Prevalence and clinical correlates of early repolarization and J wave in a large cohort of subjects without overt heart disease

Prognostic Assessment of Early Repolarization/J Wave Electrocardiographic Pattern in Patients With Stable Ischemic Heart Disease

Recent studies suggested that early repolarization (ER)/J wave at the electrocardiogram (ECG) is associated with increased risk of sudden death and ventricular arrhythmias in patients with acute myocardial infarction. In this study, we prospectively assessed whether ER/J wave has any long-term prognostic implications in patients with stable ischemic heart disease (IHD). We enrolled consecutive clinically stable patients with documented IHD, referred to undergo a routine ECG. ER (typical concave ST-segment elevation) and J wave were diagnosed according to prospectively defined criteria. The final population included 617 patients with documented IHD (455 men; age 68.1 ± 11 years). ER/J wave was found in 138 patients (22.4%), 13 of whom (2.1%) showed ER and 133 (21.6%) a J wave. At a follow-up of 8.1±2.9 years, 160 deaths occurred (25.9%), 60 (9.7%) attributed to cardiovascular causes. Total mortality was lower in patients with versus those without ER/J wave (18.8% vs 28.0%; hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.40 to 0.93, p = 0.02). The difference, however, was not significant after adjustment for confounding clinical variables (HR 0.78, 95% CI 0.51 to 1.19, p = 0.25). No significant difference was found in cardiovascular death between patients with (7.2%) and those without (10.4%) ER/J wave (adjusted HR 0.78, 95% CI 0.40 to 1.55, p = 0.48). Similar results were obtained for ER and J wave separately, and for ECG location of ER/J wave (inferior or lateral/precordial) and type of J wave (notched or slurred). The ER/J wave pattern at the ECG is not associated with increased risk of long-term mortality in clinically stable patients with a documented history of IHD.

Early repolarization is independently associated with African-American race, younger age, higher BMI and lower heart rate

Background: Early repolarization (ER) is commonly seen in young adults. The goal of this study was to evaluate predictors of ER. Method: The authors used ECGs, available from 636 subjects, performed on healthy students for screening purposes. Results: The prevalence of ER was 13.5%. The prevalence of ER was higher in African-American subjects (48.0% vs 10.8%; odds ratio: 5.9; CI: 3.5-9.7; p < 0.0001), those with a BMI >25 (18.6% vs 11.7%; p = 0.02), those age <30 (16.4% vs 2.0%; p < 0.0001), male subjects (17.1% vs 8.3%; p = 0.001) and those with heart rate <70 (18.2% vs 9.2%; p = 0.001). With multivariate analysis, except gender, all other parameters remained significantly correlating with ER. Conclusion: The authors found younger age, African-American race, higher BMI and lower heart rate to be predictors of ER.

Long-Term Follow-Up of Subjects Without Overt Heart Disease With an Early Repolarization/J Wave Electrocardiographic Pattern

Aims

The “early repolarization” (ER) pattern and J wave are frequent findings on standard ECG. Controversial data have recently been reported about their prognostic implications in healthy subjects, but no longitudinal prospective study specifically designed to investigate their long-term prognostic value has hitherto been published.

Methods and Results

We prospectively enrolled 4,176 consecutive subjects with no evidence of cardiovascular disease who were referred for standard ECG recording for routine check-ups or pre-operative assessments for non-cardiovascular surgery. ECGs were prospectively assessed for the presence of ER/J wave. A 10-year follow-up was available for 3,937 patients (94.3%), 660 of whom (16.8%) showed ER/J wave whereas 3,277 did not. A total of 644 deaths occurred (16.3%), 116 (2.95%) of which were attributed to cardiovascular causes. Both total and cardiovascular mortality adjusted for clinical and laboratory variables did not differ significantly between patients with vs. without ER/J wave (HR 0.94; 95% CI 0.75–1.19; p = 0.63 and HR 0.61; 95% CI 0.31–1.21; p = 0.16, respectively). No significant association with total and cardiovascular mortality was also found in pre-specified analyses for ER and J wave alone, ER/J wave detected in specific ECG regions (i.e., inferior, lateral, precordial), and type of J wave (notched or slurred).

