AimsSudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined... Show moreAimsSudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined manually, but vendor-provided automatic results from ECG recorders are convenient. Agreement between manual and automatic assessments is unclear for populations with aberrant QTc. We aimed to systematically assess pairwise agreement of automatic and manual QT-intervals and QTc.Methods and resultsA multi-centre cohort enriching aberrant QTc comprised ECGs of healthy controls and long-QT syndrome (LQTS) patients. Manual QT-intervals and QTc were determined by the tangent and threshold methods and compared to automatically generated, vendor-provided values. We assessed agreement globally by intra-class correlation coefficients and pairwise by Bland–Altman analyses and 95% limits of agreement (LoA). Further, manual results were compared to a novel automatic QT-interval algorithm. ECGs of 1263 participants (720 LQTS patients; 543 controls) were available [median age 34 (inter-quartile range 35) years, 55% women]. Comparing cohort means, automatic and manual QT-intervals and QTc were similar. However, pairwise Bland–Altman-based agreement was highly discrepant. For QT-interval, LoAs spanned 95 (tangent) and 92 ms (threshold), respectively. For QTc, the spread was 108 and 105 ms, respectively. LQTS patients exhibited more pronounced differences. For automatic QTc results from 440–540 ms (tangent) and 430–530 ms (threshold), misassessment risk was highest. Novel automatic QT-interval algorithms may narrow this range.ConclusionPairwise vendor-provided automatic and manual QT-interval and QTc results can be highly discrepant. Novel automatic algorithms may improve agreement. Within the above ranges, automatic QT-interval and QTc results require manual confirmation, particularly if T-wave morphology is challenging. Show less
Peltenburg, P.J.; Pultoo, S.N.J.; Tobert, K.E.; Bos, J.M.; Lieve, K.V.V.; Tanck, M.; ... ; Werf, C. van der 2023
Aims In catecholaminergic polymorphic ventricular tachycardia (CPVT), the exercise-stress test (EST) is the cornerstone for the diagnosis, risk stratification, and assessment of therapeutic... Show moreAims In catecholaminergic polymorphic ventricular tachycardia (CPVT), the exercise-stress test (EST) is the cornerstone for the diagnosis, risk stratification, and assessment of therapeutic efficacy, but its repeatability is unknown. We aimed to test the repeatability of ventricular arrhythmia characteristics on the EST in patients with CPVT. Methods and results EST-pairs (ESTs performed within 18 months between 2005 and 2021, on the same protocol, and without or on the exact same treatment) of patients with RYR2-mediated CPVT from two specialized centres were included. The primary endpoint was the repeatability of the maximum ventricular arrhythmia score [VAS: 0 for the absence of premature ventricular contractions (PVCs); 1 for isolated PVCs; 2 for bigeminal PVCs; 3 for couplets; and 4 for non-sustained ventricular tachycardia]. Secondary outcomes were the repeatability of the heart rate at the first PVC and the Delta VAS (the absolute difference in VAS between the EST-pairs). A total of 104 patients with 349 EST-pairs were included. The median duration between ESTs was 343 (interquartile range, 189-378) days. Sixty (17.2%) EST-pairs were off therapy. The repeatability of the VAS was moderate {Krippendorf alpha, 0.56 [95% confidence interval (CI), 0.48-0.64]}, and the repeatability of the heart rate at the first PVC was substantial [intra-class correlation coefficient, 0.78 (95% CI, 0.71-0.84)]. The use of medication was associated with a higher odds for a Delta VAS > 1 (odds ratio = 3.52; 95% CI, 2.46-4.57; P = 0.020). Conclusion The repeatability of ventricular arrhythmia characteristics was moderate to substantial. This underlines the need for multiple ESTs in CPVT patients and CPVT suspicious patients and it provides the framework for assessing the therapeutic efficacy of novel CPVT therapies. Show less
Background: Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for recurrent arrhythmic events. beta-Blockers decrease this risk, but studies... Show moreBackground: Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for recurrent arrhythmic events. beta-Blockers decrease this risk, but studies comparing individual beta-blockers in sizeable cohorts are lacking. We aimed to assess the association between risk for arrhythmic events and type of beta-blocker in a large cohort of symptomatic children with CPVT. Methods: From 2 international registries of patients with CPVT, RYR2 variant-carrying symptomatic children (defined as syncope or sudden cardiac arrest before beta-blocker initiation and age at start of beta-blocker therapy <18 years), treated with a beta-blocker