Objectives The aim of this study was to test the hypothesis that strain echocardiography might improve arrhythmic risk stratification in patients after myocardial infarction (MI). Background ...Prediction of ventricular arrhythmias after MI is challenging. Left ventricular ejection fraction (LVEF) <35% is the main parameter for selecting patients for implantable cardioverter-defibrillator therapy. Methods In this prospective, multicenter study, 569 patients >40 days after acute MI were included, 268 of whom had ST-segment elevation MIs and 301 non–ST-segment elevation MIs. By echocardiography, global strain was assessed as average peak longitudinal systolic strain from 16 left ventricular segments. Time from the electrocardiographic R-wave to peak negative strain was assessed in each segment. Mechanical dispersion was defined as the standard deviation from these 16 time intervals, reflecting contraction heterogeneity. Results Ventricular arrhythmias, defined as sustained ventricular tachycardia or sudden death during a median 30 months (interquartile range: 18 months) of follow-up, occurred in 15 patients (3%). LVEFs were reduced (48 ± 17% vs. 55 ± 11%, p < 0.01), global strain was markedly reduced (−14.8 ± 4.7% vs. −18.2 ± 3.7%, p = 0.001), and mechanical dispersion was increased (63 ± 25 ms vs. 42 ± 17 ms, p < 0.001) in patients with arrhythmias compared with those without. Mechanical dispersion was an independent predictor of arrhythmic events (per 10-ms increase, hazard ratio: 1.7; 95% confidence interval: 1.2 to 2.5; p < 0.01). Mechanical dispersion and global strain were markers of arrhythmias in patients with non–ST-segment elevation MIs (p < 0.05 for both) and in those with LVEFs >35% (p < 0.05 for both), whereas LVEF was not (p = 0.33). A combination of mechanical dispersion and global strain showed the best positive predictive value for arrhythmic events (21%; 95% confidence interval: 6% to 46%). Conclusions Mechanical dispersion by strain echocardiography predicted arrhythmic events independently of LVEF in this prospective, multicenter study of patients after MI. A combination of mechanical dispersion and global strain may improve the selection of patients after MI for implantable cardioverter-defibrillator therapy, particularly in patients with LVEFs >35% who did not fulfill current implantable cardioverter-defibrillator indications.
Revision of the Task Force diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) has increased their sensitivity for the diagnosis of early and familial forms of ...the disease. The epsilon wave is a major diagnostic criterion in the context of ARVC/D, which, however, remains not quantifiable and therefore may leave room for substantial subjective interpretation.
The purpose of this study was to assess interobserver agreement in epsilon wave definition and epsilon wave importance for ARVC/D diagnosis.
Electrocardiographic (ECG) tracings depicting leads V1, V2, and V3 collected from individuals evaluated for ARVC/D (n = 30) were given to panel members who were asked to respond to the question whether ECG patterns meet epsilon wave definition outlined by the Task Force diagnostic criteria. The prevalence and importance of epsilon waves for ARVC/D diagnosis were assessed in a pooled data set of patients with definite ARVC/D from European and American registries (n = 815).
The number of ECG patterns identified as epsilon waves varied from 5 to 18 per reviewer (median 13 per reviewer). A unanimous agreement was reached for only 10 cases (33%), 2 of which qualified as epsilon waves and 8 as non-epsilon waves by all panel members. From a pooled data set, 106 patients reportedly had epsilon waves (13%). In 105 of 106 patients with epsilon waves (99%), exclusion of epsilon waves from the diagnostic score would not affect the "definite" diagnostic category.
Interobserver variability in the assessment of epsilon waves is high; however, the impact of epsilon waves on ARVC/D diagnosis is negligibly low. The results urge to exercise caution in the assessment of epsilon waves, especially in patients who would not otherwise meet diagnostic criteria.
Current implantable cardioverter-defibrillator (ICD) devices are equipped with a device-embedded accelerometer capable of capturing physical activity (PA). In contrast, wearable accelerometer-based ...methods enable the measurement of physical behavior (PB) that encompasses not only PA but also sleep behavior, sedentary time, and rest-activity patterns.
This systematic review evaluates accelerometer-based methods used in patients carrying an ICD or at high risk of sudden cardiac death.
Papers were identified via the OVID MEDLINE and OVID EMBASE databases. PB could be assessed using a wearable accelerometer or an embedded accelerometer in the ICD.
A total of 52 papers were deemed appropriate for this review. Out of these studies, 30 examined device-embedded accelerometry (189,811 patients), 19 examined wearable accelerometry (1601 patients), and 3 validated wearable accelerometry against device-embedded accelerometry (106 patients). The main findings were that a low level of PA after implantation of the ICD and a decline in PA were both associated with an increased risk of mortality, heart failure hospitalization, and appropriate ICD shock. Second, PA was affected by cardiac factors (eg, onset of atrial fibrillation, ICD shocks) and noncardiac factors (eg, seasonal differences, societal factors).
