Continuous Electrocardiographic Monitoring Research Articles

Post-Exercise Syncope in a Previously Healthy 67-Year-Old Man: The Bezold–Jarisch Reflex and the Role of Autonomic Nervous System Dysfunction

A 67-year-old man started treatment due to frequent asymptomatic premature ventricular complexes (PVCs) accidentally being registered during a preventive examination by a specialist, because of which he was referred to cardiologist. During the initial 24-hour (h) ECG monitoring, 4.5% PVCs and one episode of asymptomatic non-sustained ventricular tachycardia (NSVT) with three PVCs in row, at a frequency of 150 beats per minute (bpm), were detected. After the introduction of beta blockers into therapy, a lower number of PVCs, without NSVT, were recorded in the control 24 h Holter ECG, while transthoracic echocardiography (TTE) showed normal left ventricular (LV) systolic function without cardiomyopathy. So, an exercise test was indicated, and it was interrupted in the third minute at 120 beats per minute (bpm) due to fatigue and pain in the hips, without malignant arrhythmias, angina or dyspneic complaints. During the rest period, a significant inferolateral depression of the ST junction was observed, which recovered in the ninth minute. Immediately after the ECG monitoring stopped, the patient lost consciousness; his pulse was not palpable, but breathing was audible, so cardiac massage was started. After he had regained consciousness, the ECG showed alternating sinus and junctional rhythm with the lowest frequency of 33 bpm, which was accompanied by marked hypotension (80/50 mmHg). The patient was immediately hospitalized; coronary angiography and repeated TTE were completely normal, while continuous ECG monitoring did not confirm malignant rhythm disorders or asystole. It was concluded that it was vasovagal syncope (VVS), most likely caused by the Bezold–Jarisch reflex (BJR).

Early prediction of sudden cardiac death using multimodal fusion of ECG Features extracted from Hilbert–Huang and wavelet transforms with explainable vision transformer and CNN models

Background and Objective:Sudden cardiac death (SCD) is a critical health issue characterized by the sudden failure of heart function, often caused by ventricular fibrillation (VF). Early prediction of SCD is crucial to enable timely interventions. However, current methods predict SCD only a few minutes before its onset, limiting intervention time. This study aims to develop a deep learning-based model for the early prediction of SCD using electrocardiography (ECG) signals. Methods:A multimodal explainable deep learning-based model is developed to analyze ECG signals at discrete intervals ranging from 5 to 30 min before SCD onset. The raw ECG signals, 2D scalograms generated through wavelet transform and 2D Hilbert spectrum generated through Hilbert–Huang transform (HHT) of ECG signals were applied to multiple deep learning algorithms. For raw ECG, a combination of 1D-convolutional neural networks (1D-CNN) and long short-term memory networks were employed for feature extraction and temporal pattern recognition. Besides, to extract and analyze features from scalograms and Hilbert spectra, Vision Transformer (ViT) and 2D-CNN have been used. Results:The developed model achieved high performance, with accuracy, precision, recall and F1-score of 98.81%, 98.83%, 98.81%, and 98.81% respectively to predict SCD onset 30 min in advance. Further, the proposed model can accurately classify SCD patients and normal controls with 100% accuracy. Thus, the proposed method outperforms the existing state-of-the-art methods. Conclusions:The developed model is capable of capturing diverse patterns on ECG signals recorded at multiple discrete time intervals (at 5-minute increments from 5 min to 30 min) prior to SCD onset that could discriminate for SCD. The proposed model significantly improves early SCD prediction, providing a valuable tool for continuous ECG monitoring in high-risk patients.

Successful emergency management of hemorrhagic shock due to carotid artery aneurysm: the role of awake intubation in difficult airway control

We describe the clinical scenario, analyze the decision-making process in airway management, and application of the Difficult Airway Society (DAS) guidelines for awake tracheal intubation (ATI) in a patient involving life-threatening bleeding from an internal carotid artery aneurysm caused by a fistula following radiotherapy for tongue cancer at Hong Ngoc Phuc Truong Minh General Hospital, on March, 2024. A 53-year-old male, diagnosed with tongue cancer, underwent surgery. Days before admission, he experienced pain and bleeding from the right lateral neck due to an internal carotid artery aneurysm. An attempt at tracheal intubation for endovascular intervention at another hospital failed. Upon arrival at our emergency department, he exhibited massive neck hemorrhage, remained conscious, pale, with ongoing bleeding from a right neck fistula, and limited cervical motion due to irritation. A treatment strategy for permanent occlusion of the aneurysm was devised. Awake tracheal intubation using a fiberoptic scope via the nasal route was performed. The patient received light sedation with midazolam, and the airway was topicalized with 10% lidocaine spray over the mouth, tongue, and oropharyngeal mucosa. Continuous monitoring of heart rate, ECG, and oxygen saturation showed no decrease in oxygen levels, and the patient maintained spontaneous breathing throughout. Intensive treatment with crystalloid fluids and blood transfusion, along with right internal carotid embolization with a spring coil, effectively prevented massive hemorrhage. The patient was successfully extubated after three days in the ICU and discharged 15 days post-surgery without any neurological deficits. Keywords: Awake Tracheal Intubation; Difficult Airway Management; Fiberoptic Scope; Emergency Airway Management Citation: Ba NTT. Successful emergency management of hemorrhagic shock due to carotid artery aneurysm: the role of awake intubation in difficult airway control. Anaesth. pain intensive care 2024;28(5):955−959. DOI: 10.35975/apic.v28i5.2572 Received: January 03, 2024; Reviewed: May 05, 2024; Accepted: June 11, 2024

