| 1. |
- Mann, Stefan A., et al.
(författare)
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Convergence of models of human ventricular myocyte electrophysiology after global optimization to recapitulate clinical long QT phenotypes
- 2016
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Ingår i: Journal of Molecular and Cellular Cardiology. - : Elsevier BV. - 0022-2828 .- 1095-8584. ; 100, s. 25-34
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Tidskriftsartikel (refereegranskat)abstract
- In-silico models of human cardiac electrophysiology are now being considered for prediction of cardiotoxicity as part of the preclinical assessment phase of all new drugs. We ask the question whether any of the available models are actually fit for this purpose. We tested three models of the human ventricular action potential, the O'hara-Rudy (ORD11), the Grandi-Bers (GB10) and the Ten Tusscher (TT06) models. We extracted clinical QT data for LQTS1 and LQTS2 patients with nonsense mutations that would be predicted to cause 50% loss of function in I-Ks and I-Kr respectively. We also obtained clinical QT data for LQTS3 patients. We then used a global optimization approach to improve the existing in silico models so that they reproduced all three clinical data sets more closely. We also examined the effects of adrenergic stimulation in the different LQTS subsets. All models, in their original form, produce markedly different and unrealistic predictions of QT prolongation for LQTS1, 2 and 3. After global optimization of the maximum conductances for membrane channels, all models have similar current densities during the action potential, despite differences in kinetic properties of the channels in the different models, and more closely reproduce the prolongation of repolarization seen in all LQTS subtypes. In-silico models of cardiac electrophysiology have the potential to be tremendously useful in complementing traditional preclinical drug testing studies. However, our results demonstrate they should be carefully validated and optimized to clinical data before they can be used for this purpose.
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| 2. |
- Winbo, Annika, et al.
(författare)
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Fetal heart rate reflects mutation burden and clinical outcome in twin probands with KCNQ1 mutations
- 2018
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Ingår i: HeartRhythm case reports. - : Elsevier BV. - 2214-0271. ; 4:6, s. 237-240
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Tidskriftsartikel (refereegranskat)abstract
- We present the case of a twin pregnancy of heterozygous andhomozygous long QT syndrome (LQTS) type 1 (LQT1)genotype, referred because of in utero bradycardia in thehomozygous twin at 19 weeks of gestation, with follow-upuntil.12 months of age. Fetal heart rate may predict bothgenotype and disease severity, as previously shown in2 LQTS founder populations.1This unique case report is acomparison of fetal heart rate and clinical outcome in twinprobands of heterozygous and homozygous genotype, in afamily without prior diagnosis of LQTS. In this setting, wediscuss the early management of LQTS and Jervell andLange-Nielsen syndrome (JLNS) detected in utero.
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| 3. |
- Winbo, Annika, et al.
