It is possible to have a high EF, but it could also be a heart that is compensating
for a deficit in the circulation system. The normal range
for EF (ejection fraction, amount of blood pumped with each heartbeat) is 50 to70%. When the EF is in the upper range, there is more blood pumped with each heart beat to maintain a balance of blood flow in equilibrium between the right and left side.
Or for some pathological reason, the heart is pumping harder than normal.