Which portion of the heart is in failure when it can no longer effectively pump blood into the lungs

Which portion of the heart is in failure when it can no longer effectively pump blood into the lungs

A ventricular septal defect (pronounced ven·tric·u·lar sep·tal de·fect) (VSD) is a birth defect of the heart in which there is a hole in the wall (septum) that separates the two lower chambers (ventricles) of the heart. This wall also is called the ventricular septum.

What is a Ventricular Septal Defect

A ventricular septal defect happens during pregnancy if the wall that forms between the two ventricles does not fully develop, leaving a hole. A ventricular septal defect is one type of congenital heart defect. Congenital means present at birth.

In a baby without a congenital heart defect, the right side of the heart pumps oxygen-poor blood from the heart to the lungs, and the left side of the heart pumps oxygen-rich blood to the rest of the body.

In babies with a ventricular septal defect, blood often flows from the left ventricle through the ventricular septal defect to the right ventricle and into the lungs. This extra blood being pumped into the lungs forces the heart and lungs to work harder. Over time, if not repaired, this defect can increase the risk for other complications, including heart failure, high blood pressure in the lungs (called pulmonary hypertension), irregular heart rhythms (called arrhythmia), or stroke.

Learn more about how the heart works »

Types of Ventricular Septal Defects

Which portion of the heart is in failure when it can no longer effectively pump blood into the lungs

An infant with a ventricular septal defect can have one or more holes in different places of the septum. There are several names for these holes. Some common locations and names are (see figure):

  1. Conoventricular Ventricular Septal Defect
    In general, this is a hole where portions of the ventricular septum should meet just below the pulmonary and aortic valves.
  2. Perimembranous Ventricular Septal Defect
    This is a hole in the upper section of the ventricular septum.
  3. Inlet Ventricular Septal Defect
    This is a hole in the septum near to where the blood enters the ventricles through the tricuspid and mitral valves. This type of ventricular septal defect also might be part of another heart defect called an atrioventricular septal defect (AVSD).
  4. Muscular Ventricular Septal Defect
    This is a hole in the lower, muscular part of the ventricular septum and is the most common type of ventricular septal defect.


In a study in Atlanta, the Centers for Disease Control and Prevention (CDC) estimated that 42 of every 10,000 babies born had a ventricular septal defect.1 This means about 16,800 babies are born each year in the United States with a ventricular septal defect. In other words, about 1 in every 240 babies born in the United States each year are born with a ventricular septal defect.

Causes and Risk Factors

The causes of heart defects (such as a ventricular septal defect) among most babies are unknown. Some babies have heart defects because of changes in their genes or chromosomes. Heart defects also are thought to be caused by a combination of genes and other risk factors, such as the things the mother comes in contact with in the environment or what the mother eats or drinks or the medicines the mother uses.

Read more about CDC’s work on causes and risk factors »


A ventricular septal defect usually is diagnosed after a baby is born.

The size of the ventricular septal defect will influence what symptoms, if any, are present, and whether a doctor hears a heart murmur during a physical examination. Signs of a ventricular septal defect might be present at birth or might not appear until well after birth. If the hole is small, it usually will close on its own and the baby might not show any signs of the defect. However, if the hole is large, the baby might have symptoms, including:

  • Shortness of breath,
  • Fast or heavy breathing,
  • Sweating,
  • Tiredness while feeding, or
  • Poor weight gain.

During a physical examination the doctor might hear a distinct whooshing sound, called a heart murmur. If the doctor hears a heart murmur or other signs are present, the doctor can request one or more tests to confirm the diagnosis. The most common test is an echocardiogram, which is an ultrasound of the heart that can show problems with the structure of the heart, show how large the hole is, and show how much blood is flowing through the hole.


Treatments for a ventricular septal defect depend on the size of the hole and the problems it might cause. Many ventricular septal defects are small and close on their own; if the hole is small and not causing any symptoms, the doctor will check the infant regularly to ensure there are no signs of heart failure and that the hole closes on its own. If the hole does not close on its own or if it is large, further actions might need to be taken.

Depending on the size of the hole, symptoms, and general health of the child, the doctor might recommend either cardiac catheterization or open-heart surgery to close the hole and restore normal blood flow. After surgery, the doctor will set up regular follow-up visits to make sure that the ventricular septal defect remains closed. Most children who have a ventricular septal defect that closes (either on its own or with surgery) live healthy lives.


Some children will need medicines to help strengthen the heart muscle, lower their blood pressure, and help the body get rid of extra fluid.


Some babies with a ventricular septal defect become tired while feeding and do not eat enough to gain weight. To make sure babies have a healthy weight gain, a special high-calorie formula might be prescribed. Some babies become extremely tired while feeding and might need to be fed through a feeding tube.


  1. Reller MD, Strickland MJ, Riehle-Colarusso T, Mahle WT, Correa A. Prevalence of Congenital Heart Defects in Metropolitan Atlanta, 1998-2005. J Pediatr. 2008;153:807-13.