This review demonstrated the potential of accelerometer-measured PA as a marker of clinical deterioration and ventricular arrhythmias. Notwithstanding that the evidence of PB assessed using wearable accelerometry was limited, there seems to be potential for accelerometers to improve early warning systems and facilitate preventative and proactive strategies.
Patients with an implantable cardioverter-defibrillator (ICD) are at a high risk of malignant ventricular arrhythmias. The use of remote ICD monitoring, wearable devices, and patient-reported ...outcomes generate large volumes of potential valuable data. Artificial intelligence–based methods can be used to develop personalized prediction models and improve early-warning systems.
The purpose of this study was to develop an integrated web-based personalized prediction engine for ICD therapy.
This international, multicenter, prospective, observational study consists of 2 phases: (1) a development study and (2) a feasibility study. We plan to enroll 400 participants with an ICD (with or without cardiac resynchronization therapy) on remote monitoring: 300 participants in the development study and 100 in the feasibility study. During 12-month follow-up, electronic health record data, remote monitoring data, accelerometry-assessed physical behavior data, and patient-reported data are collected. By using machine- and deep-learning approaches, a prediction engine is developed to assess the risk probability of ICD therapy (shock and antitachycardia pacing). The feasibility of the prediction engine as a clinical tool, the SafeHeart Platform, is assessed during the feasibility study.
Development study recruitment commenced in 2021. The feasibility study starts in 2022.
SafeHeart is the first study to prospectively collect a multimodal data set to construct a personalized prediction engine for ICD therapy. Moreover, SafeHeart explores the integration and added value of detailed objective accelerometer data in the prediction of clinical events. The translation of the SafeHeart Platform to clinical practice is examined during the feasibility study.
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Results on the association between P-wave duration and the risk of atrial fibrillation (AF) are conflicting.
The purpose of this study was to obtain a detailed description of the relationship between ...P-wave duration and the risk of AF.
Using computerized analysis of electrocardiograms from a large primary care population, we evaluated the association between P-wave duration and the risk of AF. Secondary end-points were death from cardiovascular causes and putative ischemic stroke. Data on drug use, comorbidity, and outcomes were collected from administrative registries.
A total of 285,933 individuals were included. During median follow-up period of 6.7 years, 9550 developed AF, 9371 died of a cardiovascular cause, and 8980 had a stroke. Compared with the reference group (100-105 ms), individuals with very short (≤89 ms; hazard ratio HR 1.60, 95% confidence interval CI 1.41-1.81), intermediate (112-119 ms; HR 1.22, 95% CI 1.13-1.31), long (120-129 ms; HR 1.50, 95% CI 1.39-1.62), and very long P-wave duration (≥130 ms; HR 2.06, 95% CI 1.89-2.23) had an increased risk of incident AF. With respect to death from cardiovascular causes, we found an increased risk for very short (≤89 ms; HR 1.20, 95% CI 1.06-1.34), long (120-129 ms; HR 1.11, 95% CI 1.04-1.19), and very long P-wave duration (≥130 ms; HR 1.30, 95% CI 1.21-1.40) compared with the reference group (106-111 ms). Similar but weaker associations were found between P-wave duration and the risk of putative ischemic stroke.
In a large primary care population we found both short and long P-wave duration to be robustly associated with an increased risk of AF.
The electrocardiographic Tpeak-Tend interval is considered a novel risk marker of cardiac arrhythmias and cardiovascular death; however, results to date have been conflicting.
The purpose of this ...study was to investigate the association between this interval and the risk of all-cause and cardiovascular mortality, atrial fibrillation, and heart failure, allowing for nonlinear relationships.
From primary care, 138,404 individuals were included and categorized into seven groups based on Tpeak-Tend interval. Cox regression models were used to describe the association between these groups and the risk of the selected outcomes.
Compared with the reference groups (104-115 ms for all-cause mortality and 98-103 ms for all other outcomes), individuals with a Tpeak-Tend interval in lead V5 <5th percentile (58-77 ms) had hazard ratios of 1.29 (95% confidence interval CI 1.21-1.38, P <.001) for all-cause mortality, 1.31 (95% CI 1.15-1.50, P <.001) for cardiovascular death, 1.18 (95% CI 1.06-1.32, P = .003) for atrial fibrillation, and 1.52 (95% CI 1.33-1.74, P <.001) for heart failure. Individuals with a Tpeak-Tend interval ≥95th percentile (116-140 ms) had hazard ratios of 1.15 (95% CI 1.08-1.23, P <.001) for all-cause mortality, 1.30 (95% CI 1.15-1.47, P <.001) for cardiovascular death, 1.09 (95% CI 0.99-1.22, P = .088) for atrial fibrillation, and 1.28 (95% CI 1.12-1.46, P <.001) for heart failure. Similar results were obtained for leads II and V2.
