Abnormalities of the R wave

Abnormalities of the R wave

On this page we will discuss and provide examples of R wave abnormalities including

  • Dominant R wave in V1
  • Dominant R wave in aVR
  • Poor R wave progression

Causes of Dominant R wave in V1

  • Normal in children and young adults
  • Right Ventricular Hypertrophy (RVH)
    • Pulmonary Embolus
    • Persistence of infantile pattern
    • Left to right shunt
  • Right Bundle Branch Block (RBBB)
  • Posterior Myocardial Infarction (ST elevation in Leads V7, V8, V9)
  • Wolff-Parkinson-White (WPW) Type A
  • Incorrect lead placement (e.g. V1 and V3 reversed)
  • Dextrocardia
  • Hypertrophic cardiomyopathy
  • Dystrophy
    • Myotonic dystrophy
    • Duchenne Muscular dystrophy

Examples of Dominant R wave in V1

Normal paediatric ECG (2 yr old)

Paediatric ECG V1 R wave

Paediatric ECG V1 R wave

Right Ventricular Hypertrophy (RVH)

RVH

 

Right Bundle Branch Block

RBBB

Right Bundle Branch Block (RBBB)

 

Right Bundle Branch Block MoRRoW

Right Bundle Branch Block MoRRoW

 

Posterior MI

Posterior AMI

Posterior AMI

 

WPW (type A)

WPW Type A

WPW Type A

 

Leads V1 and V3 reversed

Note biphasic P wave (typically seen in only in V1) in lead “V3”

Leads V1 and V3 reversed

Leads V1 and V3 reversed

 

Muscular dystrophy

positive r wave in v1 due to muscular dystrophy

 


Dominant R wave in aVR

 

Poisoning with sodium-channel blocking drugs

  • Causes a characteristic dominant terminal R wave in aVR
  • Poisoning with sodium-channel blocking agents is suggested if:
    • R wave height > 3mm
    • R/S ratio > 0.7
Na Channel blocker and dominant aVR R wave

Na Channel blockade with dominant aVR R wave

Dextrocardia

This ECG shows all the classic features of dextrocardia:

  • Positive QRS complexes (with upright P and T waves) in aVR
  • Negative QRS complexes (with inverted P and T waves) in lead I
  • Marked right axis deviation
  • Absent R-wave progression in the chest leads (dominant S waves throughout)

Dextrocardia

Left arm/right arm lead reversal

The most common cause of a dominant R wave in aVR is incorrect limb lead placement, with reversal of the left and right arm electrodes. This produces a similar pattern to dextrocardia in the limb leads but with normal R-wave progression in the chest leads.

With LA/RA lead reversal:

  • Lead I becomes inverted
  • Leads aVR and aVL switch places
  • Leads II and III switch places
Lead reversal

Lead reversal

Lead reversal reversed

Lead reversal reversed

Ventricular Tachycardia

Ventricular tachycardia


Poor R wave progression

Poor R wave progression is described with an R wave ≤ 3 mm inV3 and is caused by:

  • Prior anteroseptal MI
  • LVH
  • Inaccurate lead placement
  • May be a normal variant
Poor R wave progression

Poor R wave progression

Note that absent R wave progression is characteristically seen in dextrocardia (see previous ECG).

References

  • Surawicz B, Knilans TK. Chou’s Electrocardiography in Clinical Practice. 6th Edition. Saunders Elsevier 2008.
  • Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.

Further Reading

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