If I understand you correctly, you're saying that your 17 year old friend has left ventricular hypertrophy
and was advised to undergo surgery to correct this condition. The assumption, therefore, is that your friend has HOCM (hypertrophic obstructive cardiomyopathy
). HOCM surgery probably involves open heart surgery, so it is relatively major surgery, unless your friend is able to undergo the non-surgical option where a small amount of alcohol is injected through a tube passed from the groin to reduce the bulk of the muscle that is blocking the flow of blood in the heart. Good luck.