Cardiac Diseases
Chapter 29
Objectives:
1. Describe the basic cardiac structure and physiology and flow of blood through the heart.
a. superior vena cava (from body) → right atrium→ tricuspid valve→ right
ventricle→ pulmonic valve→ pulmonary artery→ lungs→ pulmonary vein→ left
atrium→ mitral valve→ left ventricle→ aorta→ body
b. fetal circulation: blood is oxygenated through placenta rather than lungs
i. ductus venosus: connects inferior vena cava to umbilical vein
ii. foramen ovale: opening between atria
iii. ductus arteriosus: shunt between pulmonary artery and ascending aorta
2. Define and recognize in a clinical setting the following cardiac-related terms: tachycardia,
bradycardia, tachypnea, murmurs, cardiac output, preload, afterload, and contractility.
a. tachy→ fast heart rate
b. brady→ slow heart rate
c. tachyp→ fast RR
d. murmurs: swishing sound of blood in the heart; can be benign or malignant
e. cardiac output: volume of blood ejected from the ventricle into the aorta/ pulmonary trunk
per minute
i. CO in a child is rate dependent→ watch out for bradycardia
ii. signs of decreased CO: tachy/ brady, hypotension, faint pulses, pallor, decreased
LOC, decreased urine output, exercise intolerance, chest pain, dizziness
f. stroke volume: volume of blood ejected by ventricle during each contraction
i. preload: degree of stretch on the heart before contraction/ volume of blood
returning to the heart; at end of diastole
1. increased in hypervolemia, valve regurgitation, heart failure
ii. afterload: amount of resistance against which the heart pumps
1. increased in HTN and vasoconstriction
iii. contractility: strength of contraction
3. Implement and educate families concerning various tests and procedures used in diagnosing cardiac
dysfunction (e.g., cardiac catheterization).
a. prenatal screening (predict fewer than half of CHD), pulse oximetry screening (routine,
right hand and either foot at same time, begin at 24 hours of age, passes if 95% or higher
and difference is 3% points or less)
b. EKG→ assess electrical conduction of the heart
c. CXR→ determining heart size; pulmonary vascular
d. echocardiogram→ determine size of heart and chambers, movement of valves,
presence or absence of structures and blood flow
e. cardiac catheterization: can be diagnostic or therapeutic
i. assess OxSat. and pressure in chambers, cardiac output, blood flow, anatomic
abnormalities
ii. interventional: closures, balloon catheters open narrow vessels/ valves, insertion
of valves, insertion of stents
iii. procedure: radiopaque catheter inserted through a peripheral blood vessel into
the heart; catheter is introduced through the vein in which a catheter is threaded
over a guide wire inserted through a large born needle
f. classification of CHD: increased pulmonary flow, decreased pulmonary flow, obstruction
of blood flow, mixed defect
4. Evaluate maternal and family medical history indicating increased risk for congenital heart disease.
a. anatomic abnormalities that present at birth
b. prenatal history: maternal diabetes, maternal lupus, exposure to certain infections
(rubella), alcohol consumption, smoking during pregnancy, frequent fetal loss
c. family: congenital heart defects, hypertrophic cardiomyopathy, sudden death
d. infant conditions: prematurity, trisomy 21, Turner syndrome (female is partly or completely
, missing an X chromosome), DiGeorge syndrome (part of chromosome 22 is missing),
Marfan syndrome (connective tissue disorder)
e. Health Hx: poor feeding, diaphoresis w/ feeding, tachypnea/ tachycardia,, nasal flaring,
failure to thrive/ poor weight gain, developmental delays, recurrent respiratory infections,
activity intolerance, fatigue
5. Discuss nursing care of a child undergoing cardiac catheterization including precatheterization,
postcatheterization and home care.
a. pre-catheterization
i. child will be NPO, IV fluid (apply EMLA prior to IV), assess pedal pulses,
document allergy to radiopaque dye or shellfish, sedation (apply pulse ox)
b. post-catheterization
i. child must lay supine with affected leg straight for 4-6 hours
ii. vital signs, insertion site observed, distal pulses checked q15 minutes at 1st hour
then 130 minutes
iii. observe for bleeding at site, pallor, loss of pulses, coolness in extremity distal to
site
iv. if bleeding occurs→ apply continuous pressure 1 inch above insertion
site
v. push fluids to help flush dye out of the body
vi. observe for reactions to dye (vomiting, rash, increased creatinine, decreased
urinary output)
vii. avoid baths for 3 days after catheterization
6. Discuss relative pressures in cardiac structures.
a. normally pressure on the right side of the heart is lower than the left side
7. Describe the clinical manifestations of decreased cardiac output in an infant and child.
a. tachy/ brady, hypotension, faint pulses, pallor, decreased LOC, decreased urine output,
exercise intolerance, chest pain, dizziness
8. Discuss the causes of heart failure (HF).
a. cardiac output insufficient to meet metabolic demands of body; commonly caused by
congenital heart defects
b. acquired conditions: rheumatic heart disease, severe dysrhythmias
c. infants have greater risk because heart is immature and more sensitive to volume or
pressure overload
d. causes: volume overload (L to R shunts- VSD, PDA), pressure overload (obstruction),
decreased contractility (cardiomyopathy, myocarditis), high cardiac output demands
(anemia, sepsis)
e. S/sx:
i. impaired myocardial function: tachycardia, fatigue, weakness, restlessness, pale,
cool extremities, decreased BP, decreased UOP
ii. pulmonary congestion (tachypnea, dyspnea, respiratory distress, exercise
intolerance, cyanosis
iii. systemic venous congestion: peripheral and periorbital edema, weight gain,
ascites, hepatomegaly, neck vein distention
9. Discuss the consequences and nursing care for infants and children with hypoxemia.
a. persistant hypoxia stimulate erythropoiesis (increased # of RBC)--> polycythemia
i. increased blood viscosity, increased risk of embolism, increased risk of stroke
(atrial arrythmias)
10. Describe the following cardiac defects characterized by increased pulmonary flow and their
pathophysiology, recognize clinical manifestations, and implement treatment and nursing care: atrial
septal defect, ventricular septal defect, and patent ductus arteriosus.
a. atrial septal defect (ASD): abnormal opening between atria
i. left to right shunt; right atrial and ventricular dilation/ enlargement, right
ventricular volume overload, increased pulmonary blood flow
ii. increased pulmonary vascular resistance, decreased systemic blood
flow→ decreased CO
iii. s/sx: can be asymptomatic; undiagnosed ASD→ heart failure in 3rd/4th