevent micrometastases is needed to improve survival.
Adult↗
Follow-up of arterial switch operation.
This report describes the experience of the Leiden University Hospital with the arterial switch operation for transposition of the great arteries, with and without ventricular septal defect, and for the Taussig-Bing-anomaly. The longest follow-up was 13 years and 9 months. Follow-up shows good results with almost all surviving patients in functional class I and with a sinus rhythm. Supravalvular pulmonary artery stenosis is noted in some of the patients but is almost always mild and does not show any tendency to progression. Insufficiency of the aortic valve is seen less frequently. Until now it has not caused great concern but, of course, follow-up is still limited.
Double Outlet Right Ventricle↗
Paradox of enhanced contractility in postischemic rat hearts with depressed function.
Depressed function of postischemic hearts may be related to incomplete recovery of coronary perfusion. To circumvent this factor we studied the properties of papillary muscles under controlled extracellular conditions. First, recovery of function was measured in postischemic rat hearts. Next, a muscle was dissected and superfused in a bath. After 40 min of ischemia, recovery of cardiac output was generally zero. Muscles from this group were relaxed or showed small contractures. After 20-30 min of ischemia recovery of coronary flow and cardiac output was 50-100%, and the isolated muscles showed the following properties (compared with Langendorff-perfused controls): 1) increased force at normal or low [Ca2+]; 2) action potential and postextrasystolic potentiation were unchanged, which indicates that Ca2+ influx per beat was unchanged; 3) the decay of potentiation was slowed, indicating a reduced rate of Ca2+ extrusion via Na(+)-Ca2+ exchange. This implies intracellular Ca2+ accumulation and explains the increased force. Postischemic enhancement of contractility (isovolumic pressure) was demonstrated also in whole heart preparations. We conclude that mild injury by preceding ischemia leads to enhanced contractility (Ca2+ accumulation), advanced injury to local contractures, and finally to a general contracture (Ca2+ overload). Recovery of heart function and coronary flow probably depends on the number and size of local contractures.
Action Potentials↗
Evaluation of cloxacillin concentrations in plasma and muscle tissue during cardiopulmonary bypass.
Concentrations of cloxacillin in plasma and deep thoracic muscle tissue were measured in 10 patients who underwent elective coronary bypass surgery or valve replacement. One g of cloxacillin was administered after the induction of anaesthesia and 1 g cloxacillin was added to the oxygenator pump priming fluid before the start of the procedure. Blood and tissue samples were obtained before, during and after cardiopulmonary bypass. The relation between unbound plasma concentrations and total tissue contents of the drug was calculated. It was shown that measurement of the free plasma concentration may provide fairly reliable information on the free concentrations of cloxacillin in the tissues, and that determination of tissue contents may therefore not be necessary. Due to the administration of the second dose of cloxacillin at the start of cardiopulmonary bypass free tissue contents were just adequate in most patients. However, to obtain adequate tissue concentrations after bypass it is recommended that a third dose of the antibiotic be administered before the end of the operation.
Adult↗
The neural crest as a possible pathogenetic factor in coarctation of the aorta and bicuspid aortic valve.
Patients (n = 109) operated on for coarctation of the aorta were analyzed for occurrence of associated cardiac and noncardiac anomalies. Attention was also paid to the prevalence of cardiac anomalies in the relatives of these patients. Of the patients with coarctation of the aorta, 57 (52%) had a bicuspid aortic valve. Forty-three (39%) of the 109 patients had one or more noncardiac anomalies. In 29 (27%) patients the noncardiac anomaly involved the head/neck structures. Noncardiac anomalies were much more prevalent in patients with coarctation and bicuspid aortic valve, especially anomalies involving the head/neck structures: 44% compared to 8% of patients with a normal aortic valve. Congenital cardiac malformations were present in relatives in the first or second degree of 18% of the patients. Bicuspid aortic valve was more prevalent in patients with an affected relative (75%) than in patients with unaffected relatives (47%). Recent studies showed that the neural crest plays an important role in the development of cardiac and a variety of noncardiac structures. The cardiac structures derived from the neural crest involve the outflow tract of the heart and the aortic arch system. Maldevelopment of neural crest cells could therefore be responsible for the combined occurrence of outflow tract (e.g., bicuspid aortic valve), aortic arch (e.g., coarctation), and noncardiac anomalies. This study supports the concept that some anomalies of the aortic arch system, including aortic coarctation, are cardiovascular manifestations of a spectrum of anomalies involving the head and neck region that may be due to a genetic-environmental disorder of the neural crest.
