P Wave Morphology

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Author(s)	J.S.S.G. de Jong, MD
Moderator	J.S.S.G. de Jong, MD
Supervisor
some notes about authorship

The p wave morphology can reveal right or left atrial stretch.

The P-wave morphology is best determined in leads II and V1 during sinus rhythm.

The normal P wave

Normal sinus rhythm with a positive p wave in leads I, II en AVF and a biphasic p wave in V1.

Characteristics of a normal p wave:[1]

The maximal height of the P wave is 2.5 mm in leads II and / or III
The p wave is positive in II and AVF, and bifasic in V1
The p wave duration is usually shorter than 0.12 seconds

Elevation or depression of the PTa segment (the part between the p wave and the beginning of the QRS complex) can result from Atrial infarction or pericarditis.

If the p-wave is enlarged, the atria are enlarged.

Left atrial enlargement

Criteria for left atrial voor left atrial enlargement:

P wave with a broad (>0,04 sec or 1 small square) and deeply negative (>1 mm) terminal part in V1, and / or >0,12 sec in laeds I and / or II

Left atrial enlargement

Left atrial enlargement with ECG.

Left atrial enlargement as seen in lead V1.

Left atrial enlargement is often seen in mitral valve insufficiency.

Right atrial enlargement

Right atrial enlargement is defined as either: P >2,5 mm in II / III and / or aVF; P >1,5 mm in V1.

Right atrial enlargement

Right atrial enlargement can result from increased pressure in the pulmonary artery, e.g. after pulmonary embolisation. A positive part of the biphasic p-wave in lead V1 larger than the negative part indicates right atrial enlargement. The width of the p wave does not change.

Biatriale belasting

Bifasische P in V1 > 0.04 sec, positief initieël deel >1.5mm en een negatief terminaal deel > 1mm

Biatriale belasting vertoont op het ECG tekenen van zowel rechter- als linkeratriumhypertrofie. V1 laat een groot eerste deel van de bifasische P-top en een diep breed tweede deel van de bifaische P-top zien.

Referenties

Spodick DH, Raju P, Bishop RL, and Rifkin RD. Operational definition of normal sinus heart rate. Am J Cardiol. 1992 May 1;69(14):1245-6. DOI:10.1016/0002-9149(92)90947-w | PubMed ID:1575201 | HubMed [Spodick]