We observed U-shaped associations between the Tpeak-Tend interval and risk of all-cause and cardiovascular mortality, atrial fibrillation, and heart failure.
Abstract Introduction Structural right atrial abnormalities have been described in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). However, little is known about ...electrocardiographic signs of atrial involvement in ARVC because no systematic studies have been conducted. Methods P-wave–triggered signal-averaged orthogonal electrocardiogram from 40 ARVC patients (46 ± 15 years, 16 females) was compared with recordings from age- and sex-matched healthy control subjects for assessment of P-wave duration and morphology. P-wave morphology was classified with regard to the P-wave polarity in leads X, Y, and Z. Results P-wave duration was longer in patients (135 ± 18 vs 124 ± 12 milliseconds; P = .003). Two typical P-wave morphologies were identified in the controls: positive in X and Y and negative (45%) or biphasic (55%) in Z. In patients with ARVC , typical P waves were seen in only 60%, whereas 15 patients (37%) had atypical P-wave positive in all 3 leads ( P < .0001). The presence of atypical P waves in the ARVC group was not associated with the presence of either structural or functional right ventricular abnormality. Conclusions Patients with ARVC commonly demonstrate deteriorated atrial activation expressed either as prolonged P-wave duration or abnormal P-wave morphology. The P-wave abnormalities were not secondary to right ventricular dilatation. These findings show that atrial involvement is common in ARVC and may represent yet another manifestation of the disease to be considered for inclusion in ARVC diagnostic workup.
Abstract Background Sudden infant death syndrome (SIDS) is the leading cause of death in the first 6 months after birth in the industrialized world. The genetic contribution to SIDS has been ...investigated intensively and to date, 14 cardiac channelopathy genes have been associated with SIDS. Newly published data from National Heart, Lung, and Blood Institute Grand Opportunity (NHLBI GO) Exome Sequencing Project (ESP) provided important knowledge on genetic variation in the background population. Our aim was to identify all variants previously associated with SIDS in ESP to improve the discrimination between plausible disease-causing mutations and variants most likely to be false-positive. Methods The PubMed database was searched to identify SIDS-associated channelopathy variants and the prevalence of these in the ESP population (6500 individuals) were obtained. In silico prediction tools were applied to variants present in ESP and 6 SIDS-associated variants ( CAV3 p.C72W, p.T78M; KCNH2 p.R148W, and SCN5A p.S216L, p.V1951L, p.F2004L) were genotyped in our own control population. Results Nineteen different missense variants previously associated with SIDS were identified in ESP affecting 225 of 6424 alleles. This corresponds to 1:29 individuals in the ESP population being carriers of a SIDS-associated variant. Genotyping of 6 SIDS-associated variants in our own controls revealed frequencies comparable with those found in ESP. Conclusions A very high prevalence of previously SIDS-associated variants was identified in exome data from population studies. Our findings indicate that the suggested disease-causing role of some of these variants is questionable. A cautious interpretation of these variants must be made when found in SIDS victims.
Abstract Background Despite considerable improvements in the medical management of patients with myocardial infarction (MI), patients with large MI still have substantial risk of developing heart ...failure. In the early post-MI setting, implantable cardioverter defibrillators have reduced arrhythmic deaths but have no impact on overall mortality. Therefore, additional interventions are required to further reduce the overall morbidity and mortality of patients with large MI. Methods The Pacing Remodeling Prevention Therapy (PRomPT) trial is designed to study the effects of peri-infarct pacing in preventing adverse post-MI remodeling. Up to 120 subjects with peak creatine phosphokinase >3,000 U/L (or troponin T >10 μg/L) at time of MI will be randomized to either dual-site or single-site biventricular pacing with the left ventricular lead implanted in a peri-infarct region or to a nonimplanted control group. Those randomized to a device will be blinded to the pacing mode, but randomization to a device or control cannot be blinded. Subjects randomized to pacing will have the device implanted within 10 days of MI. The primary objective is to assess the change in left ventricular end-diastolic volume from baseline to 18 months. Secondary objectives are to assess changes in clinical and mechanistic parameters between the groups, including rates of hospitalization for heart failure and cardiovascular events, the incidence of sudden cardiac death and all-cause mortality, New York Heart Association functional class, 6-minute walking distance, and quality of life. Conclusions The PRomPT trial will provide important evidence regarding the potential of peri-infarct pacing to interrupt adverse remodeling in patients with large MI.
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