(författare)
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Sex is a moderator of the association between NOS1AP sequence variants and QTc in two long QT syndrome founder populations : a pedigree-based measured genotype association analysis
- 2017
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Ingår i: BMC Medical Genetics. - : BIOMED CENTRAL LTD. - 1471-2350. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sequence variants in the NOS1AP gene have repeatedly been reported to influence QTc, albeit with moderate effect sizes. In the long QT syndrome (LQTS), this may contribute to the substantial QTc variance seen among carriers of identical pathogenic sequence variants. Here we assess three non-coding NOS1AP sequence variants, chosen for their previously reported strong association with QTc in normal and LQTS populations, for association with QTc in two Swedish LQT1 founder populations.Methods: This study included 312 individuals (58% females) from two LQT1 founder populations, whereof 227 genotype positive segregating either Y111C (n = 148) or R518* (n = 79) pathogenic sequence variants in the KCNQ1 gene, and 85 genotype negatives. All were genotyped for NOS1AP sequence variants rs12143842, rs16847548 and rs4657139, and tested for association with QTc length (effect size presented as mean difference between derived and wildtype, in ms), using a pedigree-based measured genotype association analysis. Mean QTc was obtained by repeated manual measurement (preferably in lead II) by one observer using coded 50 mm/s standard 12-lead ECGs.Results: A substantial variance in mean QTc was seen in genotype positives 476 +/- 36 ms (Y111C 483 +/- 34 ms; R518* 462 +/- 34 ms) and genotype negatives 433 +/- 24 ms. Female sex was significantly associated with QTc prolongation in all genotype groups (p < 0.001). In a multivariable analysis including the entire study population and adjusted for KCNQ1 genotype, sex and age, NOS1AP sequence variants rs12143842 and rs16847548 (but not rs4657139) were significantly associated with QT prolongation, + 18 ms (p = 0.0007) and + 17 ms (p = 0.006), respectively. Significant sex-interactions were detected for both sequent variants (interaction term r = 0.892, p < 0. 001 and r = 0.944, p < 0.001, respectively). Notably, across the genotype groups, when stratified by sex neither rs12143842 nor rs16847548 were significantly associated with QTc in females (both p = 0.16) while in males, a prolongation of + 19 ms and + 8 ms (p = 0.002 and p = 0.02) was seen in multivariable analysis, explaining up to 23% of QTc variance in all males.Conclusions: Sex was identified as a moderator of the association between NOS1AP sequence variants and QTc in two LQT1 founder populations. This finding may contribute to QTc sex differences and affect the usefulness of NOS1AP as a marker for clinical risk stratification in LQTS.
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| 4. |
- Winbo, Annika, et al.
(författare)
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Third Trimester Fetal Heart Rate Predicts Phenotype and Mutation Burden in the Type 1 Long QT Syndrome
- 2015
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Ingår i: Circulation. - 1941-3149 .- 1941-3084. ; 8:4, s. 806-814
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Tidskriftsartikel (refereegranskat)abstract
- Background—Early diagnosis and risk stratification is of clinical importance in the long QT syndrome (LQTS), however, little genotype-specific data are available regarding fetal LQTS. We investigate third trimester fetal heart rate, routinely recorded within public maternal health care, as a possible marker for LQT1 genotype and phenotype.Methods and Results—This retrospective study includes 184 fetuses from 2 LQT1 founder populations segregating p.Y111C and p.R518X (74 noncarriers and 110KCNQ1 mutation carriers, whereof 13 double mutation carriers). Pedigree-based measured genotype analysis revealed significant associations between fetal heart rate, genotype, and phenotype; mean third trimester prelabor fetal heart rates obtained from obstetric records (gestational week 29–41) were lower per added mutation (no mutation, 143±5 beats per minute; single mutation, 134±8 beats per minute; double mutations, 111±6 beats per minute; P<0.0001), and lower in symptomatic versus asymptomatic mutation carriers (122±10 versus 137±9 beats per minute; P<0.0001). Strong correlations between fetal heart rate and neonatal heart rate (r=0.700; P<0.001), and postnatal QTc (r=−0.762; P<0.001) were found. In a multivariable model, fetal genotype explained the majority of variance in fetal heart rate (−10 beats per minute per added mutation; P<1.0×10–23). Arrhythmia symptoms and intrauterine β-blocker exposure each predicted −7 beats per minute, P<0.0001.Conclusions—In this study including 184 fetuses from 2 LQT1 founder populations, third trimester fetal heart rate discriminated between fetal genotypes and correlated with severity of postnatal cardiac phenotype. This finding strengthens the role of fetal heart rate in the early detection and risk stratification of LQTS, particularly for fetuses with double mutations, at high risk of early life-threatening arrhythmias.
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| 5. |
- Winbo, Annika, et al.
