At-home ECG monitoring with a real-time outpatient cardiac telemetry system during the COVID-19 pandemic.

CONTEXT: During the COVID-19 pandemic, essential in-person electrocardiogram (ECG) recordings became unfeasible, while patients continued to suffer from cardiac conditions. To circumvent these challenges, the cardiology clinic (Long Island Heart Rhythm Center [LIHRC]) at the New York Institute of Technology College of Osteopathic Medicine (NYITCOM) transitioned to a remote real-time outpatient cardiac telemetry (ROCT) service. OBJECTIVES: The goal of this study is to test the hypothesis that at-home ROCT, provided by the LIHRC, is an effective method of providing ECG monitoring to symptomatic patients during the COVID-19 pandemic. METHODS: Seventeen patients at the LIHRC that required ECGs between March 11 and August 1, 2020, were included in this study. The patients' medical records were de-identified and reviewed for age, gender, ROCT indications, findings, patient comfort, and ease of use. A retrospective analysis of observational de-identified data obtained from the LIHRC was approved and permitted by the NYITCOM Institutional Review Board (BHS-1465). These FDA-cleared medical devices (DMS-300, DM Software, Stateline, NV) were shipped to the patients' homes and were self-applied through adhesive chest patches. The devices communicated with a cloud-based system that produced reports including a continuous 6-lead ECG and many other cardiovascular parameters. Additionally, a patient-activated symptom recorder was available to correlate symptoms to ECG findings. RESULTS: Seventeen patients (15 women) from the LIHRC were included in the analysis with an average monitoring duration of 27 h (range, 24-72 h). The patients' ages ranged from 21 to 85 years old with a mean of 37 years old and a standard deviation of 19. ROCT indications included palpitations (n=9), presyncope (n=8), chest pain (n=5), syncope (n=3), and shortness of breath (n=2). One also received ROCT due to short PR intervals observed on a prepandemic ECG. Two patients experienced palpitations while wearing the ROCT device: one had supraventricular tachycardia at 150 beats per minute; the other had unifocal premature ventricular contractions (PVCs) and eventually underwent a successful cardiac ablation. Most patients experienced no symptomatic episodes during ROCT (n=15). The 6-lead ROCT ECG for five of those patients showed arrhythmias including wandering atrial pacemaker (n=2), PVCs (n=2), sinus tachycardia (n=1), premature atrial contractions (PACs) (n=1), ectopic atrial rhythms (n=1), and sinus arrhythmia (n=1). One patient who experienced issues with our device was able to obtain a device from a separate clinic and was found to have bradycardia, PVCs, and nonsustained ventricular tachycardia. Overall, 16/17 (94.1%) patients were monitored effectively with the LIHRC ROCT system, and all (17/17, 100%) patients were monitored effectively with a ROCT system either from the LIHRC or a separate clinic. CONCLUSIONS: With the unique challenges of the COVID-19 pandemic, physicians can use this innovative ROCT method to prevent infection and diagnose cardiac diseases. Most patients and staff were able to utilize the system without issues. Therefore, this system may also be utilized to deliver patient-centered care to those with limited mobility when coupled with a telemedicine visit.

Heart rate variability comparison between young males after 4-6 weeks from the end of SARS-CoV-2 infection and controls.

