An EKG is not a very good source for identifing any structual abnormalities and there are many causes other than a heart condition that can provide a false positve,
An echo shows the left ventricle has some thickening the wall. This condition can cause some rigidity of the heart wall and as a result the chamber is not able to fill with blood to the degree that is normal, The wall size can be due to an abnormal burden for the heart and that can be the result of high blood pressure, etc., possibly if you are heavier in weight than normal that can also be an unnessary burden. How that may effect or have a bearing on your upcoming operation would be better answered by your doctor who has a more complete health history, concomitant health issues, etc.
Hope it goes well for you. Thanks for your question.
Ken