Aortic Coarctation↗
Altered calcium handling at normal contractility in hypertrophied rat heart.
Left or right ventricular hypertrophy was induced by banding of the aorta or pulmonary artery in different groups of rats. After 5 to 10 weeks the degree of hypertrophy was about 15% in left and 80-160% in right ventricles, as determined by weight of the ventricle or by myocyte size. Action potentials and force-interval relationships were measured in papillary muscles isolated from either ventricle. As compared to muscles from control and SHAM-operated rats, hypertrophied papillary muscles showed: (1) Marked prolongation of the action potential and greater degree of post-extrasystolic potentiation. This indicates enhanced influx of Ca2+ probably via Ica; (2) Delayed relaxation of isometric force and faster decay of potentiation, which indicates reduced sequestration of Ca2+ by the sarcoplasmic reticulum; (3) Minor changes in steady-state peak force under standard conditions, which is explained from the opposite inotropic effects of enhanced Ca2+ influx and impaired function of the reticulum. Myocyte volume in the normal left ventricle was almost two times larger than in the normal right ventricle, and this was associated with a longer action potential and greater degree of post-extrasystolic potentiation in left as compared with right ventricular muscles. The rate of decay of potentiation, however, was not different. This might indicate that depressed function of the sarcoplasmic reticulum occurs with pressure-overload hypertrophy and not with normal age-dependent growth.
Action Potentials↗
Time trends and survival in patients presented for surgery with non-small-cell lung cancer 1969-1985.
All evaluable patients (n = 920) with primary non-small-cell lung cancer (NSCLC) who were presented for surgery in our hospital between 1969 and 1985 were reviewed as to histological findings, postoperative stage, age group and surgical procedure. Time trend analyses showed a significant increase over time in the proportion of adenocarcinomas (p = 0.025) and in the proportion of the elderly (greater than or equal to 70 years; p = 0.014). The 5-year survival rates by year of operation showed no improvement at all over time; on the contrary they showed a decline, which however only reached significance for patients who underwent pneumonectomy (p = 0.034). It is noted that the overall survival curves up to 5 years showed no significant differences between patients with adenocarcinoma and patients with squamous cell carcinoma, or between patients aged 70 years or more and patients aged 60-69 years. Despite expanded preoperative diagnostic techniques and developments in surgical treatment, no improvement in the survival after surgery for NSCLC over the period 1969-1985 could be established.
Adenocarcinoma↗
Coronary artery fistula as source of pulmonary circulation in pulmonary atresia with ventricular septal defect.
Four patients are described with pulmonary atresia and ventricular septal defect, in whom the pulmonary circulation was dependent on a fistula from the left coronary artery to the pulmonary artery. The issue in this complex anomaly is complete preoperative diagnosis, including anatomic information on the coronary artery fistula and the pulmonary vasculature. This was achieved in the last 2 patients. In the last patient echocardiography turned out to be an important diagnostic tool in this rare anomaly and facilitated selective angiocardiography. All 4 patients were successfully operated by closing the fistula, closing other aortopulmonary connections and inserting a valved conduit between right ventricle and pulmonary artery. The ventricular septal defect was closed in 3 patients with a patch. In the setting of an already existing pulmonary hypertension and a possibly inadequate pulmonary arterial system at surgery, a perforated patch was inserted in the ventricular septal defect of the remaining patient.