(författare)
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Vestibular dysfunction is a clinical feature of the Jervell and Lange-Nielsen Syndrome
- 2015
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 49:1, s. 7-13
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. To investigate the possible association between Jervell and Lange-Nielsen Syndrome (JLNS) genotype and vestibular dysfunction. Design. In 15 cases with JLNS, clinical data obtained from a semi-structured interview and full medical records were reviewed and post-rotatory nystagmus testing was performed. Results. All genotyped cases (n = 14) had double KCNQ1 mutations. Symptoms of impaired balance were reported in 14/14 deaf JLNS cases. Gross motor developmental delay (not walking without support at 18 months of age) was seen in 11/12 cases with available data (mean age for walking: 24 months). A pathologic post-rotatory test was seen in 9/9 tested subjects, and in 3 subjects clinical testing had been performed showing complete lack of vestibular function. Vestibular dysfunction was seen in deaf JLNS cases with (n = 5) and without (n = 9) cochlear implants, including subjective symptoms (5/5 vs. 9/9) and gross motor developmental delay (5/5 vs. 6/8). Conclusions. We identified a high frequency of symptoms and signs associated with vestibular dysfunction in deaf JLNS cases, irrespective of previous cochlear implantation. Disruption of endolymph homeostasis in the inner ear, including cochlea and vestibular system, by profound KCNQ1 function loss is the proposed mechanism.
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| 6. |
- Öhman, Annika, et al.
(författare)
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Changing Epidemiology of Hypoplastic Left Heart Syndrome : Results of a National Swedish Cohort Study
- 2019
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Ingår i: Journal of the American Heart Association. - : John Wiley & Sons. - 2047-9980 .- 2047-9980. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Background Norwood surgery provides a palliative surgical option for hypoplastic left heart syndrome and has been available in Sweden since 1993. The practice of prenatal ultrasound screening was gradually implemented in the same era, resulting in an increased prenatal detection rate. Our primary aims were to study changes in the incidence of live births, prenatal detection rate, and the termination of pregnancies over time. The secondary aims were to study the proportion of live-borns undergoing surgery and to identify factors that influenced whether surgery was or was not performed. Methods and Results Neonates with hypoplastic left heart syndrome with aortic atresia born 1990-2010 were identified through national databases, surgical files, and medical records. The fetal incidence was estimated from the period when prenatal screening was rudimentary. The study period was divided into the presurgical, early surgical, and late surgical periods. The incidence was calculated as the overall yearly incidence for each time period and sex separately. Factors influencing whether surgery was performed were analyzed using Cox-logistic regression. The incidence at live birth decreased from 15.4 to 8.4 per 100 000. The prenatal detection rate increased from 27% to 63%, and terminations increased from 19% to 56%. The odds of having surgery was higher in the late period and higher in the group with prenatal diagnosis. Conclusions We observed a decrease in incidence of live-borns with hypoplastic left heart syndrome aortic atresia. There was in increase in prenatal detection rate and an increase in termination of pregnancy. The proportion of live-borns who underwent surgery increased between time periods.
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| 9. |
- Acuña Mora, Mariela, 1990, et al.
(författare)
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Patient empowerment and its correlates in young persons with congenital heart disease
- 2019
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Ingår i: European Journal of Cardiovascular Nursing. - : Oxford University Press (OUP). - 1474-5151 .- 1873-1953. ; 18:5, s. 389-398
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this study was to measure the level of empowerment and identify its correlates in young persons with congenital heart disease. Study design: Patients aged 14–18 years with congenital heart disease, and under active follow-up in one of four paediatric cardiology centres in Sweden were invited to participate in a cross-sectional study. A total of 202 young persons returned the questionnaires. Patient empowerment was measured with the Gothenburg Young Persons Empowerment Scale that allows the calculation of total and subscale scores. Univariate and multivariate linear regression analyses were undertaken to analyse possible correlates, including: sex, age, health behaviours, knowledge of congenital heart disease, quality of life, patient-reported health, congenital heart disease complexity, transition readiness and illness perception. Results: The mean empowerment score was 54.6±10.6 (scale of 15–75). Univariate analyses showed that empowerment was associated with age, quality of life, transition readiness, illness perception, health behaviours and patient-reported health (perceived physical appearance, treatment anxiety, cognitive problems and communication issues). However, multivariable linear regression analyses identified that only transition readiness (β=0.28, P<0.001) and communication (β=0.36, P<0.001) had a positive association with patient empowerment. These variables were also significantly associated with the subscale scores of the empowerment scale of knowledge and understanding (P<0.001), shared decision-making (P<0.001) and enabling others (P<0.01). The overall models’ explained variance ranged from 8% to 37%. Conclusion: Patient empowerment was associated with transition readiness and fewer problems communicating. While it is not possible to establish the directionality of the associations, interventions looking to increase empowerment could benefit from using these variables (or measurements) for evaluation purposes.
