Pd(I) phosphine carbonyl and hydride complexes implicated in the palladium-catalyzed oxo process.

Reduction of compound "Pd(bcope)(OTf)2" [bcope = (c-C8H14-1,5)PCH2CH2P(c-C8H14-1,5); OTf = O3SCF3] with H2/CO yields a mixture of Pd(I) compounds [Pd2(bcope)2(CO)2](OTf)2 (1) and [Pd2(bcope)2(mu-CO)(mu-H)](OTf) (2), whereas reduction with H2 or Ph3SiH in the absence of CO leads to [Pd3(bcope)3(mu3-H)2](OTf)2 (3). Exposure of 3 to CO leads to 1 and 2. The structures of 1 and 3 have been determined by X-ray diffraction. Complex [Pd2(bcope)2(CO)2](2+) displays a metal-metal bonded structure with a square planar environment for the Pd atoms and terminally bonded CO ligands and is fluxional in solution. DFT calculations aid the interpretation of this fluxional behavior as resulting from an intramolecular exchange of the two inequivalent P atom positions via a symmetric bis-CO-bridged intermediate. A cyclic voltammetric investigation reveals a very complex redox behavior for the "Pd(bcope)(OTf)2"/CO system and suggests possible pathways leading to the formation of the various observed products, as well as their relationship with the active species of the PdL2(2+)/CO/H2-catalyzed oxo processes (L2 = diphosphine ligands).

Measurement of leg blood pressure: the most straightforward way to the diagnosis.

Two adult patients with presumed primary hypertension are presented. In the first patient the diagnosis of coarctation of the aorta was straightforward while in the second patient there was a substantial delay in reaching the correct diagnosis. A 32-year-old patient was analysed for hypertension in the outpatient clinic. At physical examination a systolic cardiac murmur was present and leg blood pressure was not measurable. Magnetic resonance imaging angiography showed a severe coarctation of the thoracic aorta with extensive distended collateral blood vessels. A second patient was a 31-year-old man referred with longstanding hypertension and an unsatisfactory blood pressure response to treatment. Previously, a diagnosis of primary hypertension was made. Renal computed tomography angiography excluded renal artery stenosis as a cause of hypertension but disclosed many distended collateral blood vessels in the musculus rectus abdominis and in the upper abdominal area. Leg blood pressure was measured and further analysis revealed a coarctation of the aorta. Both patients illustrate and emphasise the importance of leg blood pressure measurement at a first analysis of adult hypertensive patients and should always be performed when hypertension is accompanied by murmurs or weak femoral pulsations.

[A neonate with the heart in the right hemithorax]. / Een pasgeborene met het hart in de rechter thoraxhelft.

Three neonates presented with the heart in the right hemithorax: a newborn girl with a chest deformity and secondary dextrocardia (Poland sequence), a prematurely born girl with uncomplicated Kartagener's syndrome, and a newborn boy with cyanosis and the heart in the right hemithorax, in whom a surgical correction was indicated. A diagnosis ofdextrocardia should include the differentiation between primary and secondary dextrocardia. Secondary dextrocardia, or dextroposition, is the result of chest deformities, diaphragmatic defects, severe lung disease, or the presence of a mass displacing the heart from its normal position, usually without any cardiac abnormalities. In primary dextrocardia, the position of the organs in the abdomen is important for the differential diagnosis and the prognosis. The incidence of congenital cardiac malformations in primary dextrocardia varies from 10%, in situs inversus totalis, up to 90% in solitary dextrocardia.

[Percutaneous closure of a perimembraneous ventricular septal defect: the first 4 patients in The Netherlands]. / Percutane sluiting van een perimembraneus ventrikelseptumdefect; de eerste 4 Nederlandse patiënten.

In four female patients, aged 30, 10, 8 and 2 years and 9 months (the latter with Down's syndrome), all with a perimembranous ventricular septal defect (VSD), percutaneous closure of the VSD was carried out using an Amplatzer endoprosthesis. These were the first 4 patients to undergo this procedure in The Netherlands. In 3 of the patients the procedure was without complications and complete occlusion of the defects was achieved. The last patient developed a left anterior hemiblock after implantation of the device and one week later an intermittent second degree atrioventricular block was detected, for which a pacemaker was implanted. A few days later the atrioventricular conduction time returned to normal. There was complete occlusion of the defect. Percutaneous closure of a perimembranous VSD using an Amplatzer prosthesis is a promising technique with good short-term results. In a selected group of patients this new technique can replace surgical treatment.

Severe myocardial ischaemia during mask induction of anaesthesia in an infant with unknown critical supravalvular aortic stenosis.

