XVII Glossary

Acyanotic heart defects: Congenital heart conditions where there is no significant mixing of oxygen-poor and oxygen-rich blood, meaning the individual doesn’t exhibit the typical signs of cyanosis (bluish discoloration of the skin and mucous membranes due to low oxygen levels). (Chapter 17.3)

Afterload: The amount of pressure the left ventricle must overcome to eject blood out of the heart and to the rest of the body. (Chapter 17.2)

Ascites: The abnormal accumulation of fluid in the abdominal cavity. (Chapter 17.4)

Atrial septal defect (ASD): A congenital heart defect that occurs when there is a hole in the septum that separates the right and left atria of the heart. This defect allows blood to shunt from the left atrium to the right atrium. (Chapter 17.3)

Balloon angioplasty: A procedure where a balloon catheter is inserted in a narrowed blood vessel and is inflated to widen the vessel. (Chapter 17.5)

Blow-by method: Directing a flow of oxygen at high concentration near the client’s face without making direct contact. (Chapter 17.3)

Cardiac output: The volume of blood pumped through the left ventricle over a specified time, usually expressed as liters per minute. Cardiac output equals stroke volume x heart rate. (Chapter 17.2)

Cardiopulmonary bypass: A medical device that routes a client’s blood around the heart and lungs and oxygenates it. Cannulas (special large tubes) are placed into the vena cava where oxygen-poor blood from the body moves into the bypass machine and is oxygenated. From the bypass machine, the oxygenated blood is moved through a cannula into the aorta, where it is pushed out to the body. (Chapter 17.5)

Coarctation of the aorta: A condition where there is an abnormal narrowing, or constriction, of the aorta; also called critical aortic stenosis (Chapter 17.3)

Compliance: Decreased ability to stretch. (Chapter 17.2)

Congenital heart defects (CHDs): Structural abnormalities in the heart or blood vessels that are present at birth and affect how blood flows through the heart and out to the rest of the body. (Chapter 17.1, Chapter 17.3)

Congenital mitral stenosis: A narrowing of the mitral valve, located between the left atrium and left ventricle, which is present at birth. (Chapter 17.3)

Contractility: The force of contraction of the heart muscle. (Chapter 17.2)

Cyanotic defects: Heart defects that involve right to left shunting of blood through the heart, thus bypassing the lungs and resulting in low oxygen blood being pumped throughout the body. (Chapter 17.3)

Digitalization: A procedure of providing an initial loading dose of digoxin over 24 hours to rapidly raise serum digoxin levels. (Chapter 17.5)

Digoxin toxicity: A condition caused by excessive levels of digoxin, a cardiac glycoside used to treat heart failure and atrial fibrillation. (Chapter 17.5)

Ductus arteriosus: A normal shunt during fetal circulation in the fetal pulmonary trunk that diverts oxygenated blood back to the aorta. (Chapter 17.2)

Ductus venosus: A normal shunt during fetal circulation that causes oxygenated blood from the placenta to bypass the fetal liver and move directly into the inferior vena cava. (Chapter 17.2)

Ejection fraction: Percentage of blood ejected from the left ventricle with each heartbeat. (Chapter 17.4)

Extracorporeal membrane oxygenation (ECMO): A life-support technique that provides oxygenation and circulatory support for critically ill neonates with severe respiratory or cardiac failure. (Chapter 17.4)

Fetal shunt: An alternate pathway for blood flow in fetal circulation that closes with the infant’s first breaths or within the first weeks after birth as pressure gradients in the circulatory and respiratory system change. (Chapter 17.2)

Foramen ovale: A normal shunt in fetal circulation that directly connects the right and left atria and helps to divert oxygenated blood from the fetal pulmonary circuit. (Chapter 17.2)

Gallop: An abnormal heart sound that resembles the cadence of a galloping horse. It occurs when extra heart sounds (S3 and/or S4) are present in addition to the normal “lub-dub” sounds (S1 and S2). (Chapter 17.4)

Heart failure: A cardiac disorder that occurs when the heart cannot effectively pump enough blood to supply the body with sufficient oxygen-rich blood. (Chapter 17.4)

