Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation grant to dr. P.G. Postema, MD PhD Background Stereotactic arrhythmia radiotherapy (STAR) has evolved as promising bail-out treatment in patients with therapy-refractory ventricular tachycardia (VT). The mechanism of action of STAR in preventing VT has yet to be elucidated and further understanding could improve this technique in the future. Preclinical studies reported an increase in conduction velocity and consequently a decrease in conduction intervals on electrocardiograms (ECGs) within the first months after STAR, although this has not yet been evaluated in detail in prospective studies. Purpose To evaluate the early effects of STAR on ventricular conduction as electrocardiographically assessed. Methods The STARNL-1 was a prospective, monocenter, pre-post intervention study. Six patients with VT recurrences despite optimal doses of anti-arrhythmic drugs (AADs), after one or more unsuccessful catheter ablation(s), were considered therapy-refractory. Patients were treated with a single fraction of 25 Gy. ECG evaluation included ECGs recorded pre-therapy, at 3 hours, 12 hours, 24 hours, 1 month, and 3 months after therapy. For an additional assessment, only patients in whom AADs remained unchanged up to 3 months after STAR were selected. QRS duration and QT interval were measured by a single observer using digital callipers. Four consecutive beats were used to measure and calculate a mean QRS duration and QT interval per ECG. This study was not powered to evaluate for significant changes in ECG parameters. Results All patients were male, all suffered from ischaemic cardiomyopathy, and all completed 3-month follow-up. One patient presented with atrial fibrillation on ECG recordings, and three patients with a paced rhythm. Four patients (66.7%) were selected for an additional assessment, two patients (P1 and P2, 33.3%) underwent changes in AAD dose and were therefore excluded. Figure 1 shows a line graph of the QRS duration and QTc interval of all STARNL-1 patients during 3-month follow-up. As can be appreciated from Figure 1, QRS duration and QTc interval did not appear to be altered between pre-therapy and 3 months after therapy. When excluding P1 and P2, QRS duration and QTc interval also did not appear to be altered between pre-therapy and 3 months after therapy. Conclusion(s) STAR for VT does not appear to alter QRS duration and QTc interval within the first 3 months after therapy.
Introduction The Apple Watch (AW) is one of the first commercially available wearable with built-in electrocardiogram (ECG) electrodes to perform a single-lead ECG to detect atrial fibrillation (AF). The AW ECG application showed to have a high rate of unclassifiable notifications. The interpretation of the single-lead ECG by a physician can possibly reduce the total of unclassifiable notifications and contribute to the overall accuracy to detect AF. Methods This was a prospective, non-randomized, single center observational study to evaluate the accuracy and interrater agreement of the single-lead ECG of the AW. Patients scheduled for cardioversion for atrial fibrillation were asked for participation. The AW series 6 was used with WatchiOS 7.2 or 7.3 and ECG algorithm version 2.0. A single-lead ECG was obtained pre-conversion and, when cardioversion was successful, post-conversion. All single-lead ECGs and 12-lead ECGs were adjudicated by two physicians, agreement was reached by consensus. The AW single-lead ECG notification was compared to the physicians “gold-standard” interpretation of the 12-lead ECG. Sensitivity and specificity of the AW single-lead ECG and Kappa coefficient were calculated. Results In total, 74 patients were included. Mean age was 67.1±12.3 years and 20.3% were female. In total 65 AF and 64 sinus rhythm (SR) single-lead ECG measurements were obtained. Of these measurements, 27.9% (36/129) showed an unclassifiable notification. The AW ECG notification showed a sensitivity of 93.5% to detect AF and a specificity of 100% to detect SR (K= 0.94). After adjudication of the unclassifiable notifications by two independent physicians 1.6% (2/129) of the measurements remained unclassifiable. When including the by the physicians adjudicated unclassifiable recordings the sensitivity to diagnose AF was 89.2% and the specificity to detect SR was 93.8% (K=0.83). The adjudication of all single-lead ECGs by the two physicians showed a sensitivity of 90.6% to detect AF and specificity of 95.2% to detect SR (K= 0.83) (Table 1). All SR and AF notification by the AW were similarly adjudicated by the two physicians. The kappa coefficient for interrater agreement between both physicians was 0.69 for all single-lead ECGs and 0.58 for unclassifiable notifications specific. Conclusion Unclassifiable notifications of the AW can be reduced by physicians interpretation of the single-lead ECG, however the interrater agreement is only moderate. The physicians interpretation of the single-lead ECGs did not increase the accuracy to detect AF and the clinical relevance of the single-lead ECG, in addition to the AW notification, should therefore be questioned. Funding Acknowledgement Type of funding sources: None.
Introduction The Apple Watch (AW) is one of the first commercially available wearable with built-in electrocardiogram (ECG) electrodes to perform a single-lead ECG to detect atrial fibrillation (AF). The AW ECG application showed to have a high rate of unclassifiable notifications. The interpretation of the single-lead ECG by a physician can possibly reduce the total of unclassifiable notifications and contribute to the overall accuracy to detect AF. Methods This was a prospective, non-randomized, single center observational study to evaluate the accuracy and interrater agreement of the single-lead ECG of the AW. Patients scheduled for cardioversion for atrial fibrillation were asked for participation. The AW series 6 was used with WatchiOS 7.2 or 7.3 and ECG algorithm version 2.0. A single-lead ECG was obtained pre-conversion and, when cardioversion was successful, post-conversion. All single-lead ECGs and 12-lead ECGs were adjudicated by two physicians, agreement was reached by consensus. The AW single-lead ECG notification was compared to the physicians “gold-standard” interpretation of the 12-lead ECG. Sensitivity and specificity of the AW single-lead ECG and Kappa coefficient were calculated. Results In total, 74 patients were included. Mean age was 67.1±12.3 years and 20.3% were female. In total 65 AF and 64 sinus rhythm (SR) single-lead ECG measurements were obtained. Of these measurements, 27.9% (36/129) showed an unclassifiable notification. The AW ECG notification showed a sensitivity of 93.5% to detect AF and a specificity of 100% to detect SR (K= 0.94). After adjudication of the unclassifiable notifications by two independent physicians 1.6% (2/129) of the measurements remained unclassifiable. When including the by the physicians adjudicated unclassifiable recordings the sensitivity to diagnose AF was 89.2% and the specificity to detect SR was 93.8% (K=0.83). The adjudication of all single-lead ECGs by the two physicians showed a sensitivity of 90.6% to detect AF and specificity of 95.2% to detect SR (K= 0.83) (Table 1). All SR and AF notification by the AW were similarly adjudicated by the two physicians. The kappa coefficient for interrater agreement between both physicians was 0.69 for all single-lead ECGs and 0.58 for unclassifiable notifications specific. Conclusion Unclassifiable notifications of the AW can be reduced by physicians interpretation of the single-lead ECG, however the interrater agreement is only moderate. The physicians interpretation of the single-lead ECGs did not increase the accuracy to detect AF and the clinical relevance of the single-lead ECG, in addition to the AW notification, should therefore be questioned. Funding Acknowledgement Type of funding sources: None.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.