Cardiovascular Dysfunction Flashcards
Heart starts to beat and blood begins circulating at ____ of gestation
21 days
Foramen ovale
Opening between the atria that allows blood flow from the right atrium directly to the left - closes after birth
Ductus arteriosus
Conduit between the pulmonary artery and the aorta that shunts blood away from pulmonary circulation - closes after birth
Risk factors of cardiovascular issues
Medications - corticosteroids, contraceptives, Acutane, anticonvulsants
Tobacco, alcohol
Viral illness - coxsackievirus, CMV, influenza, mumps, rubella
Maternal age greater than 40
Radiation
Chromosome abnormalities
Autoimmune disorders
Cardiac issues treatment
Decrease cardiac workload - prevent excessive crying, activities that limit energy expenditure
Evaluate food/fluid intake, weight gain - diet rich in iron and potassium, low in sodium
Defects with increased pulmonary blood flow (4)
Patent ductus arteriosus (PDA), atrial septal defect (ASD), ventricular septal defect (VSD), atrioventricular canal defect
Patent ductus arteriosus (PDA)
Fetal ductus arteriosus fails to close completely after birth - blood flows from aorta through PDA into the pulmonary artery and lungs
Causes increased left ventricular workload and increased pulmonary vascular congestion
PDA signs
Loud machine like murmur, poor feeding, fatigue, HF, hepatosplenomegaly, poor weight gain, tachypnea, irritability, widened pulse pressure, bounding pulse rate
PDA treatment
May spontaneously close
Indomethacin, ibuprofen
Surgery
Atrial septal defect (ASD)
Abnormal communication between the atria - pressure is higher in the left atrium than the right, causing blood to shunt from left to right
Causes right ventricle and pulmonary artery to enlarge
Ventricular septal defect (VSD)
Abnormal opening between the right and left ventricles - pressure from left ventricle causes blood to flow through the defect into right ventricle
Causes increased pulmonary vascular resistance and enlarged right side of heart
Atrioventricular canal defect
Results from incomplete fusion of endocardial cushions - consists of a low atrial septal defect that is continuous with a high ventricular septal defect, clefts of mitral valve and tricuspid valve creating a large central AV valve that allows blood to flow between all chambers
Associated with Down syndrome
AV canal defect signs
Moderate to severe HF, mild cyanosis that increases with crying, holosystolic murmur
Obstructive defects (8)
Coarctation of aorta, aortic stenosis, pulmonic stenosis, tricuspid atresia, tetralogy of Fallot, transposition of the great vessels, truncus arteriosus, hypoplastic left heart syndrome
Coarctation of aorta
Narrowing of the aorta - characterized by increased pressure proximal to the defect and decreased pressure distal to it
Restricted blood flow through the narrowed aorta increases pressure on the left ventricle and causes dilation of the proximal aorta and left ventricular hypertrophy –> left-sided HF
Coarctation of aorta signs
Difference in BP between upper and lower extremities - higher in arms that lower extremities
Epistaxis, headaches, fainting, lower leg muscle cramps
Aortic stenosis
Involves an obstruction to the left ventricular outflow of the valves - left ventricular pressure increases to overcome resistance of the obstructed valve and allow blood to flow into the aorta
Eventually produces left ventricular hypertrophy - myocardial ischemia may develop
Pulmonic stenosis
Involves obstruction of blood flow from the right ventricle
Right ventricular pressure increases and can cause right ventricular hypertrophy and right-sided HF
Systolic murmur
Tricuspid atresia
Tricuspid valve fails to develop - no communication between right atria and right ventricle
Causes cyanosis, hypoxia
Tetralogy of Fallot
Combination of four heart defects:
- ventricular septal defect
- right ventricular hypertrophy
- pulmonic stenosis
- overriding aorta (overrides VSD)
Tetralogy of Fallot signs
Hypercyanotic episodes (tet spells), transient cerebral ischemia, irritability, pallor, blackouts, convulsions
Tet spell treatment
Squatting posture or knees to chest position for infants - increases systemic vascular resistance which increases pulmonary blood blow and eases respiratory effort
Transposition of the great vessels
Pulmonary artery leaves the left ventricle (instead of right) and aorta leaves the right ventricle (instead of left)
Can cause HF, infective endocarditis, brain abscess, stroke
Transposition of the great vessels signs
Severe respiratory depression and cyanosis at birth
Truncus arteriosus
Failure of normal septation and division of the embryonic bulbar trunk into the pulmonary artery and aorta - results in single vessel that overrides both ventricles
Causes severe pulmonary edema and heart failure
Hypoplastic left heart syndrome
Underdevelopment of the left side of the heart and involves various left sided defects - severe coarctation of the aorta, severe aortic valve stenosis/atresia, severe mitral valve stenosis/atresia
Heart failure
Circular congestion due to decreased myocardial contractility, which results in the heart’s inability to pump sufficient blood to meet the body’s needs
Due to volume overload, pressure overload, decreased contractility, or high cardiac output
Heart failure treatment
Digoxin
Reduce cardiac demands - keep child warm, schedule nursing interventions for rest, only feed for 45 minutes at a time, provide gavage feedings if infant becomes tired
Maintain high calorie, low sodium diet
Digoxin therapeutic range
0.8-2 ng/ml
Digoxin toxicity
Bradycardia, anorexia, nausea/vomiting
Rheumatic fever
Autoimmune inflammatory process that occurs as a result of naturally acquired immunity to group A beta-hemolytic streptococcal infection - cardiac involvement in 50% of cases
Occurs 2-4 weeks after an untreated RTI with group A beta-hemolytic streptococci - begins to attack connective tissue, producing inflammation that affects the heart, joints, CNS, subcutaneous tissue
Carditis in rheumatic fever
Lesions/plaque called Aschoff bodies form on heart valves causing edema and inflammation - when healed areas become fibrous and scarred, valve leaflets fuse, causing inefficiency and leakage
Mitral and aortic valves are most commonly affected
Carditis signs
Jones Criteria
Tachycardia, cardiomegaly, murmur, pericardial friction rub, prolonged P-R interval, polyarthritis, chorea (involuntary irregular movements), erythema marginatum (non-pruritic macules with clear center, red defined border), subcutaneous nodules
Rheumatic fever treatment
Assess cardiac and neurological status
Compliance with bedrest and activity restrictions
Penicillin
Promote prevention of rheumatic fever by encouraging proper evaluation and treatment of streptococcal infections
Kawasaki disease
An acute systemic vasculitis - most common cause of acquired heart disease in children
Affected vessels enlarge until they reach their largest diameter in 4-6 weeks
Without treatment, can develop cardiac sequelae - dilation of coronary arteries resulting in aneurysm
Kawasaki disease signs
fever unresponsive to antipyretics or antibiotics, conjunctival hyperemia, pharyngitis, strawberry tongue, swollen hands and feet, truncal rash, enlarged cervical nodes, diarrhea, hepatic dysfunction
Kawasaki disease medications
Aspirin
IVIG - reduces immune response
Steroids
