The QRS patterns

Created by team@ekgdx.com on Dec. 23, 2022

Let’s talk about Q wave and QRS complex.

Q wave

A Q wave is any negative deflection that precedes an R wave. It represents the initial phase of ventricular depolarization. 

An isolated Q wave in lead III may be a normal variant. 

Abnormal Q waves causes include: MI, Heart infiltrative diseases, myocarditis, hypertrophic cardiomyopathy, myocardial tumors, hyperkalemia, pneumothorax, others.

Normal Q wave - EKGDX

 

Let’s continue with the QRS complex.

The QRS complex is the major positive deflection on the EKG and represents the ventricular depolarization.

✅ Normal axis: -30° to +90°.
✅ Normal duration: 0.06 to <0.10 sec.
✅ Marked prolongation: >0.12 sec.

Transition

✅ Normal transition occurs around V3-V4.
✅ Early R/S transition: R/S ratio >1 in V1 or V2.

Nomenclature

✅ Q wave: Any initial negative deflection.
✅ R wave: Any positive deflection.
✅ S wave: Any negative deflection after an R wave.

Under normal circumstances R wave height will increase from V1-V5 then decrease in V6. 

Poor R wave progression is considered when:

✅ The R wave in V3 <3mm.

Consider low voltage if:

✅ R+S<5 mm in limb leads.
✅ R+S<10 mm in precordial leads.

In regards to fragmented QRS (fQRS):

fQRS can be defined as the presence of additional R′ waves or a notch in the nadir of the R or S wave (fragmentation) in two contiguous leads corresponding to a coronary territory in a routine 12-lead EKG. Fragmented wide QRS (f-wQRS) is defined as two or more notches in the R or S wave, in two contiguous leads corresponding to a coronary territory (anterior, lateral or inferior). The notches should be separated by at least 40 msec. This myocardial conduction abnormality has been associated with myocardial scar. 

Now I'm going to show you various types of QRS patterns.

qRs

qRs pattern - EKGDX

 

rS

rS pattern - EKGDX

 

Rs

Rs pattern - EKGDX

 

qR

qR pattern EKGDX

 

qR

Qr pattern - EKGDX

 

QR

QR pattern - EKGDX

 

qrS

qrS pattern - EKGDX

 

qRS 

qRS pattern - EKGDX

 

QS

 

R

R patern - EKGDX

 

RS

RS pattern - EKGDX

 

 rSr' 

rSr' pattern - EKGDX

 

 rSR'

rSR' pattern - EKGDX

 

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References

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Thanks for joining us. 

Dr. Roig

QRS patterns