EXAM #2: ACYANOTIC HEART DISEASE Flashcards
Why do holes in the heart create left-to-right shunts?
PVR is less than SVR*
Blood takes the path of less resistance
What is the most common type of ASD?
Secundum type
What is a Secundum Type ASD?
Patent foramen ovale that does NOT close gets called a “Secundum ASD”
What is a Primum ASD?
Low ASD
What is a Sinus Venosum ASD?
ASD up near the SVC
What are the complications of a left-to-right shunt in an ASD?
Volume overload of the:
1) RA
2) RV
3) Lungs
What determines the magnitude of the shunt?
1) Size
2) Relative compliance of the RV
What are the physical findings associated with an ASD?
1) Ejection murmur at pulmonary listening area
- Relative pulmonary stenosis b/c of increased volume, not actual decrease in valve size
2) S2 is widely split and fixed
No murmur from the flow across the defect itself
What are the ECG findings associated with an ASD?
1) RAE
2) RAD
3) RVH (tall R-waves on right precordium, which are actually a sign of dilation, not hypertrophy)
What are the signs of an ASD on CXR?
1) Increased pulmonary vasculature
2) Enlarged heart
3) Large pulmonary artery segment
What happens if a significant ASD is not identified or fixed? When do these symptoms present?
- Pulmonary Hypertension
- Atrial arrhythmias
BOTH in 3rd or 4th decade of life
What are the interventions for an ASD?
1) Open heart surgery
- Prosthetic patch
- Patient’s own pericardium
2) Device closure in cath. lab
What is an ASO?
Amplatzer Septal Occluder
*This is the device placed in the cath. lab to treat an ASD
What is the most common form of congenital heart disease?
VSD
What is the most common type of VSD?
Perimembranous
What is a Perimembranous VSD?
VSD in the membranous portion of the IV septum that can be:
1) Just below the aortic valve on the LEFT septum
2) Adjacent to the tricuspid valve on the RIGHT side of the septum
*Note that if on the right side of the septum, the shunt may be limited by the tricuspid valve
Where are muscular VSDs located? What is the unique clinical implication about these VSDs?
Located in the muscular portion of the IV septum
*EXCELLENT chance of spontaneous closure
What is an inlet VSD?
VSD associated with the AV valves i.e. the inlet of blood into the ventricles
What is an outlet or “supracritsal VSD?”
VSD associated with the pulmonary and aortic annuli
What is the impact of a small VSD?
No hemodynamic change
What direction is the shunt in VSD?
Left-to-right
*B/c PVR is less than SVR
Where will volume overload be in VSD?
1) Lungs (also pressure overloaded)
2) LA
3) LV
Blood basically goes from the LV directly into the pulmonary artery and does NOT fill the RV as one might think
What is the utility of the QP/QS ratio? Where is this measurement taken?
In the cath. lab, the following data is obtain:
QP= pulmonary a. flow
QS= systemic arterial flow
- Normal= 1:1
- Greater than 1.7:1 ratio= significant shunt
What are the implications of a large VSD?
1) Delayed growth and development
2) Decreased excercise tolerance
3) Frequent pulmonary infections
4) CHF
What is Eisenmeger Syndrome?
Reversal of left-to-right shunt b/c of increased PVR, greater than SVR
*Inoperable
What are the PE findings associated with a large VSD?
1) Poor weight gain
2) CHF
3) Systolic thrill
4) Systolic regurgitant murmur
5) Possible diastolic rumble with large shunt
What causes the murmur in a VSD?
Turbulent flow across VSD
V.s. an ASD where the murmur is not associated with flow across the hole itself
Is it normal to not hear the murmur of a VSD in the first few day of life?
Yes–PVR and SVR are relatively equal at birth
What ECG findings are associated with a large VSD?
1) LAE
2) LVH
IF pulmonary HTN, RVH
What will a CXR show in a large VSD?
1) Cardiomegaly of varying severity
2) Increased pulmonary vascularity
Which murmurs are most likely to close spontaneously?
1) Small membranous
2) Muscular
How can VSDs be medically managed with drugs?
1) Digoxin
2) Diuretic
3) ACE inhibitor
*Also, high calorie intake
What are the surgical indications for a VSD?
