If our goal is to detect congenital heart defects before the heart fails, we're going to need some guidelines. Physical exam findings that might suggest congenital heart disease include rapid heart rate, which is known as tachycardia, irregular heart rate, rapid breathing or tachypnea, decreased perfusion of the skin, palpation of pulses, auscultation of murmurs, and cyanosis, as previously mentioned. Usually a baby with heart disease will have several of these features. Each is a clue which may not mean much alone, but taken together can lead to a diagnosis of a heart defect. Let's take each of these in turn to give you an idea of what you're looking for. The normal heart rate of a newborn is 100 to 160 beats per minute while they are at rest. A crying baby can have a greatly increased heart rate, so be sure to count when they are calm and comfortable. You can use a heart rate monitor, but it is also fine just to count the beats yourself. I find it easiest to count by placing my stethoscope over the left side of the chest and directly listening to the heart. You can count for 15 seconds and multiply by 4 to get the number of beats per minute. A heart rate greater than 160 beats per minute can be associated with a variety of things, including dehydration and fever. It can also be the sign of a heart that is not functioning well, either because it's working too hard in the case of heart failure or if there's something wrong with the electrical conduction system. A low heart rate, that is one that is less than 100 is also worrisome. We see this if a newborn does not have enough oxygen in their blood or if there's a problem with the electrical conduction system. The heartbeats to rhythm so regular that you can practically dance to it. [SOUND] Occasionally, there are additional beats or dropped beats, followed by a pause. Heartbeats that are out of place are known as ectopic beats. This is normal during the period of transition just after birth. A baby can have up to eight such beats each minute. These abnormal beats generally disappear over the first days of life. If they last longer than that, you should consult a cardiology specialist. [SOUND] Tachypnea is rapid breathing. A normal respiratory rate for a newborn is 30 to 60 breaths per minute when the baby is at rest. In another module, you'll learn that tachypnea is one of the hallmarks of respiratory distress associated with diseases of the lungs. It can also be seen in babies with congenital heart disease. Think about it. If a baby does not have enough oxygen in their blood stream for any reason, the brain will sense it. The brain in turn sends a signal to the respiratory system to take more rest to bring in more oxygen. The difference between rapid breathing for heart and lung reasons is this. When there is a heart disease, the lungs are usually healthy, at least early in the course. So we see a baby breathing rapidly, but comfortably. With lung disease, the lungs are stiff and heavy. In order to get them to expand, a great deal of muscle effort is required. We see this reflected in retractions, an increase work of breathing. When the heart begins to fail and it's pumping less effectively, the blood flow through the arteries become slower. On physical exam, we can tell this is happening by pressing on the skin until it turns white. We then released our finger and count the time until the skin regains its color. The best location to do this is over the newborn's sternum, or breastbone. The skin should regain its color in less than three seconds. If it takes longer, we say that the baby has delayed perfusion. Perfusion is the medical term which refers to the flow of blood in tissues. Decreased perfusion rate is an early sign of decreased blood flow to the tissues. If it were to continue, it would become decreased blood pressure and finally shock. Checking a patient's pulse is a quick and easy way to get a sense of heart rate and rhythm, as well as blood pressure. In a newborn, the easiest pulses to feel are the brachial, the radial, and the femoral. I want to specifically mention the femoral pulse. In a previous module, I mentioned a congenital heart lesion known as coarctation of the aorta. The term coarctation means narrowing. As you might imagine, when the aorta has an area in which it is narrowed, blood flow beyond that point will be compromised. The femoral arteries are the main arteries that bring blood flow to the legs. We can feel the pulse of the femoral artery in the groin. This should be checked at birth and at every well baby visit for the first several years of life. If the femoral pulse can not be felt, further investigation for coarctation is indicated. This would include an epicardiogram, an ultrasound of the heart and major blood vessels. About one in ever 2,500 babies born in the United States each year are born with coarctation of the aorta. If diagnosed appropriately, surgical correction is possible, usually with excellent results.
