CineECG for visualization of changes in ventricular electrical activity during ischemia.

BACKGROUND: CineECG offers a visual representation of the location and direction of the average ventricular electrical activity throughout a single cardiac cycle, based on the 12­lead ECG. Currently, CineECG has not been used to visualize ventricular activation patterns during ischemia. PURPOSE: To determine the changes in ventricular activity during acute ischemia with the use of CineECG, and relating this to changes in the ECG. METHODS: Continuous ECG's during percutaneous coronary intervention with prolonged balloon inflation from the STAFF III database were analyzed with CineECG at baseline and every 10 s throughout the first 150 s of balloon inflation. The CineECG direction was determined for the initial QRS-complex, terminal QRS-complex, ST-segment and T-wave. Changes in the CineECG were quantified by calculating the Δangle between the direction at baseline and the direction at every 10 s of inflation. Additionally, the root mean square amplitude (rmsA) of the ST-segment was computed. RESULTS: 94 patients were included. At start inflation, the median Δangle was 14.7° [7.5-33.4], 21.8° [11.4-34.2], 20.6° [8.0-43.9], and 23.5° [11.8-48.0] for the initial QRS-complex, terminal QRS-complex, ST-segment and T-wave, respectively. Meanwhile, the median rmsA increased from 0.039 mV [0.027-0.058] at baseline to 0.045 mV [0.033-0.075] at start of inflation. CONCLUSIONS: CineECG was able to detect immediate changes in ventricular electrical activity during induced ischemia, while changes in the ST-segment of the ECG were still subtle. Therefore, CineECG might support the early detection of acute ischemia, even before distinct ECG changes become visible.

Modeling ventricular repolarization gradients in normal cases using the equivalent dipole layer.

Background Electrical activity underlying the T-wave is less well understood than the QRS-complex. This study investigated the relationship between normal T-wave morphology and the underlying ventricular repolarization gradients using the equivalent dipole layer (EDL). Methods Body-surface-potential-maps (BSPM, 67­leads) were obtained in nine normal cases. Subject specific MRI-based anatomical heart/torso-models with electrode positions were created. The boundary element method was used to account for the volume conductor effects. To simulate the measured T-waves, the EDL was used to apply different ventricular repolarization gradients: a) transmural, b) interventricular c) apico-basal and d) all three gradients (a-c) combined. The combined gradient (d) was optimized using an inverse procedure (Levenberg-Marquardt). Correspondence between simulated and measured T-waves was assessed using correlation coefficient (CC) and relative difference (RD). Results Realistic T-waves were simulated if repolarization times of: (a) the epicardium were smaller than the endocardium; (b) the left ventricle were smaller than the right ventricle and (c) the apex increased towards the base. The apico-basal gradient resulted in the highest correspondence between measured and simulated T-waves (CC = 0.84(0.81-0.91);RD = 0.68(0.60-0.71)) compared to a transmural gradient (CC = 0.77(0.71-0.80);RD = 1.46(0.82-1.75)) and an interventricular gradient (CC = 0.71(0.67-0.80);RD = 0.85(0.75-0.87)). All three gradients combined further improved the correspondence between measured and simulated T-waves (CC = 0.83(0.82-0.89);RD = 0.60(0.51-0.63)), especially after optimization (CC = 0.96(0.94-0.98);RD = 0.27(0.22-0.34)). Conclusion The application of all repolarization gradients combined resulted in the largest agreement between simulated and measured T-waves, followed by the apico-basal repolarization gradient. With these findings, we will optimize our EDL-based inverse procedure to assess repolarization abnormalities.

The AirSeal® insufflation device can entrain room air during routine operation.

BACKGROUND: Surgical procedures that use insufflation carry a risk of gas embolism, which is considered relatively harmless because of the high solubility of carbon dioxide. However, an in vitro study suggested that valveless insufflation devices may entrain non-medical room air into the surgical cavity. Our aim was to verify if this occurs in actual surgical procedures. METHODS: The oxygen percentage in the pneumoperitoneum or pneumorectum/pneumopelvis of eight patients operated with use of the AirSeal® was continuously measured, to determine the percentage of air in the total volume of the surgical cavity. RESULTS: Basal air percentage in the surgical cavity was 0-5%. During suctioning from the operative field air percentage increased to 45-65%. CONCLUSIONS: The AirSeal® valveless insufflation device maintains optimal distension of the surgical cavity not only by insufflating carbon dioxide, but also by entraining room air, especially during suctioning from the operative field. This may theoretically lead to air embolism in patients operated on with this device.

