Prevalence of early repolarisation/J wave patterns in the normal population

Early repolarization pattern on ECG predicts worse outcomes in patients hospitalized due to chronic heart failure decompensation

BACKGROUND

To improve the outcomes of patients with chronic heart failure (CHF), it is important to identify reliable prognostic tools. Early repolarization pattern (ER) on 12‑lead electrocardiogram (ECG) is a predictor of worse outcomes, which has been widely researched in the general population but not in the CHF population.

OBJECTIVE

To evaluate the incidence and prognostic value of ER and compare its prognostic significance with other non-invasive diagnostic methods for CHF outcomes and hospital readmissions.

METHODS

The study included 301 patients (166 men and 135 women) hospitalized for CHF decompensation. CHF diagnosis was confirmed according to the current guidelines. The patients underwent standard tests and impedance cardiography (ICG) at enrollment and on the day of discharge.

RESULTS

Thirty-one confirmed ER cases (10.3%) were enrolled. During a median follow-up period of 18 months, 128 cardiac-related deaths were observed (42.5%), with 23 (74.2%) and 105 (38.9%) patients in the ER and non-ER groups, respectively (p < 0.001). The ER group had more readmissions than the non-ER group did at 6-months (2 [1, 2] vs. 1 [1, 2]; p=0.04) and 12-months (3 [2-4] vs. 2 [1-3]; p<0.001). ER on ECG (hazard ratio [HR] 2.59; 95% confidence interval [CI] 1.64-4.07; p<0.001), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels ≥425.5 pmoL/L (HR 5.1; 95% CI 3.33-7.83; p < 0.001), thoracic fluid content (TFC) ≥36.9 1/kΩ (HR 4.6; 95% CI 2.7-7.85, p < 0.001), and left ventricular ejection fraction (LVEF) ≤40% (HR 4.94; 95% CI 2.83-8.65; p < 0.001) were independently and significantly associated with cardiac death.

CONCLUSIONS

The combination of ER, LVEF ≤40%, NT-proBNP, or TFC provides an incremental prognostic value for cardiac-related death in patients with CHF.

Frequent coexistence of early repolarization pattern, J-point elevation, and high Sokolow-Lyon voltage in young men

Background

Earlier studies have shown male dominance of an early repolarization (ER) pattern and frequent coexistence with high Sokolow-Lyon voltage. Although possible involvement of androgen is speculated, the underlying mechanism has not been clarified yet. Previous studies were conducted in adult populations or only in children, and there has been no study in which the ER pattern was investigated in a series of individuals ranging from children before puberty to adults.

Methods

We included 600 individuals comprising six groups according to age: 10-14 years old, 15-19 years old, twenties, thirties, forties, and fifties. Each group had 50 males and 50 females. The distribution of an ER pattern and related ECG parameters were assessed by age and gender.

Results

In early teenagers, there was no significant gender difference in the prevalence of an ER pattern (24% in men vs. 28% in women, p = .82). The prevalence of an ER pattern increased after puberty and reached a peak in men in their twenties (42%). With further advance of age, the prevalence of an ER pattern decreased. On the other hand, the prevalence of an ER pattern in women peaked at 28% in teenagers, and it decreased through twenties (20%) to thirties (10%). Similar male dominance after puberty was observed in Sokolow-Lyon voltage and J-point elevation but not in P-wave amplitude.

Conclusion

The prevalence of an ER pattern, Sokolow-Lyon voltage, and J-point elevation are all augmented after puberty and decrease with aging, leading to frequent coexistence of these ECG findings in young men.

Electrocardiographic Changes Associated with Early Repolarization Pattern in Healthy Young Males

Background and Objectives: Early repolarization pattern (ERP) has recently been shown to be related with an increased risk of ventricular arrhythmias in susceptible individuals. Materials and Methods: We studied the ERP-associated ECG changes, with potential clinical relevance, in 220 young (age 22.1 ± 1.6 years), healthy, male subjects using 12-lead ECG recordings. A total of 38 subjects (17.3%) fulfilled the diagnostic criteria for ERP, and a total of 90 ECG characteristics were compared between the groups of subjects with and without ERP. Results: None of the ECGs were pathological, and 22 ECG parameters differed significantly (p < 0.05) between the subjects with and without ERP. Among them, the P wave-related parameters (e.g., average P wave duration: 101.5 ± 9.2 ms vs. 106.8 ± 9.9 ms, p = 0.004) and the presence of fragmented QRS complexes (67.6% vs. 92.1%, p = 0.002) revealed a potential propensity for atrial and ventricular arrhythmogenesis. The time-domain parameters of repolarization, those not corrected for QRS duration, showed shorter values (e.g., Tpeak-Tend interval: 70.9 ± 8.1 ms vs. 67.8 ± 8.0 ms, p = 0.036), reflecting the accelerated repolarization. Conclusions: Certain ECG characteristics seem to be more associated with ERP. The clinical significance of this finding at the individual level needs further prospective investigations.

