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Right Atrial hypertrophy

• P wave amplitude 2.5 mV or more in II, III, AVF
• P wave tall thin and peaked
• Mean electrical axis of P wave to right (equal to or >60 degree)
• The initial positive deflection of the biphasic wave is more prominent in V1
• P pulmonale

Left Atrial hypertrophy

• P wave duration 0.12 secs or longer in lead II
• Often notched or slurred
• V1 biphasic and the negative deflection is more prominent
• product of width x depth of 0.04 mm seconds of 1mm2 in lead V1

Right Ventricular Hypertrophy

Criteria

• Abnormal right axis deviation
• Tall R waves in V1-2
• Tall S waves in V5-6
• High voltage of QRS
• RV1  >7 mm
• R/S  ratio in lead V1 exceeds 1
• SV5 or V6 =>7 mm
• RAVR >5mm

• ST-T wave changes
• Normal QRS duration

Left Ventricular Hypertrophy

Criteria

• Tall R waves in V5-6
• Tall S waves in V1-2
• Increased voltage of QRS (30 yr. or older)

• SV1+RV5  >35 mm
• RV5 >25mm
• RAVL >11 mm
• RAVF >20 mm
• RI+SIII >25 mm

• ST-T changes
• Abnormal left axis deviation
• QRS duration not exceeding 0.12
• ST segment shift opposite to R wave
• Widened spatial QRS-T angle more than 100 degrees

Myocardial infarction :

Acute

Significant Q wave with typical ST segment elevation in the same lead.

Recent

• Significant Q wave
• Diminished R wave
• Twave inversion
• ST segment elevation

Old

Only characteristic abnormalities of the QRS are found.

• Significant Q wave
• Diminished R wave

Myocardial infarction by site: