Most patients battling heart failure have the same problem with their body’s most important muscle: it just can’t contract like it once did. Systolic heart failure accounts for as many as nine out of ten cases of heart failure.

But the remaining patients are in just as much danger even if they don’t have the same classic symptoms, like fatigue and shortness of breath.

That’s why UM cardiologist Jose Martinez, M.D., created a specialty clinic dedicated to diastolic heart failure. “Systolic is still more prevalent but diastolic is just as important,” says -Martinez, who is an assistant professor of clinical medicine at the Miller School of Medicine. “We’re raising our awareness, and also data is showing that it carries significant risk, just like systolic hypertension. It’s not something that we can ignore.”

Systolic refers to the compression of the ventricles to push out blood—it’s the higher first number in a blood pressure reading. Diastolic refers to the atrium refilling the ventricle with blood, like blowing up a balloon.

In diastolic dysfunction, the left ventricle becomes stiff and inflexible, especially with age. The left atrium draws in oxygenated blood from the lungs then pushes it into the left ventricle, which then sends it out into the body. If the ventricle is stiff, the atrium has to work harder to fill it. And if a patient with this problem has high blood pressure, the left atrium must work harder still.

“You don’t really lose systolic function because your blood pressure is high,” says Martinez. “You don’t lose systolic function because you’re under a lot of stress. These stressors are deadlier with diastolic problems, and that’s when they’re going to produce symptoms.”

Martinez and his colleagues have created a specialty clinic for patients who they suspect have diastolic dysfunction. It offers patients access to physicians with a growing skill set for diagnosing and treating the disease while helping teach doctors even more.