Ch. 12 Peds Cardiovascular Disorders Flashcards
How big is a child’s heart?
Size of fist
Normal HR?
60-160 bpm
The heart is composed of what 4 chambers?
- Left and right atria
- Left and right ventricle
Fxn of right atrium
collects deoxygenated blood from the entire body, except for the lungs
Fxn of right ventricle
pumps deoxygenated to the lungs via the pulmonary artery
Fxn of left atrium
Collects oxygenated blood from the capillary beds of the lungs through the pulmonary veins
Fxn of left ventricle
Pumps oxygenated blood through the aorta to the systemic circulation
The 4 valves prevent
blood from regurgitating
- Tricuspid
- Bicuspid
- Pulmonary
- Aortic
The atrioventricular valves connect
the atria and ventricles
The tricuspid valve connects
the right atria and right ventricle
-3 leafed
The bicuspid valve connects
the left atria and left ventricle
-2 leafed
Aortic valve connects
Right ventricle and pulmonary artery
-3 leafed
Aortic valve connects
Left ventricle and ascending aorta
-3 leafed
The superior vena cavae lies? and carries blood from?
- lies above the heart
- from the head, arms, and upper body
The inferior vena cavae lies? and carries blood from?
- lies below the heart
- from the legs, abdominal cavity, and lower part of the body to the right atrium
Pulmonary artery carries
deoxygenated blood from the right ventricle to the lungs to be oxygenated
Pulmonary vein carries
oxygenated blood from capillary beds of the lungs to the left atrium and left ventricle
Aorta carries
oxygenated blood from the left ventricle to the rest of the body
Cardiac output
the amount of blood ejected from the right or left ventricle per minute
SV x HR = CO (L/min)
Stroke volume
amount of blood pumped out of the left ventricle per minute, which is altered by the size of the heart and the HR
The conduction of electrical impulses through the heart results in? and is measured by?
- results in electrical discharge across the myocardium
- measured by an electrocardiogram (EKG)
What is the pacemaker of the heart? and causes?
- SA node
- caused depolarization and contraction of the atria
What is the P wave the measure of?
blood being pumped into the ventricles
P-Q interval reflects?
slowed conduction to allow R and L ventricles to fill with blood
Q wave shows?
Contraction in the walls of the ventricles
R wave? and S wave?
the L ventricle contracts (R wave) just before the R ventricle (S wave)
T wave?
ventricles relax and wait for next signal
Before birth, how much blood bypasses the lungs?
90%
-the placenta is the organ of respiration
What is the most common cause of congenital cardiac malformations?
Genetic factors
When hemoglobin is <5 mg/dL what happens?
large amounts of deoxygenated blood is pumped into systemic circulation
Cyanosis results when
O2 sat is decreased to 85% with normal hemoglobin levels
Acquired heart disease can occur in
a normal heart or in a heart with a congenital defect
Acquired heart disease is due to
- Infections
- Autoimmune factors
- Genetic factors
- Teratogens
- Chemical agents (ETOH, ACE, chemo, smoking, Accutane, lithium, cocaine, warfarin, dilantin, Vit A)
- Infectious agents (rubella, varicella, HIV)
- Maternal factors
- Physical agents (hot tubs)
Diabetic moms increase risk for what in babies?
neural tube defects, malnutrition, and thyroid disorders
Why do you need hx of sibling with heart defect?
b/c increased risk of infant having one as well
Possible indicators of heart disease in children
- FTT
- Small gestation age
- Poor weight gain
- Dysmorphic features
- Developmental disabilities
- Chest wall deformities
- Scoliosis
- Clubbing and erythema in fingers and toes
Shallow, rapid respirations with a rate more than 60 bpm in a content infant mean
investigate b/c may indicate left to right shunting
S/S of pulmonary edema
- increased work of breathing
- grunting
- nasal flaring
- retractions
Wide pulse pressure
diastolic is low with wide gap b/w S and D pressures
BP of 20 mmHg greater than that of lower extremity is
indictive of aortic arch abnormalities
Chest X-ray shows
- Pulmonary vascularity
- Cardiac size and shape
- Lung vascular markings
- Position of the stomach
Blood gases measure?
Metabolic acidosis shows?
- Metabolic acidosis shows as a decrease in pH and an increase in base excess.
- Base excess is the accumulation of metabolic acids in the blood.
- It is monitored by arterial, venous, or capillary blood. In cardiac disease, the partial pressure of carbon dioxide is generally within normal ranges.
