P pulmonale (right atrial abnormality) is a big, tall, peaked P waves on ECG.
Diagnostic criteria
- amplitude (height) of the P wave in lead 2 is > 2.5mm (0.25mV). ( > 3mm is abnormal in infants up to 6 months of age ). P wave is pointed with a single crest
- additional criteria:
- Amplitude (height) of the first half of P wave in lead C1 or lead C2 is > 1.5 mm (0.15mV).
- Rightward shift of the P wave vector - the P wave time (width) is generally normal (<120ms).
Causes of Right Atrial Enlargement
The principal cause is pulmonary hypertension due to:
- chronic lung disease (cor pulmonale)
- tricuspid stenosis
- congenital heart disease (pulmonary stenosis, Tetralogy of Fallot)
- primary pulmonary hypertension
An exaggerated right atrial abnormality is associated with:
- Ebstein’s anomaly
- total anomalous pulmonary venous return
- severe pulmonary stenosis
- tricuspid atresia
Although NOT EXAGGERATED atrial septal defect (ASD) may also show right atrial abnormalit (1)
Notes:
- previously the terms P pulmonale , P congenitale , right atrial dilatation , right atrial hypertrophy , atrial overload were used
- however, the above mentioned ECG findings can be observed not only in patients with atrial muscular hypertrophy but also in patients with increases in atrial pressure, ventricular diastolic dysfunction or intaatrial conduction disturbances
- it is suggested that use of the term right atrial abnormalitywill reflect these changes better.
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