If 1.2 was used as the critical 'normal' value of QRS duration ratio in (V2+V3)/(V4+V5) specificity was 90.8% for males and only 79.5% for females.Conclusion: QRS duration ≥110ms in the right precordial lead V1, V2 or V3 seems to be the best marker for discriminating healthy ...
normal QRS axis normal P waves height < 2.5 mm in lead II width < 0.11 s in lead II for abnormal P waves see right atrial hypertrophy, left atrial hypertrophy, atrial premature beat, hyperkalaemia normal PR interval 0.12 to 0.20 s (3 - 5 small squares) for short PR segment...
Each QRS complex is preceded by a normal P wave Normal P wave axis: P waves upright in leads I and II, inverted in aVR The PR interval remains constant QRS complexes < 100 ms wide (unless co-existent interventricular conduction delay present)Normal heart rates in childrenNew...