Sokolow-Lyon electrocardiographic criteria – Medicine MCQ

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

Cross section of heart with left ventricular hypertrophy

Sokolow-Lyon criteria

• 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
    OR
    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/).