Diagnostic capability of long-term electrocardiographic telemonitoring for detection of heart rhythm disorders

prevalence of cardiac rhythm and conduction disorders is increasing and associated with the growing amount of people of older age groups. The extended use of traditional electrocardiography (ECG) recorders is currently limited due to duration of the investigation, possible skin irritation and withdrawal of consent by the patients. The aim: evaluation of the frequency of arrythmia incidents in adult patients of different ages by assessing the patch monitoring results, and the impact of the monitoring duration on the possibility of diagnosis. Materials and methods: study included 1123 patients aged from 18 to 99 (599 women and 524 men), data about whom was collected in 2021-2022. ECG was recorded by the «Mawi Heart patch» – a single-use dual-channel device for continuous ECG recording for up to2 7 days. Results: the average ECG monitoring time was 81,03±18,5 hours or 3,37±0,7 days. The majority of the participants (74,35%) received the continuous 3-day ECG monitoring. Most rhythm disorders were recorded in the first 24 hours, but over the next 2 days, atrial fibrillation (AF) was detected in 7,66%, more often in men (48 participants, p=0,048) and with some differences in age groups. Starting above 50 years of age, the frequency of AF diagnosing on the first monitoring days is decreased and it is significantly statistically lower (61,11%, p<0,05). Three-day ECG monitoring is associated with a higher chance of detecting AF (OR=2,03; 1,53-3,02, p=0,031) regardless of gender, while the 5-day monitoring wasn’t as effective. The prolonging of the monitoring time increased the number of diagnosed supraventricular tachycardia (SVT) cases by 5,53% in men and 8,35% in women. The 3 days of monitoring are associated with a higher chance of SVT detection (OR = 4,18; 3,32–4,95, p=0,009). There is a direct correlation between SVT detection and the older age groups (r=0,53, p<0,05). SVT detection is higher in patients of 71-80 years old (OR = 2,71; 2,35–3,75, p=0,0041), and of 81-99 years (OR = 2,92; 2,56–3,49, p=0,0039). Conclusion: The frequency of arrhythmia detection, in patients referred to long-term patch monitoring, is high both for AF and SVT. The sex and age patterns for the prevalence of the described arrhythmias were statistically confirmed. The use of long-term ECG patch monitoring increases the chance of arrhythmia detection, primarily for older patients.

Effect of Screening for UndiagnosedAtrial Fibrillation onStrokePrevention.

Atrial fibrillation (AF) often remains undiagnosed, and it independently raises the risk of ischemic stroke, which is largely reversible by oral anticoagulation. Although randomized trials using longer term screening approaches increase identification of AF, no studies have established that AF screening lowers stroke rates. To address this knowledge gap, the GUARD-AF (Reducing Stroke by Screening for Undiagnosed Atrial Fibrillation in Elderly Individuals) trial screened participants in primary care practices using a 14-day continuous electrocardiographic monitor to determine whether screening for AF coupled with physician/patient decision-making to use oral anticoagulation reduces stroke and provides a net clinical benefit compared with usual care. GUARD-AF was a prospective, parallel-group, randomized controlled trial designed to test whether screening for AF in people aged≥70 years using a 14-day single-lead continuous electrocardiographic patch monitor could identify patients with undiagnosed AF and reduce stroke. Participants were randomized 1:1 to screening or usual care. The primary efficacy and safety outcomes were hospitalization due to all-cause stroke and bleeding, respectively. Analyses used the intention-to-treat population. Enrollment began on December 17, 2019, and involved 149 primary care sites across the United States. TheCOVID-19 pandemic led to premature termination of enrollment, with 11,905 participants in the intention-to-treat population. Median follow-up was 15.3months (Q1-Q3: 13.8-17.6months). Median age was 75 years (Q1-Q3: 72-79 years), and 56.6% were female. The risk of stroke in the screening group was 0.7% vs 0.6% in the usual care group (HR:1.10; 95%CI: 0.69-1.75). The risk of bleeding was 1.0% in the screening group vs 1.1% in the usual care group (HR:0.87; 95%CI: 0.60-1.26). Diagnosis of AF was 5% in the screening group and 3.3% in the usual care group, and initiation of oral anticoagulation after randomization was 4.2% and 2.8%, respectively. In this trial, there was no evidence that screening for AF using a 14-day continuous electrocardiographic monitor in people≥70 years of age seen in primary care practice reduces stroke hospitalizations. Event rates were low, however, and the trial did not enroll the planned sample size.(Reducing Stroke by Screening for Undiagnosed Atrial Fibrillation in Elderly Individuals [GUARD-AF]; NCT04126486).

