Electrocardiogram # 3


Two year old boy with Tricuspid Atresia (TA)


Superior axis (QRS negative in lead AVF and positive in lead 1 )

Left Ventricular Hypertrophy ( deep S in V1)

Right Atrial Enlargement ( tall P waves in leads 11, V1 and V2)

The right ventricle is underdeveloped, therefore electrical activity associated with this ventricle is reduced.

The finding of Left Ventricular Hypertrophy and Right Atrial Enlargement is pathognomonic of this condition as in most other lesions Right Atrial Enlargement is accompanied with Right Ventricular hypertrophy- ECG Pearl!