Did an echo last month, after an acute episode of atrial flutter. The report said "A normal sized left ventricle with minimal septal hypertrophy. The left atrium is borderline dilated". I think they meassured my septum to 13mm. Since I was worried for HCM, I got a new time for an echo, which did this friday. The new report said ""A normal sized left ventricle with normal wall thickness. The left atrium is borderline dilated". This time they meassured septum to 10mm. What am I supposed to believe? I get no good answer when asking the doctors. Hopefully, the first echo was wrong.