Cardiovascular Function & Dysfunction

• The primary function of the heart is to pump oxygenated blood to the tissues, and deoxygenated blood to the lungs, in order that it can become oxygenated.
• Blood pressure = CO x SVR

  • CO = Cardiac Output
  • SVR = Systemic vascular resistance
• Preload: The stretch of myocardium or end-diastolic volume of the ventricles. Most frequently refers to the volume in a ventricle just before the start of systole.
• Afterload: The force or load against which the heart has to contract to eject the blood. Is the ‘load’ to which the heart must pump against.
• Contractility: Relative ability of the heart to eject a stroke volume (SV) at a given afterload (arterial pressure) and preload (end diastolic volume)


  Calcium concentration and temperature affect contractility
• Cardiac output: The amount of blood that goes through the circulatory system in one minute
• Cardiac output major determinants are:

  preload, afterload, contractility, and heart rate
• Stroke volume


  The volume of blood pumped out of the left ventricle of the heart during each systolic cardiac contraction
• T/F: The cardiovascular system is the first major organ system to develop in the embryo

  true
• By the ______ week of gestation, the cardiovascular system is fully formed and functioning

  eighth
• During development, oxygenation of the fetus occurs via the

  placenta
• T/F When a newborn takes its first breath Blood flow to the left side of the heart increases the pressure in the left atrium leading to a closure of the foramen ovale.

  True
• When a newborn takes it's first breath causes a drop in pressure of the pulmonary artery promotes closure of the ductus arteriosis
• In infants and children <7 years the heart lies more ____, resulting in the apex lying higher in the chest, below the 4 th intercostal space


  horizontally
• T/F Innocent murmurs and altered heart sounds may be noted in infancy or childhood related to the size of the heart in relation to the thoracic cavity


  true
• What accounts for the largest percentage of all birth defects

  Congenital heart disease
• What lab and diagnostic test would you expect with CHD?

  • CBC
  • Echocardiogram
  • ECG
  • Chest X-ray
  • MRI
  • Cardiac catherization
• CHD Definition: Congenital heart defects can range from minor shunts which may not require extensive treatment toextremely complicated defects involving several different types of shunts, obstructions and/or misplace arteries and veins
• These 2 clinical features classify which condition

  • Presence or absence of cyanosis
  • Degree of pulmonary vascularity (increased, normal, decreased

  Congenital heart defects
• These symptoms indicate

  • Heart murmur
  • limited growth
  • SOB
  • Cyanosis during exertion


  Ventricular septal defect
• VSD: if surgery is required, it should be performed before _____ vascular changes develop

  pulmonary
• A suture closure of the VSD, transcatheter placement of a device in the defect or a Dacron patch closure will be used
• What are the 4 related heart defects associated with tetralogy of fallot?

  1. pulmonary stenosis
  2. VSD
  3. Overriding Aorta
  4. Right ventricular hypertrophy
• Which of the following is a common sign or symptom associated with pulmonary stenosis?

  a) Cyanosis

  b) Loud, harsh heart murmur

  c) Hypertension

  d) Clubbing of fingers and toes

  Correct answer is b : due to the turbulent blood flow through the narrowed pulmonary valve
• Pulmonary stenosis is a congenital or acquired heart condition characterized by narrowing or obstruction of the pulmonary valve or the pulmonary artery. Pulmonary stenosis when combined with 3 other heart defects is called

  Tetralogy of fallot
• These signs and symptoms indicate

  • Boot shaped x-ray
  • Harsh murmur
  • Tet spells
  • squatting
  • (chronic) Clubbing of nails

  Tetralogy of fallot
• Tet spells


  Sudden episodes of cyanosis (bluish discoloration of the skin) and hypoxia (low oxygen levels) during crying, feeding, or exertion. These episodes are caused by a sudden decrease in pulmonary blood flow due to increased right ventricular outflow obstruction.
• Why would a child squat during a Tet spell?

  Squatting increases systemic vascular resistance, which decreases the right-to-left shunting of blood and improves oxygenation
• Nursing management for T of F

  1. Calm & comforting approach
  2. Place in knee-to-chest position
  3. Provide supplemental oxygen
  4. Administer morphine, propranolol & IV fluid
• What is important to consider when taking a BP or venipuncture on a child with T of F post op?

  Avoid the affected arm, the shunt was placed in
• Was NSG monitoring is important for a post op T of F patient?

  Ventricular arrhythmias
• For T of F patients, the shunts may be used for temporary management while the child and their heart grow
• At what age will most children require sugery for T of F?

  Before the age of 1 years old
• During surgery for a T of F patient, a surgical patch closure of the ventricular septal defect and repair of the pulmonary valve and right ventricular outflow tract
• NSG priorities for a child with CHD:

  • Supporting oxygenation
  • Promote adequate nutrition
  • Prevent Infection
  • PRN as needed
  • Family education
• NSG priorities for a Preop child with CHD

  • Temperature and weight measurements

  • In depth cardiovascular & respiratory exam

  • Preoperative bloodwork (CBC, electrolyte, PT, PTT, INR)

  • NPO status
• NSG priorities for a post op child with CHD

  • Frequent vital signs

  • In depth cardiovascular & respiratory exam

  • In PICU environment will have additional hemodynamic monitoring and ventilation support

  • Strict Intake & Output measuremen
• Interventions to promote family coping with children with cardiac defects

  • Explain all that is happening with the child, using language the parents and child can understand
  • Provide ample time to address questions and concerns
  • Encourage the parents and the child, as developmentally appropriate, to participate in the child’s care.
  • Allow the parents and child to voice their feelings, concerns, or questions
• Idiopathic Thrombocytopenia Purpura (ITP)

  Is a type of platelet disorder. The blood does not clot asit should, dye to a low platelet count.
• Signs and symptoms of ITP

  • Petechiae (pinpoint hemorrhage)

  • Purpura (large purple hemorrhage under tissue)

  • Excessive bruising

  • Epistaxis (nose bleeding)

  • Bleeding of the gums

  • Blood in the stool