The Child with Cardiovascular Dysfunction Flashcards
Anatomy and Physiology of Pediatric Differences
- The infants heart is immature and more susceptible to volume or pressure overload
- Children respond to hypoxemia by producing more RBC in bone marrow and increasing amount of Hgb.- increased clotting
- Cardiac output is dependent solely upon the heart rate until age 5yrs
Fetal Circulation
- Infants life line to their mother is through the umbilical cord
- One large vein
— Blood leaves the placenta and enters the fetus though the umbilical vein - Two arteries
— Which returns the blood to the placenta
Cardiovascular Adaptations
- Respiration= increased PO2
- Decreased Rt. Atrial pressure & increased Lt atrial Pressure Closure of Foramen Ovale
- Cord Clamped- causes closure of Ductus Venosus
- Increased Aortic Pressure to the pulmonary artery= Closure of Ductus Arteriosis
When does the Foremen ovale close
1-2 hours post birth
When does the Ductus arteriosus close
within hours - 4 weeks
When does the Ductus venousus close
within 2 months
Congenital Heart Defects Etiology
- Fetal drug exposure
- Maternal virus- Rubella
- Maternal Metabolic disorder
- Increased Maternal age 35+>
- Genetic factors
- Chromosomal abnormalities- 25%
- Unknown Causes
Clinical Presentation of Congenital Heart Defects
- Cyanosis
- Tachycardia & tachypnea
- Respiratory Distress
- Congestive Heart Failure
- Diminished Cardiac Output
- Abnormal Cardiac Rhythm
- Cardiac Murmurs (** usually the first sign)
- Fatigue
- URI
- decreased growth
Increased Pulmonary Blood Flow
Most common defect results from a connection between left and right side of heart (septal defect) or between the great arteries (PDA) patent ductus arteriosus
The Left to Right shunt causes:
- Increased pulmonary vascular resistance
- Pulmonary artery hypertension
- Right Ventricular Hypertrophy
Patent Ductus Arteriosus (PDA)?
S/S
- Caused by persistent fetal circulation.
- Present in all preterm infants less than 27 weeks.
- Respiratory Distress
- machinery murmur
- growth failure
- tachypnea
- tachycardia
Patent Ductus Arteriosus (PDA)
Treatment
- Wait and monitor.
- Indomethacin can stimulate the closure.
— Prostaglandin inhibitor
— 3 doses 12 hours apart - Surgical ligation (tying it off)
Atrial Septal Defect (ASD)?
S/S:
Mild
Moderate
Large
abnormal opening between the atria
- Opening in Atrial Septum
- Permits Left to Right shunting of blood because pressures on the Left side are higher than the Right.
-
Mild -no symptoms. Tired
Moderate- may not be diagnosed until preschool or later. murmur
Large- CHF, tired, poor growth
Atrial Septal Defect (ASD)
Treatment
- spontaneous closure by 4 yrs. Or surgery.
- Not the Forman ovale- its a separate opening
Ventricular Septal Defect (VSD)?
S/S
abnormal opening between ventricles
- Opening in Ventricular Septum causes pulmonary flow.
- Blood is shunted from Left ventricle to pulmonary artery.
- Most common Congenital heart defect (20%)
- Murmur, pulmonary infections and hypertension
Ventricular Septal Defect (VSD)
Treatment
Most close spontaneously by 6 mo. Surgery if poor growth.
Decreased Pulmonary Blood Flow
- Right to left shunting
- Little or no blood reaches the lungs to be oxygenated
- Polycythemia- hypoxia stimulates the bone marrow to increase RBC production. – can lead to thromboembolism.
- Examples: Pulmonic Stenosis, Tetrology of Fallot, Pulmonary or Tricuspid Atresia
Pulmonic Stenosis?
S/S:
- Obstructs blood flow to pulmonary artery.
- Right ventricular hypertrophy
- Mild- no symptoms
- Moderate- dyspnea and fatigue on exertion
Pulmonic Stenosis treatment
Cardiac cath or surgery
Tetrology of Fallot?
S/S:
- Four defects: Pulmonic stenosis (narrowing), Right ventricular hypertrophy, VSD, and overriding of aorta (aorta overrides VSD).
- Right to Left shunt caused by elevated pressures in the right side of heart.
- S/S: squatting, cyanosis, Clubbing, syncope
Murmur, hypoxic and cyanotic, poor growth, clubbing, squat position.
Tetrology of Fallot: Treatment
surgery before 6 mo. Does not cure all children.
Pulmonary Atresia
treatment:
- Prostaglandin
- Vasodialator
- Surgery
Tricuspid Atresia
No tricuspid valve, so no communication between right atrium and ventricle
treatment:
- Prostaglandin
- Vasodialator
- Surgery
Mixed Defects
- Combination of defects that increase and decrease the pulmonary blood flow
- Mixture of oxygenated and deoxygenated blood.
