My Wife Recently Had An EKG At Cardiology Office.This Was

My wife recently had an EKG at cardiology office.This was a regular annual test due to her heart valve mild blockage. The EKG was done by an assistant, which is not unusual , but this was the first time we ever had them administer the EKG while patient was sitting in a regular table hard chair, rather then lying down.My question: would this enormanfowffect the recording and results of the test in any way? Thanks for your help.