were included. Cox regression analyses with time-dependent covariates for beta-blockers and potential confounders were used to assess the hazard ratio (HR). The primary outcome was the first occurrence of sudden cardiac death, sudden cardiac arrest, appropriate implantable cardioverter-defibrillator shock, or syncope. The secondary outcome was the first occurrence of any of the primary outcomes except syncope. Results: We included 329 patients (median age at diagnosis, 12 [interquartile range, 7-15] years, 35% females). Ninety-nine (30.1%) patients experienced the primary outcome and 74 (22.5%) experienced the secondary outcome during a median follow-up of 6.7 (interquartile range, 2.8-12.5) years. Two-hundred sixteen patients (66.0%) used a nonselective beta-blocker (predominantly nadolol [n=140] or propranolol [n=70]) and 111 (33.7%) used a beta 1-selective beta-blocker (predominantly atenolol [n=51], metoprolol [n=33], or bisoprolol [n=19]) as initial beta-blocker. Baseline characteristics did not differ. The HRs for both the primary and secondary outcomes were higher for beta 1-selective compared with nonselective beta-blockers (HR, 2.04 [95% CI, 1.31-3.17]; and HR, 1.99 [95% CI, 1.20-3.30], respectively). When assessed separately, the HR for the primary outcome was higher for atenolol (HR, 2.68 [95% CI, 1.44-4.99]), bisoprolol (HR, 3.24 [95% CI, 1.47-7.18]), and metoprolol (HR, 2.18 [95% CI, 1.08-4.40]) compared with nadolol, but did not differ from propranolol. The HR of the secondary outcome was only higher in atenolol compared with nadolol (HR, 2.68 [95% CI, 1.30-5.55]). Conclusions: beta 1-selective beta-blockers were associated with a significantly higher risk for arrhythmic events in symptomatic children with CPVT compared with nonselective beta-blockers, specifically nadolol. Nadolol, or propranolol if nadolol is unavailable, should be the preferred beta-blocker for treating symptomatic children with CPVT. Show less
Background: Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for recurrent arrhythmic events. beta-Blockers decrease this risk, but studies... Show moreBackground: Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for recurrent arrhythmic events. beta-Blockers decrease this risk, but studies comparing individual beta-blockers in sizeable cohorts are lacking. We aimed to assess the association between risk for arrhythmic events and type of beta-blocker in a large cohort of symptomatic children with CPVT. Methods: From 2 international registries of patients with CPVT, RYR2 variant-carrying symptomatic children (defined as syncope or sudden cardiac arrest before beta-blocker initiation and age at start of beta-blocker therapy <18 years), treated with a beta-blocker were included. Cox regression analyses with time-dependent covariates for beta-blockers and potential confounders were used to assess the hazard ratio (HR). The primary outcome was the first occurrence of sudden cardiac death, sudden cardiac arrest, appropriate implantable cardioverter-defibrillator shock, or syncope. The secondary outcome was the first occurrence of any of the primary outcomes except syncope. Results: We included 329 patients (median age at diagnosis, 12 [interquartile range, 7-15] years, 35% females). Ninety-nine (30.1%) patients experienced the primary outcome and 74 (22.5%) experienced the secondary outcome during a median follow-up of 6.7 (interquartile range, 2.8-12.5) years. Two-hundred sixteen patients (66.0%) used a nonselective beta-blocker (predominantly nadolol [n=140] or propranolol [n=70]) and 111 (33.7%) used a beta 1-selective beta-blocker (predominantly atenolol [n=51], metoprolol [n=33], or bisoprolol [n=19]) as initial beta-blocker. Baseline characteristics did not differ. The HRs for both the primary and secondary outcomes were higher for beta 1-selective compared with nonselective beta-blockers (HR, 2.04 [95% CI, 1.31-3.17]; and HR, 1.99 [95% CI, 1.20-3.30], respectively). When assessed separately, the HR for the primary outcome was higher for atenolol (HR, 2.68 [95% CI, 1.44-4.99]), bisoprolol (HR, 3.24 [95% CI, 1.47-7.18]), and metoprolol (HR, 2.18 [95% CI, 1.08-4.40]) compared with nadolol, but did not differ from propranolol. The HR of the secondary outcome was only higher in atenolol compared with nadolol (HR, 2.68 [95% CI, 1.30-5.55]). Conclusions: beta 1-selective beta-blockers were associated with a significantly higher risk for arrhythmic events in symptomatic children with CPVT compared with nonselective beta-blockers, specifically nadolol. Nadolol, or propranolol if nadolol is unavailable, should be the preferred beta-blocker for treating symptomatic children with CPVT. Show less
Lieve, K.V.V.; Verhagen, J.M.A.; Wei, J.H.; Bos, J.M.; Werf, C. van der; Noguer, F.R.I.; ... ; Wilde, A.A.M. 2019
