The abnormal EKG or ECG of left ventricle can be due to many reasons like left ventricular hypertrophy, congenital aneurysm and many more. For complete answer, I advise you to come with all the symptoms and problems which your grandson is having. One thing more the EKG in children is done by setting machine on high voltage. Usually the functions of left ventricle in children is checked by ultrasound color Doppler. Please come with complete information of the problems in your new question.