Can 24 h of ambulatory ECG be used to triage patients to extended monitoring?

BACKGROUND

Access to long-term ambulatory recording to detect atrial fibrillation (AF) is limited for economical and practical reasons. We aimed to determine whether 24 h ECG (24hECG) data can predict AF detection on extended cardiac monitoring.

METHODS

We included all US patients from 2020, aged 17-100 years, who were monitored for 2-30 days using the PocketECG device (MEDICALgorithmics), without AF ≥30 s on the first day (n = 18,220, mean age 64.4 years, 42.4% male). The population was randomly split into equal training and testing datasets. A Lasso model was used to predict AF episodes ≥30 s occurring on days 2-30.

RESULTS

The final model included maximum heart rate, number of premature atrial complexes (PACs), fastest rate during PAC couplets and triplets, fastest rate during premature ventricular couplets and number of ventricular tachycardia runs ≥4 beats, and had good discrimination (ROC statistic 0.7497, 95% CI 0.7336-0.7659) in the testing dataset. Inclusion of age and sex did not improve discrimination. A model based only on age and sex had substantially poorer discrimination, ROC statistic 0.6542 (95% CI 0.6364-0.6720). The prevalence of observed AF in the testing dataset increased by quintile of predicted risk: 0.4% in Q1, 2.7% in Q2, 6.2% in Q3, 11.4% in Q4, and 15.9% in Q5. In Q1, the negative predictive value for AF was 99.6%.

CONCLUSION

By using 24hECG data, long-term monitoring for AF can safely be avoided in 20% of an unselected patient population whereas an overall risk of 9% in the remaining 80% of the population warrants repeated or extended monitoring.

Six-lead electrocardiography compared to single-lead electrocardiography and photoplethysmography of a wrist-worn device for atrial fibrillation detection controlled by premature atrial or ventricular contractions: six is smarter than one

Background

Smartwatches are commonly capable to record a lead-I-like electrocardiogram (ECG) and perform a photoplethysmography (PPG)-based atrial fibrillation (AF) detection. Wearable technologies repeatedly face the challenge of frequent premature beats, particularly in target populations for screening of AF.

Objective

To investigate the potential diagnostic benefit of six-lead ECG compared to single-lead ECG and PPG-based algorithm for AF detection of the wrist-worn device.

Methods and results

From the database of DoubleCheck-AF 249 adults were enrolled in AF group (n = 121) or control group of SR with frequent premature ventricular (PVCs) or atrial (PACs) contractions (n = 128). Cardiac rhythm was monitored using a wrist-worn device capable of recording continuous PPG and simultaneous intermittent six-lead standard-limb-like ECG. To display a single-lead ECG, the six-lead ECGs were trimmed to lead-I-like ECGs. Two diagnosis-blinded cardiologists evaluated reference, six-lead and single-lead ECGs as "AF", "SR", or "Cannot be concluded". AF detection based on six-lead ECG, single-lead ECG, and PPG yielded a sensitivity of 99.2%, 95.7%, and 94.2%, respectively. The higher number of premature beats per minute was associated with false positive outcomes of single-lead ECG (18.80 vs. 5.40 beats/min, P < 0.01), six-lead ECG (64.3 vs. 5.8 beats/min, P = 0.018), and PPG-based detector (13.20 vs. 5.60 beats/min, P = 0.05). Single-lead ECG required 3.4 times fewer extrasystoles than six-lead ECG to result in a false positive outcome. In a control subgroup of PACs, the specificity of six-lead ECG, single-lead ECG, and PPG dropped to 95%, 83.8%, and 90%, respectively. The diagnostic value of single-lead ECG (AUC 0.898) was inferior to six-lead ECG (AUC 0.971) and PPG-based detector (AUC 0.921). In a control subgroup of PVCs, the specificity of six-lead ECG, single-lead ECG, and PPG was 100%, 96.4%, and 96.6%, respectively. The diagnostic value of single-lead ECG (AUC 0.961) was inferior to six-lead ECG (AUC 0.996) and non-inferior to PPG-based detector (AUC 0.954).

Conclusions

A six-lead wearable-recorded ECG demonstrated the superior diagnostic value of AF detection compared to a single-lead ECG and PPG-based AF detection. The risk of type I error due to the widespread use of smartwatch-enabled single-lead ECGs in populations with frequent premature beats is significant.

