▁node , ▁in ▁the ▁high ▁right ▁at rium ▁and ▁then ▁travel s ▁to ▁and ▁through ▁the ▁left ▁at rium . ▁ ▁The ▁dep olar ization ▁front ▁is ▁carried ▁through ▁the ▁at ria ▁along ▁semi - special ized ▁condu ction ▁path ways ▁including ▁Bach mann ' s ▁bundle ▁resulting ▁in ▁uniform ▁sh aped ▁waves . ▁ ▁De pol ar ization ▁origin ating ▁elsewhere ▁in ▁the ▁at ria ▁( at rial ▁e ct op ics ) ▁result ▁in ▁P ▁waves ▁with ▁a ▁different ▁morph ology ▁from ▁normal . ▁ ▁Path ology ▁ ▁Pe aked ▁P ▁waves ▁( > ▁ 0 . 2 5 ▁m V ) ▁suggest ▁right ▁at rial ▁en larg ement , ▁cor ▁pul mon ale , ▁( P ▁pul mon ale ▁rh ythm ), ▁but ▁have ▁a ▁low ▁predict ive ▁value ▁( ~ 2 0 %). ▁▁ ▁A ▁P ▁wave ▁with ▁increased ▁amplitude ▁can ▁indicate ▁hyp ok alem ia . ▁It ▁can ▁also ▁indicate ▁right ▁at rial ▁en larg ement . ▁ ▁A ▁P ▁wave ▁with ▁decre ased ▁amplitude ▁can ▁indicate ▁hyper k alem ia . ▁ ▁B if id ▁P ▁waves ▁( known ▁as ▁P ▁mit rale ) ▁indicate ▁left - at rial ▁ab normal ity ▁- ▁e . g . ▁dil at ation ▁ ▁or ▁hy pert ro phy . ▁ ▁If ▁at ▁least ▁three ▁different ▁sh aped ▁P ▁waves ▁can ▁be ▁seen ▁in ▁a ▁given ▁E CG ▁lead ▁trac ing , ▁this ▁implies ▁that ▁even ▁if ▁one ▁of ▁them ▁ar ises ▁from ▁the ▁SA ▁node , ▁at ▁least ▁two