| 11. |
- Alenius Dahlqvist, Jenny, 1972-, et al.
(författare)
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Changes in Heart Rate and Heart Rate Variability During Surgical Stages to Completed Fontan Circulation
- 2021
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Ingår i: Pediatric Cardiology. - : Springer Science and Business Media LLC. - 0172-0643 .- 1432-1971. ; 42:5, s. 1162-1169
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Tidskriftsartikel (refereegranskat)abstract
- Arrhythmia is related to heart rate variability (HRV), which reflects the autonomic nervous regulation of the heart. We hypothesized that autonomic nervous ganglia, located at the junction of the superior vena cava's entrance to the heart, may be affected during the bidirectional Glenn procedure (BDG), resulting in reduced HRV. We aimed to investigate changes in heart rate and HRV in a cohort of children with univentricular heart defects, undergoing stepwise surgery towards total cavopulmonary connection (TCPC), and compare these results with healthy controls. Twenty four hours Holter-ECG recordings were obtained before BDG (n = 47), after BDG (n = 47), and after total cavopulmonary connection (TCPC) (n = 45) in patients and in 38 healthy controls. HRV was analyzed by spectral and Poincare methods. Age-related z scores were calculated and compared using linear mixed effects modeling. Total HRV was significantly lower in patients before BDG when compared to healthy controls. The mean heart rate was significantly reduced in patients after BDG compared to before BDG. Compared to healthy controls, patients operated with BDG had significantly reduced heart rate and reduced total HRV. Patients with TCPC showed reduced heart rate and HRV compared with healthy controls. In patients after TCPC, total HRV was decreased compared to before TCPC. Heart rate was reduced after BDG procedure, and further reductions of HRV were seen post-TCPC. Our results indicate that autonomic regulation of cardiac rhythm is affected both after BDG and again after TCPC. This may be reflected as, and contribute to, postoperative arrhythmic events.
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| 12. |
- Alenius Dahlqvist, Jenny, et al.
(författare)
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Handheld ECG in analysis of arrhythmia and heart rate variability in children with Fontan circulation
- 2014
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Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 47:3, s. 374-382
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Tidskriftsartikel (refereegranskat)abstract
- Background: Our aim was to evaluate the intermittent use of a handheld ECG system for detecting silent arrhythmias and cardiac autonomic dysfunction in children with univentricular hearts. Methods: Twenty-seven patients performed intermittent ECG recordings with handheld devices during a 14-day period. A manual arrhythmia analysis was performed. We analyzed heart rate variability (HRV) using scatter plots of all interbeat intervals (Poincare plots) from the total observation period. Reference values of HRV indices were determined from Holter-ECGs in 41 healthy children. Results: One asymptomatic patient had frequent ventricular extra systoles. Another patient had episodes with supraventricular tachycardia (with concomitant palpitations). Seven patients showed reduced HRV. Conclusions: Asymptomatic arrhythmia was detected in one patient. The proposed method for pooling of intermittent recordings from handheld or similar devices may be used for detection of arrhythmias as well as for cardiac autonomic dysfunction.
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| 13. |
- 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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| 14. |
- Alenius Dahlqvist, Jenny, et al.
(författare)
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Heart rate variability in children with fontan circulation : lateral tunnel and extracardiac conduit
- 2012
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Ingår i: Pediatric Cardiology. - New York : Springer-Verlag New York. - 0172-0643 .- 1432-1971. ; 33:2, s. 307-315
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Tidskriftsartikel (refereegranskat)abstract
- The technique in Fontan surgery has developed from the lateral tunnel (LT) toward the extracardiac conduit (EC) used to reduce long-term complications such as atrial arrhythmia and sinus node dysfunction. Heart rate variability (HRV) examines cardiac nervous activity controlling the sinus node. This study aimed to investigate HRV in a cohort of children with univentricular hearts, focusing on the relation between HRV and surgical procedure. For 112 children with Fontan circulation, HRV was analyzed using power spectral analysis. Spectral power was determined in three regions: very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) regions. Patients were compared with 66 healthy controls subject. Patients with LT were compared with patients who had EC. The children with Fontan circulation showed a significantly reduced HRV including total power (P < 0.0001), VLF (P < 0.0001), LF (P < 0.0001), and HF (P = 0.001) compared with the control subjects. The LT and EC patients did not differ significantly. Reduced HRV was found in both the LT and EC patients. In terms of HRV reduction, EC was not superior to LT.
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| 15. |
- Alenius Dahlqvist, Jenny, 1972-, et al.
(författare)
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Pacemaker treatment after Fontan surgery-A Swedish national study
- 2019
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Ingår i: Congenital Heart Disease. - : Computers, Materials and Continua (Tech Science Press). - 1747-079X .- 1747-0803. ; 14:4, s. 582-589
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveFontan surgery is performed in children with univentricular heart defects. Previous data regarding permanent pacemaker implantation frequency and indications in Fontan patients are limited and conflicting. We examined the prevalence of and risk factors for pacemaker treatment in a consecutive national cohort of patients after Fontan surgery in Sweden. MethodsWe retrospectively reviewed all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n=599). ResultsAfter a mean follow-up of 12.2years, 13% (78/599) of the patients with Fontan circulation had received pacemakers. Patients operated with the extracardiac conduit (EC) type of total cavopulmonary connection had a significantly lower prevalence of pacemaker implantation (6%) than patients with lateral tunnel (LT; 17%). Mortality did not differ between patients with (8%) and without pacemaker (5%). The most common pacemaker indication was sinus node dysfunction (SND) (64%). Pacemaker implantation due to SND was less common among patients with EC. Pacemaker implantation was significantly more common in patients with mitral atresia (MA; 44%), double outlet right ventricle (DORV; 24%) and double inlet left ventricle (DILV; 20%). In contrast, patients with pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome were significantly less likely to receive a pacemaker (3% and 6%, respectively). ConclusionsThirteen percent of Fontan patients received a permanent pacemaker, most frequently due to SND. EC was associated with a significantly lower prevalence of pacemaker than LT. Permanent pacemaker was more common in patients with MA, DORV, and DILV.