Due to the prolonged inflammatory process induced by infection of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), indices of autonomic nervous system dysfunction may persist long after viral shedding. Previous studies showed significant changes in HRV parameters in severe (including fatal) infection of SARS-CoV-2. However, few studies have comprehensively examined HRV in individuals who previously presented as asymptomatic or mildly symptomatic cases of COVID-19. In this study, we examined HRV in asymptomatic or mildly symptomatic individuals 5-7 weeks following positive confirmation of SARS-CoV-2 infection. Sixty-five ECG Holter recordings from young (mean age 22.6 ± 3.4 years), physically fit male subjects 4-6 weeks after the second negative test (considered to be the start of recovery) and twenty-six control male subjects (mean age 23.2 ± 2.9 years) were considered in the study. Night-time RR time series were extracted from ECG signals. Selected linear as well as nonlinear HRV parameters were calculated. We found significant differences in Porta's symbolic analysis parameters V0 and V2 (p < 0.001), α2 (p < 0.001), very low-frequency component (VLF; p = 0.022) and respiratory peak (from the PRSA method; p = 0.012). These differences may be caused by the changes of activity of the parasympathetic autonomic nervous system as well as by the coupling of respiratory rhythm with heart rate due to an increase in pulmonary arterial vascular resistance. The results suggest that the differences with the control group in the HRV parameters, that reflect the functional state of the autonomic nervous system, are measurable after a few weeks from the beginning of the recovery even in the post-COVID group-a young and physically active population. We indicate HRV sensitive markers which may be used in long-term monitoring of patients after recovery.

Scanning of paroxysmal atrial fibrillation as an etiological risk factor in patients with acute ischemic stroke: prospective study.

BACKGROUND: Prevention of recurrence of stroke depends on recognition of the underlying mechanism of ischemia. OBJECTIVE: To screen patients who were hospitalized with diagnosis of acute ischemic stroke in terms of atrial fibrillation (AF) with repeated Holter electrocardiography recordings. DESIGN AND SETTING: Prospective study conducted at Konya Education and Research Hospital, Turkey. METHODS: Patients with a diagnosis of acute ischemic stroke, without atrial fibrillation on electrocardiography (ECG), were evaluated. Their age, gender, histories of previous ischemic attack, occurrences of paroxysmal atrial fibrillation (PAF) and other risks were assessed during the first week after acute ischemic stroke and one month thereafter. ECG recordings were obtained from 130 patients through 24-hour ambulatory Holter. Patients without PAF attack during the first Holter were re-evaluated. RESULTS: PAF was detected through the first Holter in 33 (25.4%) out of 130 acute ischemic stroke patients. A second Holter was planned for 97 patients: 53 (54.6%) of them could not attend due to COVID-19 pandemic; while 44 (45.3%) patients had the second Holter and, among these, 4 (9.1%) had PAF. The only parameter associated with PAF was older age. Four (10.8%) of the 37 patients with PAF had also symptomatic carotid stenosis. CONCLUSIONS: Detecting the presence of PAF by screening patients with no AF in the ECG through Holter ECG examinations is valuable in terms of changing the course of the treatment. It should be kept in mind that the possibility of accompanying PAF cannot be ruled out in the presence of other factors that pose a risk of stroke.

Heart rate variability and cardiac autonomic functions in post-COVID period.

BACKGROUND: The heart rate variability (HRV) is a non-invasive, objective and validated method for the assessment of autonomic nervous system. Although acute manifestations of COVID-19 were widely researched, long-term sequela of COVID-19 are still unknown. This study aimed to analyze autonomic function using HRV indices in the post-COVID period that may have a potential to enlighten symptoms of COVID long-haulers. METHODS: The 24-h ambulatory electrocardiography (ECG) recordings obtained >12 weeks after the diagnosis of COVID-19 were compared with age-gender-matched healthy controls. Patients who used drugs or had comorbidities that affect HRV and who were hospitalized with severe COVID-19 were excluded from the study. RESULTS: Time domain indices of HRV analysis (standard deviation of normal RR intervals in 24 h (SDNN 24 h) and root mean square of successive RR interval differences (RMSSD)) were significantly higher in post-COVID patients (p < 0.05 for all). Among frequency domain indices, high frequency and low frequency/high frequency ratio was significantly higher in post-COVID patients (p = 0.037 and p = 0.010, respectively). SDNN >60 ms [36 (60.0%) vs. 12 (36.4%), p = 0.028)] and RMSSD >40 ms [31 (51.7%) vs. 7 (21.2%), p = 0.003)] were more prevalent in post-COVID patients. Logistic regression models were created to evaluate parasympathetic overtone in terms of SDNN >60 ms and RMSSD >40 ms. After covariate adjustment, post-COVID patients were more likely to have SDNN >60 msn (OR: 2.4, 95% CI:1.2-12.8) and RMSSD >40 ms (OR: 2.5, 95% CI: 1.4-9.2). CONCLUSION: This study revealed parasympathetic overtone and increased HRV in patients with history of COVID-19. This may explain the unresolved orthostatic symptoms occurring in post-COVID period which may be associated with autonomic imbalance.

