ECG: the first step

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Left ventricular hypertrophy

The "cardiac vector loop during ventricular depolarization" in patients with left ventricular hypertrophy spreads more to the left than in normal subjects, which makes the positive deflection of the QRS wave in lead I (the R wave) taller.

Let's consider left ventricular hypertrophy compared with a normal heart.

  "cardiac vector loop during ventricular depolarization" Actual ECG record
Condition of the heart The direction the loop
mainly spreads
Projection to leads
(*the most diagnostic lead)
Left ventricular hypertrophy Left-left-inferior-posterior * Lead I Lead I All leads

Achievement Quiz

  1. In left ventricular hypertrophy, the "cardiac vector loop during ventricular depolarization" spreads to the left than in normal subjects.
  2. In left ventricular hypertrophy, the deflection in Lead I, is than in the normal subjects.
  3. In this ECG, the most likely diagnosis is .
  4. In this ECG, the most likely diagnosis is .