Conclusion

In this specifically designed prospective study of individuals without any evidence of cardiovascular disease, we found no significant association of ER/J wave with the risk of the total as well as cardiovascular mortality during long-term follow-up.

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.

Six-Year Outcome of Subjects Without Overt Heart Disease With an Early Repolarization/J Wave Electrocardiographic Pattern

"Early repolarization" (ER) is a frequent finding at standard electrocardiogram (ECG). In this study we assessed whether ER is associated with an increased risk of events, as recently suggested by some studies. We prospectively enrolled 4,176 consecutive subjects without any heart disease who underwent routine ECG recording. ER was diagnosed in case of typical concave ST-segment elevation ≥0.1 mV; a J wave was diagnosed when the QRS showed a notch or a slur in its terminal part. In this study we compared the 6-year outcome of all 687 subjects with ER/J wave and 687 matched subjects without ER/J wave (controls). Both groups included 335 males and 352 females, and age was 48.8 ± 18 years. Overall, 145 deaths occurred (11%), only 11 of which attributed to cardiac causes. No sudden death was reported. Cardiac deaths occurred in 5 (0.8%) and 6 (0.9%) ER/J wave subjects and controls, respectively (odds ratio [OR] 0.85, 95% confidence interval [CI] 0.26 to 2.80, p = 0.79). Both ER (OR 1.68, 95% CI 0.21 to 13.3, p = 0.62) and J wave (OR 0.91, 95% CI 0.28 to 3.00, p = 0.88) showed no association with cardiac death. Total mortality was 11.5% in the ER/J wave group and 10.6% in the control group (OR 1.10, 95% CI 0.78 to 1.56, p = 0.58). Both ER (OR 0.44, 95% CI 0.16 to 1.24, p = 0.12) and J wave (OR 1.20, 95% CI 0.85 to 1.70, p = 0.30) showed also no association with all-cause death. In subjects without any evidence of heart disease, we found no significant association of ER/J wave with the risk of cardiac, as well as all-cause, death at medium-term follow-up.

The Role of Holter Monitoring in the Diagnosis of Early Repolarisation Pattern

BACKGROUND

A slower heart rate can exaggerate J-point elevation in a 12-lead ECG. This study examined the role of Holter monitoring in the diagnosis of early repolarisation pattern (ERP).

METHODS

We examined 24-hour Holter recordings of 4000 consecutive patients seen at an outpatient clinic, and found 500 patients (12.5%) with ERP (based on J-point elevation magnitude maximum value≥0.1mV on the Holter recording). The highest magnitude of J-point elevation, R wave amplitude, the ratio between J-point elevation magnitude and R-wave amplitude on the same ECG lead (J/R ratio), QRS interval, and QT/QTc interval were measured on the Holter recording and on a surface 12-lead ECG of the 500 patients with ERP. The magnitude of J-point elevation, J/R ratio, and QT/QTc interval were compared between three groups: nighttime Holter recording, daytime Holter recording, and daytime surface 12-lead ECG.

RESULTS

The magnitude of J-point elevation of the nighttime Holter (0.20±0.10mV) was higher than that of the daytime in Holter (0.12±0.07mV, p<0.001) and the 12-lead ECG (0.12±0.06mV, p<0.001). There was no statistical difference in magnitude of J-point elevation between daytime Holter and surface 12-lead ECG. While all 500 patients were diagnosed with ERP based on J-point elevation maximum value J-point on Holter monitoring, only 425 (85%) patients could be diagnosed with ERP based on the surface 12-lead ECG. The J-point elevation maximum value on the nighttime Holter was negatively correlated with heart rate (r=-0.15, p=0.0007) and QTc (r=-0.13, p=0.0043), and positively correlated with R wave amplitude (r=0.46, p<0.0001), J/R ratio (r=0.69, p<0.0001), and QRS interval (r=0.29, p<0.0001).

CONCLUSIONS

The J-point elevation on nighttime Holter recording was higher than that on daytime Holter and daytime surface 12-lead ECG, and there was misdiagnosis of ERP based on daytime surface 12-lead ECG. Holter monitoring has a complementary role in the diagnosis of ERP, especially in patients with a suspected diagnosis of ERP based on daytime surface 12-lead ECG.

