Question 26.3

Created on Thu, 06/30/2016 - 00:03
Last updated on Sun, 04/30/2017 - 17:12
Pass rate: 49%
Highest mark: 8.9

Topic

Other SAQs in this paper

Other SAQs on this topic

Please note: The following ECGs have all been recorded at 25 mm/sec and gain setting of 10 mm/mVe 26.1

Describe the ECG shown on page 10 (Figure 3). (20% marks)

List four conditions that are associated with the axis abnormality seen in this ECG. (10% marks)

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College Answer

a)

  • Rightward QRS axis 
  • Peaked P waves in the inferior leads > 2.5 mm (P pulmonale) with a rightward P-wave axis (inverted in aVL)
  • Clockwise rotation of the heart with a delayed R/S transition point (transitional lead = V5). Right ventricular hypertrophy criteria present Right axis deviation of +110° or more.
  • Dominant R wave in V1 (> 7 mm tall or R/S ratio > 1).
  • Dominant S wave in V5 or V6 (> 7 mm deep or R/S ratio < 1).
  • QRS duration < 120 ms (i.e. changes not due to RBBB).
  • Right ventricular strain pattern = ST depression / T wave inversion in the right precordial (V14) and inferior (II, III, aVF) leads.
  • Deep S waves in the lateral leads (I, aVL, V5-V6).

b) Right ventricular hypertrophy

  • Left posterior hemi block
  • Lateral myocardial infarction
  • Acute right heart strain
  • Drug toxicity (e.g. TCAs)

Discussion

This is an ECG of RV hypetrophy stolen from LITFL.

Edward Burns gives the following electrocardiographic features:

Diagnostic criteria

  • Right axis deviation of +110° or more.
  • Dominant R wave in V1 (> 7mm tall or R/S ratio > 1).
  • Dominant S wave in V5 or V6 (> 7mm deep or R/S ratio < 1).
  • QRS duration < 120ms (i.e. changes not due to RBBB).

Supporting criteria

  • Right atrial enlargement (P pulmonale).
  • Right ventricular strain pattern = ST depression / T wave inversion in the right precordial (V1-4) and inferior (II, III, aVF) leads.
  • S1 S2 S3 pattern = far right axis deviation with dominant S waves in leads I, II and III.
  • Deep S waves in the lateral leads (I, aVL, V5-V6).

Other abnormalities caused by RVH 

Right bundle branch block (complete or incomplete).