Search Results (21)

Cardiac electrophysiology (EP) is inherently data-centric, spanning brief 12-lead electrocardiograms (ECGs), high-density electroanatomic maps, and continuous device-based monitoring. This data volume can strain provider workflows while creating an opportunity for artificial intelligence (AI). Machine learning (ML) and its deep learning subfield extract clinically actionable patterns from complex electrical signals. This narrative review summarizes contemporary AI applications across the major domains of EP. In arrhythmia detection, deep neural networks classify rhythms at a level comparable to cardiologists on internal test sets, identify occult atrial fibrillation (AF) from a normal sinus-rhythm ECG, and, through consumer wearables, extend screening to ambulatory populations. In catheter ablation, an AI algorithm that adjudicates intracardiac electrogram dispersion improved single-procedure freedom from AF in a randomized trial of persistent AF, and ML models help predict arrhythmia recurrence; we distinguish these from adjacent non-AI technologies, such as computed-tomography integration and three-dimensional mapping, that reduce fluoroscopy but are not themselves AI. In cardiac implantable electronic devices (CIEDs), AI-based filtering lowers false-positive alert burden, and multi-parametric algorithms provide earlier prediction of heart-failure decompensation. ML models may refine patient selection for cardiac resynchronization therapy (CRT) and, using late-gadolinium-enhancement cardiac magnetic resonance, may sharpen arrhythmic-risk and implantable cardioverter-defibrillator (ICD) decision-making. AI-enhanced ECG broadens the standard ECG into a low-cost screening tool for channelopathies, dyskalemias, and ventricular dysfunction. Important barriers remain, including limited external validation, incomplete explainability, and a scarcity of prospective outcome trials. Full article

Background: Wearable cardioverter-defibrillators (WCDs) are equipped with the TRENDS remote-monitoring system, enabling continuous assessment of arrhythmias, physiological parameters, and patient-reported outcomes. This study evaluated the clinical utility of TRENDS-integrated WCD management and compared it with a historical control. Methods: We prospectively analyzed 36 consecutive patients who received a WCD with TRENDS between 2019 and 2024 and compared them with 30 historical controls treated before the implementation of TRENDS. Results: The WCD indications were heart failure as primary prevention (64%) and acute coronary syndrome with ventricular arrhythmias (28%). Among 18 patients who met the criteria for an implantable cardioverter-defibrillator (ICD), including 1 patient with WCD shock, 9 ultimately underwent ICD implantation. The mean daily WCD wear-time was 21.3 h and did not differ significantly from that of the historical control. The response rate to health-related questionnaires was 89%. TRENDS detected symptom exacerbation in 31% of patients, weight gain in 19% of patients, and missed medication in 19% of patients. Daily step-count was significantly lower in patients with ICD indications than in those without (5012 ± 2980 steps vs. 7977 ± 3584 steps, p = 0.01). TRENDS data also aided in initiating anticoagulation therapy and optimizing beta-blocker therapy. Conclusions: TRENDS provided clinically actionable physiologic and patient-reported information that supported individualized cardiovascular management. Full article

We report two cases of prolonged “unexpected” asystoles in patients with a wearable cardioverter-defibrillator (WCD) and a subcutaneous implantable cardioverter-defibrillator (ICD), respectively, which were promptly recognized and successfully managed. As these devices are designed to recognize and treat malignant tachyarrhythmias but do not provide pacing capabilities, it is crucial to identify patients with paroxysmal conduction disorders who might require backup pacing. For this reason, it is also important to leverage the monitoring features of both devices and their ability to detect the occurrence of bradyarrhythmias. Full article

