Variantes ECG de la normale

Ensemble des « anomalies » ECG observées chez des sujets indemnes de pathologie et non corrélées à un risque évolutif péjoratif. Ces variantes peuvent s’observer au cours de chacune des étapes de l’activation électrique du cœur.

  • Activité atriale : bradycardie sinusale, arythmie respiratoire, pause sinusale (nocturne < 2,5 sec ou diurne < 2 sec entre 30 et 60 ans ou pause post tachycardie), bloc sino-atrial de type Wenckebach, repolarisation atriale
  • Conduction AV : bloc AV du 1er degré, bloc AV type Wenckebach (nuit, jeune, sportif) ou PR court < 0,12 s (nœud hyperdromique)
  • Complexes QRS (≤ 110 ms) : axe des QRS dévié à gauche (entre 0 et -30°) ou à droite (> 100°), complexes QRS hypervoltés, aspect QS en V1, rSr’ en V1 (avec r’ ≤ 3 mm et QRS < 110 ms) , absence d’onde q septale (V5-V6, DI-VL), onde Q en DIII ≤ 0,03 sec et < ¼ de l’onde R, transition précoce (en V1-V2 ou V2-V3 au lieu de V3-V4) ou tardive (entre V5-V6).
  • Rythme : rythme du sinus coronaire, wandering pacemaker
  • Extrasystoles supraventriculaires (isolées < 10/24 h avant 40 ans, < 100/24 h entre 40 et 60 ans, < 1000/24 h après 60 ans) ou extrasystoles ventriculaires (ESV bénignes)
  • Conduction IV : bloc incomplet droit
  • Repolarisation : Cf. Variantes de repolarisation ventriculaire

 

Les ECG normaux présentent des variations en fonction de l’âge, du sexe et des ethnies (origine africaine, hispanique, asiatique ou caucasienne) (cf. Références)

Voir :

 

Gonçalves MAA, Pedro JM, Silva C, Magalhães P, Brito M. Normal limits of the electrocardiogram in Angolans. J Electrocardiol. 2020 Oct 26;63:68-74. The normal range of the ECG differed between men and women: heart rate 49 to 100 bpm vs. 55 to 108 bpm, P wave duration 81 to 130 ms vs. 84 to 130 ms, PR interval 119 to 210 ms vs. 120 to 202 ms, QRS duration 74 to 110 ms vs. 70 to 104 ms, QT interval 324 to 441 ms vs. 314 and 438 ms, P-wave axis – 29 to 850 vs. -18 to 810, QRS-wave axis – 13 to 850 vs. -180 and 820, T-wave axis 0 to 720 vs. -8 to 730, Sokolow-Lyon index 2.13 to 6.21 mV vs. 1.60 to 4.87 mV, Cornell index 0.17 to 6.24 mV vs. 0.14 mV to 4.35 mV.

Friedman A, Chudow J, Merritt Z, Shulman E, Fisher JD, Ferrick KJ, Krumerman A. Electrocardiogram abnormalities in older individuals by race and ethnicity. J Electrocardiol. 2020 Oct 4;63:91-93. –> The ECG parameters of subjects between the ages of 75 and 99 years from a large and diverse inner-city patient population were analyzed. Subjects were grouped into one of four categories: Hispanic, Black, Non-Hispanic White, or Other. Results: 38,238 subjects were included. Of all groups, Non-Hispanic Whites exhibited more conduction abnormalities such as bundle branch block compared to the other groups, as well as the highest incidence of atrial fibrillation (AF) (12.6%, p < 0.05). Hispanics had the highest proportion of normal sinus rhythm. Blacks exhibited the least amount of AF (6.3%), as well as the highest incidence of LVH (25.5%), RAD (13.5%), and the largest percentage of abnormal ECGs (72.8%).

Silva M et al. Prevalence of major and minor electrocardiographic abnormalities in one million primary care Latinos. JEC 2021; 64, January–February 2021, Pages 36-41

van der Ende MY, Siland JE, Snieder H, van der Harst P, Rienstra M. Population-based values and abnormalities of the electrocardiogram in the general Dutch population: The LifeLines Cohort Study. Clin Cardiol. 2017 Oct;40(10):865-872. (téléchargeable) –> Median heart rate was highest in the youngest and oldest individuals of the healthy population. Median duration of P wave, PQ interval, and QRS duration were longer in males compared with females. In contrast, median QT interval corrected for heart rate was higher in females. In general, the above-mentioned parameters increased with age. The prevalences of ECG abnormalities adjusted for the Dutch population were 0.9% for atrial fibrillation or flutter, 1.4% for premature atrial complexes, 0.5% for myocardial infarction, 2.1% for ventricular premature complexes, 1.0% for left ventricular hypertrophy, 8.1% for P-R interval >200 ms, and 0.8% for bundle branch block