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Online supplement to "Regional beat-to-beat variability of repolarization increases during ischemia and predicts imminent arrhythmias in a pig model of myocardial infarction"
No full textOnline supplement to "Regional beat-to-beat variability of repolarization increases during ischemia and predicts imminent arrhythmias in a pig model of myocardial infarction" submitted to American Journal of Physiology-Heart and Circulatory Physiology.
Abstract
Background
Ventricular arrhythmia (VT/VF) can complicate acute myocardial ischemia (AMI). Regional instability of repolarization during AMI contributes to the substrate for VT/VF. Beat-to-beat variability of repolarization (BVR), a measure of repolarization lability increases during AMI. We hypothesized that its surge precedes VT/VF. We studied the spatial and temporal changes in BVR in relation to VT/VF during AMI.
Methods
In 24 pigs BVR was quantified on 12-lead electrocardiogram (ECG) recorded at a sampling rate of 1kHz. AMI was induced in 16 pigs by percutaneous coronary artery occlusion (MI), while 8 underwent sham-operation (Sham). Changes in BVR were assessed at 5-minutes after occlusion, 5- and 1-minute pre-VF in animals that developed VF and matched time points in pigs without VF. Serum troponin and ST deviation were measured. After 1-month, magnetic resonance imaging and VT induction by programmed electrical stimulation were performed.
Results
During AMI, BVR increased significantly in inferior-lateral leads correlating with ST-deviation and troponin increase. BVR was maximal 1-minute pre-VF (3.78±1.36 vs 5-minutes pre-VF: 1.67±1.56, P < 0.0001). After 1-month, BVR was higher in MI than sham and correlated with the infarct size (1.43±0.50, vs 0.57±0.30, P = 0.009). VT was inducible in all MI animals and the ease-of-induction correlated with BVR.
Conclusion
BVR increased during AMI and temporal BVR changes predicted imminent VT/VF supporting a possible role in monitoring and early-warning systems. BVR correlated to arrhythmia vulnerability suggesting utility in risk stratification post-AMI.
This supplement contains additional analysis and figures not included in the original publication
Role of the proportion of sudden cardiac death tomortality for clinical effectiveness of primary prevention ICDs
No full textsponsorship: This work was supported by the European Community's Seventh Framework Programme FP7/2007-2013 (grant agreement no. HEALTH F2-2009-602299) for 5 years (starting 1 October 2013). (European Community|HEALTH F2-2009-602299, British Heart Foundation|NH/16/2/32499)status: Publishe
Feasibility of Neurohumoral Blocker Withdrawal in Patients Optimally Responding to Cardiac Resynchronization Therapy: An Open-label, Double Randomized Controlled Pilot Trial
No full textDifferential presentation of atrioventricular nodal re-entrant tachycardia in athletes and non-athletes
No full textAIMS: Prolonged participation in exercise results in structural and electrical cardiac remodelling. The development of an athlete's heart is recognized as a risk factor for atrial arrhythmias. This study aims to evaluate the impact of athlete heart remodelling on the presentation of atrioventricular nodal re-entrant tachycardia (AVNRT). METHODS AND RESULTS: A retrospective analysis of an ablation database selecting all patients with an electrophysiologically confirmed diagnosis of AVNRT. Athletes (individuals participating in moderate to intensive sports for ≥3 h per week having done so for ≥5 years) were compared with healthy non-athletes. Atrioventricular nodal re-entrant tachycardia subforms were classified according the methods described by Katritsis and Josephson in 2013 and by Heidbuchel and Jackman in 2014. A total of 504 AVNRT patients were fully characterized, of whom 85 (17%) were athletes. Almost half of the athletes presented with atypical forms of AVNRT, where in non-athletes this frequency was about 20%. There was no difference in acute procedural success among the two groups, but the procedures in athletes were more complex, as reflected by an almost two-fold increase in the use of a long sheath to reach the slow pathway ablation area and a higher recurrence rate in athletes (10% vs. 4%). CONCLUSION: Athletes present more frequently with atypical subforms of AVNRT. This is possibly related to cardiac remodelling with dilatation of the cardiac cavities leading to changed conduction properties in the septal area. Ablation outcome is equally safe in athletes as in non-athletes with similar acute success rates. Athletes experience a higher longer-term recurrence rate.status: Publishe
Inequality between women and men in ICD implantation
No full textBACKGROUND: The impact of sex on ICD implantation practice and survival remain a topic of controversy. To assess sex-specific differences in ICD implantation practice we compared clinical characteristics and survival in women and men. METHODS: From a nationwide registry, all new ICD implantations performed between 01/02/2010 and 31/01/2019 in Belgian patients were analyzed retrospectively. Baseline characteristics and survival rates were compared between sexes. To identify predictors of mortality, multivariable Cox regression was performed. RESULTS: Only 3096 (20.9%) of 14,787 ICD implantations were performed in women. Within each type of underlying cardiomyopathy, the proportion women were lower than men. The main indication in men was ischemic vs dilated cardiomyopathy in women. Women were overall younger (59.1 ± 15.1 vs 62.6 ± 13.1 years; p 150 ms (29.4% vs 24.3%; p < 0.001), consistent with a higher use of CRT-D