Congenital supravalvular aortic stenosis is an uncommon type of aortic obstruction. When critical, it represents an extreme variant of outflow tract obstruction with increased risk of cardiovascular instability during exercise or anaesthesia. We present a case of severe myocardial ischaemia during induction of anaesthesia with sevoflurane in a 3-month baby with a presumed diagnosis of valvular aortic stenosis for which a percutaneous balloon dilatation of the aortic valve was scheduled.

The use of transesophageal echocardiography monitoring of transcatheter closure of a persistent ductus arteriosus.

We performed transesophageal echocardiography (TEE) with pediatric biplane probes throughout the procedure of transcatheter closure of the ductus arteriosus in 42 out of 46 patients who were scheduled for this intervention. Patient ages ranged from 15 months to 14 years and body weight from 9-53 kg. Both Rashkind double umbrella devices and coils were used. The described approach resulted in fewer contrast injections and was helpful in monitoring the procedure and in deciding when to release the device. To the best of our knowledge this is the first report describing a large series where continuous monitoring of transcatheter ductus closure was combined with x-ray fluoroscopy and TEE.

A European multicentric experience using the CardioSEal and Starflex double umbrella devices to close interatrial communications holes within the oval fossa.

In this review, we describe the experience from 13 European centres using the CardioSEAL and Starflex double umbrella devices to close interatrial communications within the oval fossa (so-called 'secundum' defects). Between October 1996 and April 1999, the procedure was attempted in 334 patients with a mean age of 12 years and a mean weight of 44kg. The mean measured stretched diameter of the defect was 15 mm. In the overall group, the defect was solitary in 245 patients (73%), multiple in 21 (6%), associated with an aneurysm of the flap valve in 15 (5 %), was represented by patency of the oval foramen in 44 (13%), and was a fenestration in a Fontan repair in 9 (3%). In all patients, the devices were inserted under general anesthesia, using fluoroscopic and transesophageal echocardiographic control. Implantation was achieved in 325 (97,3%). The device embolized within either a few minutes or a few hours in 13 patients (4%). Of these, uncomplicated surgical repair was undertaken in 10, while the device was retrieved in 3 using catheters and a second device was successfully implanted. Residual shunting was detected immediately after the procedure in 41% of the patients, with the incidence decreasing to 31% at discharge, 24% at 1 month, 21% at 6 months, and 20.5% at one year. During the period of follow-up, elective surgical repair became necessary in two patients, due to malposition of the device in one, and late embolization in the other. Fractures of arms were seen in 6.1 %, most commonly with the largest devices. All those with fractured arms of the device were asymptomatic, and no clinical complications related to the fractures were observed. There were no arrhythmias, endocarditis, valvar distortion, thromboembolic events, or other complications. After one year of follow-up, clinical success, defined as complete closure of the defect or presence of only a trivial leak, had been obtained in 92.5% of the patients. We conclude, therefore, that these devices produce excellent results when used to close defects of small to moderate size. Results are less than optimal, or else complications ensure, when attempts are made to close very large defects.

Difficulties generated by the small, persistently patent, arterial duct.

Over recent years, echo-Doppler cardiography has shown that a small, sometimes silent, arterial duct exists in more patients than previously recognized. To know the incidence of an arterial duct subsequent to therapy, we studied retrospectively our patients undergoing open-heart surgery and surgical or catheter closure. Three groups of patients were studied: those with patency of the duct subsequent to open heart surgery without any sign of patency before or during surgery, those with persistent duct after surgical ligation and those with persistent patency after attempted catheter occlusion with the Rashkind device. In the first group (of 431 children) four (0.9%) had persistence of this duct, of which three were silent. In the second group, patency persisted in four of 100 patients (4%), three being silent. In the last group there were five persisting shunts, three producing no murmur, in 30 patients (17%). We compared our results with those reported in the literature and conclude that echo-Doppler cardiography is needed to detect persistent shunting across a duct after therapy, since most of the residual ducts in this study were silent. This means that clinical findings alone cannot be relied upon, and careful echo-Doppler cardiography is essential. Also, the process of closure of a persistent duct by surgical ligation or transcatheter intervention is no guarantee of success. The risk of infective endocarditis is important in such persistent ducts and, at present, it is unknown either for a small, silent duct or in a persistent duct that remains open after attempted transcatheter closure, but now is in association with a foreign body.

Multicore myopathy with restrictive cardiomyopathy.

A 10-y-old girl is presented who suffered mild muscular weakness and exercise intolerance from the age of 1 y onwards, with progression appearing from the age of about 8 y. Multicore myopathy and restrictive cardiomyopathy were diagnosed. Literature concerning the coexistence of multicore myopathy and cardiomyopathy is reviewed.

Surgical treatment of a fistula between the right pulmonary artery and the left atrium: presentation of two cases and review of literature.

