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| 2. |
- Bianchi, Stefano, et al.
(författare)
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Increase of Ventricular Interval During Atrial Fibrillation by Atrioventricular Node Vagal Stimulation : Chronic Clinical Atrioventricular-Nodal Stimulation Download Study
- 2015
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Ingår i: Circulation. - 1941-3149 .- 1941-3084. ; 8:3, s. 562-568
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: -Patients with a high ventricular rate during atrial fibrillation (AF) are at increased risk of receiving inappropriate implantable cardioverter defibrillator (ICD) shocks. The objective was to demonstrate the feasibility of high frequency atrioventricular-nodal stimulation (AVNS) to reduce the ventricular rate during AF to prevent inappropriate ICD shocks.METHODS AND RESULTS: -Patients with a new atrial lead placement as part of a CRT-D implant and a history of paroxysmal or persistent AF were eligible. If proper atrial lead position was confirmed, AVNS software was uploaded to the CRT device, tested and optimized. AVNS was delivered via a right atrial pacing lead positioned in the posterior right atrium. Software allowed initiation of high frequency bursts triggered on rapidly conducted AF. Importantly, the efficacy was evaluated during spontaneous AF episodes between 1 and 6 months after implant. Forty-four patients were enrolled in 4 centers. Successful atrial lead placement occurred in 74%. Median implant time of the AVNS lead was 37 minutes. In 26 (81%) patients, manual AVNS tests increased the ventricular interval by > 25%. Between 1 and 6 months, automatic AVNS activations occurred in 4 patients with rapidly conducted AF, and in 3 patients, AVNS slowed the ventricular rate out of the ICD shock zone. No adverse events were associated with the AVNS software.CONCLUSIONS: -The present study demonstrated the feasibility of implementation of AVNS in a CRT-D system. AVNS increased ventricular interval > 25% in 81% of patients. AVNS did not influence the safety profile of the CRT-D system.
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| 3. |
- Bui, An H., et al.
(författare)
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Relationship Between Early and Late Nonsustained Ventricular Tachycardia and Cardiovascular Death in Patients With Acute Coronary Syndrome in the Platelet Inhibition and Patient Outcomes (PLATO) Trial
- 2016
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Ingår i: Circulation. - 1941-3149 .- 1941-3084. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- Background- Nonsustained ventricular tachycardia (NSVT) is common after acute coronary syndrome (ACS) and a marker of increased risk of arrhythmogenic death. However, the prognostic significance of NSVT when evaluated with other contemporary risk markers and at later time points after ACS remains uncertain. Methods and Results- In the Platelet Inhibition and Patient Outcomes (PLATO) trial, continuous ECGs were performed during the first 7 days after ACS (n=2866) and repeated for another 7 days at day 30 (n=1991). Median follow-up was 1 year. There was a time-varying interaction between NSVT and cardiovascular death such that NSVT was significantly associated with increased risk within the first 30 days after randomization (22/999 [2.2%] versus 16/1825 [0.9%]; adjusted hazard ratio, 2.84; 95% confidence interval, 1.39-5.79; P=0.004) but not after 30 days (28/929 [3.0%] versus 42/1734 [2.4%]; P=0.71). Detection of NSVT during the convalescent phase (n=428/1991; 21.5%) was also associated with an increased risk of cardiovascular death, and was most marked within the first 2 months after detection (1.9% versus 0.3%; adjusted hazard ratio, 5.48; 95% confidence interval, 1.07-28.20; P=0.01), and then decreasing over time such that the relationship was no longer significant by approximate to 5 months after ACS. Conclusions- NSVT occurred frequently during the acute and convalescent phases of ACS. The risk of cardiovascular death associated with NSVT was the greatest during the first 30 days after presentation; however, patients with NSVT detected during the convalescent phase were also at a significantly increased risk of cardiovascular death that persisted for an additional several months after the index event.
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| 4. |
- Cadrin-Tourigny, Julia, et al.