[Cardiac resynchronization therapy: who is a candidate and who is not?] / Cardiale-resynchronisatietherapie.

- Cardiac resynchronisation therapy (CRT) is a treatment for patients with impaired cardiac pump function (left ventricular ejection fraction ≤ 35%) and a wide QRS complex who, despite maximum tolerated medical therapy, remain symptomatic.- In addition to reducing symptoms, CRT can reduce hospital admissions and improve survival.- Selection of patients for CRT remains difficult. Despite the fact that predicting and influencing success of CRT has improved, ~30% of patients do not respond to the therapy.- Optimizing therapy and follow-up of patients after implantation requires a multidisciplinary approach tailored to the individual patient.- Cardiac rehabilitation with life style advices and structured exercise training maximizes patient benefit from CRT.

Systematic review of the effects of exercise therapy on the upper extremity of patients with spinal-cord injury.

OBJECTIVE: To assess the effects of exercise therapy (ET) on motor control and functional ability of the upper extremity in patients with cervical spinal cord injury (SCI). METHODS: An extensive systematic literature search in five databases was performed to identify clinical and (randomized) controlled trials, evaluating the effects of ET on motor control and functional ability in patients with SCI. The methodological quality of the selected studies was systematically assessed by three reviewers. RESULTS: Eight studies were included. Seven had good-to-fair methodological quality, six reported positive effects of ET on motor control (for example, muscle strength or muscle grade) and four also reported positive effects on functional ability. Five of these studies focused on patients with long-lasting SCI. A great variety of therapeutic approaches were applied, even within ET there was a wide range of training characteristics. CONCLUSION: Although ET is a cornerstone in the treatment of the upper extremity in patients with SCI, only a small number of studies were included in the present review. Most of the included studies reported a positive effect of ET on upper extremity motor control and functional ability in SCI patients. As ET is effective in patients with SCI in the chronic stage, this might have implications for the follow up and further treatment of these patients. Future studies should be more specific in describing the characteristics of ET to verify that the ET is in accordance with the current standards for training and motor relearning.

[The Dutch law on artificial-insemination donor data: content and consequences]. / Wet Donorgegevens Kunstmatige Bevruchting: inhoud en gevolgen.

In 2004, a law was introduced in the Netherlands that gives children conceived by artificial insemination with donor semen (AID), oocytes or embryos the right to learn the identity of the donor when they are 16. The permanently anonymous semen donor will now be replaced by donors that are anonymous at the time of insemination, but traceable later. During the period preceding and immediately following the enactment of the law, the number of semen donors and semen banks dropped drastically and there was a change in the type of donor. The law, furthermore, creates several new moral and psychological dilemmas for both parents and AID-offspring. For parents, for example: should I tell my child that he was conceived by AID, knowing that he may become acquainted with the donor, with all the consequences that may entail? And for AID-offspring, if they have been told that they were conceived by AID: do I really wish to meet the donor? It must still be shown whether AID-offspring will feel a need for contact with the donor, and whether such contact is satisfying.

[Invasive prenatal diagnosis in the Netherlands, 1991-2000: number of procedures, indications and abnormal results detected]. / Invasieve prenatale diagnostiek in Nederland, 1991-2000: aantallen ingrepen, indicaties, en gevonden afwijkingen.

OBJECTIVE: To provide an overview of invasive prenatal diagnosis in the Netherlands during the period 1991-2000 and to analyse potential trends. DESIGN: Retrospective. METHOD: The annual results from all 13 Dutch centres for invasive prenatal diagnosis over the period 1991-2000 were combined and described, with particular emphasis on indications, number and type of invasive procedures, and number and type of abnormal results. RESULTS: The percentage of pregnancies in which invasive prenatal diagnostics were carried out increased from 5% in 1991 to 6% in 1996 and remained at the same level until 2000. 'Maternal age' was the main reason for prenatal testing (69.2-73.3% of procedures). However, the number of pregnant women aged 36 or over increased by 69.9%. An abnormal result was found in an average of 4.7% of procedures, rising from 3.6% in 1991 to 5.4% in 2000. In 70.8% of cases with abnormal results, the pregnancy was terminated. Important trends were the relative decrease of cordocentesis (-82%) and chorionic villi biopsy (-18%) in favour of amniocentesis (+48%), and a strong decrease in the number of amniocentesis procedures on indication of increased risk of neural tube defect. CONCLUSION: The total number of invasive prenatal diagnostic procedures remained stable. However, there was an important decrease in the percentage of pregnant women aged 36 or over who underwent invasive prenatal diagnosis without previous prenatal screening.