Background: The wearable cardioverter defibrillator (WCD) has emerged as a valuable tool used for temporary protection from sudden cardiac death. However, since the WCD uses surface electrodes to detect arrhythmias, it is susceptible to inappropriate detection. Although shock conversion rates for the WCD are reported to be high for detected events, its efficacy in clinical practice tends to be degraded by patient noncompliance. Reasons for this include wearer discomfort and frequent false alarms, which may interrupt sleep and generate anxiety. Up to now, data on the incidence of false alarms emitted by the WCD and their predictors are rare. Objectives: The aim of our study was to assess the relationship between both artifact sensing and episode misclassification burden and wearing compliance in patients with a WCD (ZOLL LifeVest™ 4000 system, ZOLL CMS GmbH, Cologne, Germany). Methods and Results: We conducted a single-center retrospective observational study, analyzing patients with a WCD prescribed at our institution. A total of 134 patients (mean age 51.7 ± 13.8 years, 79.1% male) were included. Arrhythmia recordings were analyzed and categorized as non-sustained ventricular tachycardia, sustained ventricular tachycardia or fibrillation, artifact sensing or misclassified episodes. Indication for WCD prescription was both primary and secondary prophylaxis. A total of 3019 false WCD alarms were documented in 78 patients (average number of false alarms 38.7 ± 169.5 episodes per patient) over a mean WCD wearing time of 71.5 ± 70.9 days (daily WCD wearing time 20.2 ± 5.0 h). In a total of 78 patients (58.2% of the study population), either artifact sensing (76.9%), misclassified episodes (6.4%), or both (16.7%) occurred. Misclassified episodes included sinus tachycardias, atrial flutter, atrial fibrillation, premature ventricular contractions (PVCs), and intermittent bundle branch block. A multiple linear regression identified loop diuretics (regression coefficient [B] −0.11; 95% CI −0.21–(−0.0001); p = 0.049), angiotensin receptor–neprilysin inhibitors (ARNIs) (B −0.11; 95% CI 0.22–(−0.01); p = 0.033), and a higher R-amplitude of the WCD baseline electrocardiogram (ECG) (B −0.17; 95% CI −0.27–(−0.07); p = 0.001) as independent predictors for a lower number of artifact episodes per day. In addition, atrial fibrillation (B 0.05; 95% CI 0.01–0.08; p = 0.010), and calcium antagonists (B 0.07; 95% CI 0.02–0.12; p = 0.012) were independent predictors for increased numbers of misclassified episodes per day, while beta-blockers seemed to reduce them (B −0.06; 95% CI −0.10–(−0.01); p = 0.013). Patients terminated 61.0% of all false alarms manually by pressing the response button on average 1.9 times per false alarm with overall 3.6 manual terminations per affected patient per month. Conclusions: In conclusion, false alarms from the ZOLL LifeVest™ system were frequent, with artifact sensing being the most common cause. Hence, the occurrence of false alarms represents a significant side effect of WCD therapy, and efforts should be made to minimize false alarms. Full article

Background/Objectives: Sudden cardiac death (SCD) remains a major global health concern and represents one of the most common causes of mortality due to cardiovascular diseases. The wearable cardioverter–defibrillator (WCD) is an innovative, non-invasive medical device designed to provide continuous heart monitoring and immediate defibrillation in patients at risk for SCD. The study aimed to assess the efficacy of WCD usage in patients awaiting decision on therapy with implantable cardioverter–defibrillators (ICDs). Methods: We explored the clinical applications, benefits, and limitations of WCD usage within the BIA-VEST registry in Poland over the years 2021–2023. The study included 10 patients with a mean age of 49.1 ± 12.02 years. Results: All patients demonstrated good tolerance and compliance with the LifeVest WCD, wearing it for an average of 93.1 days, about 22.8 h per day (95.7% of the time). No interventions from LifeVests were recorded, and there were no effective, ineffective, or inadequate discharges. After the first follow-up echocardiography, five patients still required ICDs. Due to improved LVEF and overall condition in six out of ten patients undergoing WCD bridge therapy, ICD implantation was finally waived. Conclusions: The WCD acts as a bridge to therapy, such as ICD implantation or cardiac surgery, and may be particularly beneficial for patients with transient or evolving conditions, such as structural heart diseases and life-threatening ventricular arrhythmias. Full article

Heart failure (HF) is a growing issue in developed countries; it is often the result of underlying processes such as ischemia, hypertension, infiltrative diseases or even genetic abnormalities. The great majority of the affected patients present a reduced ejection fraction (≤40%), thereby falling under the name of “heart failure with reduced ejection fraction” (HFrEF). This condition represents a major threat for patients: it significantly affects life quality and carries an enormous burden on the whole healthcare system due to its high management costs. In the last decade, new medical treatments and devices have been developed in order to reduce HF hospitalizations and improve prognosis while reducing the overall mortality rate. Pharmacological therapy has significantly changed our perspective of this disease thanks to its ability of restoring ventricular function and reducing symptom severity, even in some dramatic contexts with an extensively diseased myocardium. Notably, medical therapy can sometimes be ineffective, and a tailored integration with device technologies is of pivotal importance. Not by chance, in recent years, cardiac implantable devices witnessed a significant improvement, thereby providing an irreplaceable resource for the management of HF. Some devices have the ability of assessing (CardioMEMS) or treating (ultrafiltration) fluid retention, while others recognize and treat life-threatening arrhythmias, even for a limited time frame (wearable cardioverter defibrillator). The present review article gives a comprehensive overview of the most recent and important findings that need to be considered in patients affected by HFrEF. Both novel medical treatments and devices are presented and discussed. Full article