[Epidemiology of early repolarization pattern in Maghreb]

An early repolarization variant (ERV) in inferolateral leads has recently been associated with vulnerability to ventricular fibrillation. These studies have been conducted in the occidental countries. The prevalence of ERV in the population of the Maghreb is unknown. The aim of this study was to evaluate the prevalence and risk factors of ERV in a young population from Algeria.

METHODS

We assessed the prevalence of ERV within a population of 441 healthy subjects (mean age 25 years) using 12-lead electrocardiography. ERV was stratified by three independent cardiologists according to the J-point elevation (≥0.1mV) in the inferior, apicolateral or both leads with QRS slurring or notching.

RESULTS

The inferolateral ERV pattern was present in 55 subjects (12.4%). A malign ERV (>2mm) was present in 5 subjects (9% of ER) and ER in inferior and lateral leads in 40% of ER. An ERV pattern was more frequently associated with young age, male, bradycardia and T wave in V1 lead.

CONCLUSION

An ERV is a common finding in a healthy Algerian young population. This prevalence seems to be more important than other studies due to young age and not to a racial difference. Our population were more at risk that other studies, and we found more T waves in V1 lead in this people, due to an ethnic particularities or a phenotypic association with the Brugada syndrome.

The prevalence of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 different dog breeds

INTRODUCTION

To investigate the prevalence and amplitudes of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 other dog breeds.

ANIMALS

Electrocardiograms from 206 healthy dogs representing 11 dog breeds were included in the study. Besides Petit Basset Griffon Vendéen (PBGV; n = 23) 10 other dog breeds were included.

MATERIALS AND METHODS

An electrocardiogram ruler was used for measuring the amplitudes of the J waves. The definition of a J wave was a positive deflection at the J point of ≥0.1 mV in more than 1 lead of the bipolar standard limb leads (I, II, III) or the unipolar standard limb leads (aVL and aVF).

RESULTS

The prevalence of J waves in the PBGV (n = 23) was 91% (n = 21, standard error (SE) = 5.9%), which was significantly higher compared to seven other dog breeds (p < 0.05). The overall prevalence of J waves in all 11 dog breeds (n = 206) was 43% (n = 89, robust SE = 7.8%). There was no significant difference in the prevalence between male and female dogs (p = 0.79). Neither did age (p = 0.22) nor heart rate (p = 0.25) significantly affect the prevalence of J wave.

CONCLUSIONS

The PBGV had the highest prevalence of J waves and the highest amplitudes compared to 10 other dog breeds. However J waves were also seen in other breeds. Therefore, J waves may be considered a normal variant on the canine electrocardiogram and should not be interpreted as cardiac disease.

Early repolarization pattern: innocent finding or marker of risk?

The presence of early repolarization (ER) pattern in the 12-lead ECG, defined as elevation of the QRS-ST junction (J point) often associated with a late QRS slurring or notching (J wave), is a common finding in the general population, particularly in the inferior and precordial lateral leads. In young and healthy individuals, particularly in males, blacks and athletes, this pattern has commonly been considered to represent an innocent finding. However, experimental studies, case reports and studies on healthy subjects surviving a cardiac arrest or with primary ventricular fibrillation (VF) have suggested an association between J-point elevation and/or QRS slurring in the inferior and lateral ECG leads and the risk of VF. On the other hand, in recent epidemiological studies on large general population no significant association between ER patterns and cardiac mortality was found. In athletes, changes of the QRS-ST segment are frequent. We found that in a selected group of 21 young competitive athletes, without underlying heart disease, who experienced cardiac arrest, the prevalence of J wave and/or QRS slurring in the inferior and lateral (V4 to V6) leads was significantly higher in cases than in 365 control athletes. Following sport discontinuation, during the 36-month follow-up arrhythmia recurrences did not differ between subgroups with and without J wave or QRS slurring. Recently, other studies showed that among different patterns of ER rapidly ascending ST segment after the J point seems to be almost universally benign. The conflicting data regarding the prognostic role of ER patterns can be partly due to different definitions of ER used. This emphasizes the need for standardized methods of measurements of QRS end-J point-ST segment and for detailed definitions. The knowledge of the true significance in clinical setting of the various aspects of ER is still unclear and warrants prospective, long-term epidemiological studies.