Thread by @ekgdx

1/ Let’s talk about P waves #CardioTwitter.

The P wave is the first positive deflection on the EKG and represents atrial depolarization. The first half represents right atrial depolarization and the second half represents left atrial depolarization.

By @ekgdx

2/ Normal P wave

Criteria

✅ Axis: 0° to +75°.
✅ Amplitude (L leads): <2.5 mm.
✅ Amplitude (P leads): <1.5 mm.
✅ Duration: 0.08 - 0.11 sec. 
✅ Morphology: Upright in I, II, aVF and inverted in aVR.

#Pwaves #ecg #ekg #ekgdx #medicine #MedTwitter #MedStudentTwitter #basic

3/ Peaked P wave

The morphology is peaked with amplitude ≥2.5 mm, usually in II, III and aVF.

The peaked P wave is a typical characteristic of right atrial abnormality/enlargement. 

Causes: PE, COPD, congenital heart disease, pulmonary hypertension, normal variant, others.

4/ Notched P wave

The morphology is notched like an "M" shape. 

If the duration is ≥0.12 sec consider left atrial abnormality/enlargement. 

Causes include: Heart failure, LVH, MI, mitral or aortic valve disease, others.

#ekgdx #ecg #medicine #MedTwitter #notched #pwave

5/ Inverted P waves

Possible causes include: 

✅ Ectopic atrial beat or rhythm.
✅ AV junctional premature complex or rhythm.
✅ Lead placement error.
✅ Dextrocardia.
✅ Others. 

#ekgdx #medicine #MedTwitter #basic #ecg #ekg

6/ Retrograde P wave

The impulse can travel backward, in a retrograde fashion, through the atria, producing a retrograde P wave, as long as the impulse penetrate the AV node and depolarize the atria.

#retrograde #pwave

7/ Retrograde P waves can be:

✅ Before the QRS.
✅ During the QRS.
✅ After the QRS. 

Usually inverted in II, III and aVF and upright in aVR and V1.

8/ Learn EKG using graphic explanation with a smart software that help you with the learning process.

The EKGs are courtesy of EKGDX.

You can download the App here: onelink.to/7bp23c

#CardioTwitter

9/ Let’s continue with the PR interval.

🧵👇

10/ Let’s continue with the Delta wave.

🧵👇

11/ Let’s continue with the Q wave and QRS complex.

🧵👇

12/ Let’s continue with ST segment.

🧵👇