Prospective arrhythmia surveillance after a COVID-19 diagnosis.

BACKGROUND: Cardiac arrhythmias have been observed among patients hospitalised with acute COVID-19 infection, and palpitations remain a common symptom among the much larger outpatient population of COVID-19 survivors in the convalescent stage of the disease. OBJECTIVE: To determine arrhythmia prevalence among outpatients after a COVID-19 diagnosis. METHODS: Adults with a positive COVID-19 test and without a history of arrhythmia were prospectively evaluated with 14-day ambulatory electrocardiographic monitoring. Participants were instructed to trigger the monitor for palpitations. RESULTS: A total of 51 individuals (mean age 42±11 years, 65% women) underwent monitoring at a median 75 (IQR 34-126) days after a positive COVID-19 test. Median monitoring duration was 13.2 (IQR 10.5-13.8) days. No participant demonstrated atrial fibrillation, atrial flutter, sustained supraventricular tachycardia (SVT), sustained ventricular tachycardia or infranodal atrioventricular block. Nearly all participants (96%) had an ectopic burden of <1%; one participant had a 2.8% supraventricular ectopic burden and one had a 15.4% ventricular ectopic burden. While 47 (92%) participants triggered their monitor for palpitation symptoms, 78% of these triggers were for either sinus rhythm or sinus tachycardia. CONCLUSIONS: We did not find evidence of malignant or sustained arrhythmias in outpatients after a positive COVID-19 diagnosis. While palpitations were common, symptoms frequently corresponded to sinus rhythm/sinus tachycardia or non-malignant arrhythmias such as isolated ectopy or non-sustained SVT. While these findings cannot exclude the possibility of serious arrhythmias in select individuals, they do not support a strong or widespread proarrhythmic effect of COVID-19 infection after resolution of acute illness.

Usefulness of long-term telemetric electrocardiogram monitoring in the diagnosis of tachycardia in children with a medical history of palpitations.

BACKGROUND: In children, palpitations, which may result from a life­threatening tachyarrhythmia, are one of the most common causes of cardiac visits and hospitalizations. Effective diagnosis is essential in this population of patients. AIMS: This study aimed to assess the usefulness of long­term telemetric electrocardiograms compared with Holter monitoring in the diagnostic workup in children with palpitations. METHODS: A total of 350 children with undocumented palpitations were examined in a multicenter study. In 167 patients (47.7%), the TELE group, month­long continuous telemetric electrocardiogram monitoring (using the PocketECG system) was performed. In 183 patients (52.3%), the HOLT group, 24­hour Holter electrocardiography was carried out and repeated after a month if tachyarrhythmia was not recorded. RESULTS: A total of 152 children (43.4%) reported palpitations, and 36.2% of them had sinus tachycardia during palpitations. Tachyarrhythmias were recorded in 68 patients (40.7%) in the TELE group and in 7 (3.8%) in the HOLT group after the second examination (P <0.001); the mean time to record tachycardia was 15.8 (8.7) days versus 25.4 (11.1) days (P = 0.004). In the TELE group, we noted a greater number of children with palpitations during recording (62.9% vs 18%), tachycardia with normal QRS complexes (21.6% vs 1.6%), ventricular tachycardia (11.4% vs 0.5%), and asymptomatic arrhythmias than in the HOLT group. CONCLUSIONS: In children, long­term telemetric electrocardiogram monitoring using the PocketECG system is well tolerated and has a high diagnostic efficacy. In young patients with palpitations, telemetric cardiac monitoring lasting up to a month increased the number of patients with recorded tachyarrhythmia by almost 10-fold compared with the analysis of 2 Holter electrocardiograms. We found that a large number of children have asymptomatic cardiac arrhythmias.

