Left Ventricular Hypertrophy

Background

• The left ventricle hypertrophies in response to pressure overload secondary to conditions such as aortic stenosis and hypertension.
• This results in increased R wave amplitude in the left-sided ECG leads (I, aVL and V4-6) and increased S wave depth in the right-sided leads (III, aVR, V1-3).
• The thickened LV wall leads to prolonged depolarisation (increased R wave peak time) and delayed repolarisation (ST and T-wave abnormalities) in the lateral leads.

Criteria for Diagnosing LVH

• There are numerous criteria for diagnosing LVH, some of which are summarised below.
• The most commonly used are the Sokolov-Lyon criteria (S wave depth in V1 + tallest R wave height in V5-V6 > 35 mm).
• Voltage criteria must be accompanied by non-voltage criteria to be considered diagnostic of LVH.

Voltage Criteria

Limb Leads

• R wave in lead I + S wave in lead III > 25 mm
• R wave in aVL > 11 mm
• R wave in aVF > 20 mm
• S wave in aVR > 14 mm

Precordial Leads

• R wave in V4, V5 or V6  > 26 mm
• R wave in V5 or V6 plus S wave in V1 > 35 mm
• Largest R wave plus largest S wave in precordial leads > 45 mm

Non Voltage Criteria

• Increased R wave peak time > 50 ms in leads V5 or V6
• ST segment depression and T wave inversion in the left-sided leads: AKA the left ventricular ‘strain’ pattern

Additional ECG changes seen in LVH

• Left atrial enlargement.
• Left axis deviation.
• ST elevation in the right precordial leads V1-3 (“discordant” to the deep S waves).
• Prominent U waves (proportional to increased QRS amplitude).

Causes of LVH

• Hypertension (most common cause)
• Aortic stenosis
• Aortic regurgitation
• Mitral regurgitation
• Coarctation of the aorta
• Hypertrophic cardiomyopathy

Handy Tips

• Voltage criteria alone are not diagnostic of LVH
• ECG changes are an insensitive means of detecting LVH (patients with clinically significant left ventricular hypertrophy seen on echocardiography may still have a relatively normal ECG)

ECG Examples

Example 1

This ECG demonstrates many of the features of LV hypertrophy:

• Markedly increased LV voltages: S wave in V1 + R wave in V6 > 35 mm; R wave in aVL > 11 mm.
• Increased R wave peak time: the upstroke of the QRS complex is slurred in V5-6, resulting in minor QRS broadening.
• Left ventricular strain pattern: T wave inversion in the lateral leads V5-6, I and aVL.
• Left axis deviation.
• Signs of left atrial enlargement.

 

Example 2

Another good example of LVH:

• There are massively increased QRS voltages — the S waves in V3 are so deep they are literally falling off the page!
• The ST elevation in V1-3 is simply in proportion to the very deep S waves (“appropriate discordance”).
• The LV strain pattern is seen in all leads with a positive R wave (V5-6, I, II, III, aVF).

This ECG was reproduced from Dr Smith’s ECG blog — read the original blog post here. 

Related Topics

• Right ventricular hypertrophy
• Left atrial enlargement
• Left bundle branch block

Further Reading

• ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
• ECG CLINICAL CASES — Your favourite ECG’s placed in clinical context with a challenging Q&A approach
• ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
• ECG Exam Template — a framework for the FACEM part 2 exam.
• ECG Reference Sites on the WEB — the best of the rest

Author Credits

References

• Edhouse J, Thakur RK, Khalil JM. ABC of clinical electrocardiography. Conditions affecting the left side of the heart. BMJ. 2002 May 25;324(7348):1264-7. Review. PMID: 12028984. Full text.
• Hampton, JR. The ECG in Practice (5th edition), Churchill Livingstone 2008.
• Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.