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

Sudden Cardiac Death in the Young: State-of-the-Art Review in Molecular Autopsy

Sudden cardiac death (SCD) is defined as unexpected death due to a cardiac cause that occurs rapidly. Despite the identification of prevention strategies, SCD remains a serious public health problem worldwide, accounting for 15-20% of all deaths, and is therefore a challenge for modern medicine, especially when it affects young people. Sudden cardiac death in young people affects the population aged ≤ 35 years, including athletes and non-athletes, and it is due to various hereditary and non-hereditary causes. After an autopsy, if the cause remains unknown, it is called sudden unexplained death, often attributable to genetic causes. In these cases, molecular autopsy-post-mortem genetic testing-is essential to facilitate diagnostic and therapeutic pathways and/or the monitoring of family members of the cases. This review aims to elaborate on cardiac disorders marked by genetic mutations, necessitating the post-mortem genetic investigation of the deceased for an accurate diagnosis in order to facilitate informed genetic counseling and to implement preventive strategies for family members of the cases.

Primary Electrical Heart Disease-Principles of Pathophysiology and Genetics

Primary electrical heart diseases, often considered channelopathies, are inherited genetic abnormalities of cardiomyocyte electrical behavior carrying the risk of malignant arrhythmias leading to sudden cardiac death (SCD). Approximately 54% of sudden, unexpected deaths in individuals under the age of 35 do not exhibit signs of structural heart disease during autopsy, suggesting the potential significance of channelopathies in this group of age. Channelopathies constitute a highly heterogenous group comprising various diseases such as long QT syndrome (LQTS), short QT syndrome (SQTS), idiopathic ventricular fibrillation (IVF), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and early repolarization syndromes (ERS). Although new advances in the diagnostic process of channelopathies have been made, the link between a disease and sudden cardiac death remains not fully explained. Evolving data in electrophysiology and genetic testing suggest previously described diseases as complex with multiple underlying genes and a high variety of factors associated with SCD in channelopathies. This review summarizes available, well-established information about channelopathy pathogenesis, genetic basics, and molecular aspects relative to principles of the pathophysiology of arrhythmia. In addition, general information about diagnostic approaches and management is presented. Analyzing principles of channelopathies and their underlying causes improves the understanding of genetic and molecular basics that may assist general research and improve SCD prevention.

Age and gender differences of basic electrocardiographic values and abnormalities in the general adult population; Tehran Cohort Study

BACKGROUND

Although several studies are available regarding baseline Electrocardiographic (ECG) parameters and major and minor ECG abnormalities, there is considerable controversy regarding their age and gender differences in the literature.

METHODS

Data from 7630 adults aged ≥ 35 from the Tehran Cohort Study registered between March 2016 and March 2019 were collected. Basic ECG parameters values and abnormalities related to arrhythmia, defined according to the American Heart Association definitions, were analyzed and compared between genders and four distinct age groups. The odds ratio of having any major ECG abnormality between men and women, stratified by age, was calculated.

RESULTS

The average age was 53.6 (± 12.66), and women made up 54.2% (n = 4132) of subjects. The average heart rate (HR) was higher among women(p < 0.0001), while the average values of QRS duration, P wave duration, and RR intervals were higher among men(p < 0.0001). Major ECG abnormalities were observed in 2.9% of the study population (right bundle branch block, left bundle branch block, and Atrial Fibrillation were the most common) and were more prevalent among men compared to women but without statistical significance (3.1% vs. 2.7% p = 0.188). Moreover, minor abnormalities were observed in 25.9% of the study population and again were more prevalent among men (36.4% vs. 17% p < 0.001). The prevalence of major ECG abnormalities was significantly higher in participants older than 65.

CONCLUSION

Major and minor ECG abnormalities were roughly more prevalent in male subjects. In both genders, the odds of having major ECG abnormalities surge with an increase in age.

Sudden Cardiac Death Risk Stratification of the Early Repolarization Syndrome: An Updated Review of the Literature

PURPOSE OF REVIEW

Early repolarization syndrome (ERS), once thought to be innocuous, has now been shown to be responsible for ventricular arrythmias and sudden cardiac death occurrence. This review will help the clinician to identify the patients who are most at risk for arrhythmias, so that they can adopt a preventive or secondary treatment approach, either of which is still poorly defined.

RECENT FINDINGS

Patients at high risk are found to be particularly young men, with a personal or family history of syncope or sudden death, who have an inferolateral ER on the electrocardiogram, more elevated J-point, longer J-wave duration and wider J angle, a horizontal or descending ST segment, lower T/R ratio, and small and/or inverted waves. The association with a structural heart disease or another channelopathy potentiates this arrhythmic risk. Taken together, these parameters allow prediction of the malignancy of ER pattern with a certain reliability. Further research is however needed to develop concrete risk stratification algorithms and the therapeutic strategies taken in function of it.

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.

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.