Left ventricular hypertrophy (LVH)
- QRS prolongation
– left axis deviation
– deep S wave in V1
– large R waves in V4-V6 (mid-lateral)
– ST-segment depression V5-V6 (lateral)
– negative T-waves V4-V6, aVL, I (mid-lateral)
Left ventricular hypertrophy (LVH) is present when the wall thickness of the left ventricle is increased. The hypertrophy of the left ventricle may produce:
- Increased QRS voltage: a deep S wave in V1 and a large R wave in V5 and V6. This is partly due to the increased ventricular mass in close proximity with the chest (V5 and V6 are “looking” directly at the thick left ventricle).
- Left axis deviation (LAD): the electrical axis will tend to deviate to the left.
- Broadened QRS complex (more than 90 msec).
- ST segment depression and T wave inversion in the lateral leads. This is commonly referred to as a “left ventricular strain” pattern.
- EKG findings consistent with left atrial enlargement (p-mitrale).
It is important to recognize the EKG pattern as these findings predict higher morbidity and mortality regardless of the cause. Also the EKG pattern may mimic other conditions such as myocardial ischemia.
Many different criteria or point scores have been suggested to diagnose LVH on the EKG. The classic LVH criteria presented by Sokolow and Lyon in the 1940s are:
- S-wave in V1 plus the R-wave in V5 or V6 (whichever is larger) greater than 3.5 mV (corresponding to 35 mm on standard 10 mm/mV calibration).
Other criteria such as the Cornell voltage criteria may also be useful:
- S wave i V3 + R in aVL more than 2.8 mV (28 mm) in men and 2.0 mV (20 mm) in women.
However, no set of criteria can safely diagnose or rule out LVH. Therefore a patient with suspected left ventricular hypertrophy – with or without the EKG changes – should always undergo echocardiography to confirm the diagnosis.
Left ventricular hypertrophy may be due to hypertension, aortic valve disease or hypertrophic cardiomyopathy.