Radiofrequency catheter ablation of persistent atrial fibrillation by pulmonary vein isolation with or without left atrial posterior wall isolation: long-term outcomes of the CAPLA trial.

Posterior wall isolation (PWI) is commonly incorporated into catheter ablation (CA) strategies for persistent atrial fibrillation (AF) in an attempt to improve outcomes. In the CAPLA randomized study, adjunctive PWI did not improve freedom from atrial arrhythmia at 12 months compared with pulmonary vein isolation (PVI) alone. Whether additional PWI reduces arrhythmia recurrence over the longer term remains unknown. In this multicenter, international, randomized study patients with persistent AF undergoing index CA using radiofrequency (RF) were randomized to PVI+PWI versus PVI alone. Patients underwent regular follow-up including rhythm monitoring for a minimum of 3 years post CA. AF burden at 3 years post-ablation was evaluated with either 28-day continuous ambulatory ECG monitoring, twice daily single-lead ECG or from cardiac implanted device. Evaluated endpoints included freedom from any documented atrial arrhythmia recurrence after a single procedure, AF burden, need for redo catheter ablation, rhythm at last clinical follow-up, healthcare utilisation metrics and AF-related quality of life. 333 of 338 (98.5%) patients (mean age 64.3±9.4 years, 23% female) completed 3-year follow-up, with 169 patients randomized to PVI+PWI and 164 patients to PVI alone. At a median of 3.62 years post-index ablation, freedom from recurrent atrial arrhythmia occurred in 59 patients (35.5%) randomized to PVI+PWI vs 68 patients (42.1%) randomized to PVI alone (HR 1.15, 95% CI 0.88-1.51, p=0.55). Median time to recurrent atrial arrhythmia was 0.53 years (IQR 0.34-1.01 years). Redo ablation was performed in 54 patients (32.0%) in the PVI+PWI group vs 49 patients (29.9%, p=0.68) in the PVI alone group. Pulmonary vein reconnection was present in 54.5% (mean number of reconnected PVs 2.2±0.9) and posterior wall reconnection in 75%. Median AF burden at 3 years was 0% in both groups (IQR 0-0.85% PVI+PWI vs 0-1.43% PVI alone, p=0.49). Sinus rhythm at final clinical follow-up was present in 85.1% with PVI+PWI vs 87.1% with PVI alone (p=0.60). Mean AF Effect On Quality-Of-Life (AFEQT) score at 3 years post-ablation was 88.0±14.8 with PVI+PWI vs 88.9±15.4 with PVI alone (p=0.63). In patients with persistent AF, the addition of PWI to PVI alone at index RF catheter ablation did not significantly improve freedom from atrial arrhythmia recurrence at long-term follow-up. Median AF burden remains low and AF quality of life high at 3 years with either ablation strategy.

Multi-Modal Assessment of Cerebral Hemodynamics in Resuscitated Out-of-Hospital Cardiac Arrest Patients: A Case-Series.

We assessed the feasibility of concurrent monitoring of cerebral hemodynamics in adult, comatose out-of-hospital cardiac arrest (OHCA) patients admitted to the National University Heart Centre Singapore from October 2021 to August 2023. Patients underwent continuous near-infrared spectroscopy (NIRS) monitoring in the first 72 h after return of spontaneous circulation (ROSC) and 30-min transcranial Doppler ultrasound (TCD) monitoring at least once. With constant mechanical ventilatory settings and continuous electrocardiographic, pulse oximeter and end-tidal carbon dioxide monitoring, blood pressure was manipulated via vasopressors and cerebral autoregulation assessed by measuring changes in regional cerebral oxygenation (NIRS) and cerebral blood flow velocities (TCD) in response to changes in mean arterial pressure. The primary outcome was neurological recovery at hospital discharge. Amongst the first 16 patients (median age 61, 94% males), we observed four unique patterns: preserved cerebral autoregulation, loss of cerebral autoregulation, cardio-cerebral asynchrony and cerebral circulatory arrest. Patients with preserved cerebral autoregulation had lower levels of neuro-injury biomarkers (neurofilaments light and heavy) and the majority (86%) were discharged with good neurological recovery. Multi-modal assessment of cerebral hemodynamics after OHCA is feasible and derived patterns correlated with neurological outcomes. The between- and within-patient heterogeneity in cerebral hemodynamics calls for more research on individualized treatment strategies.