Unlimited access to ECGs using an over-the-counter smartwatch constitutes a real revolution for our discipline, and the application is rapidly expanding to include patients with cardiac implantable electronic devices (CIEDs) such as pacemakers (PMs) and implantable cardioverter defibrillators (ICDs). CIEDs require periodic evaluation and adjustment by healthcare professionals. In addition, implanted patients often present with symptoms that may be related to their PMs or ICDs. An ECG smartwatch could reveal information about device functioning, confirm normal device function, or aid in the case of device troubleshooting. In this review, we delve into the available evidence surrounding smartwatches with ECG registration and their integration into the care of patients with implanted pacemakers and ICDs. We explore safety considerations and the benefits and limitations associated with these wearables, drawing on relevant studies and case series from our own experience. By analyzing the current landscape of this emerging technology, we aim to provide a comprehensive overview that facilitates informed decision-making for both healthcare professionals and patients. Full article

Background: After acute myocardial infarction (AMI), patients are at risk of sudden cardiac death. The VEST trial failed to show a reduction in arrhythmic mortality in AMI patients with an LVEF ≤ 35% prescribed with a WCD, having a lower-than-expected WCD wearing compliance. Objectives: The aim was to investigate on outcomes of patients in a real-world Austrian cohort with good compliance. Methods: A retrospective analysis of all eligible Austrian WCD patients according to the VEST trial inclusion and exclusion criteria between 2010 and 2020 was performed. Results: In total, 105 Austrian patients (64 ± 11 years, 12% female; LVEF 28 ± 6%) received a WCD for a median of 69 (1; 277) days after AMI (wearing duration 23.5 (0; 24) hours/day). Within the first 90 days, 4/105 (3.8%) patients received 9 appropriate shocks (2 (1; 5) shocks). No inappropriate shocks were delivered, and 3/105 (2.9%) patients died during follow-up. Arrhythmic mortality (1.9% Austria vs. 1.6% VEST, p = 0.52), as well as all-cause mortality (2.9% vs. 3.1%, p = 0.42) was comparable in both cohorts. Conclusions: The WCD is a safe treatment option in a highly selected cohort of patients with LVEF ≤ 35% after AMI. However, despite excellent WCD wearing duration in our cohort, the arrhythmic mortality rate was not significantly different. Full article

The wearable cardioverter defibrillator (WCD) has been proven to be effective in preventing sudden cardiac death (SCD) in patients soon after acute myocardial infarction (AMI) and left ventricular ejection fraction (LVEF) ≤35%. The aim of this study was to assess whether a WCD may shorten the length of an initial hospital stay (total length, days in the intensive care unit (ICU) and in the acute cardiac care unit (ACCU)) among these patients. This was a single-centre, retrospective observational study of patients referred for the management of SCD risk post-AMI and LVEF ≤35%, in a tertiary care hospital. The clinical characteristics and length of index hospitalization of the group of patients discharged, with or without WCD, were compared. A propensity score analysis was performed, then weighted regression models were conducted. A total of 101 patients in the WCD group and 29 in the control group were enrolled in the analysis. In the weighted regression models, WCD significantly reduced the days spent in ACCU (p < 0.001). WCD patients had significantly fewer days spent in ACCU (5.5 ± 2.6 vs. 8.4 ± 12.8 days, p < 0.001) and shorter hospitalizations (10.2 ± 5.7 vs. 13.4 ± 17.6 days, p = 0.005), compared with the control group. It was concluded that the WCD appears to reduce the total length of hospitalization and lengths of stay in ACCU for patients post-AMI and with left ventricular dysfunction. Full article

The study was designed to assess patient adherence to wearable cardioverter defibrillator as an indicator of device effectiveness. The patient training is not widely properly standardized. We enrolled 25 patients with a wearable cardioverter defibrillator to prevent sudden cardiac death between June 2020 and August 2022. Among them, 84% were male with a median age of 63.6 years. The indication was an ischemic (44%) and a non-ischemic (56%) disease. The patients were followed-up until the decision to upgrade to an implantable device was taken. We trained the patients according to our suggested protocol. The median wear time was 90 days, and the median daily wear time was 23.5 h, similar throughout sex, age, and indication groups. In total, 24% of the participants underwent cardioverter defibrillator implantation. Between the device-implanted and non-implanted groups, left ventricular ejection fraction and left ventricular indexed end-diastolic volume were significantly different (EF 35.8 ± 12 vs. 46.4 ± 8.5%, p = 0.028, iEDV 108 ± 52 vs. 70.7 ± 21.1 mL/m², p = 0.024). We did not find any differences in cardiac magnetic resonance data, even though all patients who underwent device implantation had late gadolinium enhancement spots. Our results support standardized patient training to obtain great patient adherence to the instructions to the wearable device and therefore its effectiveness. Full article