OBJECTIVE: A direct communication between the pulmonary artery and the left atrium is a rare anomaly. On the basis of two cases of our own and a literature review of 49 cases, we focus on clinical presentation, anatomy, diagnosis, and the role of surgery. METHODS: Two cases of a fistula between the right pulmonary artery and the left atrium are described in a girl of 4 years and a boy of 15 years. Both presented with unexplained cyanosis. Diagnosis was made on echocardiography and angiography. The fistula was ligated using extracorporeal circulation in the first case and not in the second case. RESULTS: The surgical results were successful with resolution of the cyanosis. CONCLUSIONS: In newborns, urgent surgery may be necessary. In other patients, early elective surgical correction should be performed to prevent complications, especially systemic and cerebral emboli, cerebral abscesses, and rupture of aneurysmal fistulas. Complete cure can be achieved by ligation and possible division or by intracardiac repair.

[Chronic central cyanosis in children; always an indication for further diagnosis]. / Chronische centrale cyanose bij kinderen; altijd een reden voor nadere diagnostiek.

A girl and a boy, both aged 4 years, had displayed a blue discolouration of the skin for several years. In the girl, electrocardiography and roentgenography of the chest revealed no abnormalities; in the boy, the cardiac murmur was attributed to an insignificant ventricular septal defect. Further examinations were performed only when the children developed sleeping problems and decrease of exercise tolerance, respectively. In both, a right-left shunt was discovered caused by a direct communication between the right pulmonary artery and the left atrium, and tetralogy of Fallot, respectively. Both patients' condition improved after operation. Chronic central cyanosis in a child constitutes an indication for consultation of a paediatric cardiologist.

Pulmonary perfusion after endovascular stenting of pulmonary artery stenosis.

UNLABELLED: Pulmonary artery stenosis is a well-known condition after surgical correction of tetralogy of Fallot. Endovascular stenting of the stenosis is a new technique for correction without surgical intervention. Objective evaluation of the procedure, however, is often hampered by moderate or severe pulmonary valve insufficiency. This disadvantage does not apply to 99mTc-macroaggregates of albumin (MAA) scintigraphy of the lungs. Moreover, quantification can be performed relatively easy. METHODS: Seven patients with surgically corrected tetralogy of Fallot (4 men, 3 women, mean age 15.7 yr, range 5-24 yr) were studied. The mean diameter decrement of a pulmonary artery was 69% +/- 8.7%. Before and after stenting, relative uptake in the left and right lung was assessed after injection of 37-55 MBq 99mTc-MAA. Three patients were studied twice after stenting. RESULTS: In all patients, perfusion of the affected lung increased significantly: before 22.7% +/- 10.8%, after 38.6% +/- 12.3% (p < 0.0001). All patients claimed clinical improvement of their condition after stenting. The perfusion gain did not correlate with the prestenting diameter decrement or with the pressure gradient over the stenosis. Lung uptake in the patients studied twice after stenting was similar between the initial and poststenting study (< or = 2% difference). CONCLUSION: Quantitative 99mTc-MAA lung imaging is a noninvasive technique without patient discomfort that objectively measures the effect of stenting pulmonary artery stenosis. The final outcome of stenting with regard to increment of pulmonary blood flow is not predicted by the severity of the stenosis or the pressure gradient over the stenosis.

[Endovascular stent in the treatment of residual pulmonary stenosis in patients operated on for congenital heart defects; initial results]. / Endovasculaire stent ter behandeling van resterende pulmonalistakstenose bij patiënten geopereerd wegens aangeboren hartafwijking; eerste ervaringen.

OBJECTIVE: Evaluation of the preliminary results of stent implantation as a new technique of intervention cardiology to treat (residual) stenosis of pulmonary arteries in congenital heart disease. DESIGN: Descriptive. SETTING: Children's Heart Centre, University Hospital Nijmegen, the Netherlands. METHODS: Data about physical condition, heart catheterization/angiography and lung perfusion scan were collected. Special attention was paid to the lung perfusion scan as a potential parameter of evaluation. RESULTS: The physical condition was not a useful parameter to judge the result of the pulmonary intravascular stenting, due to a simultaneously present important pulmonary valve insufficiency in most cases. Angiography showed a good result immediately after the procedure in all cases, except in one with kinking of the stent. The increase of lung perfusion could be confirmed by lung scintigraphy in most cases. The relative perfusion of the affected lung increased from 22.7% (SD: 10.8) to 38.6% (12.3) (p < or = 0.001). CONCLUSION: Percutaneous implantation of endovascular stents in pulmonary artery branch stenosis is a welcome alternative to (reconstructive) cardiac surgery. Objective quantification of this stenting by lung perfusion scintigraphy, a technique without patient discomfort, is possible.