Fabric and Fiber-Integrated, Washable Hydrogel Electrodes for Clinically Accurate Sleep Monitoring in-Home

Longitudinal tracking of sleep metrics is important for detecting and managing various diseases, spanning cardiorespiratory disorders to dementia. However, at present, sleep monitoring primarily occurs in specialized medical facilities that are not conducive to longterm studies. In-home solutions either compromise user comfort or signal accuracy in tracking sleep variables and have not yet provided reliable longitudinal data. We believe that human-centered design of multimodal, low-form-factor, comfortable sensing systems is needed for this increasingly-important area of preventative health monitoring. Our lab developed a suite of fabric-based and/or garment-integrated sensors and sensing modalities that accurately and reliably extract important sleep metrics, such as posture, cardiorespiratory signals, eye movement and brain activity, over the course of an eight-hour sleep session. Our garment-integrated sensing arrays do not require a medical professional for on-body positioning, maintain their function independent of sizing and fit on individual users, and can be laundered or cleaned with antibacterial wipes without compromising its varied sensing elements. Here, we describe one of these two key sensors, a fabric or fiber-based electrochemical hydrogel electrode that enables wearable biopotential monitoring, including electrocardiography (ECG), eletrooculography (EOG) and electroencephalography (EEG), from which the aforementioned sleep metrics can be recorded and quantified with clinical precision and accuracy. The hydrogel is fabricated as a coating on either commodity fabrics or threads using a low-temperature reactive deposition process, termed photoinitiated chemical vapor deposition (piCVD), during which hydrogel monomers react with a photoinitator in the vapor phase to create a polymeric hydrogel coating directly on the surface of fabrics or threads that have been temporarily surface modified with a skin-safe electrolyte gel. The resulting composite hydrogel coating isolated from this operation is ionically conductive, can be reversibly swelled in water and dried without losing ionic conductivity, and transduces the ionic signals (fluxes) experienced by the body into an electrical signal that can be captured by any commercial ECG, EOG or EEG monitoring instrument. An array of these fabric or thread-based hydrogel electrodes can be integrated into readily-available garments using simple cut-sew techniques and these garments can then be worn throughout the night to effect continuous ECG, EOG and EEG monitoring at home. Design elements of a custom-made circuit board that allows simultaneous capture of these signals will be described. Results from an ongoing user study of >50 adults will be presented to validate the clinical precision and accuracy of these garment sensor for sleep quality monitoring.

Heart Failure Events After Long-term Continuous Screening for Atrial Fibrillation: Results From the Randomized LOOP Study.

Mounting evidence indicates that even device-detected subclinical atrial fibrillation is associated with a higher risk of heart failure (HF). However, the potential impact of atrial fibrillation screening on HF remains unknown. The LOOP Study (Atrial Fibrillation detected by Continuous ECG Monitoring using Implantable Loop Recorder to prevent Stroke in High-risk Individuals) evaluated the effects of atrial fibrillation screening on stroke prevention using an implantable loop recorder (ILR) versus usual care in older individuals with additional stroke risk factors. In this secondary analysis, we explored the following HF end points: (1) HF event or cardiovascular death; (2) HF event; (3) event with HF with reduced ejection fraction (HFrEF); and (4) HFrEF event or cardiovascular death. Outcomes were assessed in a Cox model both as time-to-first events and as total (first and recurrent) events analyzed using the Andersen-and-Gill method. Of 6004 participants (mean age 74.7 and 52.7% men), 1501 were randomized to ILR screening and 4503 to the control group. In total, 77 (5.1%) in the ILR group versus 295 (6.6%) in the control group experienced the primary outcome of an HF event or cardiovascular death. Compared with usual care, ILR screening was associated with a nonsignificant reduction in the primary outcome for the time-to-first event analysis (hazard ratio, 0.78 [95% CI, 0.61-1.01]) and the total event analysis (hazard ratio, 0.77 [95% CI, 0.59-1.01]). Similar results were obtained for the HF event. A significant risk reduction in total events was observed in the ILR group for the composite of HFrEF event or cardiovascular death and for HFrEF event (hazard ratio, 0.74 [95% CI, 0.56-0.98] and 0.65 [95% CI, 0.44-0.97], respectively). In an older population with additional stroke risk factors, ILR screening for atrial fibrillation tended to be associated with a lower rate of total HF events and cardiovascular death, particularly those related to HFrEF. These findings should be considered hypothesis-generating and warrant further investigation. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02036450.

Hospital-Based Electrocardiographic Monitoring: The Good, the Not So Good, and Untapped Potential

Continuous electrocardiographic (ECG) monitoring was first introduced into hospitals in the 1960s, initially into critical care, as bedside monitors, and eventually into step-down units with telemetry capabilities. Although the initial use was rather simplistic (ie, heart rate and rhythm assessment), the capabilities of these devices and associated physiologic (vital sign) monitors have expanded considerably. Current bedside monitors now include sophisticated ECG software designed to identify myocardial ischemia (ie, ST-segment monitoring), QT-interval prolongation, and a myriad of other cardiac arrhythmia types. Physiologic monitoring has had similar advances from noninvasive assessment of core vital signs (blood pressure, respiratory rate, oxygen saturation) to invasive monitoring including arterial blood pressure, temperature, central venous pressure, intracranial pressure, carbon dioxide, and many others. The benefit of these monitoring devices is that continuous and real-time information is displayed and can be configured to alarm to alert nurses to a change in a patient’s condition. I think it is fair to say that critical and high-acuity care nurses see these devices as having a positive impact in patient care. However, this enthusiasm has been somewhat dampened in the past decade by research highlighting the shortcomings and unanticipated consequences of these devices, namely alarm and alert fatigue. In this article, which is associated with the American Association of Critical-Care Nurses’ Distinguished Research Lecture, I describe my 36-year journey from a clinical nurse to nurse scientist and the trajectory of my program of research focused primarily on ECG and physiologic monitoring. Specifically, I discuss the good, the not so good, and the untapped potential of these monitoring systems in clinical care. I also describe my experiences with community-based research in patients with acute coronary syndrome and/or heart failure.