Electrocardiogram
- Useful to determine conduction issues
- Needs to be evaluated by a cardiologist
Echocardiogram
- Ultrasound of the heart
- Noninvasive test that indicates structure, size, flow patterns, function, and the blood vessels attached to the heart
Angiography
-Visualizes the structure and function of the ventricles –Dye injected via a catheter
Cardiac Cath
small catheters or small, flexible tubes are inserted through small incisions in the neck or groin and threaded to the heart. These small tubes allow for blood samples to be taken, x-rays (fluoroscopy) to be done, and small instruments to be carried to the heart if repairs are needed
Biopsy of the Myocardium
- Frequent in heart transplants
- Monitors for rejection
Pulmonary Artery Banding
- Palliative measure to decrease pulmonary blood flow –Prevents pulmonary hypertrophy and pulmonary hypertension
- Precursor to cardiac surgery, such as in large VSDs
When do the ducts close in a full term baby?
100% within 72 hours of birth
How does PDA cause bacterial endocarditis?
Caused by irritation of the smooth muscle tissue of the pulmonary artery
Dopamine needed for
hypotension
Digoxin needed for
HR
Atrial septal defect occurs
between the right and left atria when the septal wall fails to form
ASD allows for more blood? and leads to?
- flow into the right side of the heart from the left atrium
- increasing pulmonary blood flow to the lungs leading to pulmonary HTN with right atrial enlargement that can lead to right ventricular hypertrophy
Why does a heart murmur occur with ASD?
b/c blood is being forced through pulmonary valve
What is the most common overall congenital heart disease?
Ventricular septal defect
VSD results in
right ventricle hypertrophy with left to right shunting that produces an increase in pulmonary blood flow that decreases pulmonary compliance
“stiff lungs”
Tetralogy of Fallot associated with
chromosome 22 disorders
- DiGeorge
- Downs
TOF results in
-right to left shunting which recirculates venous blood to the blood without it being oxygenated in the lungs
TOF: tet spells
sudden, marked increase in cyanosis; syncope
Pink tet
- due to left to right shunting
- Keeps child pink
Tricuspid atresia
missing or defective tricuspid valve
Tricuspid atresia defect blocks
the blood flow from the right atrium to the right ventricle, diminishing the blood flow to the lungs
-if no VSD, then systemic blood flow is shunted across the right atrium through an ASD or the PFO
Eisenmenger syndrome occurs with a
PDA, VSD, or ASD that pushes unoxygenated blood from right atrium/ventricle to left atrium/ventricle bypassing the lungs
Eisenmenger syndrome leads to
- right ventricular hypertrophy
- pulmonary hypertension
What is pulmonary hypertension?
The lungs will not be able to handle this extra blood volume. In turn, the arteries that feed the lungs will become damaged and narrow
Coarctation of the aorta
narrowing of the aorta b/w the upper and lower extremities
What for coarctation of the aorta cause the BP to do?
Higher in upper extremities compared to lower
Aortic Stenosis
Causes?
obstruction of blood flow from the left ventricle to the aorta
-causes: valve stenosis or narrowing
Aortic stenosis leads to
left ventricle hypertrophy
Scarring of the aortic valve occurs from
rheumatic fever
Pulmonary stenosis
narrowing of the opening in the pulmonary artery or valve
Pulmonary stenosis can be associated with
TOF
TOF with Pulmonary atresia: VATER
v- vertebral
A - anal
T-E - tracheo - esophageal
R - renal
**all anomalies
Supraventricular tachycardia
- occurs?
- HR?
- tx?
- med?
- teaching to BM?
- occurs in atria
- HR: >220 bpm
- Treatment:
- stimulate vagal response through nasal suctioning
- Apply crushed ice to forehead
- Adenosine- rapid IVP in proximal site, repeat within 2 mins if no response
- “bear down: when having BM to stimulate vagal response to slow HR
Ventricular Tachycardia
- occurs in ventricles
- loss of consciousness
- sudden death
Dysrhythmias: Torsades de Pointes -Prolonged? -Causes? s/s? tx?
- Prolonged QT intervals
- type of ventricular tachy
- Causes:
- inherited
- diarrhea
- malnutrition
- hypomagnesium
- hypokalemia
- hypocalcemia
- drug induced (anti-arrhymics or some ABX)
- s/s: rapid decline in BP, fainting, v-fib, and death
- tx: remove causes (drugs, fix electrolytes)
- implant defibrillator needed
Bradycardia
causes?
tx?
- sinus brady = QRS wave follows P wave
- congenital, injury, or postsurgical
- pacemarker may be needed
Dysrhythmias: Wolff-Parkinson-White Syndrome
s/s?
tx?
-electrical stimulation reaches the ventricles too soon
“pre-excitatory snydromes”
-s/s: tachycardia, syncope, chest palpitations
-tx: ablation with radiofrequency
*can lead to death