Early Repolarization Syndrome, Epilepsy and Atrial Fibrillation in a young girl with novel KCND3 mutation managed with quinidine

A 6-year-old girl presented with a difficult to control epilepsy syndrome. On evaluation, additional presyncope episodes associated with polymorphic ventricular tachycardia were also noted. A diagnosis of early repolarization syndrome was made with early repolarization pattern on ECG, documented VT episodes and clinical presyncope (Proposed Shanghai score 7). Paroxysmal atrial fibrillation was also noted on 24-hour Holter recordings. The child was stabilized with isoprenaline infusion and was later discharged with arrhythmia control on quinidine and cilostazol. Genetic evaluation revealed a potassium channel KCND3 gene missense mutation. The case highlights the association of epilepsy syndrome and atrial fibrillation with early repolarization syndrome; possible association of KCND3 gene mutation with a malignant phenotype; and management issues in a small child. This article is protected by copyright. All rights reserved.

Worldwide prevalence of early repolarization pattern in general population and physically active individuals: A meta-analysis

BACKGROUND

The early repolarization pattern (ERP) has recently been associated with cardiac events such as ventricular arrhythmias and sudden cardiac death. However, estimates of the prevalence of ERP vary widely, especially between the general population and physically active individuals. We performed this systematic review and meta-analysis to quantitatively evaluate the worldwide prevalence of ERP in the general population and physically active individuals.

METHODS

We thoroughly searched the PubMed, EMBASE, Web of science, the Cochrane Library, and Scopus databases for relevant studies published until December 20, 2020. Studies in which prevalence was presented or could be estimated from eligible data were included. The pooled prevalence was analyzed using a random-effect model.

RESULTS

Finally, we included 29 studies (182,135 subjects) in the general population and 14 studies (8087 subjects) in the physically active individuals. The worldwide pooled prevalence of ERP in the general population was 11.6% (95% confidence interval [CI]: 10.0%-13.3%). The incidence of ERP was 17.0% and 6.2% in men and women, respectively. The prevalence was 20.9% in blacks, 13.4% in Asians, and 10.1% in Caucasians. Additionally, the prevalence of ERP in physically active individuals was 33.9% (95% CI: 25.3%-42.6%).

CONCLUSION

A significant difference in the worldwide prevalence of ERP is revealed in this study. The ERP is highly prevalent in men, blacks, and physically active individuals.

Diagnostic Impact of Repeated Expert Review & Long-Term Follow-Up in Determining Etiology of Idiopathic Cardiac Arrest

Background

Recognizing the etiology of sudden cardiac arrest (SCA) has an enormous impact on the management of victims and their immediate families. A significant proportion of SCA survivors with a structurally normal heart are not offered a diagnosis and there is no clear consensus on the type and duration of follow‐up. We aimed to assess the utility of a multidisciplinary approach in optimizing diagnosis of cardiac arrest etiology during follow‐up.

Methods and Results

We retrospectively assessed 327 consecutive SCA survivors (mean age 61.9±16.2 years, 80% men) who underwent secondary prevention implantable cardioverter defibrillators between May 2015 and November 2018. The initial diagnosis was recorded at the time of admission and follow‐up diagnosis was deduced from subsequent clinic records, investigations, and outcomes of multidisciplinary team meetings. Structural heart disease accounted for 282 (86%) of SCAs. Forty‐five (14%) patients had a structurally normal heart and underwent comprehensive testing and follow‐up (mean duration 93±52 weeks). On initial evaluation, 14/45 (31%) of these received a diagnosis, rising to 29/45 (64%) with serial reviews during follow‐up. Discussion in multidisciplinary team meetings and imaging reassessment accounted for 47% of new diagnoses. No additional diagnoses were made beyond 96 weeks. Nineteen (5.8%) fatalities occurred in the entire cohort, exclusively in patients with structural heart disease.

Conclusions

Systematic comprehensive testing combined with multidisciplinary expert team review of SCA survivors without structural heart disease improves the yield and time to diagnosis compared with previously published studies. This approach has positive implications in the management of SCA survivors and their families.