Schwangerschafts protein 1 (SP1) adds little to the age-related detection of fetal Down syndrome in the first trimester of pregnancy.

Schwangerschafts Protein 1 (SP1), being a placental protein appearing in the maternal circulation early in pregnancy, has been investigated as a potential marker for Down syndrome in the first trimester. Our study compared SP1 levels in 15 pregnancies with a Down syndrome fetus and 97 matched controls. Although the median MoM in Down syndrome pregnancies (0.49) was lower than in controls, its use as a marker added very little to the detection rate above the maternal age alone.

Maternal serum levels of free beta-hCG and PAPP-A in the first trimester of pregnancy are not associated with subsequent fetal growth retardation or preterm delivery.

The purpose of this case-control study was to examine the association of first-trimester concentrations of free beta-human chorionic gonadotropin (free beta-hCG) and pregnancy-associated plasma protein A (PAPP-A) in maternal serum with subsequent preterm delivery or small-for-gestational age (SGA) fetuses. We collected all the blood samples before chorionic villus sampling in the first trimester. Concentrations of free beta-hCG and PAPP-A were expressed in multiples of the median (MOM) for gestational age. We compared the levels of both analytes in 73 SGA pregnancies (birth weight below the fifth percentile) with those in 292 normal controls, who were matched for gestational age, maternal age, parity, maternal weight, and smoking habits. We also compared the levels in 87 pregnancies with a preterm delivery (delivery before 37 completed weeks) with those in 348 matched controls. The median concentrations of PAPP-A and free beta-hCG, expressed in MOMs, in the 73 SGA pregnancies were 0.83 and 0.95, respectively, compared with 0.98 and 1.01, respectively, in the 292 matched controls (P=0.08 and 0.19, respectively). In the 87 pregnancies with a preterm delivery, the median concentrations of PAPP-A and free beta-hCG were 0.98 and 0.94, respectively, compared with 0.99 and 0.99, respectively, in the 348 matched controls (P=0.82 and 0.10, respectively). In contrast with the maternal serum analytes used in second-trimester screening--alpha-fetoprotein and human chorionic gonadotropin--this study showed that concentrations of PAPP-A and free beta-hCG in the first trimester were not associated with subsequent fetal growth retardation or preterm delivery.

Prenatal diagnosis in the Netherlands. Dutch Working Party of Prenatal Diagnosis.

Prenatal invasive diagnosis of genetic conditions in the Netherlands is well organised, based on uniform indications and has a sound financial structure. Facilities for fetal karyotyping and DNA analysis are available in the 8 academic centres. Prenatal diagnosis of metabolic diseases is mainly carried out in Rotterdam. Amniocentesis, transcervical and transabdominal chorionic villus sampling are carried out in all centres, including 4 subcentres. The national Working Party on Prenatal Diagnosis started in 1985 and is a useful platform for all obstetricians and geneticists involved in prenatal diagnosis.

46,XY,dup(10q) in direct CVS preparation and mosaic 48,XXXY,dup(10q) in CVS long-term culture and fetal tissue.

Chorionic villus sampling (CVS) was performed on a 40-year-old woman at 9 1/2 menstrual weeks because of advanced maternal age. The direct preparation showed 46,XY,dup(10)(q11.2q23.2). CVS long-term culture and fetal tissue revealed a rare additional abnormality: 48,XXXY,dup(10)(q11.2q23.2). This abnormality represented the major cell line (> 85 per cent in 691 cells) in an (XY)/XXY/XXXY/(XXXXY) mosaic (all cell lines presumably bearing the dup(10q); the presence of XY and XXXXY cell lines is uncertain). To our knowledge, this is the first report of trisomy 10q11-q23 and of prenatally detected 48,XXXY in chorionic villi. The mosaic could have resulted from early post-zygotic non-disjunctions in a 46,XY,dup(10q) or 47,XXY,dup(10q) zygote. The results from DNA studies of four polymorphisms, mapped to Xp and Xq, support this theory. The literature on prenatally detected cases with sex chromosome tetrasomy and pentasomy and those with additional autosomal abnormalities is reviewed. The reported case underlines the problem of false-negative findings when only direct CVS preparations are karyotyped.

