Aortic Valve
The aortic valve connects the left ventricle to the aorta. As the ventricle starts to contract to pump blood to the body, pressure builds. This increase in pressure causes the aortic valve to open, allowing blood to pass from the left ventricle into the aorta. As the heart then starts to relax, pressure falls and the valve closes (see normal heart anatomy and normal blood flow). Aortic regurgitation refers to a leak of blood backwards from the aorta into the left ventricle because of inadequate or incomplete closure of the aortic valve. Aortic regurgitation is also called aortic valve insufficiency, or simply an aortic valve leak.
Sinus Node
The sinus node is the pacemaker of the heart. It is responsible for generating the electrical impulses that stimulate the heart muscle to contract. Sinus bradycardia refers to a slower than normal heart rate.
Blood Flow
Normal blood flow in children describes the normal path blood takes through the heart, lungs and body. Before describing normal blood flow, it is important to have a thorough understanding of normal heart anatomy. The heart has four chambers. The upper two chambers of the heart are called the right and left atria. The atria are the receiving chambers for blood returning from the body and the lungs. The wall dividing the two atria is called the atrial septum. The lower two chambers are the right and left ventricles. The ventricles are muscular chambers responsible for pumping blood to the body and lungs (see normal blood flow). The wall dividing the two ventricles is called the ventricular septum. There are four separate valves in the heart: the tricuspid valve, pulmonary valve, mitral valve, and aortic valve. The valves open to allow blood to flow forward and close to prevent any backflow. Finally, there are a number of veins and arteries attaching to the heart. The superior and inferior vena connect to the right atrium, while the pulmonary veins connect to the left atrium. The pulmonary artery connects the right ventricle to the lungs, while the aorta connects the left ventricle to the body.
Sinus Tachycardia
The sinus node is the pacemaker of the heart. It is responsible for generating the electrical impulses that stimulate the heart muscle to contract. Sinus tachycardia refers to a faster than normal heart rate.
Rapid Breathing
Rapid breathing is one of the more common symptoms in newborns and children with congenital heart defects. The medical term for rapid breathing is tachypnea. When associated with heart disease, it is usually caused by either too much blood flow to the lungs (pulmonary overcirculation), or back up of blood into the lungs because of either poor pumping ability of the heart or some type of obstruction in the heart or blood vessels.