What is systolic heart failure?
Systolic heart failure is a form of heart failure in which the heart’s lower chambers (ventricles) have become too weak to contract and pump out enough blood to meet the body’s needs, resulting in shortness of breath and other heart failure symptoms.
Women are less likely than men to have systolic heart failure, accounting for about 25% to 35% of systolic heart failure cases. Men have double the risk of developing blood-pumping (systolic) problems compared with women, and when women do develop them they tend to be less severe.
Researchers think that the reason for this difference is that the main pumping chamber (left ventricle) in women responds differently to conditions that cause it to work harder to pump out blood, such as high blood pressure, coronary artery disease, and narrowing of the aorta (the main artery that carries blood from the heart to the body). Studies have found that in women the pumping chamber wall thickens but the pumping chamber itself doesn’t enlarge; in men, the chamber stretches and enlarges but the wall doesn’t thicken, leading to reduced blood-pumping function. As a result, women usually have better blood-pumping function and a higher ejection fraction (the percentage of blood pumped out per heartbeat) than men and are more likely to have diastolic heart failure, in which the thickened wall can’t relax as easily for the chamber to expand and fill with enough blood.
What are the symptoms of systolic heart failure?
The symptoms of heart failure are generally the same whether you have systolic heart failure or diastolic heart failure. Women with long-term systolic heart failure are more likely than men to have symptoms such as swollen ankles (22% vs. 15%), elevated pressure in the jugular veins on each side of the neck (17% vs. 5%), and shortness of breath resulting from fluid buildup in the lungs.
What causes systolic heart failure?
Systolic heart failure can be caused by any condition that impairs the heart muscle’s ability to pump blood. The most common causes of systolic heart failure are coronary artery disease (CAD) and high blood pressure, either on their own or together.
CAD is a major cause of systolic heart failure in women, although women are less likely than men to have heart failure caused by CAD or heart attack. Limited blood flow through narrowed blood vessels can weaken and damage the heart muscle, making it difficult for the heart to contract and pump out blood. Women who do have a heart attack are more likely than men to develop systolic heart failure.
Women are more likely than men to have high blood pressure before developing heart failure. High blood pressure causes the heart to work harder to pump out blood against the increased pressure in the arteries. Over time, this weakens the heart muscle, damaging its ability to contract and pump blood.
Diabetes is another important contributor to systolic heart failure in women. Women with systolic heart failure are more likely than men to have diabetes. Diabetes itself can cause heart failure by directly damaging the heart muscle, but it can also lead to systolic heart failure indirectly by accelerating the development of CAD and high blood pressure. Women with diabetes have four times the risk of dying of heart disease than women without diabetes.
While for some people there may be one main cause of systolic heart failure, most have multiple factors that work together to cause a gradual decline in the heart’s pumping ability. For more information on the risk factors for heart failure, see our Am I At Risk section.
Who is at risk for systolic heart failure?
Elderly women and women with a current or past history of high blood pressure, CAD, heart attack, or diabetes are at the highest risk for systolic heart failure.
Diagnosis & Treatment of Systolic Heart Failure
How is systolic heart failure diagnosed?
It is difficult to tell the difference between systolic and diastolic heart failure based on medical history and a physical examination alone. The main difference between these two forms of heart failure is that a patient with systolic heart failure pumps a less-than-normal amount of blood out of the heart with each heartbeat. 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 an echocardiogram to check the size of your heart’s left pumping chamber and its pumping (systolic) and filling (diastolic) ability. A normal ejection fraction is 50% or higher, meaning 50% or more of the total blood in the main pumping chamber (left ventricle) is pumped out during each heartbeat. Women tend to have a higher ejection fraction than men, even when they have systolic heart failure. The reason for this is not clear.
Ejection fraction can also be measured with a nuclear ventriculogram or cardiac MRI, but Doppler echocardiography is the primary diagnostic test used to measure ejection fraction. See Heart Failure Tests & Diagnosis for more information.
How is systolic heart failure treated?
The goal of treating systolic heart failure is to alleviate symptoms, slow down the progression of the disease, and improve the quality of life. Treating certain conditions that cause heart failure may stabilize the heart, and, in some cases, it can return to normal strength and size. Treatment options include medications, devices, and surgery.
The treatment of systolic heart failure usually includes a combination of 3 types of drugs: a diuretic, an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB), and a beta-blocker.
A diuretic is used to relieve and control fluid retention in the lungs and limbs. An ACE inhibitor lowers blood pressure and improves symptoms, clinical status, and overall sense of well-being; it also reduces the risk of dying and hospitalization. Patients who can’t take ACE inhibitors due to side effects such as coughing may be given an ARB. A beta-blocker slows your heart rate and lowers your blood pressure, and can slow down the progression of heart failure and improve survival. A beta-blocker should be given as soon as systolic dysfunction is diagnosed because of how well it can slow the progression of the disease.
It remains unclear if ACE inhibitors benefit women to the same extent as they do men, although some studies have found a trend towards a reduced risk of death and need for hospitalization in women with systolic heart failure taking ACE inhibitors. Because of the strong benefits of ACE inhibitors seen in studies involving mostly men, no study of heart failure treatment is allowed to be performed without these drugs.
Doctors may also consider adding digoxin (digitalis drug) to patients with persistent or severe symptoms who haven’t responded to treatment with a diuretic, an ACE inhibitor (or ARB), and a beta-blocker. Digoxin helps your heart pump blood more effectively. It can make you feel better, but it provides no survival benefit and needs to be monitored carefully.
Other drugs that can be added to standard heart failure medications for select patients are hydralazine and isosorbide dinitrate, which lower blood pressure and reduce the strain on the heart. In African Americans, who often don’t respond as well to ACE inhibitors as whites do, adding hydralazine and isosorbide dinitrate to the standard treatment can improve survival. Hydralazine and isosorbide dinitrate may also be considered as a substitute for ACE inhibitors in heart failure patients who can’t tolerate ACE inhibitors because of kidney failure.
Some heart failure patients may require surgery (such as coronary artery bypass graft surgery or heart valve repair) to improve damage to the heart or implantable devices (such as a pacemaker and a defibrillator) to control irregular heart rhythms. As a last resort, people with severe heart failure who do not respond to standard treatment may be eligible for a heart transplant.
Overview of Systolic Heart Failure Treatment for more information.
Is the outcome better with systolic heart failure than with diastolic heart failure?
Heart failure is a serious, potentially life-threatening condition. There is ongoing debate as to whether or not people with systolic heart failure have a worse chance of surviving than people with diastolic heart failure, with more recent studies indicating that both forms of heart failure are equally serious and have similar prognosis.However, it is clear that women with systolic heart failure have a better survival than men.
Women’s better survival with systolic heart failure may be due to the common causes of blood-pumping problems in women. Systolic heart failure caused by CAD and heart attack has a worse outcome than systolic heart failure resulting from other conditions such as high blood pressure or diabetes, which are more common causes in women. About 40% of systolic heart failure in women is caused by CAD or heart attack, and 60% is due to other causes. However, when women develop systolic heart failure as a result of CAD or heart attack, they may have a higher risk of dying, even when compared with men.
Other studies suggest that more women survive systolic heart failure because women are more likely than men to have better blood-pumping function, or higher ejection fraction. One study of 2708 adults (22% were women) with systolic heart failure found that for every 1% increase in ejection fraction in women, there was a 4% decrease in the risk of death; men had a 1% decrease for every 1% increase in ejection fraction.