Right axis deviation is seen in all except –a) VSDb) Tricuspid atresiac) Pulmonary atresiad) ASD
High-Yield Explanation
Normally, the QRS axis ranges from -30° to + 100°.
An axis more negative than -30° is referred to as left axis deviation.
An axis more positive than + 100° is referred to as right axis deviation.
Causes of left axis deviation (LAD)
Left ventricular hypertrophy
Left anterior fascicular block or hemiblock.
Inferior wall MI.
Causes of Right axis deviation (RAD)
Right ventricle overload (right ventricular hypertrophy
Left posterior fascicular block.
Lateral wall MI
Dextrocardia
Left pneumothorax
Now see the explanations of the previous question and you can easily solve this question.
Left ventricular hypertrophy causes LAD, and CHDs causing LVH are : -
1) VSD iii) Endocardial cushion ASD v) Truncus arteriosus
ii) PDA iv) COA (in older children) vi) Tricuspid atresia
vii) Pulmonary atresia
Right ventricular hypertrophy causes RAD, and CHD's causing RVH are : -
TGA
TAPVR
TOF
ASD
Eisenmenger's syndrome
COA (in infants)
About option 'a'
All patients with VSD are born with right ventricular hypertrophy, as the pulmonary vascular resistance decreases, RVH regresses and there is LVH. Hemodynamics of VSD will be explained in the respective question.
So, at birth VSD may show right axis deviation.