Heart failure with reduced ejection fraction (LV-EF < 35%) is diagnosed in app. 11,000,000 patients worldwide. For the treatment of these patients, guideline directed medical therapy has proven to reduce mortality and rehospitalization regardless of the disease’s etiology. It is implemented to treat clinical symptoms by improving the left ventricular ejection fraction. Patients with a transient risk of ventricular tachycardia and sudden cardiac death can be protected by a defibrillator vest. The defibrillator vest is capable to detect and terminate ventricular arrhythmias during Guideline Directed Medical Therapy (GDMT). It is based on the recommendations of the European society of cardiology for 3 months. Afterwards, the WCD wear time could be prolonged, or, in case of persistent low ejection fraction (LV-EF ≤ 35%), an implantable cardioverter defibrillator (ICD) should be implanted, as shown in the WEARIT-II-registry. Our goal was to evaluate the effects of GDMT on LV-recovery and reduction of ICD implantations under protection with a defibrillator vest—depending on the uptitration of GDMT. Methods: 339 consecutive patients between August 2017 and September 2020 with newly diagnosed cardiomyopathy and an EF ≤ 35% were analyzed retrospectively by chart review. All patients were protected by a wearable cardioverter defibrillator (WCD). GDMT as recommended by the ESC started at discharge from hospital. The left ventricular ejection fraction (LV-EF) was determined by transthoracic echocardiography at week 4, 8 and at week 12 (in case of prolonged WCD wear time). Uptitration was performed after 4 and 8 weeks during patient visits. We focused on baseline medication as per GDMT and the dosage increase at week 4, 8 and 12. The aim was the uptitration to the maximum dosage tolerated by the patient. We also compared the LV-EF improvement in the group with and without uptitration of medication dosage. Results: The patient age was, on average, 63.2 years (SD ± 11.9 years). A total of 129 pts (38%) had ICM, 196 (58%) had NICM (incl 66 pts (19%) with DCM and 51 pts (15%) with Myocarditis, 79 pts (24%) with unknown origin) and 14 pts (4%) had other entities (e.g., Tachycardiomyopathy). In total, 21 pts (6%) had an LV-EF of less than 16%, 130 pts (38%) between 16–25% and 183 pts (54%) between 26–35%. GDMT started at discharge from the hospital included treatment with beta blocker for 327 pts (96.5%), ACE-inhibitors/Angiotensin/ARNI for 283 pts (83.5%) and Mineralcorticoid receptor antagonists (MRA) for 334 pts (88.4%). Uptitration was performed in all groups at a rate of 82.3%, 91.1% and 81.0% after 4 weeks and 64.7%, 50.3% and 66.3% after 8 weeks, respectively. After 4 weeks, 25 pts (7.4%) and, after 8 weeks, 171 pts (50.4%) had an EF increase of 5% or more (mean 14.2%). After 4 weeks, 81 patients had an LV-EF more than 35%. A total of 169 pts had a wear time of 12 weeks and an improvement of LVEF of more than 35%. Interestingly, in our study we did not find a significant difference in LV-EF improvement between the group with no uptitration and the group with uptitration. Conclusions: Guideline-directed medical therapy under protection with a WCD from ventricular arrhythmia can reduce the need for implantation of an ICD and can lead to an improvement of ejection fraction. Interestingly, the LV-EF improvement depends on the GDMT at discharge. Current guidelines recommend an initiation of all therapy columns of GDMT (sacubitril/valsartan, ACE-inhibitor/AT1-blocker, mineralcorticoidreceptorblocker, beta blocker) at once and further uptitration to the maximal dosage (ESC Guidelines 2021). A further uptitration of all drugs of GDMT should lead to improvement of LV-EF and consequently to a reduction in ICD implantations. Full article

