Heart failure is routinely described as progressive loss of ability of the heart to pump blood. But, there is another form of heart failure where the blood–pumping ability of the heart remains near normal. This second form of heart failure is too often overlooked and is just as lethal.

In this condition the heart muscle becomes thickened. The chamber inside gets smaller and the heart is unable to relax to accommodate the blood it needs to pump out. As there is no room for the heart to relax, the blood backs up into the lungs. This kind of anomaly is not picked up by standard measurements of “ejection fraction” – the percentage of blood in the heart that goes out with every beat.

This form of the disease is called “diastolic heart failure” because the problem occurs during the diastole portion of heart activity, as the heart relaxes after a beat. Nearly one–third of these patients have an ejection fraction greater than 50 percent, which is very near normal. However, the death rate for this kind of heart failure matches that of patients with the more common form of heart failure, with more than 20% of all the patients dying within a year. There is a steady increase over 15 years of heart failure with normal or near–normal ejection fraction.

For patients, the symptoms of both types of heart failure are the same: Shortness of breath, difficulty exercising and fluid retention in the body. Physicians cannot make a diagnosis on the basis of symptoms or routine examinations. One has to have an echocardiogram and see the heart pumping and see if the ejection fraction is normal or reduced. Until now, relatively little attention has been paid to diastolic heart failure. Advances have been made against systolic heart failure, in which the ejection fraction falls below normal but not much has been done about diastolic heart failure.