[Italian Society of Cardiology (SIC) Position paper: Technical, instrumental and standards of interpretation for electrocardiography, ambulatory electrocardiographic and blood pressure monitoring in telemedicine]. / Position paper della Società Italiana di Cardiologia (SIC): Requisiti tecnici, strumentali e di refertazione per elettrocardiografia a riposo, monitoraggio elettrocardiografico ambulatoriale secondo Holter, monitoraggio ambulatoriale della pressione arteriosa in telemedicina.

The current COVID-19 pandemic has renewed interest in providing healthcare services based on the implementation of innovative technologies. Such strategy capillarizes the therapeutic opportunities for larger urban areas, mostly when people are living under extraordinarily difficult circumstances. Improving care delivery in cardiovascular diseases appears particularly feasible when telemedicine is pursued, especially with regard to baseline standard 12-lead electrocardiography, ambulatory electrocardiographic monitoring, and 24-hour ambulatory blood pressure monitoring. Nowadays, these first-line cardiovascular examinations are also available in health centers and pharmacies, and in recent months, there has been an increasing demand of such local services in the absence of specific rules and regulations regarding technical requirements and standards of interpretation that ensure a high quality clinical consultation.The purpose of this position paper is to provide critical requirements for the type/model of devices to be used, training dedicated to healthcare personnel, ensuring security of sensitive data, highlighting type of platforms to be used, as well as for maintaining high reporting quality and standards.

Heart-rate-variability (HRV), predicts outcomes in COVID-19.

BACKGROUND: Patients with COVID-19 present with a variety of clinical manifestations, ranging from mild or asymptomatic disease to severe illness and death. Whilst previous studies have clarified these and several other aspects of COVID-19, one of the ongoing challenges regarding COVID-19 is to determine which patients are at risk of adverse outcomes of COVID-19 infection. It is hypothesized that this is the result of insufficient inhibition of the immune response, with the vagus nerve being an important neuro-immuno-modulator of inflammation. Vagus nerve activity can be non-invasively indexed by heart-rate-variability (HRV). Therefore, we aimed to assess the prognostic value of HRV, as a surrogate marker for vagus nerve activity, in predicting mortality and intensive care unit (ICU) referral, in patients hospitalized with COVID-19. METHODS: A retrospective cohort study including all consecutive patients (n = 271) diagnosed and hospitalized with COVID-19 between March 2020 and May 2020, without a history of cardiac arrhythmias (including atrial and ventricular premature contractions), pacemaker, or current bradycardia (heart rate <50 bpm) or tachycardia (heart rate >110 bpm). HRV was based on one 10s ECG recorded at admission. 3-week survival and ICU referral were examined. RESULTS: HRV indexed as standard deviation of normal to normal heartbeat intervals (SDNN) predicted survival (H.R. = 0.53 95%CI: 0.31-0.92). This protective role was observed only in patients aged 70 years and older, not in younger patients. HRV below median value also predicted ICU referral within the first week of hospitalization (H.R = 0.51, 95%CI: 0.29-0.90, P = 0.021). CONCLUSION: Higher HRV predicts greater chances of survival, especially in patients aged 70 years and older with COVID-19, independent of major prognostic factors. Low HRV predicts ICU indication and admission in the first week after hospitalization.

Effect of Continuous Electrocardiogram Monitoring on Detection of Undiagnosed Atrial Fibrillation After Hospitalization for Cardiac Surgery: A Randomized Clinical Trial.