devices (31.7% vs 25.1%; p < 0.001). Women had more complications, reflected by the need to more re-interventions within 1 year (4.3% vs 2.7%, p < 0.001). After correction for covariates, sex-category was not a significant predictor of mortality (p = 0.055). CONCLUSION: There is a significant sex-disparity in ICD implantation rates, not fully explained by epidemiological differences in the prevalence of cardiomyopathies, which could imply an undertreatment of women. Women differ from men in baseline characteristics at implantation suggesting a selection bias. Further research is necessary to evaluate if women receive equal sudden cardiac death prevention.sponsorship: The authors want to thank the RIZIV/INAMI and the full board of the Belgian Heart Rhythm Association for their support of this project. (RIZIV/INAMI, full board of the Belgian Heart Rhythm Association)status: Publishe
Implantable cardiac defibrillators in octogenarians
No full textOBJECTIVE: Implantable cardiac defibrillators (ICD) implantation in the very elderly remains controversial. We aimed to describe the experience and outcome of patients over 80 years old implanted with an ICD in Belgium. METHODS: Data were extracted from the national QERMID-ICD registry. All implantations performed in octogenarians between February 2010 and March 2019 were analysed. Data on baseline patient characteristics, type of prevention, device configuration and all-cause mortality were available. To determine predictors of mortality, multivariable Cox proportional hazard regression modelling was performed. RESULTS: Nationwide, 704 primo ICD implantations were performed in octogenarians (median age 82, IQR 81-83 years; 83% male and 45% secondary prevention). During a mean follow-up of 3.1 ± 2.3 years, 249 (35%) patients died, of which 76 (11%) within the first year after implantation. In multivariable Cox regression analysis age (HR = 1.15, P = 0.004), oncological history (HR = 2.43, P = 0.027) and secondary prevention (HR = 2.23, P = 0.001) were independently associated with 1-year mortality. A better preserved left ventricular ejection fraction (LVEF) was associated with a better outcome (HR = 0.97, P = 0.002). Regarding overall mortality multivariable analysis withheld age, history of atrial fibrillation, centre volume and oncological history as significant predictors. Higher LVEF was again protective (HR = 0.99, P = 0.008). CONCLUSIONS: Primary ICD implantation in octogenarians is not often performed in Belgium. Among this population, 11% died within the first year after ICD implantation. Advanced age, oncological history, secondary prevention and a lower LVEF were associated with an increased one-year mortality. Age, low LVEF, atrial fibrillation, centre volume and oncological history were indicative of higher overall mortality.status: Publishe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Changes in Implantation Patterns and Therapy Rates of Implantable Cardioverter-Defibrillators Over Time in Ischemic and Dilated Cardiomyopathy Patients
No full textClinical guidelines on implantable cardioverter-defibrillator (ICD) therapy changed significantly in the last decades with potential inherent effects on therapy efficacy. We aimed to study therapy rates in time and the association between therapies and mortality.sponsorship: This work was supported by the European Community's Seventh Framework Program FP7: EU-CERT-ICD (Grant Agreement No. HEALTH-F2-2013-602299). (European Community's Seventh Framework Program FP7: EU-CERT-ICD|HEALTH-F2-2013-602299)status: Publishe
Regional differences in survival after ICD implantation
No full textBackground: The implantable cardioverter-defibrillator (ICD) remains the cornerstone in the prevention of sudden cardiac death. Cost-effectiveness depends on survival after implantation. In Belgium there are unexplained major differences in 3-year mortality after ICD implantation. Centre volume and socioeconomic differences might affect survival after implantation. Methods: In total, 9647 patients underwent a first ICD implantation between February 2010 and 2016 in Belgium and were retrospectively compared for demographics, 30-day and 3-year mortality. Chi-squared and Mann-Whitney U tests were used to determine differences across centre volume. Results: Low-volume centres treated patients with different characteristics and implanted more patients with ischaemic heart disease (50.2 vs 47.9%, p = 0.002), in primary prevention (66.7 vs 62.0%, p < 0.001) and with overall more comorbidities. Kaplan-Meier survival analysis showed a significant higher 3-year mortality in low-volume centres (16.3 vs 11.4%, p < 0.001). After adjudication with a multivariable Cox model, centre volume remained an independent predictor of 3-year mortality (low volume HR 1.300 [95% CI 1.124-1.504]. However similar 30-day mortality (0.6% in low vs 0.5% in high volume centres, p = 0.393) suggests that implantation related determinants alone are insufficient to explain the long-term survival difference. Socioeconomic factors like regional average income (wealth) and overall survival (health) also were associated with the survival difference between low-and high-volume centres. Conclusions: There exist large survival differences after ICD implantation between implanting centres in Belgium that cannot only be explained by a volume-outcome effect. Centres size and characteristics are inhomogeneous and vary according to different socioeconomic variables. Some of these variables are also significantly associated with survival and warrant further investigation
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