Right axis deviation (>+90)
R in V1 >6 mm
R in V1 + S in V5 or V6 >10.5 mm
R/S ratio in V1 >1
S/R ratio in V6 >1
Late intrinsicoid deflection in V1 (>0.035 sec)
Incomplete right bundle branch block
ST-T wave abnormalities (“strain”) in inferior leads
Right atrial hypertrophy/overload (“P pulmonale”)
S>R in leads I, II, III, particularly in children (S1S2S3 pattern)