Abstract Background Cardiac arrhythmias are remarkably common and routinely go undiagnosed because they are often transient and asymptomatic. Effective diagnosis and treatment can substantially ...reduce the morbidity and mortality associated with cardiac arrhythmias. The Zio Patch (iRhythm Technologies, Inc, San Francisco, Calif) is a novel, single-lead electrocardiographic (ECG), lightweight, Food and Drug Administration–cleared, continuously recording ambulatory adhesive patch monitor suitable for detecting cardiac arrhythmias in patients referred for ambulatory ECG monitoring. Methods A total of 146 patients referred for evaluation of cardiac arrhythmia underwent simultaneous ambulatory ECG recording with a conventional 24-hour Holter monitor and a 14-day adhesive patch monitor. The primary outcome of the study was to compare the detection arrhythmia events over total wear time for both devices. Arrhythmia events were defined as detection of any 1 of 6 arrhythmias, including supraventricular tachycardia, atrial fibrillation/flutter, pause greater than 3 seconds, atrioventricular block, ventricular tachycardia, or polymorphic ventricular tachycardia/ventricular fibrillation. McNemar's tests were used to compare the matched pairs of data from the Holter and the adhesive patch monitor. Results Over the total wear time of both devices, the adhesive patch monitor detected 96 arrhythmia events compared with 61 arrhythmia events by the Holter monitor ( P < .001). Conclusions Over the total wear time of both devices, the adhesive patch monitor detected more events than the Holter monitor. Prolonged duration monitoring for detection of arrhythmia events using single-lead, less-obtrusive, adhesive-patch monitoring platforms could replace conventional Holter monitoring in patients referred for ambulatory ECG monitoring.
There is uncertainty about whether and how to perform screening for atrial fibrillation (AF). To estimate the incidence of previously undetected AF that would be captured using a continuous 14-day ...ECG monitor and the associated risk of stroke.
We analysed data from a cohort of patients >65 years old with hypertension and a pacemaker, but without known AF. For each participant, we simulated 1000 ECG monitors by randomly selecting 14-day windows in the 6 months following enrolment and calculated the average AF burden (total time in AF). We used Cox proportional hazards models adjusted for CHA2DS2-VASc score to estimate the risk of subsequent ischaemic stroke or systemic embolism (SSE) associated with burdens of AF > and <6 min. Among 2470 participants, the median CHA2DS2-VASc score was 4.0, and 44 patients experienced SSE after 6 months following enrolment. The proportion of participants with an AF burden >6 min was 3.10% (95% CI 2.53-3.72). This was consistent across strata of age and CHA2DS2-VASc scores. Over a mean follow-up of 2.4 years, the rate of SSE among patients with <6 min of AF was 0.70%/year, compared to 2.18%/year (adjusted HR 3.02; 95% CI 1.39-6.56) in those with >6 min of AF.
Approximately 3% of individuals aged >65 years with hypertension may have more than 6 min of AF detected by a 14-day ECG monitor. This is associated with a stroke risk of over 2% per year. Whether oral anticoagulation will reduce stroke in these patients is unknown.
The Zio® (Zio) XT Patch is a 14-day continuous ambulatory ECG monitor. During the Covid-19 pandemic, Zios were mailed directly to patients for self-application. The purpose of this study was to ...compare the percent artifact, a marker for quality, of in-clinic (IC) to mail-home (MH) applications in a pediatric population. A single-center, IRB-approved study of patients 0- < 21 years of age with Zios was studied for wear and artifact time filtered out based on iRhythm's proprietary algorithm. In total, 284 Zios were randomly selected and analyzed for total wear time and artifact. Of these, 149 were IC prior to 12/31/2019 and 135 MH patches prescribed after 1/1/2020. No significant difference was found for percent artifact between the IC (7.8%) and MH (8.3%) group. Average IC wear-time was 127 h compared to MH at 99 h (p = 0.02). In conclusion, application of Zio patches outside of the pediatric cardiology clinic offers equivalent artifact, a marker of quality, as those applied in clinic and should be consideration as a viable alternative.