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| 16. |
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| 17. |
- Alenius Dahlqvist, Jenny, 1972-, et al.
(författare)
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Sinus node dysfunction in patients with Fontan circulation: could heart rate variability be a predictor for pacemaker implantation?
- 2019
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Ingår i: Pediatric Cardiology. - : Springer Science and Business Media LLC. - 0172-0643 .- 1432-1971. ; 40:4, s. 685-693
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Tidskriftsartikel (refereegranskat)abstract
- Sinus node dysfunction (SND) causes significant morbidity in patients after Fontan surgery. Heart rate variability (HRV) reflects the autonomic regulation of the heart, and changes in HRV have been associated with SND in adults. We aimed to study whether changes in HRV could be detected in 24-h electrocardiographic (ECG) recordings in Fontan patients with SND. We compared HRV results from two patient groups; patients with Fontan circulation who later required a pacemaker due to severe SND (n = 12) and patients with Fontan circulation and SND, without indication for pacemaker treatment (n = 11), with two control groups; patients with Fontan circulation without SND (n = 90) and healthy controls (n = 66). The Poincare plot index SD2 (representing changes in heart rate over 24-h) and the very low-frequency (VLF) HRV component were significantly higher in both SND groups, both compared with healthy controls and patients with Fontan circulation without SND. In SND patients with pacemakers, SD2 and VLF were slightly reduced compared to SND patients without pacemaker (p = 0.06). In conclusion, in Fontan patients with SND the HRV is significantly higher compared to healthy controls and Fontan patients without SND. However, in patients with severe SND requiring pacemaker, SD2 and VLF tended to be lower than in patients with SND without pacemaker, which could indicate a reduced diurnal HRV in addition to the severe bradycardia. This is a small study, but our results indicate that HRV analysis might be a useful method in the follow-up of Fontan patients regarding development of SND.
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| 18. |
- Almby, Kristina E., et al.
(författare)
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Effects of Gastric Bypass Surgery on the Brain : Simultaneous Assessment of Glucose Uptake, Blood Flow, Neural Activity, and Cognitive Function During Normo- and Hypoglycemia
- 2021
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 70:6, s. 1265-1277
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Tidskriftsartikel (refereegranskat)abstract
- While Roux-en-Y gastric bypass (RYGB) surgery in obese individuals typically improves glycemic control and prevents diabetes, it also frequently causes asymptomatic hypoglycemia. Previous work showed attenuated counterregulatory responses following RYGB. The underlying mechanisms as well as the clinical consequences are unclear. In this study, 11 subjects without diabetes with severe obesity were investigated pre- and post-RYGB during hyperinsulinemic normo-hypoglycemic clamps. Assessments were made of hormones, cognitive function, cerebral blood flow by arterial spin labeling, brain glucose metabolism by F-18-fluorodeoxyglucose (FDG) positron emission tomography, and activation of brain networks by functional MRI. Post- versus presurgery, we found a general increase of cerebral blood flow but a decrease of total brain FDG uptake during normoglycemia. During hypoglycemia, there was a marked increase in total brain FDG uptake, and this was similar for post- and presurgery, whereas hypothalamic FDG uptake was reduced during hypoglycemia. During hypoglycemia, attenuated responses of counterregulatory hormones and improvements in cognitive function were seen postsurgery. In early hypoglycemia, there was increased activation post- versus presurgery of neural networks in brain regions implicated in glucose regulation, such as the thalamus and hypothalamus. The results suggest adaptive responses of the brain that contribute to lowering of glycemia following RYGB, and the underlying mechanisms should be further elucidated.
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| 19. |
- Almby, Kristina E., et al.
(författare)
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Effects of GLP-1 on counter-regulatory responses during hypoglycemia after GBP surgery
- 2019
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Ingår i: European Journal of Endocrinology. - : Bioscientifica. - 0804-4643 .- 1479-683X. ; 181:2, s. 161-171
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of the study was to explore the role of GLP-1 receptor activation on the counter-regulation and symptoms of hypoglycemia in subjects who have undergone gastric bypass surgery (GBP).Design: Experimental hyperinsulinemic–hypoglycemic clamp study.Methods: Twelve post-GBP subjects participated in a randomized cross-over study with two hyperinsulinemic, hypoglycemic clamps (glucose nadir 2.7 mmol/L) performed on separate days with concomitant infusions of the GLP-1 analog exenatide or with saline, respectively. Continuous measurements of metabolites and counter-regulatory hormones as well as assessments of heart rate variability and symptoms of hypoglycemia were performed throughout the clamps.Results: No effect of GLP-1 receptor activation on counter-regulatory hormones (glucagon, catecholamines, cortisol, GH) or glucose infusion rate was seen, but we found indications of a downregulation of the sympathetic relative to the parasympathetic nerve activity, as reflected in heart rate variability. No significant differences in symptom of hypoglycemia were observed.Conclusions/interpretation: Short-term exposure to a GLP-1 receptor agonist does not seem to impact the counter-regulatory hormonal and metabolic responses in post-GBP subjects during hypoglycemic conditions, suggesting that the improvement in symptomatic hypoglycemia post-GBP seen following treatment with GLP-1 receptor agonists may be mediated by mechanism not directly involved in counter-regulation.
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| 20. |
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