Congestive Heart Failure Causes
There are two main categories of causes of congestive heart failure.
The first category is more common in babies and younger children. In this situation, the heart muscle pumps well, but the route that blood takes is very inefficient. It occurs when too much blood goes to the lungs, which the lungs and eventually the heart find difficult to handle. This happens with certain kinds of holes or connections with which some babies are born. With these connections (also known as shunts), blood that has already returned from the lungs filled with oxygen to the heart actually ends up back in the lungs then back in the heart again. Examples of these types of lesions include:
- A patent ductus arteriosus is a blood vessel between the aorta and main pulmonary artery that all babies require in fetal life but which usually closes within the first couple of days of life. If it is large and does not close, the baby will have an excessive amount of blood flow to the lungs. This is a very common problem in premature infants.
- Another problem that leads to excessive blood flow to the lungs is a large ventricular septal defect (VSD) or a hole between the two lower pumping chambers of the heart. These will cause congestive heart failure only if the hole is big enough to allow so much extra blood flow to the lungs that the heart has to work a lot harder to pump blood out to the body.
- Some babies are born with other connections between the two main arteries leaving the heart, i.e., aortopulmonary window or truncus arteriosus. These babies are also at risk for having too much blood flow to the lungs.
- Holes between the two upper chambers of the heart (atrial septal defects) rarely cause problems with congestive heart failure no matter how large.
The second cause for congestive heart failure is when the heart muscle is not strong enough to pump a normal amount of blood. This is usually seen in older children but can be seen in babies.
A major cause of this type of congestive heart failure in babies is when structures on the left side of the heart are so small or narrowed that blood has a difficult time ejecting from the heart leading to backup into the lungs. This can be seen in critical aortic stenosis, critical coarctation of the aorta, or hypoplastic left heart syndrome.
In older children where the structure of the heart is normal, it is usually due to a weakening of the heart muscle, or cardiomyopathy, infection of the heart muscle (myocarditis) or Kawasaki disease, which all can lead to congestive heart failure.
Cardiomyopathy can also be seen in babies and can be due to a number of problems such as rhythm disturbances or infections.
Congestive Heart Failure Signs & Symptoms
Signs and symptoms are different for children of different ages. Potential ones are listed below for babies as well as older children:
Signs & Symptoms in Babies
- Poor growth because a significant amount of energy is used up by the heart as it works harder to do its job
- Difficulty breathing because lungs fill with fluid and they will use more of the muscles of their chest and belly to compensate. With significant congestive heart failure, the heart is pumping so hard that one can feel or even see the heart impulse on the surface of the chest quite easily.
- Faster breathing and heart rate
- Difficulty eating or may not eat as fast or as well as other babies. They can become very sweaty with feedings because of the extra work needed to eat.
- Sleep more or have less energy than other babies because their heart has to work harder
- Small and wasted appearance
- The liver may also be enlarged due to congestion on the right side of the heart and may be more easily palpated (felt).
- There may be puffiness of the eyes or feet as the right heart fails.
- Delays in reaching developmental milestones
Timing of Signs and Symptoms
These symptoms will not usually occur as soon as the baby is born. This is because the pressures in the lungs of all babies are equal to the pressures of the rest of the body when babies are first born.
It can take anywhere from two days to eight weeks before the pressures in the lungs fall to normal. Babies with ventricular septal defects or other sources of extra flow to the lungs can often feed and grow as expected for all babies in the first one to two weeks of life because their high pressures in the lungs will prevent excessive blood flow to the lungs.
The symptoms of poor growth − difficulty with feeds and fast breathing − will gradually appear during the first or second week of life as the pressures in the lungs begin to fall and blood flows across the hole into the lungs.
Babies with obstruction to blood flow out of the left side of the heart or a weak heart muscle may have these symptoms much sooner, sometimes in the first few days of life depending on the degree of obstruction or weakness. Blood pressures and pulses can be normal or can be diminished in infants with left-sided obstruction. On examination of the heart, there may be a particular type of heart murmur called a diastolic rumble that may indicate extra blood flow to the lungs.
Signs & Symptoms in Older Children
- Inability to tolerate exercise. They become short of breath more quickly compared to their peers and need to rest more often. Shortness of breath can occur even with minimal exertion, such as climbing stairs or taking a walk.
