ECG Topic - Left Ventricular Hypertrophy - Beware OMI

Last updated 8/22/24

Learning Objectives

• Recognize the common ECG characteristics of LVH
• Understand the limitations of ECG diagnostic criteria for OMI in patients with LVH and utilize strategies to workup these patients
• Differentiate between LVH and OMI

LVH ECG

Voltage Characteristics

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ECG finding #2: Left sided leads may have tall R waves

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Electrophysiology: more more muscle, more voltage

• In LVH, the muscle mass of the left ventricle is increased. Since the ECG measures the electrical activity generated by the heart, this increased muscle mass results in greater electrical activity being recorded by the ECG leads that are positioned over the left ventricle. The more muscle there is to depolarize, the more voltage is generated leading to tall R waves.
• Normally, the heart's electrical activity moves from the right atrium towards the left ventricle. With LVH, this depolarization vector is even stronger and more directed towards the left and posteriorly. The left-sided ECG leads pick up this intensified signal, which manifests as taller R waves.

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What are the left sided leads? (Hint: think “lateral” )

• I, avL, V5-V6

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Which of left sided leads will have the tallest R waves?

• V5-V6 are located on the lateral chest wall directly over the LV and will therefore have the tallest R waves.

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Some LVH voltage findings of left sided leads

• R in I ≥ 12 mm
• R in aVL is ≥ 11 mm
• Tall R in V5-V6 ≥ 26mm
• QRS complexes ≥ 45mm in any precordial complex

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Example

• Here you can appreciate tall R waves in I, avL and V5-V6
• Additionally the QRS complexes are touching in the precordial leads

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ECG finding #3: Right sided and anterior leads may have deep S waves

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Electrophysiology

• As discussed above, in LVH, there is a large positive depolarization vector moving towards the left and posterior of the heart. That means there is a large negative depolarization vector moving away from the right and anterior side of the heart.
• This "moving away" effect causes the ECG to register a deep S wave.

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What are the right sided and anterior leads?

• Right: III, avR
• Right/anterior: V1-V2 which lie over the septum
• Anterior: V3-V4

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LVH voltage findings of left and anterior leads

• Deep S waves in V1-V4
• aVR S wave ≥ 14 mm
• QRS complexes ≥ 45mm in any precordial complex
• The deepest S wave in any part of the ECG (usually V1-V3) + S wave in V4 ≥ 23 mm in women and ≥ 28 in men. This is known as the Peguero-Lo Presti criteria for LVH which was demonstrated to have a sensitivity of 0.62 and specificity of 0.90. [Pubmed]

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Example

• Deep S waves in V1-V4 + III
• S wave in V4 (20mm) + deepest S wave (V3 ~ 45 mm) ≥ 28 mm

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ECG finding #4: A combination of #2 and #3 increases the specificity for LVH.

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Some various voltage criteria.

• S in V1 + tallest R in V5 or V6 ≥ 35 mm (Sokolow-Lyon)
• R in avL + S in V3 ≥ 20 mm in women and 28 mm in men (Cornell)
• These all have very poor sensitivity.

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Example

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S in V1 + tallest R in V5 or V6 ≥ 35 mm (Sokolow-Lyon)?

• Yes: V1 ~ 20 mm, V5 + 40-45mm ≥ 35 mm

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R in avL + S in V3 ≥ 20 mm (F) and 28 mm (M) (Cornell)?

• Yes: R in aVL (~12mm) + S in V3 (40-45 mm) ≥ 20 or 28mm

ECG Practice (7 ECGs)

What voltage findings are suggestive of LVH? Just focus on voltage.

Hold up…I’m an EM doctor. Do I care about diagnosing LVH in the ED?

In most cases…no. However, you do care about diagnosing MI in LVH. The presence of LVH on ECG makes the diagnosis of ischemia very difficult and this has tortured EM doctors since the dawn of our specialty. In fact, the Fourth Universal Definition of MI excludes the LVH from “classic” STEMI findings (Table 2 below). Knowing that the typical rules of ST segment elevation and depression may not apply to LVH is crucial.

Non-voltage Characteristics

The following LVH findings are classically known as “strain pattern” but now are often referred to as “repolarization abnormalities.” Not every ECG with LVH will have these abnormalities.