Design, Fabrication, and Evaluation of 3D Biopotential Electrodes and Intelligent Garment System for Sports Monitoring.

This study presents the development and evaluation of an innovative intelligent garment system, incorporating 3D knitted silver biopotential electrodes, designed for long-term sports monitoring. By integrating advanced textile engineering with wearable monitoring technologies, we introduce a novel approach to real-time physiological signal acquisition, focusing on enhancing athletic performance analysis and fatigue detection. Utilizing low-resistance silver fibers, our electrodes demonstrate significantly reduced skin-to-electrode impedance, facilitating improved signal quality and reliability, especially during physical activities. The garment system, embedded with these electrodes, offers a non-invasive, comfortable solution for continuous ECG and EMG monitoring, addressing the limitations of traditional Ag/AgCl electrodes, such as skin irritation and signal degradation over time. Through various experimentation, including impedance measurements and biosignal acquisition during cycling activities, we validate the system's effectiveness in capturing high-quality physiological data. Our findings illustrate the electrodes' superior performance in both dry and wet conditions. This study not only advances the field of intelligent garments and biopotential monitoring, but also provides valuable insights for the application of intelligent sports wearables in the future.

Physical activity cut-points for older adults using the Zio XT onboard accelerometer

IntroductionThe Zio® XT continuous ambulatory electrocardiographic monitor (Zio) contains an accelerometer that can help quantify an individual’s physical activity in the free-living environment.Purpose(1) To estimate activity cut-points to estimate daily time spent performing very light, light, or moderate to vigorous physical activity (VLIPA, LIPA, MVPA) for the Zio accelerometer. (2) To describe how Zio’s 24-h wear protocol affects estimates of daily MVPA relative to a waist-worn accelerometer’s waking-wear protocol.MethodsThree hundred eighty one participants from the Atherosclerosis Risk in Communities (ARIC) study wore a waist-mounted ActiGraph GT3X (except while sleeping or water-based activities) and a Zio (24-h) simultaneously for three to seven days. For each person-minute, physical activity was summarized as the Mean Amplitude Deviation (MAD) for the Zio and Vector Magnitude Counts (VMC) for the GT3X. Cut points previously used in ARIC were mapped from GT3X VMC to Zio MAD using a conditional two-sample quantile–quantile approach.ResultsEvenson VMC cut-points for the GT3X (VLIPA≥76, LIPA≥903, MVPA≥2075 counts/min) were mapped to MAD for Zio (9.04, 28.2, and 58.1 mili-g). Daily hours spent in each intensity category were each strongly correlated (ICC > 0.7) between summaries produced by Zio and GT3X when restricting estimates to overlapping wear time. Zio and GT3X-estimated MVPA had high agreement (ICC = 0.77) when using device-specific wear time, but Zio measured one hour more of daily LIPA and VLIPA (95% CI = 0.83, 1.07 hrs/day).ConclusionsWe recommend the use of our cut-points for clinical research with Zio accelerometry in populations of older adults.

Spontaneous atrial fibrillation occurrence following transesophageal atrial burst pacing in rats

Abstract Purpose Animal models play a crucial role in elucidating the complex pathophysiology of atrial fibrillation (AF) and in identifying and testing novel antiarrhythmic strategies. We aimed to develop and characterize a new experimental rat model of AF, induced by long-term transesophageal atrial electrical stimulation, and to investigate whether the "AF begets AF" concept applies to small rodent hearts. Method Twelve adult male Wistar rats were randomized into two groups: Sham (n = 5) and AF (n = 7). All rats were implanted at the beginning of the study with ECG radiotelemetry devices and underwent continuous ECG monitoring throughout the study. To induce AF, the rats in the AF group underwent atrial pacing for 10 consecutive days (15 successive cycles of stimulation/day, 20 s each, with a free interval of 5 min between cycles; 4,000 stimuli/min, stimulus duration 6 ms, voltage 3 V above the diastolic threshold). A similar procedure was applied to the Sham group, but without performing the actual electrical stimulation. The number and duration of spontaneous AF episodes were evaluated based on continuous ECG monitoring prior to, during, and for one week after transesophageal atrial pacing. The inducibility of AF and the occurrence and duration of spontaneous AF episodes were evaluated and compared between the two groups. Results Atrial fibrillation was induced in 85.7% of the rats subjected to atrial electrical pacing (Figure, A), with an average global inducibility of 44.0% ± 16.9% and a mean AF duration of 123.2 ± 96.3 s. No induced or spontaneous AF episodes were recorded in any of the Sham animals. In the AF group, none of the animals presented spontaneous AF before transesophageal atrial pacing. However, in the AF rats, after atrial electrical stimulation initiation, the number of atrial premature beats significantly increased (21.3 ± 6.8 / 24-h post-stimulation vs. 7.3 ± 6.5 / 24-h at baseline; p< 0.01; Figure, B), and all rats presented spontaneous AF episodes (Figure, C). At the end of the study, AF rats presented a total number of 23.9 ± 2.3 AF episodes / 24-h (Figure, D), with a mean AF burden of 337.7 ± 25.06 s / 24-h. Conclusions Our data demonstrate that, despite the small size of the atria, the "AF begets AF" concept is applicable in small rodents. The study presents a novel rat model of AF, in which spontaneous AF occurs following long-term atrial electrical stimulation. Given that the model is relatively rapid and easy to implement, it provides a setup for further investigation of AF pathophysiology, and for identifying and testing novel therapeutic strategies for AF.Figure 1