Which portion of the heart is in failure when it can no longer effectively pump blood into the lungs

Heart failure happens when your heart can’t pump blood or relax as well as it should. The good news is that there’s a lot you can do to manage heart failure. Find out what you can do to feel better and stay out of hospital.

The term heart failure can be frightening, but it doesn’t mean that your heart is going to stop working. It means that your heart muscle isn’t pumping blood around your body, or relaxing, as well as it should.

Although heart failure can’t usually be cured, there’s a lot you can do to manage it. By taking your medication, following a heart failure action plan and making some lifestyle changes, you can feel better, stay out of hospital and continue to lead an active, fulfilling life.

See all our heart failure information

What is heart failure?

Heart failure is a long-term heart condition which occurs when your heart isn’t pumping or relaxing as well as it should.

When you have heart failure, the heart muscle becomes:

  • weak and floppy or
  • thickened and stiff.

This means the heart can’t pump or fill like normal, making it harder for the heart to pump blood around the body.

What causes heart failure?

Heart failure happens when the heart muscle has been damaged in some way. Common causes of this damage include:

Symptoms of heart failure

When your heart can’t pump or relax effectively, excess fluid may build up in your lungs, legs and other parts of your body.

This fluid build-up can lead to a range of symptoms including:

  • swelling in the feet, ankles, legs and around your tummy or back
  • shortness of breath when active or when lying down
  • need for more pillows at night or to sleep upright
  • coughing or wheezing
  • extreme tiredness
  • loss of appetite.

Heart failure tests

Your doctor may order some heart tests to confirm that you have heart failure and to help identify how well your heart is functioning. These tests may include:

  • blood tests to indicate heart damage, find out how other organs are functioning and rule out any other health conditions with similar symptoms
  • electrocardiogram (ECG) to check your heart’s electrical conduction system
  • chest X-ray to show fluid build-up and rule out lung conditions with similar symptoms
  • echocardiogram (echo) scan to show the heart's movement and how well it’s pumping.

Heart failure treatment

In most cases heart failure can’t be cured, however, there’s a lot you can do to manage the condition and keep yourself well.

Medication will be an important part of your heart failure treatment. Some people may require a small device, such as a pacemaker implanted under the skin to help control their heart rate and rhythm and improve how well the heart functions.

Lifestyle and condition management are also very important for treating heart failure.


Medication is a really important part of your heart failure treatment. Taking the right pills at the right time can:   

  • improve your symptoms and make you feel better    
  • improve your heart function    
  • keep you well and out of hospital   
  • help you to live longer.

Your medication plan will be personalised for you and specific pills will be introduced at different stages. Medications will be started at low doses and gradually increased until the right dose is reached.

It’s really important that you keep taking your medication even when you start to feel better. Heart medications aren’t one-off prescriptions and you need to stay on them in order to stay well and out of hospital.

You will probably be on one or more of the following types of medication:

ACE inhibitor or ARB

These medications help your blood vessels relax, lowering your blood pressure. This makes it easier for your heart to pump blood around your body.

Common ACE inhibitors (angiotensin-converting enzyme inhibitors) include:

  • cilazapril
  • enalapril
  • quinapril
  • lisinopril
  • perindopril
  • trandolapril
  • captopril.

Common ARBs (angiotensin receptor blockers) include:

Read more about ACE inhibitors and ARBs and find the common brand names in our medication section.

Aldosterone antagonist

Aldosterone antagonists reduce fluid and sodium build-up in your blood. This helps to decrease the volume of blood that your heart needs to pump.

Common aldosterone antagonists include:

  • spironolactone
  • eplerenone (also called INSPRA).


These medications combine two medicines that relax blood vessels and reduce the amount of water you have in the body. This reduces the strain on your heart. Currently, the only one available is Entresto.

Read more about ARNIs in our medication section.

Beta blocker

Beta blockers steady your heart rate and rhythm and help lower your blood pressure. Common beta blockers include:

  • atenolol
  • bisoprolol
  • carvedilol
  • celiprolol
  • labetalol
  • metoprolol
  • sotalol.

Read more about beta blockers and their common brand names.


Diuretics, also commonly called water tablets, help your body to get rid of extra fluid. This decreases the amount of blood that your heart has to pump. Common diuretics include:

  • frusemide
  • bumetanide
  • metolazone
  • bendrofluazide.

Read more about diuretics and their common brand names in our medication section.


Digoxin helps to control your heart rate and rhythm, which helps to reduce the strain on your heart.

Read more about digoxin.

Device-based therapies

As well as heart failure medication, some people may need an implantable electronic device to keep their heart rate and rhythm beating steadily. These small, battery-operated devices are inserted under the skin on the chest or in your side. They include:

Cardiac Ablation

Cardiac ablation is a heart procedure that is sometimes recommended if you have problems with your heart rate and rhythm, contributing to your heart failure.

Read more about cardiac ablation.

Lifestyle and heart failure management

Your lifestyle also plays a key part in your heart failure treatment. This includes:

The Heart failure action plan and Daily checks record are free tools to help you manage your heart failure.

For more information about staying well with heart failure, click on the buttons below.

Visit the heart failure hub for more information

Get the heart failure resources