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ECG finding #1: Leads with tall R waves may have ST depressions (STD) and T wave inversions

• Abnormal depolarization leads to abnormal repolarization.

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Which leads typically have tall R waves in LVH?

• The left sided leads: I, avL, V5-V6 therefore you may expect these leads to have TWI and STD

• Since the negative T wave inversions and ST depressions are in the opposite direction of the positive QRS complex with a tall R wave, they are considered discordant to the QRS complex.

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Examples

• Note the discordant STD and TWI in leads with tall R waves

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Source: ECG 457, 241

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ECG finding #2: Leads with deep S waves may have ST Elevations (STE) and upright T waves. Some of these STE may be ≥ 2 mm in V2-V3 and ≥ 1mm in other leads.

• Remember abnormal depolarization leads to abnormal repolarization. This is simply the opposite of ECG finding #1.

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Which leads typically have deep S waves in LVH?

• The right sided and anterior leads: III, aVR, V1-V4, so you may expect these leads to have STE and upright T waves

• Because the positive upright T wave and ST elevations are in the opposite direction of the negative QRS complex with a deep S wave, they are considered discordant to the QRS complex.

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Examples

• Note the discordant STE and T waves in the leads with deep S waves. Some of these STE are > 3mm. Neither of these patients had heart attacks.

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ECG finding #4: STE and STD are generally concave and T waves are asymmetric

ST segment progression from V1-V6

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Examples

• Blue = concaved down STD, red = concave up STE

LVH and OMI

Why is it difficult to distinguish LVH and OMI?

1. LVH is excluded when using STEMI criteria
2. LVH might cause enough STE to meet STEMI criteria
3. Common patterns normally specific for OMI can be normal in LVH
1. Have you noticed in LVH that the tallest R waves and deepest S waves are in leads that may be reciprocal to each other? This means there may be ST segments that are reciprocal to each other.
4. ECG findings that look like strain pattern may also represent OMI in LVH
5. Patients may clinically present exactly as a patient with ACS may present

Tips for identifying OMI in LVH

The following are ECG findings that may indicate OMI in LVH. The absence of these findings does not rule out OMI and the presence of these findings does not necessarily rule in OMI.

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Tip #1: Discordant STE is disproportionally tall compared to accompanying S wave.

• Unfortunately there is no validated diagnostic criteria like Sgarbossa’s for LVH. STE / S wave ratio > 15 % should raise your concern for ischemia.
• Sometimes the voltages are so large, it’s hard to tell if the ST elevations are appropriately or inappropriately proportioned. Consider setting the ECG to half calibration.

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Example

• The STE in V1-V5 appear > 15% the accompanying S wave. This is most apparent in lead V5 where the S wave is only ~10mm and STE is 4mm.

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Source ECG 525

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Tip #2: The largest discordant ST deviation does NOT accompany the tallest R or deepest S wave

• You would expect the tallest STE to be in with deepest S wave in V3 in typical strain pattern, but here the largest STE are in III and aVF where the S waves are small.

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Source 551

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Tip #3: The ST segments are linear, horizontal, or convex.

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Source ECG 554

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Source ECG 127

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Tip #5: The T waves are symmetrical and may be disproportionally large relative to QRS complexes

• Here the T wave inversions appear symmetrically sloped.

• T wave inversions appear symmetrically sloped on each side

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Source 878

Lastly, accept that there are no perfect ways to distinguish LVH from OMI with ECG, so use your adjuncts to aid your decision making (serial ECGs, troponin, echo)

ECG Practice (14 half ECGs)

Evaluate each set of limb or precordial limbs.

After completion

Consider reviewing the following additional resources:

• LVH with anterior ST Elevation. When is it anterior STEMI?
• Jesse McLaren EM cases | ECG cases 13: LVH + occlusion MI
• ECG Weekly: STAT ECG Diagnoses: How to identify acute coronary occlusion in LVH with strain
• Chapters 11 and 14 of Tomas Garcia’s 12 Lead ECG: Art of Interpretation
• Ed Burns Left Ventricular Hypertrophy (LVH)

This post is for education and not medical advice.