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PubMed1982

Left-sided anomalies in Ebstein's malformation of the tricuspid valve.

A review of 34 autopsied cases with classical Ebstein's malformation of the tricuspid valves revealed 8 cases with left-sided anomalies. Among these, appearing in 1 case each, were aortic atresia and persistent common atrioventricular canal. The latter 2 conditions were dominant clinically. In the remaining 6 cases the left-sided anomalies were not apparent clinically and probably of no functional significance. These conditions were parachute mitral valve, bicuspid aortic valve, cor triatriatum and pulmonary stenosis, cleft mitral valve, stenosis of individual pulmonary veins, and prolapse of mitral valve.

Adolescent↗
PubMed1998

Endocrine mechanisms of stress-induced DHEA-secretion.

Acute psychological stress of a first time parachute jump stimulated DHEA and cortisol secretion in healthy volunteers. A significant shift from cortisol to DHEA occurred during this stress exposure. This effect was more pronounced in subjects receiving the beta-adrenoceptor antagonist propranolol prior to the jump. In contrast, infusion of epinephrine (0.10 microgram/kg/min) or norepinephrine (0.15 microgram/kg/min) for 20 min neither affected DHEA plasma levels nor the DHEA/cortisol ratio. However, pretreatment with propranolol resulted in a significant increase of the DHEA/cortisol ratio upon infusion of the beta-adrenoceptor agonist epinephrine. These data demonstrate that during acute psychological stress stimulation of adrenal steroid release is accompanied by a shift towards DHEA. Augmentation of this effect by beta-adrenoceptor blockade indicates a beta-adrenoceptor-dependent mechanism affecting DHEA release.

Acute Disease↗
PubMed2005

[Crossing borders. The motivation of extreme sportsmen].

In his article "Crossing borders -- the motivation of extreme sportsmen" the author gets systematically to the bottom of the question of why extreme sportsmen voluntarily take risks and endanger themselves. Within the scope of a representative sampling 217 extreme sportsmen -- from the fields of mountain biking, trekking and free climbing, canoyning, river rafting and deep sea diving, paragliding, parachuting, bungee jumping and survival training -- give information about their personal motives. What fascinates them? The attraction of risk? The search for sensation? Or the drop out of everyday life? And what comes afterwards? Does in the end the whole life become an extreme sport? Fact is: they live extremely, because they want to move beyond well-trodden paths. To escape the boredom of everyday life they are searching for the kick, the thrill, the no-limit experience. It's about calculated risk between altitude flight and deep sea adventure.

Attitude to Health↗
PubMed2005

Background factors as determinants of satisfaction with care among first-episode psychosis patients.

OBJECTIVE: To evaluate the impact of demographic and psychosocial background factors and psychiatric and functional status before and at admission on the patients' satisfaction with care (PSC) among first-episode psychosis (FEP) patients. METHOD: One year after entering the Parachute Project, 134 FEP patients completed a patient satisfaction questionnaire. The association with demographic and psychosocial background factors, together with psychiatric and functional status before and after admission, was analysed. RESULTS: Twenty-nine per cent of the variance of PSC was explained by factors such as educational level, social network, duration of untreated psychosis (DUP) and Global Assessment of Functioning (GAF) the year prior to onset. Negative symptoms and lack of hope at admission were also predictors of PSC. The strongest predictor was DUP. CONCLUSION: Affecting the public knowledge in psychiatric problems and psychiatric treatment, together with early intervention strategies aiming to decrease the prodromal and DUP period among FEP patients, can positively influence the patients' experience of given care. By increasing the knowledge of available psychiatric treatment, the sense of powerlessness might decrease among the affected persons, and the possibility of early help seeking might increase.

Adult↗
PubMed1998

Adaptational effects during human split-belt walking: influence of afferent input.