- Lack of energy when compared to their friends, although this may be harder to determine because all children have different levels of energy.
- Passing out during exercise
- Poor appetite
- Weight loss or lack of weight gain can be seen even in older children.
- Fluid retention and weight gain, causing a puffy appearance
- Extra sound when listening to the heart (called a gallop)
- Enlargement of the liver due to congestion on the right side of the heart, and it may be more easily felt
- Eyes or feet may be puffy as the right heart fails
- Chest pain
- Palpitations (irregular heartbeat)
- Syncope (fainting)
As it is harder to determine parameters for heart failure in older children, it is important to look for change in exercise capabilities or progression of symptoms with time.
Congestive Heart Failure Diagnosis
Congestive heart failure is a clinical diagnosis. The symptoms described above are important clues to the problem. A good physical examination is of major importance.
- An electrocardiogram may be helpful to indicate if the chambers of the heart are enlarged and can point to specific congenital heart diseases or rhythm disturbances that can cause heart failure.
- A chest X-ray can be very useful to determine if the heart is enlarged and if there is extra blood flow or fluid in the lungs. This can be very important in determining the progression of congestive heart failure.
- A graded exercise test can also be used to follow progression of heart failure in some instances for older children.
- An echocardiogram confirms the diagnosis of structural problems of the heart, and can be used in evaluating the function of the heart muscle.
- Finally, for some older children and adolescents, a cardiac MRI provides a useful means to evaluate heart function.
Congestive Heart Failure Treatment
Treatment can vary with age and type of disease. A treatable cause, such as a rhythm problem, may require specific medications or procedures. In babies with ventricular septal defects, medical therapy can be used as a temporary solution to allow the hole to get smaller or close on its own, or to give the baby a little time to grow prior to heart surgery.
In more complex problems such as aortopulmonary window, truncus arteriosus, or hypoplastic left heart syndrome, when it is known that surgery will be needed, it is currently the practice in most centers to perform surgery in the first weeks of life.
Some congenital heart disease cannot undergo surgery and a heart transplant is the only option. In older children with weak heart muscles, medication can help decrease the workload of the heart to give it time to heal, though some of these children will also eventually require transplants.
Treatment can also include devices, such as ventricular assist devices (VADs) or the SynCardia Total Artificial Heart. These devices can help stabilize and support patients while they wait for a donor heart to become available for transplantation (bridge-to-transplant therapy), or to support patients who are not eligible for transplant (destination therapy). Destination therapy may be an alternative to heart transplant for some patients.
There are several types of medications used to treat congestive heart failure.
- A diuretic like furosemide (Lasix), which helps the kidneys to eliminate extra fluid in the lungs, is often the first medicine given both in babies and older children.
- Sometimes medicines to lower the blood pressure like an ACE inhibitor (Enalapril), or beta blockers (Carvedilol) are used. Theoretically, lowering the blood pressure will decrease the workload of the heart by decreasing the amount of pressure against which it has to pump.
- Sometimes a medication called Digoxin is used to help make the heart squeeze better, and help pump blood more efficiently. Since weight gain is a major challenge for infants with congestive heart failure, giving babies high calorie formula or fortified breast milk can help give the extra nutrition they require.
Sometimes babies will need to have extra nutrition given to them via a tube that goes directly from the nose to the stomach, a nasogastric feeding tube. This is good for babies who work hard or get very tired from feeding in order to prevent them from using up all the extra calories needed for growth.
Older children with significant heart failure can also benefit from nasogastric feeding to give them more calories and energy to do their usual activities.
Oxygen can worsen blood flow to the lungs in babies with large ventricular septal defects but may be helpful as a buffer to children with weak hearts.
Some kids with cardiomyopathy may also need restriction of certain kinds of exercise and competitive sports, although they may benefit from light activity like swimming.
Congestive Heart Failure Long-Term Outlook
All outcomes depend on the cause. If congestive heart failure is due to a structural problem of the heart that can be fixed, the outcome is excellent.
Babies with large ventricular septal defects whose holes get smaller or are closed surgically are able to lead a normal life. Babies with more complex congenital heart disease may have more variable results.
Older children with cardiomyopathy tend to progress, unless the cause of the cardiomyopathy is reversible. The key in managing heart failure is making the proper diagnosis, having close follow-up with a cardiologist and taking medications prescribed on a daily basis.