Symptoms are different for children of different ages. In babies, regardless of the cause of congestive heart failure, the end result of significant congestive heart failure is poor growth. This is because in babies with congestive heart failure a significant amount of energy is used up by the heart as it works harder to do its job.
In addition, as the lungs fill with fluid, it becomes more difficult for babies to breathe and they will use more of the muscles of their chest and belly to compensate.
These babies will also have a harder time eating and 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.
Some babies work so hard that they wear themselves out and sleep more or have less energy than babies without heart problems, although this is hard to gauge as different babies will have different sleeping habits regardless of whether they have heart problems.
All of this extra work will result in the baby's inability to take in enough nutrition to grow, which is an infant's top priority in the first year of life.
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.
Older children with congestive heart failure are beyond the time of rapid growth and therefore do not have major growth problems like infants. Their symptoms are usually related to their 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 if the heart failure is severe. These children will often lack energy when compared to their friends, although this may be harder to determine because all children have different levels of energy.
In children with heart failure, passing out during exercise may be very serious and needs to be evaluated immediately. Appetite may be poor when heart failure is severe and weight loss or lack of weight gain can be seen even in older children.
Some children will retain fluid and will actually gain weight with heart failure and appear puffy. 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.