How Diastolic Dysfunction Is Diagnosed

Diastolic dysfunction, a type of heart failure in which the heart isn't able to fully relax after each beat, is diagnosed with an echocardiogram (ECG) and, sometimes, other imaging tests.

B-type natriuretic peptide (BNP), which is measured with a blood test, can be elevated in association with diastolic dysfunction.

Symptoms

There's no home test for diastolic dysfunction. In fact, the condition rarely causes discernible symptoms. Diastolic dysfunction tends to develop gradually, and some people may begin to experience classic symptoms of heart failure as it progresses.

Symptoms of diastolic dysfunction include:

• Dyspnea (shortness of breath)
• Labored breathing during exercise that gets progressively worse
• Difficulty breathing while lying down
• Difficulty breathing while sleeping
• A chronic cough
• Excessive fatigue
• Unusual weight gain
• Edema (swelling) of the legs and ankles
• Fast or irregular heartbeat

You can experience any combination of these symptoms with diastolic dysfunction, and some may affect you more than others.

B-Type Natriuretic Peptide (BNP) Blood Test

BNP is a molecule released into the blood by heart cells in response to elevated pressure within the heart. It causes the kidneys to excrete sodium and water, which serves to lower the pressure in the blood vessels and the heart.

This protein can be elevated in association with heart failure with diastolic dysfunction. BNP can be measured with a blood sample.

There is a large gray zone between what is considered a normal level of BNP and what is not, and so this test cannot be a reliable indicator of heart failure on its own. Sometimes, a BNP blood test is used in conjunction with other tests to support a diagnosis of diastolic dysfunction.

Imaging Tests

Imaging tests are useful in diagnosing diastolic dysfunction and for assessing the severity of the condition.

Echocardiogram (Echo)

This specialized non-invasive ultrasound provides views of the heart as it is moving. It can give an indication of how well the heart muscle and valves are functioning. It also can be used to assess diastolic relaxation and the degree of left ventricular stiffness.

An echocardiogram can also sometimes reveal conditions that may be the cause of diastolic dysfunction:

• Ventricular hypertrophy, a thickened left ventricular muscle associated with hypertension and hypertrophic cardiomyopathy
• Aortic stenosis, a narrowing of the valve in the aorta (the largest blood vessel branching off the heart)
• Restrictive cardiomyopathy, when the walls of the lower chambers of the heart are too rigid to expand as they fill with blood

Left Ventricular Ejection Fraction (LVEF)

An echocardiogram also can measure left ventricular ejection fraction (LVEF). This is the percentage of blood the left ventricle of the heart is able to pump out with each beat.

A normal LVEF is greater than 50%, which means the left ventricle is able to pump out more than half of the blood that's inside it.

Usually, heart failure is associated with a low LVEF, which is a reflection of systolic function (the heart's ability to eject blood with a strong pumping action). Some people with diastolic heart failure have a normal systolic function and a normal left ventricular ejection fraction.

Electrocardiogram (ECG, EKG)

An electrocardiogram (ECG) is a noninvasive test that evaluates the electrical system of the heart. During this test, electrodes (flat metal discs) are placed in certain positions on a person's chest, arms, and legs.

The electrodes are attached to a machine that reads the electrical charges generated by each heartbeat. The test takes 10 to 15 minutes and the information is graphed as wave patterns.

Cardiac magnetic resonance imaging (MRI, CMR)

Cardiac MRI uses a powerful magnetic field, radio waves, and a computer to produce detailed pictures of the structures within and around the heart. It requires that you remain completely still while lying inside an MRI scanner—a tube large enough to surround the entire body.

A cardiac MRI can tell a doctor a lot about how much strain the heart is undergoing and can assess deformation, left atrial size, and trans-mitral blood flow.

This test yields high contrast and high-resolution images by mapping radio wave signals absorbed and emitted by hydrogen nuclei (protons) in a powerful magnetic field. Because it's costly, it is not widely used.

Nuclear imaging

Imaging tests such as the positron emission test (PET) and the single-photon emission computerized tomography (SPECT) sometimes are used to identify diastolic dysfunction before symptoms begin.

These tests involve the injection of radioactive dyes known as radiotracers. The heart's absorption of the tracers depends on how it's functioning. The resulting color changes indicate whether certain muscles of the heart are not able to pump as they normally would.

Cardiac Stress Test

A cardiac stress test (also known as a cardiac exercise test) measures the heart's response to physical exertion in a controlled setting. It involves walking on a treadmill or pedaling a stationary bike for approximately 20 minutes during which your blood oxygen level, heart rhythm, pulse, and blood pressure are simultaneously monitored.

There are several types of stress tests, any of which might be used to help diagnose diastolic dysfunction and heart failure:

• Electrocardiogram stress test: Electrode patches attached to the chest measure electrical signals triggered by the heart during exercise.
• Echocardiogram stress tests (or echo or cardio ultrasound): Sound waves create a moving picture of how the chambers and valves of the heart function while under stress. It can reveal areas of diminished blood flow, dead muscle tissue, and areas of the heart muscle wall that aren’t contracting well or may not be getting enough blood.
• Nuclear stress tests: Radioactive dye is injected into the bloodstream to highlight blood flow. Images created by the test show how much dye has reached various parts of the heart during exercise and at rest.
• Multiple gated acquisition (MUGA) scan: Uses radionuclide ventriculography (RVG) or radionuclide angiography (RNA) to produce a computerized image of the beating heart and the pumping function of the left and right ventricles. It is particularly useful for reading the overall pumping ability of the heart.
• Chemical stress tests: A medication such as regadenoson, dobutamine, or adenosine, is injected into the bloodstream to stress the heart.

Cardiac Catheterization

Cardiac catheterization is an invasive procedure in which a long, thin, flexible tube is inserted into the arm or groin and guided to blood vessels in the heart. Dye is injected into blood vessels so they can be observed with an X-ray or ultrasound.

Cardiac catheterization can reveal if there are problems with how the heart relaxes and if the ventricles are not relaxing and filling normally.

Spirometry

A spirometry test measures lung function, which is frequently impaired in association with heart failure. It involves breathing into a tube attached to a spirometer device that can measure how forcefully a person is able to push air out of their lungs.

Chest X-ray

A chest X-ray can show if the heart is enlarged or if there are signs of congestion in the lungs.

A Word From Verywell

Although diastolic dysfunction is common, many people with this disease may never experience symptoms. Those who do may dismiss their symptoms as just normal aging. It's important to know what the symptoms are and take them seriously if you begin to experience them. Getting an early diagnosis may prevent you from suffering the serious consequences of heart failure.