What is diastolic heart failure?
Diastolic heart failure is a form of heart failure in which the heart’s lower chambers (ventricles) have become too stiff to relax and expand to fill with enough blood (blood-filling problems). This causes the heart to pump less blood, resulting in the backup of fluid in the lungs and symptoms of heart failure.
Diastolic heart failure is twice as common in women as in men. The risk of developing diastolic heart failure increases with age. Nearly half of all heart failure patients over the age of 70 have diastolic heart failure, compared with 33% between the ages of 50 and 70 years and 15% at younger than 50 years; women-specific information is not available.
The symptoms of heart failure are generally the same for both diastolic heart failure and systolic heart failure: shortness of breath, fatigue, and fluid buildup. In diastolic heart failure, the most common symptoms are fatigue and shortness of breath during mild physical activity or when lying down.
for an illustration of the difference between systolic and diastolic heart failure.
What causes diastolic heart failure?
Diastolic heart failure becomes more common as we get older. As people age, the heart and blood vessels lose elasticity, eventually leading to stiffness and limiting the heart’s ability to fill with blood. Women with diastolic heart failure tend to be older and are more likely than men to have severe thickening of the heart muscle wall in response to conditions such as high blood pressure and diabetes. This response seems to make women more susceptible to the cumulative effect of aging on the heart’s blood-filling (diastolic) function.
Other than the natural effects of aging on the heart, most cases of diastolic heart failure are caused by high blood pressure or diabetes or both; coronary artery disease and obesity are also common causes.
High blood pressure causes your heart to work harder to pump blood, eventually resulting in the heart muscle becoming thicker or larger to help the heart pump against the increased pressure. Over time, the thickened heart muscle becomes stiff and the heart is unable to relax and expand to fill with enough blood, leading to diastolic heart failure. High blood pressure is the most widespread cause of diastolic heart failure in women. Women with high blood pressure are more likely than men to have a thickened heart.
Diabetes can cause increased wall thickness of the heart’s main pumping chamber in women but not in men, leading to more frequent cases of blood-filling problems in women and perhaps explaining why women more often than men have diastolic heart failure. Diabetes has been shown to damage the heart muscle in women as young as 15 years of age.
Coronary artery disease (CAD) reduces or blocks blood flow to the heart muscle, which can eventually damage the heart’s ability to relax and fill with enough blood. CAD is an important cause of heart failure in women independent of other risk factors, although women are less likely than men to have CAD as the main underlying cause of diastolic heart failure. Women with heart failure are less likely than men to have had a heart attack, but they have a higher chance of developing heart failure after a heart attack.
Obesity can cause your heart to work harder to pump blood to the added fatty tissue, causing the heart’s main pumping chamber to become thicker. Over time, this limits your heart’s ability to fill with blood, setting the stage for diastolic heart failure.
Who is at risk for diastolic heart failure?
Women tend to have more of the risk factors associated with blood-filling problems and diastolic heart failure, such as high blood pressure, diabetes, and older age. Diastolic heart failure is more common in older women with high blood pressure.
The risk of developing diastolic heart failure increases with age, mostly because of the increased risk of high blood pressure, diabetes, and CAD that comes with age.
Diagnosis & Treatment of Diastolic Heart Failure
How is diastolic heart failure diagnosed?
The main difference between diastolic heart failure and systolic heart failure is that the heart of a patient with diastolic heart failure has a normal ability to pump out blood. This is measured by ejection fraction, the percentage of blood pumped – or “ejected”- out of a filled pumping chamber (ventricle) during each heartbeat.
To measure your ejection fraction, your doctor will order a Doppler echocardiogram to check the size of your main pumping chamber and determine if it is pumping out blood as it should. Diastolic heart failure usually has a normal ejection fraction of 50% or higher because the main pumping chamber is still pumping half or more of the blood it holds. However, the heart still pumps out less blood than normal because it is unable to relax and fill with enough blood. Women are more likely than men to have a high ejection fraction.
You will be diagnosed with diastolic heart failure if your doctor finds you have signs and symptoms of heart failure, especially the backup and buildup of fluid (congestion) in the lungs, normal ejection fraction, and blood-filling problems caused by pumping chambers that have become too stiff to relax and fill with enough blood.
How is diastolic heart failure treated?
Diastolic heart failure has been less studied and understood than systolic heart failure. Although research on the conditions is progressing, the treatment of diastolic heart failure remains less well established than the treatment of systolic heart failure because there are only a few, small clinical trials on treating this type of heart failure. Therefore, many of the medications used to treat systolic heart failure are used to treat diastolic heart failure, focusing on reducing symptoms (such as fluid buildup) and controlling or treating the underlying cause.
The backup and buildup of fluid in the lungs and body can be controlled with diuretics. If your diastolic heart failure was caused by uncontrolled high blood pressure, your doctor can use angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) to normalize your blood pressure and reverse some of the ventricular thickening and impaired relaxation. Beta-blockers, digoxin, and some calcium channel blockers may be used to slow a rapid heart rate (tachycardia). Slowing your heart rate allows your heart’s pumping chambers more time to relax and fill with blood.
Is the outcome better with diastolic heart failure than with systolic heart failure?
Heart failure is a serious, potentially life-threatening condition, especially for those with more severe symptoms. Research regarding the outcome of diastolic heart failure compared with systolic heart failure varies greatly. Earlier studies reported a better outcome for people with diastolic heart failure, but more recent studies indicated that both forms of heart failure are equally serious and have similar prognosis. Women with diastolic heart failure have a better chance of survival than men.
It was thought that diastolic heart failure patients had a somewhat better outcome than those with systolic heart failure, from a yearly chance of death of 5% to 8% for diastolic heart failure compared with 10% to 15% for systolic heart failure. More recent studies, however, have found that diastolic heart failure can be almost as lethal as systolic heart failure, with about 30% dying in the first year and an additional 30% dying in the next four years. These studies did not report results in women separately.