Hypertrophy

Hypertrophy criteria are fairly straightforward; we will be looking for enlargement of any of the four chambers.

1. LVH: (Left ventricular hypertrophy). Add the larger S wave of V1 or V2 (not both), measure in mm, to the larger R wave of V5 or V6. If the sum is > 35mm, it meets "voltage criteria" for LVH. Also consider if R wave is > 12mm in aVL. LVH is more likely with a "strain pattern" which is asymmetric T wave inversion in those leads showing LVH.

2. RVH: (Right ventricular hypertrophy). R wave > S wave in V1 and R wave decreases from V1 to V6.

3. Atrial hypertrophy: (leads II and V1). Right atrial hypertrophy - Peaked P wave in lead II > 2.5mm amplitude. V1 has increase in the initial positive deflection. Left atrial hypertrophy - Notched wide (> 3mm) P wave in lead II. V1 has increase in the terminal negative deflection.

Figure 32: Right ventricular hypertrophy and right atrial enlargement.

Figure 33: Left ventricular hypertrophy (S wave V2 plus R wave of V5 greater than 35mm) and left atrial enlargement (II and V1).

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