Timing of detection of atrial fibrillation recurrence in patients with transient new-onset atrial fibrillation detected during hospitalization for noncardiac surgery or medical illness

Abstract Background Approximately one third of patients who experience transient new-onset atrial fibrillation (AF) during a hospitalization for noncardiac surgery or medical illness will have recurrent AF within 1 year. Purpose To estimate the expected rate of detection of AF recurrence using different durations of continuous ECG monitoring during follow-up of patients who have had AF occurring transiently during physiologic stress. Methods We used continuous ECG data from participants enrolled in the AFOTS Follow-up Study. Participants had transient new-onset AF while hospitalized for noncardiac surgery or medical illness and were discharged from hospital in sinus rhythm. We calculated the median time to detection of the first recurrent AF episode and the proportion of recurrent AF events that would be captured with an ECG monitor worn for 24 h, 48 h, 7 days and 14 days, and with a repeated 14-day monitor worn approximately 6 months after the first monitor. Results A total of 139 participants (41.0% female, median CHA2DS2-VaSC Score 3.0 (Interquartile Range [IQR] 2.0- 4.0)) wore at least one ECG monitor for a median of 13.5 days (IQR 11.7-13.8). A second ECG monitor was worn by 83 (59.7%) participants for a median of 12.9 days (IQR 10.0-13.9); the second monitor was worn a median of 175.0 days (IQR 153.0-216.0) after the first monitor. Among the study participants in whom recurrent AF was detected (n = 40, 28.8%), the median time to AF lasting at least 30 seconds was 128.0 hours (IQR 32.5-232.5). The proportion of AF recurrences detected after more than 24 hours of monitoring was 75.0% (n = 30). The yield of AF detection increased with longer monitoring times (Figure 1). AF was detected in 5.0% of participants at 24 hours, 5.8% at 48 hours, 6.5% at 72 hours, 12.2% at 7 days, 21.6% at 14 days and in 28.8% of participants by the end of the second 14-day monitor. Conclusions In patients who have experienced transient new-onset AF during a hospitalization for noncardiac surgery or medical illness, the rate of capture of AF recurrence in follow-up increases with longer monitoring durations. 14-day monitors capture nearly 4 times as many AF events as 48 h monitors.

Useful aid or futile hassle - continuous rhythm monitoring following acute myocardial infarction

Abstract Background Patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) face an increased risk of cardiac events, including arrhythmias. Current guidelines therefore recommend ECG monitoring for at least 24 hours after AMI in patients with ST segment elevation myocardial infarction (STEMI) and high-risk non-ST segment elevation myocardial infarction (NSTEMI). However, in the last decades medical treatment of AMI has been substantially improved, limiting the risk of arrhythmias post-PCI. Furthermore, continuous ECG monitoring puts additional strain on healthcare personnel during an international healthcare crisis. Purpose To evaluate the contemporary burden of ventricular arrhythmias (VA) in AMI patients post-PCI. Methods This is a retrospective analysis of consecutive patients undergoing PCI for AMI between 2016 and 2020 at a secondary care centre. We defined the primary endpoint as any VA requiring intervention (electric cardioversion or pharmacologic treatment) after PCI. Baseline characteristics and outcome were compared in patients with NSTEMI vs. STEMI. Results A total of 931 patients were included in the analysis, with a mean age of 65 years and 28.6% were female. Patients with NSTEMI (47.3%) were older (median 66 vs. 63 years) and had significantly more comorbidities: hypertension (67.5% vs. 52.1 %), diabetes mellitus (25.4% vs. 15.8%), chronic obstructive pulmonary disease (11.5% vs. 6.7%), and peripheral arterial disease (11.4% vs. 5.3%, p<0.05 for all). VAs requiring intervention occurred in 3.6% vs. 7.1% (p = 0.017) before PCI and in 0% vs. 2.2% (p < 0.001) during PCI in NSTEMI vs. STEMI patients. After PCI the primary endpoint occurred in no NSTEMI patient and in 1.6% of patients with STEMI (p = 0.004). Discussion In a cohort of contemporary AMI patients, ventricular arrhythmias occurred rarely and significantly less often in NSTEMI patients compared to STEMI patients. Due to the low risk of VAs in patients with NSTEMI after PCI, the need for post-procedural rhythm monitoring in NSTEMI patients may be questioned. The identification of predictors for VA after AMI should be subject for future trials.

