• Left Ventricle
• Concentric Left Ventricular Hypertrophy
• Eccentric Left Ventricular Hypertrophy
• Main Ventricular Vector and Ventricular Hypertrophy
• Left Ventricular Hypertrophy
• ECG and Left Ventricular Hypertrophy
• Sokolow Index
• Lewis Index
• aVL(R) ≥ 11mm
• aVL(R) ≥ 13mm and III(S) ≥ 15mm
• Prolonged R Wave Peak Time (V6) ≥ 50ms
• Left Ventricular Overload and Concentric Hypertrophy of the LV

Left Ventricle

• The left ventricle has a physiological thickness of 10-12mm
• Hemodynamic overload of the ventricle (volume or pressure) causes remodeling of the ventricle
• Left ventricular hypertrophy
• It is wall thickening > 12mm
• The wall of the left ventricle has a physiological thickness of 10-12mm
• Right ventricular hypertrophy
• It is wall thickening > 5mm
• The wall of the right ventricle has a physiological thickness of 3-4mm
• According to hemodynamic overload, we recognize 2 types of hypertrophy:
• Concentric hypertrophy
• Excentric hypertrophy

Eccentric Left Ventricular Hypertrophy

• The ventricle is overloaded by volume (increased preload)
• It becomes filled with blood during diastole
• During systole, it is overloaded by pressure (pumps a larger volume of blood)
• Dilation and hypertrophy of the ventricular cavity occurs
• With chronic volume overload, only dilation occurs
• Eccentric left ventricular hypertrophy, causes:
• Aortic insufficiency
• Eccentric right ventricular hypertrophy, causes:
• Pulmonary insufficiency

Left Ventricular Hypertrophy

• ECG cannot differentiate between concentric and eccentric hypertrophy
• ECG in the diagnosis of left ventricular hypertrophy has:
• Low sensitivity (20-50%)
• Many patients with hypertrophy have a normal ECG (false negatives)
• High specificity (90%)
• If a patient has ECG signs of hypertrophy, then hypertrophy is very likely
• Diagnosis of hypertrophy is performed using echocardiography
• The principle of ECG diagnosis of LVH is that the cardiac vector rotates:
• Toward lateral leads (I, aVL, V5-V6)
• A high R wave is generated
• Away from right-sided leads (aVR, III, V1-V2)
• A deep S wave is generated

Sokolow Index

• S(V1/2) + R(V5/6) ≥ 35mm
• It is the most commonly used criterion
  
  
• Cornell Index
• More sensitive than the Sokolow index
• Less commonly remembered (often not used)
• Men: R(aVL) + S(V3) > 28mm
• Women: R(aVL) + S(V3) > 20mm
• Cornell Product Duration
• Has the highest sensitivity
• Less commonly remembered (often not used)
• Cornell Index (mm) x QRS Duration (ms) > 2440 mm.ms

aVL(R) ≥ 11mm

• aVL(R) ≥ 11mm
• Used in cases of normal cardiac axis

Prolonged R Wave Peak Time (V6) ≥ 50ms

• The time from the start of the QRS complex to the peak of the R wave is referred to as:
• R Wave Peak Time (Intrinsicoid Deflection)
  
  
• Prolonged R Wave Peak Time (V6) ≥ 50ms
• Is seen in left ventricular hypertrophy
  
  
• In hypertrophy, the time for wall activation is prolonged
• Thus, the distance between:
• the beginning of the QRS complex (start of ventricular activation)
• and the peak of the R wave (end of depolarization of the left ventricle)

Left Ventricular Overload and Concentric Hypertrophy of the LV

Left ventricular strain pattern

• Only concentric hypertrophy of the LV (pressure overload) is created
• Not eccentric hypertrophy of the LV (volume overload)
  
  
• Descending ST depressions in lateral leads (I, aVL, V5-6)
• Occur due to prolonged repolarization

Left Ventricular Hypertrophy

• Large S and R waves in precordial leads that extend into adjacent leads
• Positive Sokolow Index
• S(V1/2) + R(V5/6) ≥ 35mm
• Left Axis Deviation
• aVL(R) ≥ 13mm and III(S) ≥ 15mm
• Left Ventricular Overload
• Descending ST depressions in lateral leads (V5-V6, I, aVL)
• Likely concentric hypertrophy of the LV
• Discordant ST Elevations (V1-3)
• Prolonged R Wave Peak Time (V6) ≥ 50ms
• Definitive diagnosis is through echocardiography