Makindo Medical Notes"One small step for man, one large step for Makindo" |
![]() |
---|---|
Download all this content in the Apps now Android App and Apple iPhone/Pad App | |
MEDICAL DISCLAIMER: The contents are under continuing development and improvements and despite all efforts may contain errors of omission or fact. This is not to be used for the assessment, diagnosis, or management of patients. It should not be regarded as medical advice by healthcare workers or laypeople. It is for educational purposes only. Please adhere to your local protocols. Use the BNF for drug information. If you are unwell please seek urgent healthcare advice. If you do not accept this then please do not use the website. Makindo Ltd. |
Abnormality | Cause | ECG Appearance |
---|---|---|
Peaked P (P Pulmonale) | Right atrial enlargement (e.g. pulmonary HTN, COPD) | 📈 Tall >2.5 mm in lead II |
Broad/Notched (P Mitrale) | Left atrial enlargement (mitral valve disease, LVH) | ⏱️ >0.12 sec, notched "M-shaped" P in I, II |
Inverted P | Ectopic atrial / junctional rhythm | ↘️ P inverted in leads normally upright (I, II) |
Absent P | Atrial fibrillation, AV junctional rhythm | 🌀 No P; fibrillatory baseline in AF |
Prolonged P | Left atrial enlargement, interatrial block | ⏱️ P >0.12 sec in I, II |
Varying Morphology | Multifocal atrial tachycardia (MAT), wandering pacemaker | 🎭 ≥3 different P morphologies |
P Wave Axis Deviation | Atrial enlargement / conduction abnormality | 📐 Abnormal axis → unexpected inversion |
💡 Clinical Pearl: 👉 In practice, always check P wave morphology in lead II and V1 first: - Lead II = tells you size (RAE/LAE). - Lead V1 = tells you phase balance (RA vs LA). 🔑 Subtle P wave changes often give the first clue to atrial disease.