(författare)
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Sudden Cardiac Death Prediction in Arrhythmogenic Right Ventricular Cardiomyopathy : A Multinational Collaboration
- 2021
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Ingår i: Circulation: Arrhythmia and Electrophysiology. - : Lippincott Williams & Wilkins. - 1941-3149 .- 1941-3084. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with ventricular arrhythmias (VA) and sudden cardiac death (SCD). A model was recently developed to predict incident sustained VA in patients with ARVC. However, since this outcome may overestimate the risk for SCD, we aimed to specifically predict life-threatening VA (LTVA) as a closer surrogate for SCD. Methods: We assembled a retrospective cohort of definite ARVC cases from 15 centers in North America and Europe. Association of 8 prespecified clinical predictors with LTVA (SCD, aborted SCD, sustained, or implantable cardioverter-defibrillator treated ventricular tachycardia >250 beats per minute) in follow-up was assessed by Cox regression with backward selection. Candidate variables included age, sex, prior sustained VA (≥30s, hemodynamically unstable, or implantable cardioverter-defibrillator treated ventricular tachycardia; or aborted SCD), syncope, 24-hour premature ventricular complexes count, the number of anterior and inferior leads with T-wave inversion, left and right ventricular ejection fraction. The resulting model was internally validated using bootstrapping. Results: A total of 864 patients with definite ARVC (40±16 years; 53% male) were included. Over 5.75 years (interquartile range, 2.77-10.58) of follow-up, 93 (10.8%) patients experienced LTVA including 15 with SCD/aborted SCD (1.7%). Of the 8 prespecified clinical predictors, only 4 (younger age, male sex, premature ventricular complex count, and number of leads with T-wave inversion) were associated with LTVA. Notably, prior sustained VA did not predict subsequent LTVA (P=0.850). A model including only these 4 predictors had an optimism-corrected C-index of 0.74 (95% CI, 0.69-0.80) and calibration slope of 0.95 (95% CI, 0.94-0.98) indicating minimal over-optimism. Conclusions: LTVA events in patients with ARVC can be predicted by a novel simple prediction model using only 4 clinical predictors. Prior sustained VA and the extent of functional heart disease are not associated with subsequent LTVA events.
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| 5. |
- Clur, Sally-Ann B, et al.
(författare)
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Left Ventricular Isovolumetric Relaxation Time Is Prolonged in Fetal Long-QT Syndrome
- 2018
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Ingår i: Circulation. - : Lippincott Williams & Wilkins. - 1941-3149 .- 1941-3084. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Long-QT syndrome (LQTS), an inherited cardiac repolarization disorder, is an important cause of fetal and neonatal mortality. Detecting LQTS prenatally is challenging. A fetal heart rate (FHR) less than third percentile for gestational age is specific for LQTS, but the sensitivity is only ≈50%. Left ventricular isovolumetric relaxation time (LVIRT) was evaluated as a potential diagnostic marker for fetal LQTS.METHODS AND RESULTS: <0.001), as was the N-LVIRT. The best cutoff to diagnose LQTS was N-LVIRT ≥11.3 at ≤20 weeks (92% sensitivity, 70% specificity). Simultaneous analysis of N-LVIRT and FHR improved the sensitivity and specificity for LQTS (area under the curve=0.96; 95% confidence interval, 0.82-1.00 at 21-30 weeks). N-LVIRT, LV myocardial performance index, and FHR trends differed significantly between LQTS fetuses and controls through gestation.CONCLUSIONS: The LVIRT is prolonged in LQTS fetuses. Findings of a prolonged N-LVIRT and sinus bradycardia can improve the prenatal detection of fetal LQTS.
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| 6. |
- Husser, Daniela, et al.