The modification of the normal locomotor pattern of humans was investigated using a split-belt locomotion protocol (treadmill belt speeds of 4.5 km/h and 1.5 km/h for the right and left legs, respectively) and also by changing afferent input from the legs (30% reduction or increase in body weight by suspending subjects in a parachute harness or by wearing a lead-filled vest). After a control-speed training period (10 min) of symmetrical walking (3 km/h each leg) and a period (10 min) of split-belt walking, the adjustment back to the control speed resulted in a mean speed difference between the right leg and the left leg of 0.85 km/h. Adjustment of belt speed on either side was performed by the hands using a potentiometer. For comparison, also speed adjustment by the feet via feedback derived from changes in the treadmill drive current was studied. No significant difference was obtained when both modes of adjustment were compared. Body unloading or loading during the training period resulted in an improved adjustment of treadmill belt speed. This suggests that load receptor information plays a major role in the programming of a new walking pattern.

Adaptation, Physiological↗
PubMedDate not supplied

Transposition of the great arteries, pulmonary atresia, and multiple ventricular septal defects associated with multiple cardiac rhabdomyomas in a case of tuberous sclerosis.

Multiple cardiac rhabdomyomas are frequently associated with tuberous sclerosis. However, very few cardiac malformations have been described with tuberous sclerosis. We report an unusual case of tuberous sclerosis with cerebral and renal lesions associated with dextrotransposition of the great arteries, pulmonary atresia, patent ductus arteriosus, multiple ventricular septal defects, and parachute mitral valve deformity. After reviewing other cases of congenital heart diseases associated with tuberous sclerosis, emphasis is made on the potential influence of multiple rhabdomyomas developing very early during fetal life on final cardiac structures.

Abnormalities, Multiple↗
PubMed1998

MR findings in Shone's complex of left heart obstructive lesions.

BACKGROUND: Shone's complex is a series of four obstructive or potentially obstructive left-sided cardiac lesions (supravalvular mitral ring, parachute deformity of the mitral value, subaortic stenosis, and coarctation of the aorta). Both the complete form (all four lesions) and incomplete forms (less than four lesions) have been described. OBJECTIVE: To determine which abnormalities of Shone's complex could be characterized by MR. MATERIALS AND METHODS: MR examinations in three patients (one complete, two incomplete) were retrospectively reviewed. RESULTS: A supravalvular mitral ring, found at surgery in one patient, was not identified. Regurgitant and stenotic flow across the mitral valve, abnormal motion of the valve leaflets and abnormalities of the papillary muscles were identified. Individual chordal attachments were difficult to resolve. Narrowing in the subaortic region and abnormal flow from the subaortic region through the valve plane were demonstrated. A discrete subaortic diaphragm in one patient was not resolved. Both focal and diffuse types of coarctation of the aorta were well characterized. CONCLUSION: MR imaging is suited to evaluation of patients with Shone's complex. Individual chordal attachments and thin diaphragms of the mitral and aortic valves were difficult to resolve.

Aortic Coarctation↗
PubMed1997

[Accessory mitral valve tissue as a rare cause of subaortic stenosis and valvular aortic insufficiency].

An unusual case of subaortic stenosis and aortic regurgitation caused by accessory mitral valve tissue in a 10 year old boy is reported. Two-dimensional and Doppler echocardiography revealed the characteristic feature of a mobile, parachute-like mass in the left ventricular outflow tract pro-lapsing into the aortic valve during systole and, thus, producing a systolic pressure gradient of 70 mm Hg between the left ventricle and aorta and causing mild aortic regurgitation. The accessory valve tissue was completely excised via an aortotomy without injury to the normal mitral and aortic valves. Two dimensional echocardiography provides excellent morphological information about the relationship between the accessory mitral valve tissue and the mitral and aortic valves, respectively. Accurate preoperative evaluation by two-dimensional echocardiography facilitates the successful surgical management of this rare condition.

Aortic Stenosis, Subvalvular↗
PubMed1998

Effects of beta-adrenoceptor-blockade on stress-induced adrenocorticotrophin release in humans.

We investigated the mechanisms of stress-induced alterations in adrenocorticotrophin (ACTH) release. Tandem parachutists received either a placebo or the beta-adrenoceptor antagonist propranolol prior to a first time parachute jump. Blood samples were drawn 4 h before, immediately after, and 1 h after the jump. Cortisol and catecholamine concentrations displayed a significant stress-induced increase in both groups. The ACTH plasma concentrations significantly increased in the placebo and the propranolol group, with significantly more pronounced changes in the propranolol-treated subjects compared to the placebo group. These data demonstrated a stress-induced increase of ACTH plasma concentrations in humans that was enhanced by beta-blockade.

