Hospital referral of detainees during police custody in Amsterdam, The Netherlands.

This study describes how many detainees have been referred to emergency departments for further evaluation or emergency care while in police custody in Amsterdam (years 2012/2013). It provides insights into the diagnoses assigned by forensic doctors and hospital specialists and the appropriateness of the referrals. We made use of the electronic registration system of the Forensic Medicine Department of the Public Health Service Amsterdam. This department is in charge of the medical care for detainees in the Amsterdam region. Hospital diagnoses were obtained through collaboration with several Amsterdam-based hospitals. According to our results, in 1.5% of all consultations performed, the detainee was referred to hospital. The most frequent reasons for referral were injuries (66%), intoxication/withdrawal (11%) and cardiac problems (7%). In 18% of all referrals, hospital admission (defined as at least one night in the hospital) was the consequence. After review of hospital files, the indication for referral as stated by the forensic physician was confirmed in 77% of all cases. A minority of referrals was considered unnecessary (7%). The identified cases allow for a discussion of cases of over-referral. Future research should focus on the problem of under-referral and associated health risks.

Dehiscence of the Freestyle stentless bioprosthesis.

This study aimed to identify and characterize patients who developed prosthetic dehiscence after aortic valve replacement with the Freestyle Stentless bioprosthesis. Review of patients' records and preoperative echocardiogram was performed. Prosthetic dehiscence developed in 10 patients after 2.5 to 49 months (mean 19). Most patients were symptomatic at presentation. Nine patients were reoperated. Dehiscence was typically located at the inflow suture line beneath the noncoronary cusp. Four patients died. The cause of dehiscence is assumed to be related primarily to surgical technique.

Acute elevation of coronary venous pressure does not affect left ventricular contractility in the normal and stressed swine heart: implications for the Fontan operation.

OBJECTIVE: After the Fontan operation the right atrium and, thus, the coronary sinus are connected to the pulmonary arterial system, which causes the coronary venous pressure to increase. We investigated the acute effects of elevation of coronary venous pressure on baseline hemodynamics, coronary venous flow, and left ventricular contractility. METHODS: In acutely instrumented pigs, during complete right heart bypass and during constant cardiac output, pressure in the right atrium, right ventricle, and coronary sinus was altered by a height-adjustable reservoir. At various levels of coronary venous pressure (up to 4 kPa or up to 30 mm Hg), flow from the reservoir was measured and left ventricular hemodynamics and contractility were measured from catheter-derived left ventricular pressure and (conductance) volume data. Contractility of the left ventricle was assessed by the end-systolic pressure-volume relationship derived during an unloading intervention by adjusting the bypass pump speed. RESULTS: Left ventricular end-diastolic pressure increased slightly (about 5%) with each kilopascal increase in coronary venous pressure, most likely related to diastolic ventricular interaction. No other changes in hemodynamic parameters occurred. Neither coronary venous flow nor left ventricular contractility was influenced by changes in coronary venous pressure. Imposing myocardial stress with dobutamine, 10 microg/kg per minute, did not change these findings. CONCLUSION: Increasing coronary venous pressure to 4 kPa in the intact circulation with intact autoregulation does not affect coronary flow or left ventricular contractility. We found no experimental evidence for the usefulness of diversion of the coronary sinus to the left atrium during Fontan-type operations

The orientation of the bi-leaflet CarboMedics valve in the mitral position determines left ventricular spatial flow patterns.

