R Wave

Abnormalities of the R wave

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

 

Normal paediatric ECG (2 yr old)

Paediatric ECG V1 R wave

Paediatric ECG V1 R wave

 

Right Ventricular Hypertrophy (RVH)

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

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

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

Poor R wave progression

Defined as an R wave ≤ 3 mm in V3

Causes

  • 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).

Related Topics

Further Reading

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.

Author Credits

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