Sokolow-Lyon electrocardiographic criteria is for the diagnosis of:
A) Left atrial enlargement
B) Left ventricular hypertrophy
C) Right atrial enlargement
D) Right ventricular hypertrophy
Correct answer: B) Left ventricular hypertrophy
It is used to detect left ventricular hypertrophy (LVH) using an ECG.
In a case of LVH, the amplitude of the S wave is increased in right oriented leads (like V1) and that of the R wave is increased in left oriented leads (like V5 and V6).
LVH is said to be present if:
S wave in V1 + R wave in lead V5 or V6 > 3.5 mV
R wave in V5 or V6 > 2.6 mV
It is one of the simplest ECG criteria for the detection of left ventricular hypertrophy.
As it is solely dependent on ECG voltages, it can produce erroneous results in certain conditions.
In obese patients, the voltages will be less even in the presence of LVH.
Similarly, in thin patients, the voltages will be higher even if they don’t have LVH.
Other factors which modify the lead voltages can also influence the calculation.
Read more on Sokolow-Lyon criteria at: https://cardiophile.org/sokolow-lyon-criteria-for-left-ventricular-hypertrophy/
Image credits: Patrick J. Lynch (http://patricklynch.net), Creative Commons Attribution 2.5 License 2006 (http://creativecommons.org/licenses/by/2.5/).