(författare)
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A Genotype-Dependent Intermediate ECG Phenotype in Patients With Persistent Lone Atrial Fibrillation Genotype ECG-Phenotype Correlation in Atrial Fibrillation
- 2009
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Ingår i: Circulation: Arrhythmia and Electrophysiology. - 1941-3149 .- 1941-3084. ; 2:1, s. 24-28
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Konferensbidrag (refereegranskat)abstract
- Background-Atrial fibrillation (AF) is heterogeneous at the clinical and molecular levels. Association studies have reported that common single-nucleotide polymorphisms in KCNE1 and SCN5A may predispose to AF In this study, we tested the hypothesis that specific AF-associated genotypes confer variation on the appearance of AF assessed by analysis of fibrillatory rate of the atria. Methods and Results-Twenty-six nonrelated patients (21 males, mean age 55 +/- 12 years) with persistent lone AF (median AF duration 5 weeks) not taking class I or III antiarrhythmic drugs were studied. Fibrillatory rate was obtained by spatiotemporal QRST cancellation and time-frequency analysis of the index surface ECG. Genotypes at the AF-associated loci in KCNE1 (S38G) and SCN5A (H558R) were determined by direct DNA sequencing. The atrial fibrillatory rate was 418 +/- 50 fibrillations per minute (range, 336 to 521) in the study cohort. Carriers of the 38 GG KCNE1 genotype (n=13) had significantly lower fibrillatory rates (392 +/- 36 versus 443 +/- 49 fibrillations per minute, P=0.006) compared to those with GS or SS genotype (n=13). Six patients (23%) with fibrillatory rates >450 fibrillations per minute, all had either the GS or SS genotype (chi(2) P=0.008). In contrast, both the heterozygeous and homozygeous SCN5A H558R polymorphism had no effect on fibrillatory rate. There were no significant associations between fibrillatory rate and clinical (age, gender, AF duration, drug treatment) or echocardiographic (left atrial diameter, left ventricular ejection fraction) variables. In multivariable regression analysis, the KCNE1 S38G genotype (SS/GS coded 0, GG coded 1) was the only independent predictor of fibrillatory rate (beta = -0.437, P=0.006) with a SE of the estimate of 44 fibrillations per minute. Conclusions-This study suggests that atrial fibrillatory rate obtained from the surface ECG is at least in part determined by KCNE1 (S38G) genotype, implying that this variant exerts functional effects on atrial electrophysiology. This intermediate ECG phenotype may be useful for elaborating genetic influences on AF mechanisms and identifying subsets of patients for variability in AF susceptibility or response to therapies. (Circ Arrhythmia Electrophysiol. 2009;2:24-28.)
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| 7. |
- Ottesen, Anett H., et al.
(författare)
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Secretoneurin Is an Endogenous Calcium/Calmodulin-Dependent Protein Kinase II Inhibitor That Attenuates Ca2+-Dependent Arrhythmia
- 2019
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Ingår i: Circulation. - : Lippincott Williams & Wilkins. - 1941-3149 .- 1941-3084. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Circulating SN (secretoneurin) concentrations are increased in patients with myocardial dysfunction and predict poor outcome. Because SN inhibits CaMKII delta (Ca2+/calmodulin-dependent protein kinase II delta) activity, we hypothesized that upregulation of SN in patients protects against cardiomyocyte mechanisms of arrhythmia. METHODS: Circulating levels of SN and other biomarkers were assessed in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT; n=8) and in resuscitated patients after ventricular arrhythmia-induced cardiac arrest (n=155). In vivo effects of SN were investigated in CPVT mice (RyR2 [ryanodine receptor 2]-R2474S) using adeno-associated virus-9-induced overexpression. Interactions between SN and CaMKII delta were mapped using pull-down experiments, mutagenesis, ELISA, and structural homology modeling. Ex vivo actions were tested in Langendorff hearts and effects on Ca2+ homeostasis examined by fluorescence (fluo-4) and patchclamp recordings in isolated cardiomyocytes. RESULTS: SN levels were elevated in patients with CPVT and following ventricular arrhythmia-induced cardiac arrest. In contrast to NT-proBNP (N-terminal proB- type natriuretic peptide) and hs-TnT (high-sensitivity troponin T), circulating SN levels declined after resuscitation, as the risk of a new arrhythmia waned. Myocardial pro-SN expression was also increased in CPVT mice, and further adeno-associated virus-9-induced overexpression of SN attenuated arrhythmic induction during stress testing with isoproterenol. Mechanistic studies mapped SN binding to the substrate binding site in the catalytic region of CaMKII delta. Accordingly, SN attenuated isoproterenol induced autophosphorylation of Thr287-CaMKII delta in Langendorff hearts and inhibited CaMKII delta-dependent RyR phosphorylation. In line with CaMKII delta and RyR inhibition, SN treatment decreased Ca2+ spark frequency and dimensions in cardiomyocytes during isoproterenol challenge, and reduced the incidence of Ca2+ waves, delayed afterdepolarizations, and spontaneous action potentials. SN treatment also lowered the incidence of early afterdepolarizations during isoproterenol; an effect paralleled by reduced magnitude of L-type Ca2+ current. CONCLUSIONS: SN production is upregulated in conditions with cardiomyocyte Ca2+ dysregulation and offers compensatory protection against cardiomyocyte mechanisms of arrhythmia, which may underlie its putative use as a biomarker in at-risk patients.
