Diastolic heart failure
Trouble arises when the heart can't properly relax.
Relaxation is every bit as important for your heart as it is for the rest of you. If for some reason the heart has trouble relaxing between beats, then it can't fill completely. Less blood pumped with each contraction sets the stage for a "new" type of heart failure that goes by many names: diastolic heart failure, heart failure with normal ejection fraction, heart failure with preserved systolic function, and others.
Diastolic heart failure isn't really new. It's just that doctors now have tools that let them see how this form of heart failure differs from "regular" (systolic) heart failure. Up to half of the 600,000 Americans who develop heart failure each year have diastolic heart failure. Both types of heart failure result in the same thing — the heart has trouble supplying the body's organs and tissues with the oxygen-rich blood they need.