Circadian factors likely influence the occurrence, development, therapy, and prognosis of cardiovascular diseases (CVDs). To determine the association between the heart rate (HR) diurnal parameters ...and CVD risks, we designed an analytical strategy to detect diurnal rhythms of HR using longitudinal data collected by clinically used Holter monitors and wearable devices. By combining in-house developed algorithms with existing analytical tools, we obtained trough phase and nocturnal variation in HR for different purposes. The analytical strategy is robust and also sensitive enough to identify variations in HR rhythms influenced by multiple effectors such as jet lag, geological location and altitude, and age from total 211 volunteers. A total of 10,094 sets of 24-h Holter ECG data were analyzed by stepwise partial correlation to determine the critical points of HR trough phase and nocturnal variation. The following HR diurnal patterns correlate with high CVD risk: arrhythmic pattern, anti-phase pattern, rhythmic patterns with trough phase less than 0 (extremely advanced diurnal pattern) or more than 5 (extremely delayed diurnal pattern), and nocturnal variation less than 2.75 (extremely low) or more than 26 (extremely high). In addition, HR trough phases from wearable devices were nearly identical to those from 24-h Holter monitoring from 12 volunteers by linear correlation and Bland-Altman analysis. Our analytical system provides useful information to identify functional diurnal patterns and parameters by monitoring personalized, HR-based diurnal changes. These findings have important implications for understanding how a regular heart diurnal pattern benefits cardiac function and raising the possibility of non-pharmacological intervention against circadian related CVDs. With the rapid expansion of wearable devices, public cardiovascular health can be promoted if the analytical strategy is widely applied.
The aim of the study was to assess the interaction of the cardiostimulation system of the patient and the source of electromagnetic interference (EMI) during the patient’s work by Holter monitoring ...of ECG. Finally, to analyze ECG recording and evaluate possible pacemaker (PCM) program responses to the presence of EMI. The observation was performed in the selected patient with the single-chamber conventional pacemaker during practicing of a profession in an industrial environment with a real risk of interaction with the defined source of interference. The heart rhythm was monitored with a standard Holter monitor and the measurement was repeated during three work shifts. The PCM was revised before each measurement and at the same time the programming was adjusted for monitoring purposes. The ECG record was back-analyzed and the device response to the presence of EMI was evaluated. No program response to the presence of an interfering electromagnetic field (EMF) was observed from the ECG recording analysis. This program response would manifest to abnormalities in the ECG curve (asynchronous pacing, pacing inhibition, competitive pacing). There were no events in the PCM memory indicating the effect of the EMI.
Background
Availability of portable and home‐based electrocardiography (ECG) is an important medical innovation, which has a potential to transform medical care. We performed this review to ...understand the current state of out‐of‐hospital portable ECG technologies with respect to their scope, ease of use, data transmission capabilities, and diagnostic accuracy.
Methods
We conducted PubMed and Internet searches for “handheld” or “wearable” or “patch” electrocardiography devices to enlist available technologies. We also searched PubMed with names of individual devices to obtain additional citations. We classified available devices as a “single limb lead ECG recording devices” and chest‐lead “ECG recording devices.” If a device used more than three electrodes, it was defined as a conventional electrocardiography or Holter machine and was excluded from this review.
Results
We identified a total of 15 devices. Overall, only six of these devices (five single lead and one chest lead) featured in published medical literature as identified from PubMed search. A total of 13 citations were available for the single limb lead ECG recording devices and 6 citations for the chest‐lead ECG recording devices.
Conclusions
Despite the increase in number of such devices, published biomedical literature regarding their diagnostic accuracy, reproducibility, or utility is scant.
A 10-year-old male American Shorthair cat was presented after a witnessed syncopal event. A Holter monitor demonstrated a long QT interval and revealed a rhythm characteristic of torsades de pointes ...(TdP) coincident with a bout of syncope. On subsequent Holter monitor recordings, sotalol did not prolong the QT interval further and did not reduce the severity of the underlying ventricular tachyarrhythmias, but no TdP was identified. When another syncopal event occurred, sotalol was discontinued, and oral amiodarone and magnesium were started. This resulted in improvement in the ventricular tachyarrhythmia. No syncopal events occurred in the ensuing 3 months, but the cat died of an unrelated disease shortly after. This is the first report of naturally occurring torsades de pointes in a domestic cat.