Baseline ST elevation and myocardial scar: Results from the multi-ethnic study of atherosclerosis

BACKGROUND

The mechanism of ST elevation on baseline electrocardiograms (ECG) unknown but it may be associated with abnormal myocardial substrate. This paper evaluates whether clinically unrecognized myocardial scar on cardiac magnetic resonance imaging (CMR) is associated with ST elevation at baseline.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) study is a population-based cohort in the United States. Participants were aged 45 through 84 years and free of clinical cardiovascular disease at enrollment in 2000-2002. Our cohort included 1365 participants who underwent both ECG and contrast enhanced CMR in the 5th examination (2010-2012). Multivariable logistic regression examined the association of ST elevation and CMR defined regional myocardial scar after adjusting for cardiovascular risk factors.

RESULTS

Of 1365 participants (58 ±9 years, 52% men), 105 (8%) had scar on CMR. Of these, the scar in 40 participants followed an ischemic pattern and in the other 65 participants followed a non-ischemic pattern. ST elevation at the 5th examination was present in 435 participants: 40 (0.9%) had ST elevations in inferior and 427 (98%) in lateral leads. 2/40 (5%) and 22/427 (5%) participants with inferior and lateral ST elevations, respectively, had evidence of scar. 15 (1.0%) had myocardial scar noted in the basal anterior region. In the fully adjusted models, ST elevation was associated with scar in basal anterior region (OR 18.2, p = 0.031).

CONCLUSIONS

In a community population, ST elevation at baseline in the inferior or lateral leads was associated with myocardial scar in the basal inferior and anterior segments. The previously described association between ST elevation and increased mortality may be mediated by myocardial scar.

Early Repolarization vs. Acute Pericarditis Morphology: A Case Report of Electrocardiographic Mimicry

A 27-year-old male presented to the outpatient clinic with a two-week history of daily episodes of palpitations, chest pain, and shortness of breath. He also complained of fatigue and nausea that continued after he recovered from an upper respiratory infection (URI) one month prior. Of note, he described the chest pain as increasing in intensity when sitting or standing upright. Auscultation revealed regular rate and rhythm with no audible rubs or murmurs. An electrocardiogram (ECG) was performed and showed diffuse ST-segment elevations that the machine interpreted as pericarditis. Based on the patient’s symptoms and ECG findings, he was sent for an evaluation by cardiology. After he failed a trial of non-steroidal anti-inflammatory drugs (NSAIDs), the patient was started on colchicine and his symptoms ultimately resolved within a few weeks. Review of his records showed an ECG performed in the emergency department (ED) a year prior demonstrated morphology consistent with early repolarization (ER). The ECG morphology of ER, acute pericarditis (AP), and even acute myocardial infarction (AMI) can often be similar and difficult to differentiate. In this patient, confusing ER with AP may have led to unnecessary evaluation and treatment by a specialist.

Early repolarization pattern as a predictor of atrial fibrillation recurrence following radiofrequency pulmonary vein isolation

BACKGROUND

Early repolarization patterns (ERP) have been found to be associated with poor cardiovascular end points. We aimed to evaluate the ERP prevalence among patients with structurally normal hearts undergoing radiofrequency (RF) pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) ablation and its association with the AF recurrence.

METHODS

All consecutive patients who underwent RF-PVI as index procedure for paroxysmal AF in our center were evaluated.

EXCLUSION CRITERIA

structural heart disease, ongoing use of Class I/III antiarrhythmics, complete-bundle-branch-block. Lateral (I, aVL, V₅ -V₆ ), inferior (II, III, aVF), or infero-lateral (both) ERP were defined in baseline ECG as horizontal/downsloping J-point elevation ≥1 mm in two consecutive leads with QRS slurring/notching. Documented episodes of AF lasting ≥30 s were considered recurrence.

RESULTS

Of 701 cases, 434 patients (305 males, 58 ± 11 years) were included for analysis. ERP observed in 67 patients (15.4%) (Infero-lateral n = 26, inferior n = 23, lateral n = 18) which were significantly younger, demonstrating longer PR-interval and lower heart rates. At a mean follow-up of 22.1 ± 9.7 months, AF recurrences were found in 107 patients (24.6%). In middle-aged patients (≥40-<60 years; n = 206, 79% male), those with an infero-lateral ERP had higher recurrence compared with the ones without (56.3% vs. 19%; p = 0.002). Infero-lateral ERP was significantly predicting recurrence (HR 2.42, 95% CI 1.21-4.82; p = 0.01).

