ERROR: Mistakes found: At about 21:50 we meant "a" when we said "e". ERROR: Te'-E is CORRECT. We incorrectly use TE-e' in this lecture. It is written BOTH ways TE-e' in the ASE guidelines and Te'-E in the original article. VERY confusing but the important thing to remember is: 1. Te' is PROLONGED with diastolic dysfunction. Te' is time from R on EKG to ONSET of e', TE is the time from R on EKG to onset of E wave. Te'-E is the difference: Te' minus TE. it is also called (incorrectly I think) TE-e' in the ASE guidelines 2. The TIME INTERVAL (Te'-E) is ALSO prolonged with diastolic dysfunction. Whatever you call it, it is prolonged. Te'-E is prolonged with diastolic dysfunciton and Te' is prolonged with diastolic dysfunction. Special thanks to Tariq Naseem and Antonio Hernandez and others who alerted us to the error. We will re-record the lecture and remove the error when time permits. Sorry for the mistake.