- 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.
- 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
- 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
Causes of LVH
- Hypertension (most common cause)
- Aortic stenosis
- Aortic regurgitation
- Mitral regurgitation
- Coarctation of the aorta
- Hypertrophic cardiomyopathy
- 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)
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.
Another good example of LVH:
- Markedly increased LV voltages: huge precordial R and S waves that overlap with the adjacent leads (SV2 + RV6 >> 35 mm).
- R-wave peak time > 50 ms in V5-6 with associated QRS broadening.
- LV strain pattern with ST depression and T-wave inversions in I, aVL and V5-6.
- ST elevation in V1-3.
- Prominent U waves in V1-3.
- Left axis deviation.
Severe LVH such as this appears almost identical to left bundle branch block — the main clue to the presence of LVH is the excessively high LV voltages.
- 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.
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- ECG Exam Template — a framework for the FACEM part 2 exam.
- ECG Reference Sites on the WEB — the best of the rest
- 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.