Abstract Objectives This study was conceived to perform a comprehensive systematic review and meta-analysis of the available evidence to compute the incidence of atrial fibrillation (AF) after ...successful atrial flutter (AFL) catheter ablation, defined by targeting for bidirectional block, using different types of follow-up modalities and durations. Background Cavotricuspid-isthmus dependent AFL is usually initiated by short bursts of AF. The incidence of AF after AFL ablation is variable. We evaluated the variation in the reported incidence of AF depending on the type and duration of follow-up, and AF incidence in patients with prior AF versus no prior AF. Methods A systematic review and meta-analysis of published studies between January 1996 and April 2015 and abstracts in the last 2 years describing patients who underwent AFL ablation and the subsequent incidence of AF was performed. Results Forty-eight studies were included (8,257 patients, ablation success rate: 96%, 79% male). Incidence of new-onset AF correlated with follow-up duration (29% for a weighted mean follow-up duration of 30 months). New-onset AF incidence with <2 years follow-up was 12.4% among group 1 (electrocardiogram and symptoms-driven evaluation, n = 759), 19% for group 2 (outpatient Holter monitoring for 1 day to 7 days/year, n = 315), and 45% for group 3 (>7 days/year Holter monitoring or by implanted cardiac devices, n = 178). Mean follow-up duration was 15.3 months, 18.5 months, and 16.3 months, respectively. In patients with and without prior AF, the incidence for AF after AFL ablation was 35.3% during mean follow-up duration of 29.7 months. In studies with <2 years follow-up duration, AF incidence was 54% in patients with prior AF versus 13.9% without prior AF (odds ratio: 7.43, 95% confidence interval: 4.96 to 11.11; p <0.00001). In studies with >2 years follow-up duration, AF incidence was 51.3% in patients with prior AF versus 26.2% without prior AF (odds ratio: 2.93, 95% confidence interval: 2.42 to 3.56; p < 0.00001). Conclusions The incidence of AF after AFL ablation is high especially in patients with prior AF when compared to those without prior AF. The detection of AF in patients without prior AF significantly increases with more frequent monitoring and/or longer follow-up duration.
Introduction
Frequent premature ventricular contractions (PVCs) can cause cardiomyopathy (CM). Postextrasystolic potentiation (PESP) and irregularity have been in implicated as triggers of PVC‐CM. ...Because both phenomena can also be found in premature atrial contractions (PACs), it is speculated that frequent PACs have similar consequences.
Methods and results
A single‐center, retrospective study included all consecutive patients undergoing a 14‐day Holter monitors (November 2014 to October 2016). Patients were divided into four groups by ectopy burden group 1 (<1%) and remaining by tertiles (group 2‐4). Echocardiographic and arrhythmic data were compared between PAC and PVC burdens. In addition, a translational PAC animal model was used to assess the chronic effects of frequent PACs. A total 846 patients were reviewed. In contrast to PVCs, we found no difference in left ventricular ejection fraction (LVEF), end‐systolic and end‐diastolic dimensions and presence of CM (LVEF <50%) between different PAC groups. Multivariate regression analysis demonstrated that only PVC burden predicted low EF (odds ratio, 1.1; confidence interval, 1.03‐1.13; P = .001). While there was a weak correlation between PAC burden and supraventricular tachycardia (SVT) episodes and atrial fibrillation (AF) burden (r = 0.19; P < .001), there was no correlation between PAC burden and LVEF or CM. Finally, atrial bigeminy in our animal model did not significantly decrease LVEF after 3 months.
Conclusion
PAC burden is associated with increased AF and SVT episodes. In contrast to a high PVC burden, a high PAC burden is not associated with CM. Our findings suggest that heart rate irregularity and/or PESP may play a minimal role in the pathophysiology of PVC‐CM.
Poincaré plots remain largely unused for heart rate variability (HRV) analysis in dogs. The aims of this study were to describe, qualitatively and quantitatively, Poincaré plots in healthy dogs, to ...compare them with other methods of HRV analysis, to assess their day-to-day variability and to investigate the effect of activity on the plots.
Twenty-five healthy dogs.
Poincaré plots, their standard descriptors, and other measures of HRV were generated from 24-hour ambulatory electrocardiographic recordings and 6 hours of rest and activity.
The 24-hour Poincaré plot demonstrated a ‘Y’ pattern. The arms of the ‘Y’ were derived mostly from periods of rest and activity populated the stalk. The quantitative descriptors of the plot had strong correlations in the time-domain, with weaker correlations in the frequency-domain. Individuals showed low day-to-day variability of the plot pattern and of the standard deviation of points along the major axis of the plot (SD2), which measures overall HRV. Day-to-day variability was higher for the standard deviation of points perpendicular to the major axis of the plot (SD1), which is a measure of short-term HRV, and for the SD1/SD2 ratio.
Twenty-four-hour Poincaré plots in healthy dogs show a ‘Y’ pattern with subtle variations unique to the individual. The amount of activity and rest within the recording has a significant effect on the plot. Quantitative analysis of the plot can be used as a surrogate for time-domain analysis of HRV but visual analysis of the pattern provides additional information.
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