A wide and notched P wave is ty pically seen in -
Ans. is 'a' i.e., Mitral stenosis o Mitral stenosis is typically associated with a Wide and Notched P wave from Left Atrial Enlargement (LAE).o Cor-Pulmonate, COPD and Pulmonary embolism are all associated with Right Atrial Enlargement resulting in a Tall P wave (not a wide p wave).o P wave becomes "tall" in RA enlargement and "wide " with LA enlargement.Components of P waveo RA componentThe SA node depolarises the RA first, so the initial pan of P wave represents RA current.After about 40 msec the wave front reaches LA and it begins it s depolarisation,o LA componentBy the time LA is maximally depolarized the RA already starts its repolarisation. So there is overlap and also a short time iag between these two wave forms.This is very important to recognise as, even if the RA conduction is prolonged in pathology the RA component of P- wave still falls within the LA wave.Hence it is not shown in the ECG and P wave is not widened in RA enlargement.This is in contrast to LA enlargement, when the terminal half of P vector delayed it stretches the P wave wide beyond the normal 100ms. Hence LAE widens the P wave.P wave becomes taller in RA enlargemento In classical P pulmonale, the P wave is tall > 2.5 mm.o It is easy to explain why it not getting wide than why it is gettingtaller.The atrial vector has two components.The initial RA vector, is directed anteriorly. The main reason is due to the anatomical proximity of RA to the chest wall. Further the atrial electrical dp/dt is fast, so the slope of forward limb is steep. Any R.4 voltage increase is easily picked up by the chest leads.LAE can not produce tall P waveo The left atrial vector which follows RA vector is mainly directed posteriorly and hence inscribe a descending limb ofP wave.o This causes the P terminal force.o So the direction of vector forces and the anatomical locality' make a tall and positive P deflection highly improbable in LAE.
Mitral stenosis
Cor-Pulmonale
COPD
Pulmonary embolism
Electrocardiography