Background: Two new parameters have recently emerged as possible new markers to evaluate in the ECG of the young athlete: 1. Low QRS voltages (LQRSV), which have shown good potentialities in screening of cardiomyopathies; 2. fragmentation of the QRS (fQRS), the significance of which in young athletes needs further investigations. Purpose: To study, in a large population of pediatric and adolescent athletes, (i) the physiological distribution and major determinants of precordial and peripheral QRS voltages, so as to assess the adequacy of the cut-offs used to define LQRSV, and (ii) the prevalence and possible significance of fQRS. Methods: Athletes with age ≤18 years who had participated in the annual examination for competitive fitness were selected. The resting ECG was assessed with the 2017 international criteria. R waves and S waves in V1, V5, and V6 and the maximum QRS amplitudes in peripheral leads were measured. Fragmented QRS morphologies were coded and detected in each lead and then grouped into five patterns. Results: The sample included 2'146 athletes (mean age 12.45 ±2.61; 48.9% males). The averages of maximum voltages in peripheral leads were 1.43 ±0.42 mV in males and 1.35 ±0.39 mV in females. The cut off of peripheral LQRSVs fell in the 0.25th percentile. A significant correlation emerged between peripheral LQRSVs and exercise-induced arrhythmias (p=0.010). The maximum QRS amplitude in V1/V5/V6 was 2.36 ±0.59 mV in males and 1.81 ±0.49 mV in females. In contrast to peripheral voltages, puberty and sex were associated with important differences. No athletes had precordial LQRSV. The leads most affected by QRS fragmentations were V1, V2 and DIII, where recurrent patterns were present. In total, 1.3% of the athletes had fQRS in ≥2 contiguous leads, however these were only 0.14% if recurrent patterns were excluded. No correlation emerged between fQRS and exercise-induced arrhythmias. Conclusions: Peripheral LQRSV defined with the cut off of 0.5 mV are a rare electrocardiographic parameter that is little affected by age and sex. This corroborates its potential use in pre-participation screening. The fQRSs are present in young athletes, but could be due to conduction delays and axis variability. Their possible clinical interest remains to be discovered.
Contesto: Recentemente sono emersi due nuovi parametri da valutare nell’ECG del giovane atleta: i bassi voltaggi del QRS (LQRSV), che hanno mostrato ottime potenzialità nello screening delle cardiomiopatie; le frammentazioni del QRS (fQRS), di cui il significato nei giovani atleti rimane ancora da approfondire. Scopo: Studiare, in un’ampia popolazione di atleti in età pediatrica e adolescenziale, (i) la distribuzione fisiologica e i principali determinanti dei voltaggi precordiali e periferici del QRS, in modo da valutare l’adeguatezza dei cut off utilizzati per definire i LQRSV, e (ii) la prevalenza e il possibile significato dei fQRS. Metodi: Sono stati selezionati retrospettivamente atleti con età ≤18 anni che hanno partecipato alla visita annuale per l’idoneità agonistica. L’ECG a riposo è stato valutato con i criteri internazionali del 2017. Sono state misurate le onde R e S in V1, V5 e V6 e le ampiezza massime del QRS nelle derivazioni periferiche. Le morfologie frammentate del QRS sono state codificate e rilevate in ogni singola derivazione e poi raggruppate in cinque pattern. Risultati: Il campione comprendeva 2’146 atleti (età media 12.45 ±2.61; 48.9% maschi). Le medie dei massimi voltaggi periferici erano di 1.43 ±0.42 mV nei maschi e 1.35 ±0.39 mV nelle femmine. Il cut off dei LQRSV periferici cadeva nel 0.25° percentile. E’ emersa una correlazione significativa tra LQRSV periferici e aritmie al test da sforzo (p=0.010). L’ampiezza massima del QRS in V1/V5/V6 era 2.36 ±0.59 mV nei maschi e 1.81 ±0.49 mV nelle femmine. Diversamente dai voltaggi periferici, pubertà e sesso si associavano a importanti differenze. Nessun atleta presentava LQRSV precordiali. Le derivazioni maggiormente coinvolte da frammentazioni del QRS erano V1, V2 e DIII, dove erano presenti dei pattern ricorrenti. In totale, 1.3% degli atleti presentava fQRS in ≥2 derivazioni contigue, tuttavia questi erano solo 0.14% se si escludono tutti i pattern ricorrenti e associati a ritardi di conduzione. Nessuna correlazione è emersa tra fQRS e aritmie al test da sforzo. Conclusioni: I LQRSV periferici definiti con il cut off di 0.5 mV sono un parametro elettrocardiografico raro e poco influenzato da età e sesso. Questo ne rafforza le potenzialità come parametro da inserire nello screening. I fQRS sono presenti nei giovani atleti, ma potrebbero essere dovuti a ritardi di conduzione e variabilità dell’asse. Il loro eventuale interesse clinico rimane ancora da scoprire.
Frammentazione e bassi voltaggi del complesso QRS: due nuovi parametri da valutare nell'elettrocardiogramma del giovane atleta?
GENTA, EDOARDO OSCAR
2022/2023
Abstract
Background: Two new parameters have recently emerged as possible new markers to evaluate in the ECG of the young athlete: 1. Low QRS voltages (LQRSV), which have shown good potentialities in screening of cardiomyopathies; 2. fragmentation of the QRS (fQRS), the significance of which in young athletes needs further investigations. Purpose: To study, in a large population of pediatric and adolescent athletes, (i) the physiological distribution and major determinants of precordial and peripheral QRS voltages, so as to assess the adequacy of the cut-offs used to define LQRSV, and (ii) the prevalence and possible significance of fQRS. Methods: Athletes with age ≤18 years who had participated in the annual examination for competitive fitness were selected. The resting ECG was assessed with the 2017 international criteria. R waves and S waves in V1, V5, and V6 and the maximum QRS amplitudes in peripheral leads were measured. Fragmented QRS morphologies were coded and detected in each lead and then grouped into five patterns. Results: The sample included 2'146 athletes (mean age 12.45 ±2.61; 48.9% males). The averages of maximum voltages in peripheral leads were 1.43 ±0.42 mV in males and 1.35 ±0.39 mV in females. The cut off of peripheral LQRSVs fell in the 0.25th percentile. A significant correlation emerged between peripheral LQRSVs and exercise-induced arrhythmias (p=0.010). The maximum QRS amplitude in V1/V5/V6 was 2.36 ±0.59 mV in males and 1.81 ±0.49 mV in females. In contrast to peripheral voltages, puberty and sex were associated with important differences. No athletes had precordial LQRSV. The leads most affected by QRS fragmentations were V1, V2 and DIII, where recurrent patterns were present. In total, 1.3% of the athletes had fQRS in ≥2 contiguous leads, however these were only 0.14% if recurrent patterns were excluded. No correlation emerged between fQRS and exercise-induced arrhythmias. Conclusions: Peripheral LQRSV defined with the cut off of 0.5 mV are a rare electrocardiographic parameter that is little affected by age and sex. This corroborates its potential use in pre-participation screening. The fQRSs are present in young athletes, but could be due to conduction delays and axis variability. Their possible clinical interest remains to be discovered.File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/47001