Criteria for Left Ventricular Hypertrophy

 

Early abnormalities present in left ventricular hypertrophy:

(1) depressed RS-T segment with flat or low diphasic T waves

(2) abnormally high voltage in the QRS complex, and

(3) delayed onset of the intrinsicoid deflection.

 

Observed Criteria

 

Standard Limb Leads (SLL)

(1) (R in I) + (S in III) >= 25 mm

(2) RS-T in I depressed 0.5 mm or more

(3) T in I flat, diphasic, or inverted, particularly when associated with (SLL 2) and a prominent R wave

(4) T in II and T in III diphasic or inverted in the presence of tall R waves and (SLL 2)

(5) T in III > T in I, in the presence of left axis deviation and high voltage QRS complex in leads I and III

 

Precordial Leads (PL)

(1) R in V5 or V6 > 26 mm

(2) RS-T segment depressed more than 0.5 mm in V4, V5 or V6

(3) A flat, diphasic or inverted T wave in V4, V5 and V6 with normal R and small S waves and (PL 2)

(4) Ventricular activation time in V5 or V6 >= 0.06 seconds (delayed onset of intrinsic deflection), especially when associated with a tall R wave.

(5) (R in V5) + (S in V1) >= 35 mm

 

Unipolar Limb Leads (ULL)

(1) RS-T segment depressed more than 0.5 mm in aVL or aVF

(2) Flat, diphasic or inverted T wave in aVL or aVF with an R wave >= 6 mm, with (ULL 1)

(3) R in aVL > 11 mm

(4) upright T wave in aVR.

 

where:

• 1 mm = 0.1 mV

 

The intrinsicoid deflection is the duration from the beginning of the earliest appearing Q or R wave to the peak of the R wave

• The end of the deflection represents the time of arrival of the electrical impulse at the epicardial surface located beneath the recording electrode.

• It is called intrinsic when the electrode is on the epicardial surface and intrinsicoid when the electrode is on the body surface.

• The intrinsicoid deflection for the right ventricle is measured in leads V1 and V2 and has an upper limit of 0.035 seconds.

• The intrinsicoid deflection for the left ventricle is measured in leads V5 and V6 and has an upper limit of 0.045 seconds.

• The intrinsicoid deflection may be increased either with ventricular hypertrophy or intraventricular conduction delay.