- Examples: TOF, Pulmonary or tricuspid atresia, Transposition of the Great Arteries, Truncus Arteriosus.
Transposition of the Great Vessels
- Pulmonary artery =outflow for left ventricle
- Aorta=outflow for right ventricle
- Survival depends on open ductus arteriosus and foramen ovale.
- Respiratory distress, poor feeding, right ventricular hypertrophy, polycythemia.
- Treatment: Prostaglandin and surgery before 1 week. Without surgery=death.
Transposition of the Great Vessels (TGV)
- PA leaves Lt ventricle
- Aorta exits from Rt Ventricle
- No communication between systemic & Pulmonary circulations
Transposition of the Great Vessels (TGV)
Treatment
Treatment: keep ductus atreriosis open
Prostaglandin
Truncus Arteriosus?
S/S
Failure of normal septation resulting in single vessel, overriding both ventricles
- Single large vessel empties both ventricles.
- VSD usually present
- Cardiomegaly, large aorta, right and left ventricle hypertrophy, absence of 2 semilunar valves.
Truncus Arteriosus: Treatment
Surgery, digoxin, diuretics.
Obstruction of blood flow to Ventricles ?
S/S
- Valve stenosis obstructs blood flow and increases pressure on left ventricle and decreases cardiac output. Backs up in lungs causing CHF and pulmonary edema.
- S/S: Diminished pulses, delayed cap refill, decreased urinary output
Aortic Stenosis
- May be asymptomatic
- May have narrow pulse pressure, weak pulses, chest pain after exercise, fainting, dizziness, systolic murmur
Aortic Stenosis Treatment
cardiac cath, surgery, valve replacement.
Coarctation of the Aorta?
S/S:
- Narrowing of descending aorta near the ductus arteriosus.
- Many are asymptomatic but up to 30% develop CHF by 3 mo.
- BP and pulses low in lower extremities.
Coarctation of the Aorta: Treatment
- Balloon dilation in cardiac cath. Or surgery. Prefer to repair in 1st yr. of life to decrease exposure to hypertension
- If pt has this: BP/ and pulses are lower in lower extremities
- Cardiac cath w/ balloon
Hypoplastic Left Heart Syndrome?
S/S:
- Mitral and Aortic valve absent or stenosed.
- Cyanosis, respiratory and cardiac failure.
Hypoplastic Left Heart Syndrome:
Treatment
- Prostaglandin to keep PDA, surgery or heart transplant. Poor prognosis
- Multiple surguries
Rheumatic Fever (RF)
- Inflammatory connective tissue autoimmune disorder following an initial infection of some strains of group A beta- hemolytic streptococcal infection. Self-limited disease that involves
- (Strep throat most common)
- Joints: pain
- Skin: rash- erythema marginatum
- Brain: Chorea- involuntary movements
- Serous surfaces: at joints
- *Heart (mitral valve)
Rheumatic Fever (RF)
Therapeutic Management
- Eradication of hemolytic streptococci- *Penicillin is the drug of choice
- Prevention of permanent cardiac damage- prophylactic antibiotics
- Palliation of the other symptoms
- Prevention of recurrences of RF
- Aspirin: (ringing in ears)
— Usually not given to children; can cause Reye’s syndrome which would cause encephalopathy (causes retardation) - Culture Sore Throat
Kawasaki Disease (KD) (Mucocutaneous Lymph Node Syndrome)
- Acute systemic Vasculitis of unknown cause that leads to scarring and thrombosis
- 80% of cases under the age of 4 years
- Self-limiting
- Without treatment 20% to 25% develop cardiac sequelae
- Infants less than 1 year of age increased risk for heart involvement
- Treatment: IV IG (immunoglobulin) and Aspirin
Stages of KD
Acute
- lasts 1-2 weeks.
- Irritability
- high fever for >5 days
- conjunctivitis
- red throat
- swollen hands and feet
- rash
- enlarged cervical lymphnodes.
Stages of KD
Subacute
- lasts 2-4 weeks
- cracking lips
- desquamation of skin
- joint pain
- cardiac disease
Stages of KD
Convalescent
- 6-8 weeks.
- Appears normal but may have signs of inflammation
— measure CRP, ESR
Kawasaki Disease (KD) s/s:
Fever > 102.2°F
Strawberry tongue
Red lips
Pallor of proximal fingernails and toenails
Superficial skin layers desquamate easily
Red soles and palms
Usually children < 5 years old
Conjunctival redness
Lethargy
Irritability
Cardiac complications in 5-20%
Rash over trunk and perineal area
Occasional intermittent colicky ABD pain
May last 2-12+ weeks
