Chapter 26: Caring for the Child with a Cardiovascular Condition Flashcards
Anatomy: Contraction of heart
- contracts 60 to 180 times per minute depending on age
- decelerates during rest and sleep
- accelerates during excitement, exercise, or illness
Chambers of the Heart
4 chambers:
-2 Atria (reservoirs)
-2 Ventricles (pumping chambers that direct the blood flow of the heart)
>the right atrium is a reservoir, or collecting chamber, for the peripheral venous return; receives deoxygenated blood from the entire body (except lungs) through the superior and inferior vena cava and coronary sinus with an oxygen saturation of 70%
>the left atrium receives fully oxygenated blood from the lungs through the pulmonary veins, with an oxygen saturation of 100%
>From the atria, blood empties into the ventricles through atrioventricular valves
-the right ventricle receives blood from the right atrium and pumps it into the lungs via pulmonary artery
-the left ventricle is thicker with a smooth interior; left ventricle receives blood from the left atrium and pumps it into the systemic circulation via the aorta
Heart: Valves
4 valves
-2 Atrioventricular: connecting the atria to the ventricles
>Tricuspid valve: connects the right atrium to the right ventricle; consists of 3 cusps or “doors” that open to allow blood flow into the adjoining chamber and then close to prevent backflow
>Mitral/Bicuspid Valve: connects the left atrium to the left ventricle; consists of 2 cusps
-2 Semilunar Valves:
>Pulmonary valves: located at the junction of the right ventricle and pulmonary artery; prevents regurgitation of blood from the pulmonary artery to the right ventricle
>Aortic Valve: located at the junction of the left ventricle and the ascending aorta, prevents regurgitation into the left ventricle
Heart: Vessels
the venae cavae carry the blood from the body tissues to the right atrium
>Superior vena cava: enters from above the heart and carries blood from the head, arms, and upper body
>Inferior Vena Cava: enters from below the heart and carries blood from legs, abdominal organs and lower part of the body
>Pulmonary Artery: only artery in the body that carries deoxygenated blood; it is called an artery because it carries blood away from the heart, but because it arises from the right ventricle, it carries deoxygenated blood; it carries this blood to the pulmonary capillary bed, where it interfaces with the alveoli in the lungs, and “picks up” oxygen; from the lungs, the blood returns to the heart through the pulmonary veins into the left atrium (the only veins that carry oxygenated blood) ; the blood leaves the left ventricle through the aortic valve, through the aorta, and out to the body
Importance of normal flow
any disruption or interruption in any one of the vessels, valves, or chambers causes a disruption in the cardiac output
>heart must maintain a cardiac output at all times
Purpose of the heart
pump blood
- vital pumping function provides a means to carry oxygen via the hemoglobin to the tissues
- without oxygen delivery, cells die and body systems fail
Cardiac Output
the amount of blood discharged from the left or right ventricle per minute
>cardiac output is the product of stroke volume (SV) and heart rate (HR)
-(CO= SV + HR)
Stroke Volume
amount of blood ejected by the left ventricle with each heartbeat
- stroke volume is the product of preload, afterload, and contractility (inotropy)
- (SV= preload x afterload x contractibility)
Preload
amount the ventricles stretch at the end of diastole
-equivalent to the venous blood return to the atria from the body and end diastolic volume of the heart
Afterload
pressure the ventricles must work against to open the semilunar valve to pump blood from out of the heart
-aortic impedance or the wall stress
Contractility
strength of the cardiac cells to contract/ shorten
-force exerted at ejection taking into account the end diastolic volume (preload) and the wall stress (afterload)
Growth and Development
child with a cardiovascular condition requires:
-adequate sleep, nutrition, and rest; may require more rest than a healthy child b/c of activity intolerance and fatigue from the underlying cardiac condition
>to optimize regular growth and development, activities should be tailored to the child’s energy level
-during low levels= frequent naps and quiet play
-crying can be stressful on the child and quickly use up reserved energy; provide education to the family about being attentive to the child’s cry to conserve energy
-supplemental oxygen may be indicated to alleviate shortness of breath with activity, promote rest, and reduce stress
Growth and Development: Frequent Hospitalizations and Surgery
may be required to correct cardiac defects and manage disease regression
- frequently assess for delays in growth and development b/c of chronic hospitalization
- educate family about promoting healthy nutritional intake, prevention of infection and complications of the disease process, and lifestyle changes required to prevent disease regression and comorbidities
- encourage the family to create a sense of normalcy for the child
- nurse should encourage the healthy attainment and maturation of the child with activities and stimulation that are appropriate
Prevention of Heart Disease in Children
- good prenatal care
- vitamins
- low viral exposure
- woman should maintain optimal health
- avoid smoking, excessive alcohol consumption and illicit drug use
- woman should get good sleep and eat a healthy diet
- exercise
- all women of childbearing years, whether or not they are planning a pregnancy, should take folic acid supplements at least 1 month prior to conception
- current existing disease such as diabetes, thyroid, mental illness, or STIs should be well controlled prior to conception; some meds that treat these disease can be teratogenic and these drugs must be weaned or stopped under the guidance of a physician or nurse practitioner
Who has an increased risk of delivering a baby with cardiac defects?
-women who are obese, smoke, or have diabetes
