Coarctation of the Aorta Flashcards
(25 cards)
Definition
A discrete narrowing of the descending thoracic aorta location generally just opposite the insertion of the ductus arterioles resulting in LV pressure overload
Prevalence
- 6-8% of congenital heart disease
-1.5:1 male predominance (body builder physique)
-familial occurence
Embryology
- hypotheses include 1. decreased blood flow through the aortic arch during fetal life and 2. constriction of the aorta at the juxtaductal position due to a deformity in the media of the aorta
Types
Preductal:(simple, discrete, infantile): ductal dependent (associated with VSD, PDA, d-transposition of the great arteries)
juxtaductal
post ductal
Pathology/physiology
- aortic media develops posterior shelf causing obstruction
- principle cardiac abnormality is left ventricular hypertrophy
-Prominent collaterals are usually present in adolescence and adults
-blood pressure and pulse difference between the upper and the lower body
Associated conditions
- bicuspid aortic valve 46%
-ventricular septal defect
-patient ductus arteriosus
- Hypoplasia of aortic arch
-left ventricular in flow tract obstruction (example fused cordae)
-LVOTO (ex aortic stenosis)
-d-transposition of the great arteries
- Aberrant right subclavian artery
-atrioventricular canal defect
-double outlet right ventricle
-atrial septal defect
-abnormal papillary muscle architecture
-Necrosis of the papillary muscles with resultant mitral regurg
History
-asymptomatic
-CHF
-Poor feeding
-Dyspnea
-Systemic HTN(upper extremities)
-frequent headaches
-poor weight gain
-fatigue (older)
-diaphoresis
-tachycardia
-cyanosis (preductal) w exercise
-lower extremity claudication w exercise (older)
Physical examination
-congestive heart failure
-systolic systemic hypertension
-systolic blood pressure
differential in arm versus leg (>20 mmHg)
-difference in upper and lower extremity pulses
-impalpable femoral pulses (2/3 of cases)
-systolic thrill (suprasternal notch area, back)
-Hyperdynamic LV impulse
-Extremity edema
-tachypnea
-respiratory distress
-Pale
-oliguria
-anuria
-differential cyanosis
-Hepatomegaly
-Prominent arterial pulsations at intercostal level (older children)
cardiac auscultation
EKG
RVH (pre ductal)
RBBB (pre ductal)
RAE (pre ductal)
Left axis deviation
conduction abnormalities
LVH (older)
Chest xray
-cardiomegaly (due to LV prominence)
-pulmonary venous congestion
-pulmonary edema
-poststenotic dilation of ascending due to bicuspid AoV
Figure 3 sign (older children)
-“Rib notching” (older children)
cardiac Cath
- aortogram demonstrates the location and length of coarctation, collateral circulation, PDS (if present)
-Pressure gradient between LV and femoral artery
-increased LA and LV pressures
Assess pulmonary artery pressure
-ventriculogram may deminstrate MV abnormality if VSD if present
natural history/ complications
-CHF
-infective endocarditis/endarteritis
- intracranial hemorrhage
-hypertensive encephalopathy
-hypertensive cardiovascular disease
-dissecting aortic aneurysm
-persistent headache
-renal shutdown
-aortic rupture
-bicuspid AoV may cause stenosis and/or regurgitation
medical management
-prostaglandin E2 infusion (to reopen ductus arteriosus)
Treat CHF (diuretics digitalis, dopamine)
Oxygen therapy
treat hypertensive crisis
precautions against infective endocarditis/endarteritis
surgical management
- percutaneous balloon angioplasty
-resection with end to end anastamoses
-subclavian flap aortoplasty
-dacron patch
-dacron graft
-combination end to end graft
bypass tub graft
pulmonary artery banding for large ventricular septal defect
echo views
- suprasternal long axis (view of choice), subcostal “candy cane” view
mode/2d
-Assess the entire length of the aorta by combining 2D views, (parasternal long axis, short axis, suprasternal, subcostal)
-identify location and extent of coarctation
-identification of posterior and lateral aspects of the descending thoracic aorta (“shelf” of tissue)
–pre and post stenotic dilation of the DTA
-dilation/exaggerated pulsation of ascending aorta
-Left carotid/left subclavian dilation
-diminished systolic pulsation of the thoracic/abdominal aorta
-distal displacement of the left subclavian artery and the left common carotid arteries (1.5 times than the distance between the left common carotid and innominate arteries)
-evaluate poststenotic dilation of Ascending Ao (bicuspid AoV)
-evaluate papillary muscle architecture (reduced distance between the papillary muscles)
-measure the diameter of the ascending aorta, proximal aortic arch, distal aortic arch, aortic isthmus, coarctation and the descending thoracic aorta for suitability for balloon angioplasty
PW/CW/color doppler
- CW demonstrates high peak systolic velocity with diastolic runoff across coarctation
-color flow will demonstrate flow acceleration (Pisa) proximal to the site of obstruction
-color flow will demonstrate aliasing at the site of the obstruction
-PW/CW/ color flow demonstrate continuous runoff throughout diastole in DTA
-continuous anterograde flow throughout systole and diastole suggest a significant obstruction
-persistent high velocity flow throughout systole and diastole suggests a significant obstruction
-determine peak pressure gradient across bicuspid aortic valve when present
-determine peak velocity across coarctation
-determine peak pressure gradient across coarctation.(Utilize lengthened Barnole equation)
-determine mean pressure gradient across coarctation. (Utilize lengthened Barnole equation)
-determine the flow pattern and the abdominal aorta. (“Damped” flow pattern with low systolic and diastolic velocities)
-determine the presence and severity of associated lesions. (Example bicuspid aortic valve, PDA, VSD, hypoplasia of aortic arch, ASD, lesions associated with shones complex)
postop responsibilities
-measure the diameter of the repaired coarctation
-evaluate the degree of residual stenosis
-evaluate for the presence of iatrogenic pathology (example catheter induced aortic dissection, aortic aneurysm)
-evaluate for the presence of valvular regurgitation
-determine peak velocity, peak pressure gradient, mean pressure gradient across repaired coarctation.
-determine left ventricular dimensions, thickness, and systolic/diastolic function
-determine the presence and severity of coexisting lesions (example by bicuspid aortic valve, PDA, VSD, mitral valve pathology, lesions associated with shones complex)
In neonates with long tunnel like obstruction, the ____
Bernoulli equation may be invalid
The Doppler pressure gradient may be ______ if a PDA, aortic stenosis, mitral stenosis, and/or decreased left ventricular function is present
underestimated
Coarctation is a component of Shone’s Complex:
Supramitral valve ring
Parachute mv
Subaortic stenosis
_____ may be present in coarcation
Left ventricular endocardial fibroelastosis(secondary)
Coarctation may occur in the
Ascending aorta or abdominal aorta