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| 8. |
- Pedrotty, Dawn M., et al.
(författare)
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Three-Dimensional Printed Biopatches With Conductive Ink Facilitate Cardiac Conduction When Applied to Disrupted Myocardium
- 2019
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Ingår i: Circulation: Arrhythmia and Electrophysiology. - 1941-3149 .- 1941-3084. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Reentrant ventricular arrhythmias are a major cause of sudden death in patients with structural heart disease. Current treatments focus on electrically homogenizing regions of scar contributing to ventricular arrhythmia with ablation or altering conductive properties using antiarrhythmic drugs. The high conductivity of carbon nanotubes may allow restoration of conduction in regions where impaired electrical conduction results in functional abnormalities. We propose a new concept for arrhythmia treatment using a stretchable, flexible biopatch with conductive properties to attempt to restore conduction across regions in which activation is disrupted. METHODS: Carbon nanotube patches composed of nanofibrillated cellulose/single-walled carbon nanotube ink 3-dimensionally printed in conductive patterns onto bacterial nanocellulose were developed and evaluated for conductivity, flexibility, and mechanical properties. The patches were applied on 6 canines to epicardium before and after surgical disruption. Electroanatomic mapping was performed on normal epicardium, then repeated over surgically disrupted epicardium, and then finally with the patch applied passively. RESULTS: We developed a 3-dimensional printable carbon nanotube ink complexed on bacterial nanocellulose that was (1) expressable through 3-dimensional printer nozzles, (2) electrically conductive, (3) flexible, and (4) stretchable. Six canines underwent thoracotomy, and, during epicardial ventricular pacing, mapping was performed. We demonstrated disruption of conduction after surgical incision in all 6 canines based on activation mapping. The patch resulted in restored conduction based on mapping and assessment of conduction direction and velocities in all canines. CONCLUSIONS: We have demonstrated 3-dimensional custom-printed electrically conductive carbon nanotube patches can be surgically manipulated to improve cardiac conduction when passively applied to surgically disrupted epicardial myocardium in canines.
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| 9. |
- Sun, Ying, et al.
(författare)
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Sweetened Beverages, Genetic Susceptibility, and Incident Atrial Fibrillation : A Prospective Cohort Study
- 2024
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Ingår i: Circulation. - : American Heart Association. - 1941-3149 .- 1941-3084. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: An association between sweetened beverages and several cardiometabolic diseases has been reported, but their association with atrial fibrillation (AF) is unclear. We aimed to investigate the associations between consumption of sugar-sweetened beverages (SSB), artificially sweetened beverages (ASB), and pure fruit juice (PJ) and risk of consumption with AF risk and further evaluate whether genetic susceptibility modifies these associations.METHODS:A total of 201 856 participants who were free of baseline AF, had genetic data available, and completed a 24-hour diet questionnaire were included. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).RESULTS: During a median follow-up of 9.9 years, 9362 incident AF cases were documented. Compared with nonconsumers, individuals who consumed >2 L/wk of SSB or ASB had an increased risk of AF (HR, 1.10 [95% CI, 1.01-1.20] and HR, 1.20 [95% CI, 1.10-1.31]) in the multivariable-adjusted model. A negative association was observed between the consumption of ≤ 1 L/wk of PJ and the risk of AF (HR, 0.92 [95% CI, 0.87-0.97]). The highest HRs (95% CIs) of AF were observed for participants at high genetic risk who consumed >2 L/wk of ASB (HR, 3.51 [95% CI, 2.94-4.19]), and the lowest HR were observed for those at low genetic risk who consumed ≤ 1 L/wk of PJ (HR, 0.77 [95% CI, 0.65-0.92]). No significant interactions were observed between the consumption of SSB, ASB, or PJ and genetic predisposition to AF.CONCLUSIONS: Consumption of SSB and ASB at >2 L/wk was associated with an increased risk for AF. PJ consumption ≤ 1 L/wk was associated with a modestly lower risk for AF. The association between sweetened beverages and AF risk persisted after adjustment for genetic susceptibility to AF. This study does not demonstrate that consumption of SSB and ASB alters AF risk but rather that the consumption of SSB and ASB may predict AF risk beyond traditional risk factors.
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