The Diagnostic Value of the 12-Lead ECG in Arrhythmogenic Left Ventricular Cardiomyopathy: Novel ECG Signs

Prevalence and determinants of low QRS voltages and QRS fragmentation in children and adolescents undergoing sports pre-participation screening

AIMS

Low QRS voltages (LQRSV) in limb leads and QRS fragmentation (FQRS) are possible electrocardiographic signs of myocardial fibrosis and cardiomyopathy, but they are not listed in current criteria for interpreting athlete's electrocardiogram (ECG). We investigated the prevalence and determinants of LQRSV and FQRS in a cohort of young apparently healthy athletes undergoing pre-participation screening (PPS).

METHODS AND RESULTS

We analysed a consecutive series of 2140 ECG obtained during PPS of young athletes (mean age 12.5 ± 2.6 years, 7-18-year-old, 49% males). The peak-to-peak QRS voltage was measured in all limb leads, and LQRSV were defined when maximum value was <0.5 mV. Fragmented QRS morphologies were grouped into five patterns. Lead aVR was not considered. Maximum peak-to-peak QRS voltage in limb leads was 1.4 ± 0.4 mV, similar between younger and older athletes, but significantly lower in females than males (1.35 ± 0.38 mV vs. 1.45 ± 0.42 mV; P < 0.001). There was a weak correlation between maximal QRS voltages and body mass index (BMI), but not with type of sport or training load. Only five (0.2%) individuals showed LQRSV. At least one fragmented QRS complex was identified in 831 (39%) individuals but excluding the rSr' pattern in V1-V2, only 10 (0.5%) showed FQRS in ≥2 contiguous leads. They were older than those without FQRS, but did not differ in terms of gender, BMI, type of sport, or training load.

CONCLUSION

Low QRS voltages in limb leads and FQRS in ≥2 contiguous leads excluding V1-V2 are rare in young apparently healthy athletes and are not related to the type and intensity of sport activity. Therefore, they may require additional testing to rule out an underlying disease particularly when other abnormalities are present.

The rare cause of ST segment elevation in left precordial leads - Diagnostic clues from subtle waveforms

We report a case of ST segment elevation in left precordial leads with a convex shape caused by a rare etiology. By carefully analyzing the electrocardiogram (leads I, II, V3 to V9) of a patient with convex ST segment elevation in the left-sided chest leads, relevant etiological clues were derived. The findings were further supported by cardiac ultrasound and cardiac magnetic resonance imaging, ruling out other common causes. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) was postulated as the underlying cause, and potential mechanisms were discussed. The diagnosis was further confirmed through a follow-up period of over three years.

Unlocking the enigma: decoding premature ventricular complexes for effective clinical assessment and risk management

The identification of ventricular premature complexes during a cardiological evaluation necessitates the implementation of diagnostic processes aimed at discerning the clinical context that may predispose individuals to a high risk of sudden cardiac death. Epidemiological studies reveal that ventricular premature beats occur in approximately 75% of healthy (or seemingly healthy) individuals, as long as there is no evidence of underlying structural heart disease, such as benign idiopathic ventricular extrasystole originating from the right and left ventricular outflow tracts. In the real world, however, ventricular ectopic beats with morphologies very similar to seemingly benign occurrences are not uncommon. They are notable in subjects exhibiting rapid and complex repetitive forms during exercise testing and Holter electrocardiogram. Additionally, these subjects may display more or less extensive scarring signs on cardiac magnetic resonance and may have a family history of cardiomyopathy and/or sudden cardiac death. Therefore, the purpose of this review is to critically analyse the process of evaluating premature ventricular complexes, which is crucial for accurate risk stratification. The latter cannot overlook some inevitable elements, including morphology, origin, complexity, and the associated clinical setting (absence or presence of structural heart disease).

Inherited Arrhythmias in the Pediatric Population: An Updated Overview

Pediatric cardiomyopathies (CMs) and electrical diseases constitute a heterogeneous spectrum of disorders distinguished by structural and electrical abnormalities in the heart muscle, attributed to a genetic variant. They rank among the main causes of morbidity and mortality in the pediatric population, with an annual incidence of 1.1-1.5 per 100,000 in children under the age of 18. The most common conditions are dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). Despite great enthusiasm for research in this field, studies in this population are still limited, and the management and treatment often follow adult recommendations, which have significantly more data on treatment benefits. Although adult and pediatric cardiac diseases share similar morphological and clinical manifestations, their outcomes significantly differ. This review summarizes the latest evidence on genetics, clinical characteristics, management, and updated outcomes of primary pediatric CMs and electrical diseases, including DCM, HCM, arrhythmogenic right ventricular cardiomyopathy (ARVC), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), long QT syndrome (LQTS), and short QT syndrome (SQTS).