Adrenergic beta-Antagonists↗
PubMed2005

Numerical simulation of cell motion in tube flow.

A theoretical model is presented for describing the motion of a deformable cell encapsulating a Newtonian fluid and enclosed by an elastic membrane in tube flow. In the mathematical formulation, the interior and exterior hydrodynamics are coupled with the membrane mechanics by means of surface equilibrium equations, and the problem is formulated as a system of integral equations for the interfacial velocity, the disturbance tube-wall traction, and the pressure difference across the two ends to the tube due to the presence of the cell. Numerical solutions obtained by a boundary-element method are presented for flow in a cylindrical tube with a circular cross-section, cytoplasm viscosity equal to the ambient fluid viscosity, and cells positioned sufficiently far from the tube wall so that strong lubrication forces do not arise. In the numerical simulations, cells with spherical, oblate ellipsoidal, and biconcave unstressed shapes enclosed by membranes that obey a neo-Hookean constitutive equation are considered. Spherical cells are found to slowly migrate toward the tube centerline at a rate that depends on the mean flow velocity, whereas oblate and biconcave cells are found to develop parachute and slipper-like shapes, respectively, from axisymmetric and more general initial orientations.

Animals↗
PubMed1984

Two-dimensional echo Doppler study of congenital disorders of the mitral valve.

To define the use of two-dimensional echocardiography (2DE) and Doppler methods for diagnosis of forms of congenital mitral stenosis, we studied 16 children, age range 2 months to 13 years, with congenital deformities of the mitral valve documented at cardiac catheterization. Thirteen had additional congenital heart defects, most commonly aortic stenosis or aortic coarctation. In eight patients features of mitral valve anatomy were observed and described during cardiac surgery and in one child the anatomy was verified by postmortem examination. 2DE studies allowed anatomic subclassification of 10 valves which had asymmetric or single dominant papillary muscles (parachute) and six which had arcade mitral valve attached by short chords to multiple diminutive papillary muscle heads. All patients' echoes exhibited shortened and thickened mitral chordae and doming of the mitral leaflets during diastole, and seven children had restricted mitral orifices imaged on the short-axis imaging plane. All seven of the patients studied by Doppler echocardiography had increased maximal transmitral inflow velocity (range 111 to 260 cm/sec) greater than the 95% confidence limits for mitral flow velocities in 34 normal children who served as the control group. Our study suggests that 2DE studies, especially when combined with Doppler interrogation, are sensitive for defining forms of congenital mitral stenosis.

Adolescent↗
PubMed1984

Echocardiographic assessment of congenital mitral stenosis.

To assess the severity and precise anatomy of congenital mitral stenosis (MS), 17 patients with congenital left ventricular inflow obstruction were studied by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. In six patients MS was an isolated lesion and in 11 it was combined with other cardiovascular malformations. The diagnosis was confirmed at operation or autopsy in 15 patients. Twenty normal subjects of the same age and sex were selected as controls. M-mode amplitude and speed of diastolic closure (E-F slope) of the anterior mitral valve leaflet were determined in all patients. Mitral valve areas were traced after careful short-axis 2DE scans in 15 patients. Supravalvar, valvar, or subvalvar obstruction was evaluated in patients with surgical or autopsy documentation. Analysis of M-mode echocardiograms showed a reduction of E-F slope in all patients compared to normal control subjects but a poor correlation between E-F slope and hemodynamic data (mitral valve areas or pressure gradients). Diastolic fluttering of either or both mitral valve leaflets was found in 12 patients. It is concluded that M-mode echocardiography may be useful for qualitative assessment of congenital MS, even in the presence of associated heart defects, but less useful in evaluating its severity. Analysis of 2DE revealed good correlation between mitral valve areas as calculated with 2DE and with the Gorlin formula at cardiac catheterization, despite the complexity of the congenital mitral lesion. Anatomic varieties of congenital left ventricular inflow obstruction, such as stenosing supravalvar mitral ring or parachute deformity of the mitral valve, were recognized at 2DE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Transesophageal echocardiography in adults with congenital cardiopathies.

