Download Congenital Heart Defects

Congenital Heart Defects
Kirsten H. Ohler, PharmD, BCPS
Clinical Assistant Professor
Neonatal / Pediatric Clinical Pharmacist
University of Illinois at Chicago
Objectives
• Review normal fetal and pediatric cardiac
anatomy
• Describe the diagnosis of congenital heart
disease
• Discuss select congenital heart defects and their
surgical repairs
• Describe the pharmacist’s role in the care of a
neonate or child with congenital heart disease
Background
• ~35,000 babies born per year w/ a cardiac defect
• Cause of more deaths in 1st year of life than any
other birth defect
• Risk factors: diabetes, illicit drugs, hereditary (?),
maternal viral infection (ex. rubella)
♦ association with genetic abnormalities like Trisomy 21
(i.e. Downs syndrome) and DiGeorge syndrome
Fetal Circulation
• Oxygenated blood enters
right atrium via inferior
vena cava
• Pulmonary pressure
greater than systemic
• Right to Left shunt across
foramen ovale and PDA
Normal Cardiac Anatomy
• Right side = deoxygenated
blood
• Left side = oxygenated
blood
• Systemic pressure greater
than pulmonary
• Foramen ovale and PDA
closed
Congenital Heart Defects: Diagnosis
• Clinical Presentation
♦ murmur
♦ cyanosis
♦ blood pressure
• hypotension
• four extremity variation - CoA
♦ widened pulse pressure
• PDA
♦ failure to thrive
♦ respiratory distress/ tachypnea / exercise intolerance
♦ congestive heart failure
• Echocardiogram findings
Congenital Heart Defects
• Acyanotic defects
♦ atrial septal defect (ASD)
• 1 in 1500 live births
• ~6 – 10% of CHD


frequently asymptomatic
diagnosed in later childhood
♦ ventricular septal defect (VSD)
• 1.5-3.5 in 1000 live births
• 20 – 25% of CHD


symptoms depend on size
endocarditis prophylaxis
♦ endocardial cushion defects (AV canal / AVSD)
• 0.19 in 1000 live births
• ~4 – 5% of CHD