Lipase kinetics: hydrolysis of triacetin by lipase from Candida cylindracea in a hollow-fiber membrane reactor.

The aptitude of a hollow-fiber membrane reactor to determine lipase kinetics was investigated using the hydrolysis of triacetin catalyzed by lipase from Canadida cylindracea as a model system. The binding of the lipase to the membrane appears not to be very specific (surface adsorption), and probably its conformation is hardly altered by immobilization, resulting in an activity comparable to that of the enzyme in its native form. The reaction kinetics defined on the membrane surface area were found to obey Michaelis-Menten kinetics. The specific activity of the lipase in the membrane reactor was found to be significantly higher than in an emulsion reactor. The activity and stability of the enzyme immobilized on a hydrophilic membrane surface seem not to be influenced significantly by the choice of the membrane material. The hollow-fiber membrane reactor is a suitable tool to assess lipase kinetics in a fast and convenient way.

Elevated folate levels in amniotic fluid after oral supplementation.

During oral supplementation of 5 mg folic acid and 1 microgram vitamin B12, the daily folate levels in plasma, red cells and midtrimester amniotic fluid were significantly higher in ten pregnant women during the 15th-18th week of menstrual age as compared to ten non-supplemented women serving as controls. In the control group as well as in the supplemented group, the folate concentrations in amniotic fluid were found to be lower than in the corresponding maternal plasma and red cells. Of all women investigated there was a significant positive correlation between maternal plasma folate concentrations and amniotic fluid levels (r = 0.72, p less than 0.001) and no correlation between red cell folate concentrations and amniotic fluid levels (r = 0.30, p = 0.22). Oral supplementation of vitamin B12 did not elevate maternal blood concentrations and amniotic fluid levels. Vitamin B12 levels in amniotic fluid in this group and controls were always higher than in plasma. These data suggest that the orally administrated dosages of folic acid unlike those of vitamin B12 augment both plasma, red cells and amniotic fluid levels.

The predictive value of cytogenetic diagnosis after CVS: 1500 cases.

The cytogenetic results of 1500 chorionic villus samples (CVS) are presented. In these 1500 samples, 23 samples (1.5 per cent) could not be provided with a diagnosis because of laboratory failure. This failure rate dropped from 3 per cent in the first 500 samples to 0.2 per cent in the last 500. In the remaining 1477 samples, 58 (3.9 per cent) chromosomal aberrations were found. Of these, 21 (36 per cent) proved not to represent the karyotype of the fetus proper. Predictive values of (different groups of) chromosomal aberrations in CVS are calculated. The impact of (differences between) the predictive value for some major chromosomal aberrations is discussed. A tissue- and chromosome-specific selection mechanism is postulated.

Detection of truncated dystrophin in fetal DMD myotubes.

An immunohistochemical study was carried out on a twelve-week old fetus, aborted for high risk of Duchenne muscular dystrophy. Southern and FIGE analysis showed an intragenic duplication in the DMD gene, which had previously resulted in a severe Duchenne phenotype in three relatives. Polyclonal antibodies directed against the NH2-terminal half of dystrophin showed a positive reaction an a similar distribution of dystrophin in the skeletal myotubes of a twelve-week old normal fetus and the affected fetus. In contrast, a polyclonal antibody directed against the COOH-terminus of dystrophin, i.e., distal to the mutation in this family, did only react with the myotubes of the normal fetus and not with those of the affected fetus. This indicates the presence of a truncated dystrophin in the affected fetus. Apparently at this stage, before binding of dystrophin to the sarcolemma, no distinction is made yet between normal and abnormal dystrophins. This implies that the potential to bind to the sarcolemma could be a major point of discrimination between normal and defective dystrophins. The truncated dystrophin will probably be degraded in a later stage during fetal development. So it appears that the use of dystrophin immunostaining to confirm high Duchenne risk abortions requires great caution. To prevent false-positive results, the combined use of NH2- and COOH-terminal antibodies is mandatory.

Primary ovarian carcinoid tumor in combination with carcinoid heart disease; a case report.

Primary ovarian carcinoid tumors (POCT) with secondary carcinoid heart disease are rare, only 13 cases have been reported in the literature to date. In most instances POCT can be completely removed surgically contrary to primary carcinoid tumor of the gastro-intestinal tract. Laparoscopy may be helpful in localizing the tumor. We present a case in which the carcinoid heart lesions progressed despite total eradication of the carcinoid.