What does it mean if the ecg showed signs of ischemia in the postural valve?

Lack of blood flow: First to clarify: there's no such thing as the "postural valve." ekgs can show signs of ischemia in certain regions of the heart muscle, which means there could be a lack of blood flow to those areas, often caused by clogged arteries.

Posterior wall?: You probably meant to say posterior wall, instead of posterior valve. But it probably means there is a blockage in the coronary artery that is feeding the posterior wall of your heart. This can be confirmed with a coronary angiogram and potentially fixed with coronary angioplasty and stent placement or else coronary bypass surgery.