Adolescent↗
Imaging of acute myocardial infarction in pigs with Indium-111 monoclonal antimyosin scintigraphy and MRI.
Indium-111 antimyosin F(ab')2 was used in a series of scintigraphic studies on experimentally induced myocardial infarctions in pigs. Antimyosin distribution recorded by planar images of in vivo pigs and by single photon emission computed tomography (SPECT) of excised hearts delineated areas of myocardial necrosis if infarct volume exceeded 3.3 cm3. Scintigraphic images were compared with magnetic resonance images (MRI) obtained from excised hearts and with photographs of slices of the hearts. Infarct size and localization determined with antimyosin were compared. The MR images, with or without gadolinium-DTPA (Gd-DTPA), of the in vivo pigs were all false-negative; some myocardial wall thinning and high bloodpool signals were visible. Results show that both the antimyosin and the MR technique are specific methods for the visualization of induced myocardial necrosis in this animal model. However, the use of antimyosin is limited to a period ranging from 24 to 72 hours after infarction.
Animals↗
Comparison of rigid and flexible rings for annuloplasty of the porcine mitral valve.
Seven rigid (Carpentier) and six flexible (Duran) annuloplasty rings were implanted in healthy pigs. First, in the intact pig, cinefluoroscopy was used to record movements of the anulus. Results were compared with data from three pigs instrumented with a continuous radiopaque marker on the anulus. Pump function of all hearts with annuloplasty rings and function of the mitral valve were studied 4-6 weeks after the operation, first in the exposed heart and then subsequently in the isolated heart in a perfusion chamber at maximal filling pressure and normal or low arterial pressure. Separation of the blood-perfused coronary circulation from the crystalline solution pumped by the left heart allowed videoendoscopy of the working valve. Flexible rings interfered less with normal movements of the mitral anulus than rigid rings and caused less impairment of filling of the basal part of the ventricle, and the unloaded stroke volume was 16% larger. For normal arterial pressures, the differences were smaller and will be difficult to detect in clinical situations. A stiff anulus was seen to be pushed underneath the aortic valve during systole, which caused a mild subvalvular obstruction. The mean diastolic pressure gradient across rigid annuloplasty rings was slightly larger than across flexible rings of the same or slightly smaller diastolic size. Rigid rings change the pattern of movement of the leaflets; the mural leaflet remains immobile throughout diastole. Although Duran rings interfere less with valvular function and filling of the basal part of the ventricle than do Carpentier rings, the differences are small and probably only of limited clinical importance.
Animals↗
[Number of operations and mortality in surgery of the heart and large intrathoracic vessels].
Explore the source record for details and available documents.
Cardiac Surgical Procedures↗
Development of the origin of the coronary arteries, a matter of ingrowth or outgrowth?
Inconsistencies still exist with regard to the exact mode of development of proximal coronary arteries and coronary orifices. In this regard 15 quail embryos were investigated using a monoclonal anti-endothelium antibody, enabling a detailed study of the development of endothelium-lined vasculature. Coronary orifices emerged at 7-9 days of incubation (Zacchei stages 24-26) and were invariably present at 10 days of incubation (Zacchei stage 27). We never observed more than 2 coronary orifices; these were always single in either of the facing sinuses of the aorta. A coronary orifice was always observed being connected to an already developed proximal coronary artery, which belonged to a peritruncal ring of coronary arterial vasculature. We did not find any coronary orifice without a connection to a proximal coronary artery. Moreover, at 7-9 days of incubation (Zacchei stages 24-26) we observed coronary arteries from the peritruncal ring penetrating the aortic media. In 2 specimen this coronary artery, with a lumen, was in contact with the still intact endothelial lining of the aorta. We conclude that coronary arteries do not grow out of the aorta, but grow into the aorta from the peritruncal ring of coronary arterial vasculature. This throws new light on normal and abnormal development of proximal coronary arteries and coronary orifices.