OBJECTIVES: In the mitral annulus bi-leaflet mechanical valves can be oriented in two ways: the anatomical orientation with the hinge line parallel to a line through the commissures of the native valve (90 degrees). The influence of this orientation on the left ventricular spatial flow pattern and valve leaflet opening was investigated in pigs. METHODS: In 9 pigs a CarboMedics mitral valve prosthesis was implanted in the ) degree position and in 9 pigs in the 90 degree orientation. Two dimensional echocardiographic and color Doppler recordings were performed before surgery, immediately after surgery and after 6 weeks. RESULTS: In the native valve the diastolic flow pattern was characterized by a central inflow and backflow away from the apex along the left ventricular wall. In the 0 degree orientation a diastolic flow pattern with an asymmetrical inflow was observed, resulting from a greater extension of the jet along the lateral wall compared to the jet along the interventricular septum. Mid-diastolic back-flow away from the left ventricular apex was directed towards the valve prosthesis. In the 2-dimensional echocardiographic recordings the opening angle of both prosthetic leaflets was different showing a larger opening angle of the posterior leaflet. In the 90 degree orientation a diastolic flow pattern with paradoxical flow directions was recorded, that could only be explained in a 3-dimensional way: one inflow jet along the anterior wall, one inflow jet along the posterior wall and back-flow away from the apex sandwiched in between the two inflow jets. In this orientation the 2-dimensional echocardiographic recordings showed symmetrical opening of the two leaflets of the prosthesis. CONCLUSIONS: The orientation of the CarboMedics bi-leaflet mechanical valve prosthesis in the mitral valve annulus determines the left ventricular spatial flow pattern. The flow pattern resulting from the 0 degree orientation, was associated with asymmetrical leaflet motion, while the 90 degree orientation flow pattern was associated with symmetrical leaflet motion. These findings may be of importance for prosthetic valve function as well as for left ventricular kinetics.

Mitral valve anatomy and morphology: relevance to mitral valve replacement and valve reconstruction.

An endoscope was used to study the anatomy and morphology of the native mitral valve inside an isolated pig heart working under physiological conditions. Annulus motion, valve leaflet function, and the anatomy of the chords and branching pattern are described. Anatomical and functional details relevant to mitral valve reconstruction and valve replacement are outlined. Because of the similarity with the human heart, we have assumed that the observations made in the pig heart also apply to humans.

Prosthetic valve endocarditis: analysis of risk factors for mortality.

Between 1975 and 1990, 70 episodes of prosthetic valve endocarditis (PVE) were diagnosed in 65 patients at Leiden University Hospital. The overall mortality rate was 27%. Antecedent endocarditis attributable to the same micro-organism (mortality 63%, P = 0.02) and Staphylococcus aureus as the causative micro-organism (mortality 100%, P = 0.001) were significant predictors for mortality. Sex, type and position of the valve and therapy had no significant influence on the mortality. All patients infected with S. aureus died, irrespective of whether they received medical treatment alone or in combination with surgery. None of the patients with streption, endocarditis had abscesses at reoperation; the mortality rate for this group was 14%. Abscess formation, especially in aortic valves, was the most important finding at reoperation and corresponded with a mortality rate of 55%. Ring abscesses occurred equally in patients with mechanical and bioprosthetic valves. Seven of the 15 patients (47%) with significant prosthetic valve dehiscence died. In patients with mitral valve endocarditis, localized dehiscence of the valve was observed. In conclusion a previous endocarditis attributable to the same micro-organism and the causative micro-organism (S. aureus) were important risk factors for mortality due to PVE.

Geometrical reconstruction of images obtained with electronic endoscopy.

We use an electronic video endoscope (Fujinon EG7-HR2) to image the mitral valve in situ in an isolated pig heart preparation. From video recordings, images are digitized and analysed with a computer. A complication encountered during the study concerned the geometric wide angle distortion caused by the device. The present paper describes a method developed to reconstruct the image, and to correct for this distortion. In order to quantify the relation between object and image, model equations were formulated based on mild assumptions. Points in object space are transformed through a non-linear relation to corresponding points in image space. Furthermore, an oblique camera view, and an aspect ratio correction factor, are accounted for. As a test object, a regular grid of points was recorded at several distances from the camera. The images of the grid points were digitized, and the model equations were fitted to these data. From test measurements, carried out in air as well as in water, it was concluded that the distortion could be quantified by three parameters. Application of the straightforward correction procedure enables us to obtain quantitative information from endoscopic images.

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.

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.

Calcium metabolism and depressed contractility in isolated human and porcine heart muscle.