Head-to-head comparison of single-lead and six-lead electrocardiography of a wrist-worn device for atrial fibrillation detection

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Funded by the European Regional Development Fund under agreement with the Research Council of Lithuania.

Background

The increasing numbers of available mHealth tools for electrocardiography (ECG)-based atrial fibrillation (AF) detection promote long-term screening. A common feature of smartwatches is lead-I-like ECG. However, only limited data exists directly comparing the performance of single-lead and six-lead wearable-recorded ECGs.

Purpose

To compare the accuracy of single-lead and six-lead ECGs of the same wrist-worn device for AF detection.

Methods

We included patients with AF which represent the main group for testing the diagnostic ability of wearable. In addition, authors selected control groups of stable sinus rhythm (SR) and SR with frequent premature contractions. Cardiac rhythm was monitored using an investigational wrist-worn device which provides six-lead ECG, similar to standard limb leads. To display a single-lead wearable-recorded ECGs, the same six-lead ECG tracings were trimmed to a width of lead-I-like ECGs. A validated Holter ECG device constituted a gold standard test for rhythm verification. Two independent diagnosis-blinded cardiologists evaluated reference, six-lead and single-lead ECGs as "AF", "SR", or "Inconclusive". A third cardiologist evaluated ECGs only in cases of physician disagreement.

Results

A total of 344 adult patients were enrolled in this study including AF group (121 patients) and control group of SR with or without frequent premature contractions (223 patients). Patients with missing (11/420; 2.62%) or insufficient quality (43/420; 10.24%) of wearable-recorded ECGs were excluded. AF detection based on single-lead and six-lead ECGs yielded sensitivity of 95.73% (95% CI 90.31–98.6%) and 99.16% (95% CI 95.41–99.98%), respectively. Specificity was 100% (95% CI 96.19–100%) for both single-lead and six-lead ECGs when differentiating between AF and stable SR. If patients with frequent premature beats were included in the control group, the specificity of single-lead and six-lead ECGs dropped to 95.81% (95% CI 92.31–98.07%) and 99.1% (95% CI 96.78–99.89%), respectively. False positive cases were more common for single-lead ECG (9/332) compared to six-lead ECG (2/341) (P=0.02). There was a strong association between reference ECGs and wearable-recorded ECGs (P&lt;0.001): Cramer‘s V 0.91, (95% CI 0.82–1.0) for single-lead ECG and 0.98 (95% CI 0.89–1.0) for six-lead ECG. After including a control group of frequent premature contractions, single-lead ECG (12/344) was more frequently labelled "Inconclusive" than six-lead ECG (3/344) (P=0.01). Inter-rater agreement, measured as Cohen’s kappa, indicated great concordance in both methods but was higher for six-lead ECG (0.945, P&lt;0.001) than single-lead ECG (0.887, P&lt;0.001).

Conclusions

Six-lead ECG of a wearable device demonstrated higher diagnostic accuracy of AF detection than single-lead ECG when controlled by patients with frequent premature contractions. The performance of both methods was equivalent when controlled by patients with stable SR.

High Specificity Wearable Device With Photoplethysmography and Six-Lead Electrocardiography for Atrial Fibrillation Detection Challenged by Frequent Premature Contractions: DoubleCheck-AF

Background

Consumer smartwatches have gained attention as mobile health (mHealth) tools able to detect atrial fibrillation (AF) using photoplethysmography (PPG) or a short strip of electrocardiogram (ECG). PPG has limited accuracy due to the movement artifacts, whereas ECG cannot be used continuously, is usually displayed as a single-lead signal and is limited in asymptomatic cases.

Objective

DoubleCheck-AF is a validation study of a wrist-worn device dedicated to providing both continuous PPG-based rhythm monitoring and instant 6-lead ECG with no wires. We evaluated its ability to differentiate between AF and sinus rhythm (SR) with particular emphasis on the challenge of frequent premature beats.