CONCLUSION

Early repolarization patterns was more prevalent in our AF population than in the general population. Infero-lateral ERP in baseline ECG might predict AF recurrence in the follow-up after RF-PVI in middle-aged patients.

The prognostic significance of the 12-lead ECG in peripartum cardiomyopathy

BACKGROUND

Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure, which appears in previously healthy women towards the end of pregnancy or within five months following delivery. Although the ECG is widely used in clinical practice, its prognostic value has not been established in PPCM.

METHODS

We analysed 12-lead ECGs of patients with PPCM, taken at index presentation and follow-up visits at 6 and 12 months. Poor outcome was determined by the composite endpoint of death, readmission, NYHA functional class III/IV or left ventricular ejection fraction (LVEF) of ≤35% at follow-up.

RESULTS

This cohort of 66 patients had a median age of 28.59 (IQR 25.43-32.19). The median LVEF at presentation (33%, IQR 25-40) improved significantly at follow-up (LVEF 49%, IQR 38-55, P < 0.001 at 6 months; 52% IQR 38-57, P = 0.001 at 12 months). Poor outcome occurred in 27.91% at 6 months and 41.18% at 1 year. Whereas sinus tachycardia at baseline was an independent predictor of poor outcome at 12 months (OR 6.56, 95% CI 1.17-20.41, P = 0.030), sinus arrhythmia was associated with event free survival (log rank P = 0.013). T wave inversion was associated with an LVEF ≤35% at presentation (P = 0.038), but did not predict poor outcome. A prolonged QTc interval at presentation (found in almost half of the cohort) was an independent predictor of poor outcome at 6 months (OR 6.34, 95% CI 1.06-37.80, P = 0.043).

CONCLUSION(S)

A prolonged QTc and sinus tachycardia at baseline were independent predictors of poor outcome in PPCM at 6 months and 1 year respectively.

Ventricular Arrhythmias in the Patient with a Structurally Normal Heart

Ventricular arrhythmias (VAs) are among the most common cardiac rhythm disturbances encountered in clinical practice. Patients presenting with frequent ventricular ectopy or sustained ventricular tachycardia represent a challenging and worrisome clinical scenario for many practitioners because of concerning symptoms, frequent associated acute hemodynamic compromise, and the adverse prognostic implications inherent to these cases. While an underlying structural or functional cardiac abnormality, metabolic derangement, or medication toxicity is often readily apparent, many patients have no obvious underlying condition, despite a comprehensive diagnostic evaluation. Such patients are diagnosed as having an idiopathic VA, which is a label with specific implications regarding arrhythmia origin, prognosis, and potential for pharmacologic and invasive management. Further, a subset of patients with otherwise benign idiopathic ventricular ectopy can present with polymorphic ventricular tachycardia and ventricular fibrillation, adding a layer of complexity to a clinical syndrome previously felt to have a benign clinical course. Thus, this review seeks to highlight the most common types of idiopathic VAs with a focus on their prognostic implications, underlying electrophysiologic mechanisms, unique electrocardiographic signatures, and considerations for invasive electrophysiologic study and catheter ablation. We further address some of the data regarding idiopathic ventricular fibrillation with respect to the heterogeneous nature of this diagnosis.

The Early Repolarization ECG Pattern – An Update

Early repolarization pattern (ERP), a form of J-wave syndromes, was considered long time a benign ECG phenomenon. However, recent data confirmed that certain phenotypes of ERP are related to an increased risk of sudden cardiac death (idiopathic ventricular fibrillation). Our paper gives a short and practical update regarding the main issues related to ERP: epidemiological data, molecular and electrophysiological background, clinical significance and risk stratification. At the end, the future directions of research and clinical management related to ERP are presented.

2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry

Ambulatory ECG (AECG) is very commonly employed in a variety of clinical contexts to detect cardiac arrhythmias and/or arrhythmia patterns which are not readily obtained from the standard ECG. Accurate and timely characterization of arrhythmias is crucial to direct therapies that can have an important impact on diagnosis, prognosis or patient symptom status. The rhythm information derived from the large variety of AECG recording systems can often lead to appropriate and patient-specific medical and interventional management. The details in this document provide background and framework from which to apply AECG techniques in clinical practice, as well as clinical research.