The vibratory innocent heart murmur in schoolchildren: a case-control Doppler echocardiographic study.

In 810 schoolchildren (aged 5-14 years) the prevalence of a grade 1-3/6 vibratory innocent heart murmur (VIHM) is 41%. Restricted to a grade 2 or 3 VIHM, the prevalence is 14%, decreasing from 21% in the age-class 5-6 years to 8% for children 13-14 years of age. The prevalence of a grade 3 VIHM is 1%. Together with a matched control, 84 children with a grade 2 or 3 VIHM underwent further cardiologic examination including electrocardiography, phonocardiography, and Doppler echocardiography. A positive correlation was found between the presence of a VIHM and higher left ventricular voltages on the ECG, but within the normal range; lower heart rate; smaller diameter of the ascending aorta (AAO); and higher blood flow velocity and higher maximal acceleration of the blood flow in the LVOT and the AAO. In 40% of the children with a VIHM, a systolic aortic valve vibration was seen with a frequency > or = 100 Hz and an amplitude > or = 1 mm, whereas this type of vibration was present in only one case control. No significant difference was found concerning the prevalence of false tendons in the left ventricle, systolic and diastolic diameter of the left ventricle, systolic time intervals, and shortening fraction of the left ventricle. The VIHM is strongly associated with a smaller AAO, with higher velocity and acceleration of the blood flow in the LVOT and AAO, and with a vibratory phenomenon of the aortic valve, pointing towards the LVOT-aortic valve region as the site of origin of the VIHM.

The vibratory innocent heart murmur in schoolchildren: difference in auscultatory findings between school medical officers and a pediatric cardiologist.

In 810 schoolchildren heart auscultation was performed by both a school medical officer (SMO) and a pediatric cardiologist (PC). The prevalence for a grade 1, 2, or 3 vibratory innocent heart murmur (VIHM), a grade 2 or 3 VIHM, and a grade 3 VIHM heard by the PC was 41%, 13%, and 1%, respectively. The SMO noted such murmurs in 26%, 9%, and 1%, respectively. In 30% of the cases in which the PC had noted a grade 2 or 3 VIHM, the SMO agreed; in 30% of such cases the SMO did not hear any heart murmur. If the PC heard a grade 2 or 3 VIHM phonocardiography was performed in a case-control study in which the controls did not have a heart murmur (94 pairs). In four children with a grade 2 or 3 VIHM no heart murmur could be registered and in three other children the murmur did not have the typical diamond shape. In contrast, in three children without a heart murmur at school a VIHM was seen on the phonocardiogram. In 26 children with a phonocardiographically proven grade 2 or 3 VIHM the SMO did not hear any heart murmur. One child with a grade 3 VIHM (both by the PC and SMO) had a minor subvalvular aortic stenosis. There is quite a difference in auscultatory detection of a venous hum: 9% (PC) and 2% (SMO). The prevalence of the pulmonary ejection murmur is identical at 4%. The carotid bruit is heard in 4% (PC) and 2% (SMO).(ABSTRACT TRUNCATED AT 250 WORDS)

Coarctation developing after arterial switch repair for transposition of the great arteries.

We describe 2 patients with simple transposition of the great arteries in whom coarctation of the aorta developed after uncomplicated arterial switch operation. Both patients showed no symptoms or signs of this coarctation at the time of arterial switch operation.

Right-sided valvular regurgitation in normal children determined by combined colour-coded and continuous-wave Doppler echocardiography.

Using Doppler echocardiography, the prevalence of tricuspid and pulmonary valve regurgitation was determined prospectively in 173 normal children, aged 8.3 +/- 2.7 (range 5-14) years. Pulmonary regurgitation was defined as a red-yellow or mosaic coloured regurgitant flow, continuing to end-diastole with continuous-wave Doppler. It was found in 84% of the children. Tricuspid regurgitation was defined as a blue-green or mosaic coloured regurgitant flow from the tricuspid valve into the right atrium lasting > 0.5 systole, as determined by continuous-wave Doppler. Tricuspid regurgitation was present in only 8% of the children. Tricuspid regurgitation flow of very short duration, considered to be due to valve closure, was found in 75%. No effect of age, presence of a vibratory innocent heart murmur or gender on the prevalence of right-sided valvular regurgitation could be demonstrated. All regurgitations were haemodynamically insignificant. Thus right-sided valvular regurgitation in normal schoolchildren is a normal physiological finding with relatively high prevalence. In the absence of functional reasons for these regurgitations and in the absence of structural pulmonary or tricuspid valve disease, these signals should be considered physiological in order to avoid iatrogenic heart disease.