Complex sentence: Alcohol septal ablation is a technique designed to reduce the obstruction to blood being ejected from the heart; the technique creates a small controlled heart attack, killing the area of heart muscle responsible for the obstruction, and eventually causing it to become less thick.
Split into simpler sentences: Alcohol septal ablation is a technique designed to reduce the obstruction to blood being ejected from the heart. The technique creates a small controlled heart attack, killing the area of heart muscle responsible for the obstruction, and eventually causing it to become less thick.