Hemoptysis: Bloody sputum. (Chapter 17.5)

Hypercyanotic episode: A severe episode of hypoxia that typically occurs in clients with Tetralogy of Fallot, also known as a “Tet Spell.” During these episodes, there is a significant decrease in blood flow moving to the lungs due to a sudden increase in shunting of blood from the right side to left side of the heart. Deoxygenated blood is pumped out to the body, resulting in signs and symptoms of severe hypoxia. (Chapter 17.3)

Left-sided heart failure: Occurs when the left side of the heart is unable to pump blood effectively to the rest of the body, resulting in in a buildup of fluid in the lungs and making it difficult to breathe. (Chapter 17.4)

Murmur: A blowing or whooshing sound that signifies turbulent blood flow. (Chapter 17.3)

Negative chronotropic effect: Slowing of the heart rate by inhibition of atrioventricular (AV) node conduction, resulting in a slower ventricular response to electrical stimulation.

Negative inotropic effect: A decrease in contractility (force of cardiac contraction), which results in decreased cardiac output. (Chapter 17.5)

Obstructive defects: Heart defects that cause a restriction, or obstruction, in blood flow from within the left side of the heart or out through the body. (Chapter 17.3)

Patent ductus arteriosus (PDA): A congenital heart defect that occurs when the ductus arteriosus does not close immediately after birth. (Chapter 17.3)

Patent foramen ovale (PFO): An opening between the right and left atria that fails to close at birth when the infant takes its first breaths and pressures within the atria begin to rise. (Chapter 17.3)

Persistent pulmonary hypertension of the newborn (PPHN): A condition in which a newborn’s circulation does not adapt to breathing outside the womb, causing high blood pressure in the lungs and poor oxygenation. (Chapter 17.4)

Polycythemia: Elevated number of red blood cells. (Chapter 17.3)

Positive inotropic effect: Improvement in cardiac output by increased contractility (force of the cardiac contraction). (Chapter 17.5)

Preload: The degree to which the left ventricle stretches due to fluid volume just before the ventricle contracts. (Chapter 17.2)

Pulmonary hypertension: Increased pressure in the arteries of the lungs. (Chapter 17.4)

Right-sided heart failure: Occurs when the right side of the heart is unable to pump blood effectively to the lungs for oxygenation. As a result, blood backs up in the veins, leading to fluid accumulation in various parts of the body. (Chapter 17.4)

Sarcoplasmic reticulum (SR): The part of the muscle responsible for releasing and storing calcium ions in muscle fibers, causing contraction and relaxation of muscles. (Chapter 17.5)

Septum: A muscular wall that separates the atria or ventricles of the heart. (Chapter 17.3)

Stroke volume: The amount of blood ejected with each cardiac cycle (heartbeat). (Chapter 17.2)

Systemic vascular resistance (SVR):  The amount of force exerted by the vasculature of the body, which contributes to afterload. (Chapter 17.2)

Tetralogy of Fallot (ToF): A complex set of potentially fatal congenital heart defects, including pulmonary stenosis, a ventricular septal defect, an overriding aorta, and right ventricular enlargement. (Chapter 17.3)

Thrombosis: Blood clots. (Chapter 17.5)

Umbilical arteries: A pair of vessels that runs within the umbilical cord and carries fetal blood low in oxygen and high in waste to the placenta for exchange with maternal blood. (Chapter 17.2)

Umbilical vein: A single vessel that originates in the placenta and runs within the umbilical cord, carrying oxygen- and nutrient-rich blood from the mother to the fetus. (Chapter 17.2)

Valvuloplasty: A procedure where a balloon catheter is inserted into a narrowed (stenosed) valve and inflated to widen the valve. (Chapter 17.5)

Ventricular septal defects (VSD): A heart defect occurring when there is a hole in the septum separating the right and left ventricles that allows blood to shunt from the left to right ventricle.

Widened pulse pressure: An increased difference between systolic and diastolic blood pressure readings. (Chapter 17.3)