Electrophysiology-guided algorithm for patients with conduction abnormalities post TAVR: one-year follow-up

Abstract Introduction Transcatheter aortic valve replacement (TAVR) revolutionized the treatment of aortic stenosis [1]. Although TAVR is an effective treatment for AS patients, it is associated with high incidence of new-onset conduction disturbances and pacemaker implantations. The two most common conduction disturbances after TAVR are new onset left bundle branch block (LBBB) and high-degree atrioventricular block (HDAVB) [2]. While patients with HDAVB require a permanent pacemaker implantation (PPM), the management of LBBB is not completely established yet. According to the ESC 2021 guidelines, a PPM is indicated in patients with persistent HDAVB or new onset alternating BBB after TAVR. Yet, the recommendations regarding other conduction abnormalities are not well defined. In patients with persistent new onset LBBB, ambulatory continuous ECG monitoring or electrophysiology study (EPS) are recommended [3]. Purpose To evaluate the clinical outcomes of patients with conduction disorders after TAVR who were managed according to electrophysiology-guided algorithm (Figure 1), including mortality, late pacemaker’s implantations, and heart failure hospitalizations. Predictors of periprocedural LBBB and HDAVB were also assessed. Methods Retrospective population-based cohort study including all patients who developed new onset LBBB after TAVR at a tertiary University Medical Center from October 1, 2018, to December 31, 2022, and were managed according to specific electrophysiology-guided algorithm. Results The study cohort included 230 consecutive patients who underwent TAVR. Mean age was 80.3 and 56.5% were females (Figure 2). Twenty patients (8.7%) developed HDAVB and required a PPM, whereas 40 patients (17.4%) developed persistent LBBB. According to the algorithm, 8 patients (20%) with a QRS<130ms were discharged without PPM [group A], 20 patients (50%) with a QRS of 130-160ms underwent EPS, and 12 patients (30%) with a QRS>160ms [Group C] received a PPM. Among the EPS group: 9 patients (22.5%) with HV>65ms underwent PPM [group B2], while 11 patients with HV<65ms (27.5%) were discharged without PPM [group B1]. During a one-year follow-up only one patient required late PPM [group B1]. Mortality was higher among the subgroups with PPM [B2 and C] compared to the subgroups without a PPM [A and B1]: 4 vs. 1 patient accordingly. Conclusions The presented electrophysiology-guided algorithm for patients with persistent LBBB after TAVR appears safe and efficient, with a modest incidence of PPM (17.6% of the total cohort) during hospitalization and a minimal need for late PPM at one year follow-up. Importantly, there was no excess of mortality among patients who were discharged without a pacemaker implantation. Thus, we suggest that the presented algorithm may serve as a reliable strategy to distinguish between individuals with new onset persistent LBBB after TAVR who require PPM compared to those in whom a PPM can be safely avoided.

Post-operative atrial fibrillation after noncardiac surgery: diagnostic role of ambulatory rhythm monitoring for recurrent arrhythmia after hospital discharge

Abstract Introduction Postoperative atrial fibrillation (POAF) after noncardiac surgery constitutes 10-15% of all cases of incident atrial fibrillation (AF) in the community and has been associated with an increased risk of stroke. The risk of subsequent AF among patients with POAF is not well defined. Purpose To evaluate the role of systematic 30-day electrocardiographic (ECG) monitoring in the detection of AF recurrence after POAF. Methods In a prospective interventional study, patients who underwent major noncardiac surgeries and had new AF documented by ECG in the post-operative period between May 2022 and April 2023 were identified. For these patients, a 30-day ambulatory ECG monitor was recommended upon discharge, with final ordering deferred to the primary inpatient teams. Rates of recurrent AF of any duration detected by 30-day monitoring plus routine care versus routine care alone after the surgery were compared. Results Eighty-five patients with new-onset POAF were included (mean age 72 years, male 67%). Of these, 35 (41%) patients underwent up to 30 days [median 23 (IQR 6-27) days] of continuous ECG monitoring after hospital discharge. There were no significant differences in baseline characteristics between patients who did or did not undergo monitoring (Table 1). During median 281 (IQR 197-385) days of follow-up, recurrent AF was documented in 14/35 (40%) patients in the monitoring group as opposed to 7/50 (14%) patients in the usual care group (log-rank p=0.003, Figure 1). The median time from day of surgery until documented AF recurrence was 25 (IQR 6-53) days in the monitoring group and 66 (IQR 25-145) in the usual care group. Overall, 81% of recurrent AF events in both groups were detected in the first 3 months after surgery. The median burden of AF in the cardiac monitoring group was 7% (IQR 1-15), with the longest AF event lasting a median of 6 (IQR 2-18) hours. Anticoagulation for AF was prescribed in 24/64 (37%) patients with POAF without recurrence and in 16/21 (76%) patients with recurrent AF. Conclusion Recurrent AF following POAF is common and detected most frequently in the first 3 months after noncardiac surgery. Systematic ambulatory rhythm monitoring is associated with a higher rate of AF detection following hospital discharge and may identify a patient subgroup who might benefit from anticoagulation therapy.Table 1Figure 1