Ventricular arrhythmia (VA) is a leading cause of sudden death and health deterioration. Recent advances in predictive analytics and wearable technology for behavior assessment show promise but require further investigation. Yet, previous studies have only assessed other health outcomes and monitored patients for short durations (7–14 days). This study explores how behaviors reported by a consumer wearable can assist VA risk prediction. An exploratory observational study was conducted with participants who had an implantable cardioverter-defibrillator (ICD) and wore a Fitbit Alta HR consumer wearable. Fitbit reported behavioral markers for physical activity (light, fair, vigorous), sleep, and heart rate. A case-crossover analysis using conditional logistic regression assessed the effects of time-adjusted behaviors over 1–8 weeks on VA incidence. Twenty-seven patients (25 males, median age 59 years) were included. Among the participants, ICDs recorded 262 VA events during 8093 days monitored by Fitbit (median follow-up period 960 days). Longer light to fair activity durations and a higher heart rate increased the odds of a VA event (p < 0.001). In contrast, lengthier fair to vigorous activity and sleep durations decreased the odds of a VA event (p < 0.001). Future studies using consumer wearables in a larger population should prioritize these outcomes to further assess VA risk. Full article

Background: Wearable cardioverter-defibrillators (WCDs) are a well-established tool to bridge the recovery time of left ventricular ejection fraction (LVEF) until the implantation of an implantable cardioverter defibrillator (ICD), as recommended by the current guidelines. Besides their function to detect and treat malignant arrhythmias, WCDs may be used as a telemonitoring system. In this study, we sought to illustrate and discuss the telemonitoring potential of WCDs and to analyze physical activity in specific patient cohorts. Methods and Results: We retrospectively included 140 patients with reduced LVEF who were prescribed WCDs in our clinic. We analyzed the patients’ physical activity (n = 105 with a WCD compliance above 21 h/day), body position and resting position. We found a reduced physical activity in women and in patients over the age of 65 compared to younger patients. Furthermore, the patients who were overweight or obese showed significantly reduced physical activity compared to the patients with a normal weight (6365 ± 3572 vs. 4972 ± 2476 vs. 7045 ± 3521, p = 0.02). Conclusion: WCDs may be used as a telemonitoring and intervention tool in patients with reduced LVEF. Specific patient groups may benefit from guidance from their treating physician regarding physical activity. Full article

Guideline-directed medical therapy (GDMT) is crucial in reducing mortality in patients with heart failure with heart rate lowering by a beta blocker (BB) being an important therapeutic concept. We aimed to assess the usefulness of a wearable cardioverter/defibrillator (WCD) to provide detailed information about heart rate for managing patients with reduced left ventricular ejection fraction (LVEF) and symptoms of heart failure and to correlate mortality with the mean heart rate. A total of 4509 consecutive patients (mean age: 59 + 13 years, 88% male) were analyzed retrospectively. All patients had reduced LVEF and were prescribed a WCD for protection from sudden cardiac death (SCD) during GDMT uptitration awaiting LVEF recovery. The device continuously measured nighttime and daytime HR at the beginning and end of WCD use. Patients who died during wear time had significantly higher HRs compared with survivors: daytime beginning of use (BOU), 80 ± 15 bpm vs. 76 ± 13, p < 0.01; nighttime BOU, 76 ± 14 vs. 69 ± 13, p < 0.0001; daytime end of use (EOU), 84 ± 20 vs. 73 ± 13, p < 0.0001; nighttime EOU, 80 ± 20 vs. 65 ± 12, p < 0.0001). In conclusion, HR monitoring with a WCD yields important prognostic information and may assist in optimal usage of BB in patients with low LVEF. Full article

In patients with newly diagnosed heart failure with reduced ejection fraction (HFrEF), three months of optimal therapy are recommended before considering a primary preventive implantable cardioverter-defibrillator (ICD). It is unclear which patients benefit from a prolonged waiting period under protection of the wearable cardioverter-defibrillator (WCD) to avoid unnecessary ICD implantations. This study included all patients receiving a WCD for newly diagnosed HFrEF (n = 353) at our center between 2012 and 2017. Median follow-up was 2.7 years. From baseline until three months, LVEF improved in patients with all peripartum cardiomyopathy (PPCM), myocarditis, dilated cardiomyopathy (DCM), or ischemic cardiomyopathy (ICM). Beyond this time, LVEF improved in PPCM and DCM only (10 ± 8% and 10 ± 12%, respectively), whereas patients with ICM showed no further improvement. The patients with newly diagnosed HFrEF were compared to 29 patients with a distinct WCD indication, which is an explantation of an infected ICD. This latter group had a higher incidence of WCD shocks and poorer overall survival. All-cause mortality should be considered when deciding on WCD prescription. In patients with newly diagnosed HFrEF, the potential for delayed LVEF recovery should be considered when timing ICD implantation, especially in patients with PPCM and DCM. Full article