Eighty-seven adult patients with congenital cardiopathy were studied by using transesophageal echocardiography (TEE) over a period of 30 months. Transthoracic echocardiography was practiced on all patients, after which TEE with monoplanar and biplanar probes (74 and 15 patients, respectively) was used to confirm principal diagnoses and determine specific information. TEE findings were compared with those of cardiac catheterization in all 87 cases and with those of surgery in 15 cases. Dextrocardia was found in 11 cases and mesocardia in 2. Situs inversus was demonstrated in 6 and levoisomerism in 4. Intracardiac and extracardiac shunts were diagnosed in 20 cases, Ebstein's anomaly in 27, corrected transposition of great vessels in 15, univentricular atrioventricular connection in 7, cor triatriatum in 1, parachute mitral valve in 1, crisscross heart in 1, and double-outlet left atrium in 1. TEE was of particular value in evaluating total anomalous pulmonary venous connection, common atrioventricular canal, Ebstein's anomaly, corrected transposition of great vessels, and univentricular atrioventricular connection and in diagnosis of the rarer congenital cardiopathies.

Adult↗
PubMed1981

Relation between aortic arch hypoplasia of variable severity and central muscular ventricular septal defects: emphasis on associated left ventricular abnormalities.

Among 25 heart specimens with a central muscular ventricular septal defect (including 3 with the architecture of a spontaneously closed defect), only 6 (24 percent) had an aortic arch of normal size and configuration. Isthmus atresia was present in one case, isthmus hypoplasia in eight cases, local coarctation in six and a combination of isthmus hypoplasia and local coarctation in another four. A study of the left ventricular morphologic features of the 25 hearts revealed the presence of a spectrum of additional anomalies. The aortic valve was bicuspid in 16 and mitral valve anomalies were present in 13 specimens. Mitral valve deformities present in the 13 specimens included congenital stenosis (5), deficient chordae tendineae (4), parachute valve (2), adherent valve leaflets (1) and a hypoplastic posteromedial papillary muscle (1). Furthermore, there was a large incidence of abnormal left ventricular muscular structures that could be classified into three basic types: (1) the anteroseptal "twist": thickening and deviation of the anterobasal septum and anterior wall, resulting in a relatively posterior position of the aortic ostium (16 cases); (2) a prominent anterolateral muscle (9 cases); and (3) a posteromedial muscle (9 cases). It is concluded that a central muscular ventricular septal defect is not an isolated malformation but is commonly part of a complex developmental anomaly. This complex of associated inflow and outflow tract lesions presumably may cause reduced aortic flow during morphogenesis, resulting in aortic arch hypoplasia of various degrees of severity.

Adult↗
PubMed1983

Subxyphoid 2-dimensional echocardiographic identification of left ventricular papillary muscle anomalies in complete common atrioventricular canal.

Mitral valve dysfunction is probably the major cause of operative mortality from total repair of complete common atrioventricular (AV) canal in infancy. The presence of a solitary left ventricular (LV) papillary muscle appears to be 1 anatomic factor influencing the success of mitral reconstruction because suturing of the cleft between the superior and inferior components of the anterior mitral leaflet creates a parachute mitral valve deformity, which may result in stenosis or in unduly high tension on the components of the repair. This study reports on (1) the 2-dimensional (2-D) echocardiographic appearance of the LV papillary muscle architecture in patients with complete common AV canal compared with that in normal subjects, and (2) the incidence of solitary LV papillary muscle in patients with complete common AV canal. Two-dimensional echocardiography was performed in 31 infants with complete common AV canal, 14 normal infants, and 9 infants with a large ventricular septal defect not involving the AV canal region. Of 31 infants with complete common AV canal, 26 (80%) had 2 LV papillary muscles on 2-D echocardiography, 3 (10%) had 3 LV papillary muscles, and 3 (10%) had 1 LV papillary muscle. In patients with 2 LV papillary muscles, the anterolateral papillary muscle was displaced posteriorly compared with that in normal subjects and in patients with ventricular septal defect, whereas the posteromedial papillary muscle was in its normal location. Among the 25 patients with complete common AV canal with 2 LV papillary muscles, there was 1 operative death. Among the 6 infants with complete common AV canal with LV papillary muscle anomalies, 5 underwent surgical repair with 4 early deaths. Subxyphoid 2-D echocardiography is a useful technique for evaluating LV papillary muscle architecture in complete common AV canal and permits identification of patients who may be at higher risk for unsuccessful mitral reconstruction.