VASOSPASTIC INFARCTION STARTED WITH PULSELESS ELECTRICAL ACTIVITY CARDIAC ARREST

Abstract We report the case of a 48–year–old female with a special history of ischemic heart disease. It started in 2021 with an acute anterior ST myocardial infarction: the coronary angiography showed subocclusive stenosis at the first tract of the left anterior descending (LAD), without other coronary stenoses. The patient was treated with primary PCI + DES; the echocardiogram showed EF 30% and akinesia of apex, intermediate segments of anterior wall and interventricular septum. During the same hospitalization the patient experienced recurrence of angina with transient ST elevation in the anterior and inferior leads; a control coronary angiography was unchanged. She was started on therapy with nitrates and diltiazem up to the tolerated dose, statin as well as antiplatelet and anticoagulant therapy due to apical thrombus. She underwent ICD implantation in primary prevention in January 2022. During 2022, there were several accesses to the ED for vasospastic angina despite medical therapy at the maximum tolerated dose. In October 2023 the patient experienced an acute chest pain followed by cardiac arrest, pulseless electrical activity and acute cardiogenic shock. After resuscitation procedures, she underwent an emergency coronary angiography which showed excellent result of the previous PCI, as well as stenosis of the distal edge of the stent resolving after injection of i.c. nitrates. No arrhythmic events at ICD recording and continuous electrocardiographic monitoring in ICU were observed. Cardiac MRI showed areas of subendocardial LGE involving the apex, anterior, anterolateral and septal segments due to ischemic scar; we also observed areas of edema and LGE with an ischemic pattern at the infero–septal and inferior wall in toto, suggesting recent ischemia; EF was 31%. During hospitalization the patient experienced episodes of typical angina with poor response to medical therapy at the maximum tolerated dose. The current clinical case most likely points to acute myocardial infarction due to vasospasm of the right coronary artery with acute pump failure resulting in cardiac arrest and no specific recommendations exist in recent cardiologic guidelines on the strategy to adopt for this acute clinical setting. In the hypothesis of a vasospastic pathogenesis of the problem, counseling for modulation of the stellate ganglion was requested.

Typical Atrial Flutter in acute coronary syndrome with ST segment elevation: incidence, predictive factors and related mortality.

Background: Typical Atrial Flutter in acute coronary syndrome with ST segment elevation is very rare and never reported as a separate electrocardiographic entity, but associated with atrial fibrillation. Its incidence isn’t reported in the literature, and no data about its predictive factors or related mortality, also its epidemiological data is lacking in Algeria. Aims: The main objective of our study is the determination of the frequency of typical atrial flutter in acute coronary syndrome with ST segment elevation, the secondary objective was the analysis of its predictive factors, and related mortality. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached for continuous ECG monitoring during 48 hours Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of typical atrial flutter is 0.4 % (2 patients), CI 95%: [0%-1%], multivariate analysis identified right heart failure as the only predictive factor. The risk of mortality expressed by Hazard Ration (HR) is 27 (CI95%: [3.5-207], p = 0.001); right heart failure is the only predictive factor of mortality identified in our study. Conclusion: typical atrial flutter is very rare in acute coronary syndrome with elevated ST segment, its predictive factor according to our study is right heart failure, and its occurrence increases the risk of hospital mortality.

Accelerated Idioventricular Rhythm in Acute Coronary Syndrome with ST Segment Elevation: Clinical Significance

Background: Accelerated Idioventricular rhythm in acute coronary syndrome with ST segment elevation is common after thrombolysis and it is relatively benign; its occurrence is considered as a sign of reperfusion of the occluded coronary artery. Aims: The main objective of our study is the determination of the frequency of Accelerated Idioventricular rhythm in acute coronary syndrome with ST segment elevation after thrombolysis, the secondary objective is checking with coronary angiography if this rhythm really means the success of thrombolysis and reperfusion of the occluded coronary artery. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached in 448 patients, for continuous ECG monitoring during 48 hours, coronary angiography was performed in 329 patients. Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of Accelerated idioventricular rhythm recorded by the Holter ECG is 17.2 % (77 patients), CI 95%: [13.7%-20.7%], this frequency is 18.71 % (73 patients) CI 95%: [14.8 %-22.6%] in patients undergoing thrombolytic treatment. There is no significant difference between the frequencies of persistence of chest pain in the groups of patients with or without accelerated idioventricular rhythm after thrombolysis: 5.47 % (4 patients) versus 5.99 % (19 patients) respectively, p = 0.979; also for the frequencies of persistence of ST segment elevation after thrombolysis: 4.10 % (3 patients) versus 6.94 % (22 patients) respectively, p = 0.476). The frequency of occluded coronary artery (TIMI 0) is low in group of patients with accelerated idioventricular rhythm 14.51 %, (9 patients) compared to group of patients without this rhythm 21.39 % (52 patients), but the difference isn’t significant (p= 0.227). Conclusion: Accelerated idioventricular rhythm is common in acute coronary syndrome with elevated ST segment and generally considered as a sign of reperfusion; in our study, this rhythm may occur even in the absence of reperfusion of the occluded coronary artery and does not necessarily mean reperfusion or success of thrombolysis.