symptoms similar to large VSD
endocarditis prophylaxis
♦ patent ductus arteriosus (PDA)
♦ coarctation of the aorta (CoA)
Patent Ductus Arteriosus
• 1 in 2500 live births
• incidence
in preterms
• ~9 – 12% of CHD
• connects pulmonary artery to
aorta
♦ usually closes by 3 -7 days
• closure by PGE inhibition or
surgical ligation
♦ endocarditis prophylaxis
until closed
PDA: Pharmacological Closure
• Indomethacin vs. Ibuprofen
♦ MOA: prostaglandin inhibition
♦ similar closure rate (60-80%)
• ~40% with second course
♦ IV administration
• INDO: q 12 hours x 3 doses
– Infuse over 20 – 30 minutes
• IBU: q 24 hours x 3 doses
♦ Oral administration
• 64 VLBW randomized to oral or IV IBU
• No difference in closure rates or side effects
PDA: Pharmacological Closure
• Indomethacin vs. Ibuprofen
♦ Prophylactic indomethacin
• Reduces PDA, need for surgical ligation, severe IVH
• No effect on renal function, NEC, bleeding
• Long-term benefits unknown
♦ Side effects
• Nephrotoxicity: IBU < INDO (7% vs 19%)
– reversible
• NEC: IBU < INDO
• CLD/BPD and hemorrhage:
PDA: Surgical Closure
• Success of drug therapy
decreases significantly
after ~ 10 - 14 days of life
• May be indicated if
pharmacological closure
fails or is contraindicated
Coarctation of the Aorta
• ~ 5 – 8 % of CHD
• Degree of aortic narrowing
varies
• Upper extremities’ blood
pressure higher than lower
extremities’
• PGE1 may improve systemic
blood flow
CoA: Repair
• Resection with end-to-end
anastomosis
• Restenosis at the site of
repair may occur
• Post-procedure rebound
hypertension may occur
♦ β-blockers, ACEI
CoA: Repair
• Other options:
♦ graft bypass
♦ subclavian flap repair
♦ patch aortoplasty
Congenital Heart Defects
• Cyanotic defects
♦
♦
♦
♦
♦
♦
hypoplastic left heart syndrome (HLHS)
tetralogy of Fallot (TOF)
transposition of the great arteries (TGA)
truncus arteriosus (TA)
total anomalous pulmonary venous return (TAPVR)
tricuspid valve atresia
Hypoplastic Left Heart Syndrome
• Hypoplastic left ventricle is
unable to support systemic
circulation
• Often, aortic and mitral valves
are atretic or nearly atretic
• Patent foramen ovale and
ASD allow mixing of blood
• Systemic blood flow is
dependent on PDA
• Right ventricle acts as single
ventricle
Hypoplastic Left Heart Syndrome
• Ductus Arteriosus: allows R
L shunting of
mixed blood from pulmonary artery to aorta
• Patency is dependent on prostaglandin
concentration and oxygen tension
• Prostaglandin E1 (PGE1,alprostadil, Prostin VR®)
♦ continuous IV administration maintains patency of DA
♦ administer via large vein or umbilical artery catheter
♦ side effects: apnea, flushing, hypotension, fever
HLHS: Stage I Repair
• Norwood Procedure
♦ usually w/in 1st few weeks of life
♦ ligation of PDA
♦ “neoaorta”: attaches RV to aortic
arch using pulmonary artery
♦ Blalock-Taussig (BT) shunt:
provides pulmonary blood flow
from aortic arch to branch
pulmonary artery
HLHS: Stage II Repair
• Bidirectional Glenn Shunt
(Hemi-Fontan procedure)
♦ usually at 4 – 6 months of age
♦
volume load of single RV
♦ removes BT shunt
♦ connects SVC to branch
pulmonary artery
HLHS: Stage III Repair
• Fontan Procedure
♦ usually at ~ 2 years old
♦ completes the separation of
systemic and pulmonary
blood flow
♦ connects IVC to branch
pulmonary artery
♦ fenestration allows run-off if
PVR acutely increases
Tetralogy of Fallot
• 10% of CHD
• 4 defects
♦ VSD
♦ overriding aorta
♦ pulmonary stenosis / atresia
♦ RV hypertrophy
• Pulmonary blood flow may be
ductal dependent
♦ PGE1
• “Tet” spells
♦ hyperpnea, cyanosis,
syncope
♦ Propranolol
TOF: Repair
• Palliative repair with modified
BT shunt may occur first
• Patch closure of VSD
• Patch to enlarge PA
• Removal of subpulmonary
obstructive tissue
Transposition of the Great Arteries
• 5% of CHD
• Parallel blood flow circuits
♦ Aorta originates from RV
♦ Pulmonary artery originates
from LV
• Oxygenation of systemic blood
is ductal dependent
♦ PGE1
TGA: Temporary Repair
• Balloon atrial septostomy
♦ cardiac cath via PFO
• Removes atrial septum to
allow mixing of oxygenated
and deoxygenated blood
• PGE1 no longer required
TGA: Repair
• Arterial switch
♦ usually w/in the 1st few
weeks of life
• Stenosis at the
reanastomosis sites may
occur
Truncus Arteriosus
• 1 – 3% of CHD
• One great vessel gives rise to
coronary arteries, branch
pulmonary arteries, and aortic
arch
• Large VSD with RV
hypertrophy
• Not generally ductal
dependent unless interrupted
aortic arch is present
TA: Repair
• Initial management is
symptomatic
♦ diuretics, digoxin, ACEI
• Definitive repair usually
occurs at 6-8 weeks of life
♦ Patch closure of VSD
♦ Valved homograft from RV to
pulmonary artery
• Homograft does not grow
must be replaced at ~ 3-6 yrs
and again in adolescence
Bacterial Endocarditis Prophylaxis
Circulation 2007;116:1736-54.
Bacterial Endocarditis Prophylaxis
Dental Procedures
Prophylaxis is Reasonable
• All dental procedures involving manipulation of
gingival tissue or perforation of oral mucosa
Prophylaxis is NOT Warranted
• Placement / adjustment of orthodontic appliances
• Shedding of deciduous teeth
• Bleeding from lips or oral mucosa
Circulation 2007;116:1736-54.
Bacterial Endocarditis Prophylaxis
Other Procedures
Prophylaxis is Reasonable
• Incision or biopsy of respiratory mucosa
• Tonsillectomy or adenoidectomy
Prophylaxis is NOT Warranted
• Cardiac catheterization, implanted pacemaker
• Respiratory Tract
♦ intubation, bronchoscopy, tympanostomy tube insertion
• GI / GU Tract
♦ transesophageal echo, endoscopy
♦ urethral catheterization, circumcision
Circulation 2007;116:1736-54.
Circulation 2007;116:1736-54.
Role of the Pharmacist
• Identify patients requiring endocarditis
prophylaxis
• Identify patients at risk for altered
pharmacokinetic parameters
Conclusions