Echocardiography↗
PubMed1988

Double-orifice mitral valve: a study of 27 postmortem cases with developmental, diagnostic and surgical considerations.

What is double-orifice mitral valve anatomically and embryologically? In 27 postmortem cases, an anomaly of the tensor apparatus was always found. These malformations may be summarized as: (1) chordal ring; (2) accessory papillary muscle or muscles; (3) subdividing muscular ridge; (4) fused papillary muscles (parachute mitral valve); (5) crossing chordae tendineae; and (6) central fibrous subdivision. More than 1 of these anomalies often coexisted per case. Double-orifice mitral valve almost always consisted of abnormal holes in essentially normal leaflets, rather than of abnormal fibrous bridges or adhesions between normal leaflets. Since these fibrous "bridges" between the smaller accessory orifice and the larger main orifice are composed of mitral leaflet tissue and chordae, not fibrous adhesions, these bridges should not be transected surgically, to avoid iatrogenic mitral regurgitation. The accessory (smaller) orifice was at the anterolateral commissure in 11 cases (41%), at the posteromedial commissure in 12 (44%) and there was a central fibrous subdivision with approximately equal-sized orifices in 4 (15%). The atrioventricular (AV) canal was normally divided in 12 cases (44%) and a common AV canal was present in 15 (56%). When the accessory orifice was at the anterolateral commissure, the AV canal usually was normally divided (8 of 11, 73%). But when the accessory orifice was at the posteromedial commissure, a common AV canal almost always was present (11 of 12, 92%). Functionally, the mitral valve was normal in 13 (48%), regurgitated in 7 (26%) and stenotic in 7 (26%). The key to the diagnostic and surgical understanding of the double-orifice mitral valve is the underlying tensor apparatus.

Humans↗
PubMed1994

Flow dynamics of erythrocytes in microvessels of isolated rabbit mesentery: cell-free layer and flow resistance.

A part of microvascular bed isolated from rabbit mesentery (composed of a few branches of superior mesenteric artery) was used for the study of the flow dynamics of erythrocytes in microvessels. The flow resistance in the microvascular bed was analyzed with respect to the thickness of a cell-free layer formed along the inner wall of vessels and the suspension viscosity of erythrocytes (in terms of hematocrit and erythrocyte deformability). The thickness of the cell-free layer increased with the increase in the inner diameter of microvessels. By lowering the hematocrit, the thickness increased and the flow resistance decreased. Meanwhile, by decreasing the erythrocyte deformability with diamide, the thickness decreased and the flow resistance increased. However, the thickness was not altered in microvessels less than 10 microns by the diamide treatment. The maximum inner diameter of microvessel required to induce parachute- and/or slipper-like deformation (at flow velocity of erythrocytes less than 2 mm s-1) was 13 microns for control cells and 6 microns for diamide-treated cells. The thickness of the cell-free layer could not be closely related to the flow resistance, while a good relationship applicable to both control and diamide-treated cells was obtained between the flow resistance and the suspension viscosity. The present results conclude that the flow resistance in the isolated microvascular bed is mainly provided by both hematocrit and erythrocyte deformability.

Animals↗
PubMed1992

Acute psychological stress increases plasma levels of cortisol, prolactin and TSH.

The effects of acute stress during a parachute jump on hormonal responses were studied in 12 experienced and 11 inexperienced military parachutists. Each subject performed two jumps. Prior to and immediately after each jump blood samples were drawn and analysed for plasma levels of cortisol, prolactin, thyrotropin (TSH), somatotropin (STH), and luteinizing hormone (LH). While there was a significant increase in cortisol, prolactin and TSH levels after both jumps, no alterations could be observed in STH and LH levels. Stress-induced hormonal responses were not affected by jump experience. There was also no association between the endocrine variables and anxiety scores.

Acute Disease↗