Importance: Postoperative atrial fibrillation (POAF) occurring after cardiac surgery is associated with adverse outcomes. Whether POAF persists beyond discharge is not well defined. Objective: To determine whether continuous cardiac rhythm monitoring enhances detection of POAF among cardiac surgical patients during the first 30 days after hospital discharge compared with usual care. Design, Setting, and Participants: This study is an investigator-initiated, open-label, multicenter, randomized clinical trial conducted at 10 Canadian centers. Enrollment spanned from March 2017 to March 2020, with follow-up through September 11, 2020. As a result of the COVID-19 pandemic, enrollment stopped on July 17, 2020, at which point 85% of the proposed sample size was enrolled. Cardiac surgical patients with CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female sex) score greater than or equal to 4 or greater than or equal to 2 with risk factors for POAF, no history of preoperative AF, and POAF lasting less than 24 hours during hospitalization were enrolled. Interventions: The intervention group underwent continuous cardiac rhythm monitoring with wearable, patch-based monitors for 30 days after randomization. Monitoring was not mandated in the usual care group within 30 days after randomization. Main Outcomes and Measures: The primary outcome was cumulative AF and/or atrial flutter lasting 6 minutes or longer detected by continuous cardiac rhythm monitoring or by a 12-lead electrocardiogram within 30 days of randomization. Prespecified secondary outcomes included cumulative AF lasting 6 hours or longer and 24 hours or longer within 30 days of randomization, death, myocardial infarction, ischemic stroke, non-central nervous system thromboembolism, major bleeding, and oral anticoagulation prescription. Results: Of the 336 patients randomized (163 patients in the intervention group and 173 patients in the usual care group; mean [SD] age, 67.4 [8.1] years; 73 women [21.7%]; median [interquartile range] CHA2DS2-VASc score, 4.0 [3.0-4.0] points), 307 (91.4%) completed the trial. In the intent-to-treat analysis, the primary end point occurred in 32 patients (19.6%) in the intervention group vs 3 patients (1.7%) in the usual care group (absolute difference, 17.9%; 95% CI, 11.5%-24.3%; P < .001). AF lasting 6 hours or longer was detected in 14 patients (8.6%) in the intervention group vs 0 patients in the usual care group (absolute difference, 8.6%; 95% CI, 4.3%-12.9%; P < .001). Conclusions and Relevance: In post-cardiac surgical patients at high risk of stroke, no preoperative AF history, and AF lasting less than 24 hours during hospitalization, continuous monitoring revealed a significant increase in the rate of POAF after discharge that would otherwise not be detected by usual care. Studies are needed to examine whether these patients will benefit from oral anticoagulation therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT02793895.

Deceleration capacity is associated with acute respiratory distress syndrome in COVID-19.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is considered the main cause of COVID-19 associated morbidity and mortality. Early and reliable risk stratification is of crucial clinical importance in order to identify persons at risk for developing a severe course of disease. Deceleration capacity (DC) of heart rate as a marker of cardiac autonomic function predicts outcome in persons with myocardial infarction and heart failure. We hypothesized that reduced modulation of heart rate may be helpful in identifying persons with COVID-19 at risk for developing ARDS. METHODS: We prospectively enrolled 60 consecutive COVID-19 positive persons presenting at the University Hospital of Tuebingen. Arterial blood gas analysis and 24 h-Holter ECG recordings were performed and analyzed at admission. The primary end point was defined as development of ARDS with regards to the Berlin classification. RESULTS: 61.7% (37 of 60 persons) developed an ARDS. In persons with ARDS DC was significantly reduced when compared to persons with milder course of infection (3.2 ms vs. 6.6 ms, p < 0.001). DC achieved a good discrimination performance (AUC = 0.76) for ARDS in COVID-19 persons. In a multivariate analysis, decreased DC was associated with the development of ARDS. CONCLUSION: Our data suggest a promising role of DC to risk stratification in COVID-19.

Comparison of electrocardiograms (ECG) waveforms and centralized ECG measurements between a simple 6-lead mobile ECG device and a standard 12-lead ECG.

