2.8 ECG of Ventricular Hypertrophy

Question 1

Which ventricle dominates R wave activity and how is this affected by its hypertrophy?

Answer 1

Left ventricle is larger than right ventricle and is responsible for R wave. LVH causes an increase in th size of the R wave, as there is increased electrical activity due to larger myocytes.

Question 2

Describe the 6 major types of ECG changes you could expect in left ventricular hypertrophy.

Answer 2

1. Tall R waves - due to increased electrical activity in LV.
2. Deep S waves - seen in opposite leads to large R waves.
3. QRS widening - due to larger muscle taking a longer time to depolarise
4. Left axis deviation - due to overall vector of current changing.
5. ST-T changes - indicate a poorer prognosis.
6. LAE - left atrial enlargement, as filling pressure increases with LVH.

Question 3

List 4 different algorithms for diagnosing LVH.

Answer 3

1. R in lead I >13mm.
2. R in lead aVL >12mm.
3. S wave in V1-V2 + R wave in V5-V6 >35mm if age >30y.o.
4. R aVL + SV3 is >20mm in F, >28mm in M

Changes 1 and 3 are shown in the image. Another example of how to calculate combined voltage is shown.

Question 4

What ECG change would indicate left atrial enlargement?

Answer 4

Large P waves >1mm wide and >1mm deep, with inverted component.

Note that the attached ECG also has high voltage in V1-V6, indicating LVH.

Question 5

What ST-T ECG change would indicate LVH?

Answer 5

Inverted T waves in V5-V6 and downsloping ST segment. Usually indicative of a poorer prognosis.

Question 6

What does this ECG show?

Answer 6

Question 7

Describe the types of ECG changes you would expect for right ventricular hypertrophy.

Answer 7

1. Tall R waves in V1.
   
   • V1 electrode is located over the R ventricle, hence it reflects changes in RVH
   • Normal V1 R wave is usually 1-2mm
   • Large R waves especially accompanied by deep S waves usually indicative of RVH
2. Deep S waves in lateral leads (I, aVL)
3. RAD, usually >90 degrees due to vector change.
4. Tall, peaked P wave, >2mm, often accompanies RVH

Question 8

Point out the ECG changes which indicate RVH.

Answer 8

1. Tall R waves in V1 electrode (green)
2. Deep S waves noted in lateral leads I, aVL, V6 (red)
3. RAD - right axis deviation (blue)
4. Tall P wave (black)

Question 9

Point out the ECG changes which indicate RVH.

Answer 9

Question 10

What does this ECG show?

Answer 10

Right ventricular hypertrophy.

1. Large R waves in V1
2. V6 shows deep S wave, reflective of V1 changes
3. RAD
   
   • Largest R wave is somewhere between III (+120) and aVR (-150), so approximately 180+ degrees deviation, i.e. > +90 degrees = RAD.

Question 11

What does this ECG show?

Answer 11

This shows LVH and RVH.

LVH Changes

• Large R waves - V4-V6, III

RVH Changes

• Large R wave - V1
• Tall, spiky P waves in V1 and V2