Early Repolarization Syndrome; Mechanistic Theories and Clinical Correlates

The early repolarization (ER) pattern on the 12-lead electrocardiogram is characterized by J point elevation in the inferior and/or lateral leads. The ER pattern is associated with an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). Based on studies in animal models and genetic studies, it has been proposed that J point elevation in ER is a manifestation of augmented dispersion of repolarization which creates a substrate for ventricular arrhythmia. A competing theory regarding early repolarization syndrome (ERS) proposes that the syndrome arises as a consequence of abnormal depolarization. In recent years, multiple clinical studies have described the characteristics of ER patients with VF in more detail. The majority of these studies have provided evidence to support basic science observations. However, not all clinical observations correlate with basic science findings. This review will provide an overview of basic science and genetic research in ER and correlate basic science evidence with the clinical phenotype.

Relationship between J Waves and Vagal Activity in Patients Who Do Not Have Structural Heart Disease

BACKGROUND

J waves are associated with increased vagal activity in patients with idiopathic ventricular fibrillation in several studies to date. However, the relationship between J waves and autonomic nervous activity in patients without structural heart disease remains under investigation. We investigated whether the presence of a J wave on the surface electrocardiogram (ECG) was related to increased vagal activity in patients without structural heart disease.

METHODS

This retrospective study included 684 patients without structural heart disease who had undergone Holter ECG and surface ECG monitoring. Based on the presence of J waves on the surface ECG, patients were divided into two groups: those with J waves (group 1) and those without J waves (group 2). We compared heart rate variability (HRV), reflecting autonomic nervous activity, using 24-h Holter ECG between the groups.

RESULTS

J waves were present in 92 (13.4%) patients. Heart rate (HR) in group 1 was significantly lesser than that in group 2 (P = 0.031). The ratio of low-frequency (LF) components to high-frequency (HF) components (LF/HF) in group 1 was significantly lower than that in group 2 (P = 0.001). The square root of the mean squared differences of successive NN intervals in group 1 was also significantly higher than that in group 2 (P = 0.047). In a multivariate regression analysis, male sex, HR, and LF/HF ratio remained independent determinants for the presence of J waves (P = 0.039, P = 0.036, and P < 0.001, respectively).

CONCLUSION

In patients without structural heart disease, the presence of a J wave was associated with a slow HR, male sex, and increased vagal activity, independently.

Evaluation Of Patients With Early Repolarization Syndrome

In recent years, the early repolarization pattern has emerged as a risk factor for malignant ventricular arrhythmias and sudden cardiac death. The identification of the subset of patients who are at high risk of sudden death represents a significant challenge to the clinician. Multiple clinical and ECG features have been associated with an increased risk of sudden deathin however the majority of risk factors confer a small increase in absolute risk. The present article reviews current evidence and potential management strategies in patients with early repolarization.

Transient and rapid QRS-widening associated with a J-wave pattern predicts impending ventricular fibrillation in experimental myocardial infarction

BACKGROUND

Certain types of the early repolarization phenomenon, previously considered to be benign, have been reported to be associated with ventricular fibrillation (VF), both in population-based studies and in the myocardial infarction (MI) settings.

OBJECTIVE

To analyze whether QRS widening and appearance of a J-wave pattern in experimental MI settings is predictive of VF.

METHODS

MI was induced in 32 pigs by 40-minute inflation of an angioplasty balloon in the left descending artery, and electrocardiogram was continuously recorded. Multilead QRS boundaries were computed, and QRS duration was calculated on a beat-to-beat basis during the occlusion period for each pig. An association between QRS widening and subsequent VF was studied using receiver operating characteristic curve analysis. Electrocardiograms at maximum QRS duration were reviewed for the presence of a J-wave pattern.

RESULTS

Sixteen animals had VF episodes during the occlusion period. Two peaks of QRS widening were found in all animals: the first peak immediately on left descending artery occlusion and the second peak 19.1 ± 4.0 minutes later. The magnitude of changes in the QRS width over time had significant interindividual differences. A QRS widening of ≥28 ms during a 3-minute time window was observed in 14 animals and predicted impending VF (selectivity 80%, specificity 73%, positive predictive value 57%, and negative predictive value 89%; P = .008). In 10 of 14 (71%) pigs, a J-wave pattern appeared at maximal QRS duration. The appearance of a J-wave pattern predicted VF with selectivity 80%, specificity 68%, positive predictive value 53%, and negative predictive value 88% (P = .02).

CONCLUSION

Transient QRS widening, commonly associated with a J-wave pattern, appears to predict impending VF in acute ischemia settings and motivates further clinical studies for monitoring immediate risk of VF in MI.