BACKGROUND: Interval duration measurements (IDMs) were compared between standard 12-lead electrocardiograms (ECGs) and 6-lead ECGs recorded with AliveCor's KardiaMobile 6L, a hand-held mobile device designed for use by patients at home. METHODS: Electrocardiograms were recorded within, on average, 15 min from 705 patients in Mayo Clinic's Windland Smith Rice Genetic Heart Rhythm Clinic. Interpretable 12-lead and 6-lead recordings were available for 685 out of 705 (97%) eligible patients. The most common diagnosis was congenital long QT syndrome (LQTS, 343/685 [50%]), followed by unaffected relatives and patients (146/685 [21%]), and patients with other genetic heart diseases, including hypertrophic cardiomyopathy (36 [5.2%]), arrhythmogenic cardiomyopathy (23 [3.4%]), and idiopathic ventricular fibrillation (14 [2.0%]). IDMs were performed by a central ECG laboratory using lead II with a semi-automated technique. RESULTS: Despite differences in patient position (supine for 12-lead ECGs and sitting for 6-lead ECGs), mean IDMs were comparable, with mean values for the 12-lead and 6-lead ECGs for QTcF, heart rate, PR, and QRS differing by 2.6 ms, -5.5 beats per minute, 1.0 and 1.2 ms, respectively. Despite a modest difference in heart rate, intervals were close enough to allow a detection of clinically meaningful abnormalities. CONCLUSIONS: The 6-lead hand-held device is potentially useful for a clinical follow-up of remote patients, and for a safety follow-up of patients participating in clinical trials who cannot visit the investigational site. This technology may extend the use of 12-lead ECG recordings during the current COVID-19 pandemic as remote patient monitoring becomes more common in virtual or hybrid-design clinical studies.

Differential cardiopulmonary monitoring system for artifact-canceled physiological tracking of athletes, workers, and COVID-19 patients.

Soft, skin-integrated electronic sensors can provide continuous measurements of diverse physiological parameters, with broad relevance to the future of human health care. Motion artifacts can, however, corrupt the recorded signals, particularly those associated with mechanical signatures of cardiopulmonary processes. Design strategies introduced here address this limitation through differential operation of a matched, time-synchronized pair of high-bandwidth accelerometers located on parts of the anatomy that exhibit strong spatial gradients in motion characteristics. When mounted at a location that spans the suprasternal notch and the sternal manubrium, these dual-sensing devices allow measurements of heart rate and sounds, respiratory activities, body temperature, body orientation, and activity level, along with swallowing, coughing, talking, and related processes, without sensitivity to ambient conditions during routine daily activities, vigorous exercises, intense manual labor, and even swimming. Deployments on patients with COVID-19 allow clinical-grade ambulatory monitoring of the key symptoms of the disease even during rehabilitation protocols.

A pandemic response to home delivery for ambulatory ECG monitoring: Development and validation.

In response to the COVID-19 pandemic, a protocol was designed for mail-out devices and educational materials created to teach patients how to install a device for 2 weeks of continuous ambulatory ECG monitoring. We compared data collection from two sequential patient populations; one who received standard device application in the same clinic in the months before the pandemic response, and another, who received their device by mail for self-installation. Patients received a single phone call when the device was mailed and were able to contact the manufacturer as needed for support. A total of 47 devices were assessed from each group. Each group was similar in age (70 vs 65 years), and clinical indication for monitoring. Noise signal magnitude (22.34 vs 26.28%), symptom based manual activation (10 vs 8 events) and APB/recorded hour burden measurements (37.05 vs 23.36%) were similar in both groups (all comparisons were statistically non-significant). Both groups had a similar mean of hours recorded (240.37 vs. 245.05 h). Zero patient kits were lost, and all reports were delivered. Overall, it was found that a mail-delivered home-based recording platform can be reliably used to acquire clinical data with similar data quality and patient compliance as a conventional in-clinic model for long term ambulatory ECG monitoring.