Methods and Results

We performed a prospective, non-randomized study of 344 participants including 121 patients in AF. To challenge the specificity of the device two control groups were selected: 95 patients in stable SR and 128 patients in SR with frequent premature ventricular or atrial contractions (PVCs/PACs). All ECG tracings were labeled by two independent diagnosis-blinded cardiologists as “AF,” “SR” or “Cannot be concluded.” In case of disagreement, a third cardiologist was consulted. A simultaneously recorded ECG of Holter monitor served as a reference. It revealed a high burden of ectopy in the corresponding control group: 6.2 PVCs/PACs per minute, bigeminy/trigeminy episodes in 24.2% (31/128) and runs of ≥3 beats in 9.4% (12/128) of patients. AF detection with PPG-based algorithm, ECG of the wearable and combination of both yielded sensitivity and specificity of 94.2 and 96.9%; 99.2 and 99.1%; 94.2 and 99.6%, respectively. All seven false-positive PPG-based cases were from the frequent PVCs/PACs group compared to none from the stable SR group (P < 0.001). In the majority of these cases (6/7) cardiologists were able to correct the diagnosis to SR with the help of the ECG of the device (P = 0.012).

Conclusions

This is the first wearable combining PPG-based AF detection algorithm for screening of AF together with an instant 6-lead ECG with no wires for manual rhythm confirmation. The system maintained high specificity despite a remarkable amount of frequent single or multiple premature contractions.

Mitigating arrhythmia risk in Hydroxychloroquine and Azithromycin treated COVID-19 patients using arrhythmia risk management plan

Aims

To assess cardiac safety in COVID-19 patients treated with the combination of Hydroxychloroquine and Azithromycin using arrhythmia risk management plan.

Methods and results

We retrospectively examined arrhythmia safety of treatment with Hydroxychloroquine and Azithromycin in the setting of pre-defined arrhythmia risk management plan. The data was analyzed using R statistical package version 4.0.0. A two-tailed p-value<0.05 was considered significant. 81 patients were included from March 23rd to May 10th 2020. The median age was 59 years, 58.0% were female. The majority of the study population (82.7%) had comorbidities, 98.8% had radiological signs of pneumonia. Fourteen patients (17.3%) experienced QTc ≥ 480 ms and 16 patients (19.8%) had an increase of QTc ≥ 60 ms. Seven patients (8.6%) had QTc prolongation of ≥ 500 ms. The treatment was discontinued in 4 patients (4.9%). None of the patients developed ventricular tachycardia. The risk factors significantly associated with QTc ≥ 500 ms were hypokalemia (p = 0.032) and use of diuretics during the treatment (p = 0.020). Three patients (3.7%) died, the cause of death was bacterial superinfection with septic shock in two patients, and disseminated intravascular coagulation with multiple organ failure in one patient. None of these deaths were associated with cardiac arrhythmias.

Conclusion

We recorded a low incidence of QTc prolongation ≥ 500 ms and no ventricular tachycardia events in COVID-19 patients treated with Hydroxychloroquine and Azithromycin using cardiac arrhythmia risk management plan.

Impact of single versus double transseptal puncture on outcome and complications in pulmonary vein isolation procedures

BACKGROUND

The aim of the current study was to analyze the impact of single versus double transseptal puncture (TSP) for atrial fibrillation (AF) ablation.

METHODS

Consecutive patients undergoing AF ablation were prospectively included in the AF ablation registry and were analyzed according to single versus double TSP.

RESULTS

A total of 478 patients (female 35%, persistent AF 67%) undergoing AF ablation between 01/2014 and 09/2014 were included. Single TSP was performed in 202 (42%) patients, double TSP in 276 (58%) patients. Age, gender, body mass index, CHA2DS2-VASc score, left ventricular ejection fraction and operator experience (experienced operator defined as ≥ 5 years of experience in invasive electrophysiology) were equally distributed between the two groups. Repeat procedures (re-dos) were more frequently performed using single TSP access (p < 0.001). Left atrial (LA) diameter was larger in patients with double TSP (p = 0.001). Procedure duration in single TSP was identical to double TSP procedures (p = 0.823). Radiation duration was similar between the two groups (p = 0.217). There were 49 (10%) patients with complications after catheter ablation. There were no differences between complication rates and TSP type (p = 0.555). Similarly, recurrence rates were comparable between both TSP groups (p = 0.788).

CONCLUSIONS

There was no clear benefit of single or double TSP in AF ablation.