ECG CHANGES IN CHAMBER HYPERTROPHIES/ENLARGEMENTS

CHAMBER HYPERTROPHIES/ENLARGEMENTS ::

LEFT ATRIAL ENLARGEMENT
-- Left atrium forms the later part of the P wave. Hence enlargement of left atrium will produce an increase in the duration of the P wave, as well as delayed depolarization leading to "Double peaks" in P wave
-- Also called " P - mitrale "
-- This is evident very clearly in Chest leads 
-- P wave is generally > 120 ms

Image : LAE ... typical "bipeaked " P mitrale

 

RIGHT ATRIAL ENLARGEMENT
-- Right atrium forms the initial part of the p wave... hence Right atrial enlargement will produce Peaked/Tall P wave, and not widen the duration of P wave.
-- Refered to as P - pulmonale
-- Tall peaked P wave is seen in lead II and many leads (especially in right precordial leads) 
-- P wave is Pointed
-- Usually > 2.5 mm