Animals↗
Progressive coronary vasoconstriction during 25 hours of myocardial preservation in vitro impairs functional capacity following preservation.
We have developed perfusion techniques for preserving rat hearts for 25 h and have quantified haemodynamic function after preservation to establish the relation between coronary vascular resistance during preservation and the quality of postpreservation pump function. Thirteen rat hearts underwent hypothermic (8 degrees C), low-pressure (15 mmHg) perfusion with an hyperosmotic (385 mOsm/l) crystalloid preservation buffer for 25 h. During this period, the coronary flow rate decreased from 1.12 +/- 0.28 ml/min to 0.87 +/- 0.12 ml/min (+/- SD). Following the preservation period, the quality of pump function was tested in the isolated working heart model. At a fixed value of left atrial pressure (15 mmHg), the afterload was increased stepwise (5 mmHg) from 45 mmHg to 70 mmHg, making use of a Starling resistor in series with an air compliance. Each afterload step was maintained for 5 min to obtain stable readings of cardiac output and coronary flow. These measurements were compared with those from a control group of 10 rat hearts undergoing the same test protocol for haemodynamic function without previous preservation. The 13 hearts which underwent 25 h preservation had subnormal haemodynamic function: cardiac output was 50% +/- 4% compared to 10 control hearts. If preserved hearts were divided into two groups based on coronary vascular resistance measured at the end of the preservation period lower than 18 mmHg.min per ml (group 1), and higher than or equal to 18 mmHg.min per ml (group 2), it appeared that the haemodynamic function of group 2 hearts was about half that of group 1 hearts.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Predictors of perioperative mortality, morbidity and late quality of life in coronary bypass surgery.
Between January 1, 1977 and January 1, 1988, 220 patients over 70 years of age underwent coronary artery bypass surgery (CABG). Patients undergoing combined procedures, e.g. CABG and valve surgery, were not included. 39% of the patients were emergencies or urgent cases. Hospital mortality (less than 30 days after surgery or in hospital) was 7.7%. Mean hospital stay was 13.9 days. Postoperative morbidity consisted mainly of infections (n = 51), peri-operative infarction (n = 35), bleeding (n = 13), and renal failure (n = 13). 72% of the patients were in NYHA functional class I at the time of follow-up (mean 3.66 years postoperatively). Many factors were analysed as possible indicators for mortality, morbidity and postoperative functional class. Mortality was only related to the presence of pre-operative hypertension (P = 0.038), previous infarction (P = 0.056) and severity of coronary disease (P = 0.0458). Morbidity was weakly related to emergency procedures, previous infarction and severity of coronary artery disease (P less than 0.05). For postoperative functional class, no specific predictors were found.
Aged↗
The effect of fresh versus stored blood on post-operative bleeding after coronary bypass surgery: a prospective randomized study.
In a prospective study, 237 patients undergoing a primary coronary bypass operation were randomized to receive 2 units of fresh whole blood (study group) or stored (2-5 d) blood (control group) at the end of the extracorporeal circulation. Serious post-operative bleeding necessitating a re-thoracotomy occurred in 4.2% of all patients with an equal distribution over the two groups. Post-operative haemoglobin content and platelet counts were higher in the study group, but the differences were small and clinically not important. There were no differences in transfusion requirements, post-operative blood losses and haemostatic parameters between the trial groups. At low post-operative platelet counts (below 120 X 10(9) platelets/l) however, patients in the control group lost significantly more blood and had increased transfusion requirements compared with patients in the study group (7.1 versus 4.8 units). These differences must be attributed to qualitative platelet defects in the transfused units of stored blood. The small, clinically insignificant, differences in two laboratory parameters between the study and control groups, and the increased transfusion requirements of a subpopulation of patients with low platelet counts in the control group do not justify giving fresh blood or prophylactic platelet transfusions to coronary bypass patients.
Blood Preservation↗