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| 10. |
- Alenius Dahlqvist, Jenny, 1972-
(författare)
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Heart rate variability and pacemaker treatment in children with Fontan circulation
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Fontan surgery is performed in children with univentricular heart defects. Arrhythmias are frequent complications, occasionally requiring pacemaker treatment. Previous data regarding indications and risk factors for pacemaker treatment in Fontan patients is limited and conflicting. Heart rate variability (HRV) reflects autonomous nervous activity controlling the sinus node and has been associated with tachyarrhythmias in both adults and children, as well as in adults with sinus node dysfunction (SND).Aim: To study HRV, arrhythmia and pacemaker treatment in children with Fontan circulation— with the purpose of contributing to the reduction of long term complications in this patient group.Methods: We have retrospectively reviewed pacemaker therapy in all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n=599). We have also analysed HRV from 24-hour Holter ECG recordings in 112 children with Fontan circulation and in children with univentricular heart defects before bidirectional Glenn (BDG) procedure (n=47), before and on completion of Fontan surgery (n=47 and 45 respectively). Analysis was performed by power spectral analysis and Poincaré method, and results compared with healthy controls. Furthermore, HRV was analysed in Fontan patients who later required a pacemaker due to severe SND. Results were compared with Fontan patients who had SND, without indication for pacemaker treatment, with patients with Fontan circulation without SND and healthy controls. In addition we evaluated the possibility to analyse arrhythmias and HRV in 27 Fontan children using intermittent ECG recordings with a handheld devices at home during a 14-day period.Results: After a mean follow-up of 12 years, 13% (78/599) of patients with Fontan circulation had received a pacemaker. Patients operated with the extracardiac conduit (EC) had a significantly lower prevalence of pacemaker implantation (6%) than patients with a lateral tunnel (LT) (17%). The most common pacemaker indication in patients with Fontan circulation was SND (64%). Children with Fontan circulation showed significant reductions in several HRV parameters, compared with controls. No significant differences were found between patients operated with LT versus EC (paper I). After BDG the RR interval and SD2 (representing changes in heart rate over 24-hours) significantly increased compared to pre-BDG. Compared with healthy controls, patients post-BDG, had significantly longer RR intervals and reduced overall HRV. PHF (reflecting parasympathetic control of the heart) was significantly reduced after TCPC as compared to before (paper II). Fontan patients with SND showed significantly elevated SD2 (representing changes in heart rate over 24-hours), somewhat reduced in patients that later required a pacemaker (Paper V). Handheld ECG analysis revealed frequent ventricular extra systoles in one patient and episodes of supraventricular tachycardia in another. Seven Fontan patients showed reduced HRV recorded with the handheld device over a 14-day period (paper III).Conclusions: Overall HRV was reduced in patients with univentricular heart defects during the different surgical stages of Fontan surgery, compared to healthy controls. HRV was reduced in both patients with LT and EC with no significant difference between them. After BDG heart rate was significantly reduced as compared to before. PHF, reflecting the parasympathetic innervation of the heart was reduced after as compared to before TCPC. Pacemaker treatment is commonly needed in patients with Fontan circulation, and SND was the most prevalent indication for implantation. The prevalence of Fontan patients requiring pacemaker treatment was significantly lower in patients with EC. HRV analysis can contribute to management when following-up patients with Fontan circulation.
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