Contractility is often depressed in isolated heart muscle. To analyze this phenomenon, we measured the derivative of left ventricular pressure (dP/dt) in intact and in isolated, blood perfused pig hearts, and peak force (F) or stress (F/mm2) in ventricular trabeculae of man and pig. When the heart was in the steady state at a priming frequency of 2 Hz an extrasystolic interval of 0.3 s was interposed, followed by four postextrasystolic intervals of 0.8 s. In the case of isolated trabeculae the priming frequency was 0.2 Hz, the extra interval 0.4 s, and the post-extrasystolic intervals were 5 s. The exponential decay of potentiation is characterized by the constant D: a low value of D indicates a rapid decay of potentiation. DP/dt was about 1000 mm Hg/s in the intact hearts, but within 1 h after isolation dP/dt decreased to about 700 mm Hg/s, and this was associated with a decrease in D from 0.63 to 0.40. Developed stress in the isolated trabeculae was about 2 mN/mm2 and D was about 0.20 under standard, in vitro conditions (a.o. 1.5 mM Ca2+. 0.2 Hz stimulus frequency). This stress is only 10% of the calculated stress in the intact heart. An increase of priming frequency, or of [Ca2+], or addition of 30 nM isoproterenol to the perfusate caused a marked increase in F and D. Properties of human and porcine trabeculae were quantitatively similar. The strong correlation between dP/dt, or F, and D suggests a causal relationship. This is consistent with the current model of e-c coupling in heart muscle, in which the activity of the Ca2+ pump of the sarcoplasmic reticulum determines the decay of potentiation and the amount of releasable Ca2+ in the reticulum determines force of contraction. Since isoproterenol stimulates the Ca2+ pump in the reticulum, the increase in D and F induced by this drug is consistent with the model. We conclude, that the decreased dP/dt, F, and D in isolated preparations was due to impaired sarcoplasmic reticulum function. The role of this phenomenon in the stunned heart syndrome, species differences and possible causes are discussed.

Influence of mitral valve prosthesis or rigid mitral ring on left ventricular pump function. A study on exposed and isolated blood-perfused porcine hearts.

We have studied the effects on cardiac function of a Björk-Shiley mitral prosthesis or a rigid mitral ring implanted in pigs for as long as 6 weeks. We studied these effects first in the exposed heart and subsequently in the isolated heart. The coronary arteries were cannulated and perfused with fresh whole blood. The left ventricle was filled with an electrolyte solution and was allowed to pump against an artificial load. Studies were completed in 37 of 45 animals (19 controls, 12 with mitral prostheses and six with mitral rings). In the open-thorax situation, surgically treated hearts differed little from controls, apart from a higher pressure drop over the mitral ostium. Compared with controls, isolated hearts with a prosthesis showed a 28% lower peak isovolumic pressure and a 25% lower unloaded maximal stroke volume; hearts with a mitral ring showed 14% and 25% lower values, respectively. Prosthetic valve or ring implantation causes obstruction of the mitral ostium, impedes pressure development, and restricts movement of the basal ventricular wall. Resection of the native valve doubles the loss of contractile function.

Cold ischemic arrest: comparison of calcium-free and calcium-containing solutions.

Isolated pumping rat hearts, perfused with reconstituted blood, were studied to compare the effects of 30 minutes of ischemic arrest following calcium-free or normal, calcium-containing cold cardioplegia on recovery of mechanical function, lactate production, myocardial adenosine triphosphate concentration, and release of creatine kinase (CK). As in clinical situations, the volume of the infusate was only three to four times the intracavitary blood volume. Hearts arrested with calcium-free solution showed incomplete recovery of mechanical function, whereas hearts arrested with calcium-containing solution recovered completely. After calcium-free arrest, stroke volume recovered to 76 +/- 29% (standard deviation [SD]) of its prearrest value. Enzyme release (CK) was significantly higher after calcium-free cardioplegia (7.7 +/- 4.6 units [SD]) than after cardioplegia with normal calcium (2.1 +/- 1.6 units [SD]). Since the addition of only 0.025 mmol calcium ions to a liter of calcium-free solution completely prevented its negative effect, it was concluded that calcium-free cardioplegia may cause limited but pronounced damage to myocardial cells, presumably because it removes calcium from the cellular membranes--the so-called calcium paradox. Probably due to residual calcium in blood and extracellular fluid, the damage is not so extensive after calcium-free cardioplegia as to be noticeable in clinical surgical situations. Residual calcium in the heart does not exclude the possibility, however, that a calcium paradox occurs in small scattered areas of the heart.