Heart wall impairment can be due to a number of different causes that effect the heart muscle. It can be heart
cell damage due to a heart attack,
cell damage from toxic environment and/or ingestion (med, drugs, medication), high blood pressure, etc.
Whether your father can ioncrease the contractility of the heart depends on the underlying cause. You father may have an enlarged left ventricle and this condition can cause weaker than normal contractions.