1) Growth failure
2) Large VSD at 6-12 months (i.e. no spontaneous closure)
What are the contraindications for surgical intervention in a VSD?
1) Increased PVR
2) Cyanosis from Eisenmenger Syndrome
What direction is the shunt in PDA?
Aorta to PA b/c PVR is less than SVR
When is PDA a common problem?
Premature infants
How does a PDA present on PE?
1) Tachycardia
2) Hyperactive precordium
3) Bounding peripheral pulses with a wide pulse pressure
*Wide pulse pressure b/c you have systole followed by run-off into the PDA, dropping the diastolic pressure
How is the murmur of PDA described?
Continuious machine-like murmur
What ECG changes associated with a PDA?
1) LAE
2) LVH
3) LAD
What CXR finding is associated with a large PDA?
Cardiomegaly
What is the deciding point about whether or not a PDA will close spontaneously?
1 week
How can a PDA be medically managed, especially in a premature infant?
Indomethacin (prostaglandin synthetase inhibitor)
How is a PDA managed surgically?
Ligation and division via left thoracotomy
What is an Atrioventricluar Septal Defect (AVSD)?
Large communication at center of the heart
- Lower atrial septum missing
- Inlet portion of ventricular septum missing
*Note that this is also called an: endocardial cushion defect, complete ASD , or AVSD
What is a complete atrioventricular septal defect associated with?
Down Syndrome
Definite test question
How does a AVSD present?
1) Failure to thrive
2) CHF
What should you do with a child that has Down’s Syndrome and left axis deviation at birth?
Highly suspicious for AVSD
When are murmurs caused by ventricular outflow obstruction first heard?
At birth
Outline the pathophysiology of pulmonary stenosis.
1) Elevated RV pressure to force blood across stenotic valve
2) RVH ensues
3) Causes RV heart failure
*Possible tricuspid regurgitation
What is “critical” pulmonary stenosis?
PS with Cyanosis!
- Possible hypoplasia of RV
- Right-to-left shunt across patent foramen ovale
How will the ECG appear in a child with pulmonary stenosis?
Relatively normal at first with:
- RAD
- RVH
What is the preferred treatment for Pulmonary Stenosis?
Balloon valvuloplasty
Outline the pathophysiology of aortic stenosis.
1) Elevated LV pressure to overcome stenotic aortic valve
2) LVH ensues
3) Left-sided failure
*Mitral valve regurgitation may occur
How is aortic stenosis treated?
Balloon valvuloplasty in cath lab
*Note that results not as good as for PS AND need to be much more conservative
What is the Ross Procedure?
1) Remove diseased aortic valve
2) Transplant patient’s pulmonic valve to aortic position–it will grow
3) Cadaver pulmonary valve
What is the defect seen in Coarctation of the Aorta?
- Abnormal tissue “shelf” is located in the “juxtaductal” region of the aorta itself
- Left Subclavian a. is often near the site of the shelf/coarctation
Outline the pathophysiology of Coarctation of the Aorta.
- Abnormal tissue shelf obstructs blood flow from the LV
- Obstruction is PAST the subclavian arteries
- Consequently, BP in arms is HIGH and legs is LOW
What is the classic sign of Coarctation of the Aorta?
Arm BP/pulses higher/stronger than leg
What causes acute obstruction in Coarctation of the Aorta?
Closure of the ductus arteriosus
*This is like a pressure valve allowing some of the LV blood an “escape”–until it closes
What are historical indications of Coartation of the Aorta?
- Poor feeding
- Dyspnea
- Poor weight gain
*Or acute circulatory shock if ductus arteriosus closes
What are the physical exam signs of Coarctation of the Aorta?
- Pallor
- Dyspnea
What are the ECG findings associated with Coarctation of the Aorta?
- RVH in young children
- LVH in older children
Describe the natural history of Coarctation of the Aorta.
1) CHF by 3 months of age
2) Renal impairment if late diagnosis
How is Coarctation of the Aorta managed medically?
1) PGE1 to maintain ductal patency
2) Anti-congestive medications
3) Balloon angioplasty
How is Coarctation of the Aorta managed surgically?
Resection via:
1) End-to-end anastomosis (small tissue shelf)
2) Conduit between “good” ends if defect is long
