Unit 2 Day 7 (Wed 4/15) Flashcards
Ventricular Septal Defects
- very common defect
- high incidence of spontaneous closure
Risk Factors for Congenital Heart Disease
- maternal diabetes
- family history of cardiac defect in first degree relative
Patent Ductus Arteriosus (PDA)- Clinical Presentation Presentation
- neonate may be asymptomatic if small, if large: may cause repiratory effects, congestive HF, feeding intolerance, renal insufficiency, hemorrhage, stroke, death
- older infant may have hoarse cry, hx of pneumonias, failure to thrive
PDA- Physical Exam
- a large PDA with L to R flow in a neonate:
- -wide pulse pressure
- -bounding pulses (palpable palmar pulses)
- -inc. work of breathing
- -hyperactive precordium
- -murmur- variable
PDA- murmur
- classic: continuous machinery sounding murmur along L upper sternal border
- -can be associated with a diastolic rumble if shunt is large
- no murmur if there is a low velocity or tiny shunt
- accentuated P2 comonent of heart sounds if there is associated pulm. hypertension
PDA- Diagnosis
- Often can diagnose based on history and physical exam
- Chest radiograph
- -Normal if the PDA is small
- -Increased pulmonary vascular markings, enlarged left atrium and left ventricle if large
- Confirm with echocardiogram
PDA- Management
- depends on age of pt and sx
- asymptomatic neonate: conservative management
- symptomatic neonate: trial of COX inhibitors, if meds fail, surgical ligation via lateral thoracotomy
- NSAIDs block conversion of arachidonic acid to prostaglandin
- symptomatic older child or larger ductus in an older child: percutaneous occlusion
- asymptomatic older child: controversial, murmur-percutaneous closure, silent- no need to intervene
- of untreated, may result in eisdenmenger’s pulmonary hypertension
Atrial Septal Defect (ASD)- Clinical Presentation
- rarely presents in infancy
- as pulm. vascular resistance falls and RV wall thins, L to R shunting inc.
- small defects or neonate: normal exam
- large defect: inc. resp. rate, liver 2-3 cm below costal margin, 2-3/6 systolic ejection murmur at upper L sternal border +/- diastolic rumble at lower L sternal border
- second heart sound widely split
ASD- Murmur
- NOT related directly to blood flowing across defect
- systolic ejection murmur
- -secondary to excessive blood flow across pulm valve
- diastolic rumble
- -excessive blood flow in diastole across the tricuspid valve
- widely split S2
- -A2 is aortic valve closure
- -P2 represents pulm. valve closure
- -RV volume overload secondary to an ASD results in delayed RV emptying and therefore wide splitting of S2 in all phases of respiration
ASD- Diagnosis
- chest radiograph
- -main pulm. artery is enlarged
- echo is diagnostic
- -size and location of defect
- -magnitude of shunt
- -associated lesions
- often undetected in childhood
- long term risks of a hemodynamically significant ASD: pulm. vascular disease, atrial arrhythmia, onset of cardiac failure
ASD- Management
- medical therapy can be instituted for sx in infants
- in older children and adults: CLOSE THE HOLE with surgery of percutaneous device closure
ASD- Embryologic Basis
-excessive osium secundum or inadequate septum secundum
VSD- Embryology
- post loop stage: days 28-42
- 4 endocardial cushions form suptum
VSD- Clinical Presentation
- Asymptomatic until PVR falls after birth, even if defect is large.
- -Fall in PVR is delayed at elevated altitudes
-Large VSD: Respiratory distress and diaphoresis- especially noted with feeds, Failure to thrive n Active precordium, Accentuated second heart sound, 2-3/6 harsh, holosystolic murmur loudest at LLSB, but can usually be heard throughout the chest, Diastolic murmur- secondary to increased flow across the mitral valve
-Small VSD: Tachypnea, diaphoresis usually mild or absent, Precordial activity usually normal, Normal second heart sound, 2-4/6 early systolic murmur, No diastolic murmur

Loud VSD Murmur
- good
- closing
- low PVR
Soft VSD Murmur
- large VSD with equalization of RV and LV pressure
- elevation in PVR
VSD- Diagnosis
- characteristic exam
- echo is gold standard
- ECG- R axis deviation and inc. in RV and LV voltages (combined hypertrophy) in large defects
VSD- Clinical Presentation
- Asymptomatic until PVR falls after birth, even if defect is large.
- -Fall in PVR is delayed at elevated altitudes
-Large VSD: Respiratory distress and diaphoresis- especially noted with feeds, Failure to thrive, Active precordium, Accentuated second heart sound, 2-3/6 harsh, holosystolic murmur loudest at LLSB, but can usually be heard throughout the chest, Diastolic murmur- secondary to increased flow across the mitral valve
-Small VSD: Tachypnea, diaphoresis usually mild or absent, Precordial activity usually normal, Normal second heart sound, 2-4/6 early systolic murmur, No diastolic murmur

VSD- Management
- Symptom-based management in infancy
- -HR sx
- -pulm. edema
- -diuretics are mainstay
- small defects are usually asymptomatic: no tx necessary
- indications for surgical closure of a VSD: pulm vascular changes, persistent sx or poor growth despite therapy, development of secondary complications
Tetralogy of Fallot (TOF)
- R vent. outflow tract obstruction
- R vent. hypertrohpy
- dextraposition of aorta
- VSD
- most common of the cyanotic defects
TOF- Embryological Basis
- monology of fallot
- abnormal development of conal crests resulting in infundibular (outlet) septum that is displaced anteriorly, rightwardly, and superiorly
- results in obstruction of pulmonary outflow tract
Blue TOF
- R to L shunt if RV outflow resistance is higher than systemic vascular resistance = cyanosis
Pink TOF
-L to R shunt if RV outflow resistance is less than systemic vascular resistance = no cyanoss
Tet Spells
- hypoxic spells
- can be life threatening
- mechanism is unclear
- causes blue baby with dec. intensity of murmur and altered consciousness/seizures
- tx: knee chest position, phenylephrine, morphine, IV fluids
- prevention: BBs
