Cardiology Lecture 5 -- Congenital Heart Disease Flashcards
(125 cards)
1
Q
7 acyanotic congenital heart defects
A
- Atrial septal defects (ASD)
- Ventricular septal defects (VSD)
- Patent ductus arteriosus (PDA)
- Congenital aortic stenosis (AS); Bicuspid aortic valve (BAV)
- Pulmonary stenosis (PS)
- Coarctation of the aorta
- Congentially corected transposition of the Great Arteries (cc-TGA)
2
Q
3 cyanotic congential heart defects
A
- Tetralogy of Fallot
- Complete transposition of the great arteries (D-TGA)
- Eisenmenger Syndrome
3
Q
O2 sat associated with cyanosis
A
80-85%
4
Q
What causes cyanotic heart disease?
A
Defects that allow a R –> L shunt (poorly oxygenated blood goes from right side of heart to left, bypassing lungs)
5
Q
Color of acyanosis
A
Pink
6
Q
3 general condiitions included in acyanotic lesions
A
Intracardiac or vascular stenoses
Valvular regurgitation
L –> R shunts
7
Q
When can acyanotic heart disease become cyanotic?
A
LARGE, uncorrected, longstanding L –> R shunts: Eisenmenger Syndrome
8
Q
Cause of pulmonary arterial hypertension
A
Large L –> R shunts (by unknown mechanism)
9
Q
Define the findings of pulmonary arterial hypertension
A
Hypertrophy of pulmonary arteriolar media
Intimal proliferation
Decreased cross-sectional area of the pulmonary vascular bed
10
Q
Effect of decreased cross-sectional area of pulmonary vascular bed (i.e. in pulmonary arterial hypertension)
A
- Increased resistance to blood flow
- Vessel thrombosis Increased PVR
- Decreased L –> R shunt
- PVR > 2/3 SVR and shunt reverses (Eisenmenger)
11
Q
Define Eisenmenger syndrome
A
Condition of severe irreversible pulmonary vascular obstruction that results from reversal of a large chronic left-to-right shunt to right-to-left with systemic cyanosis when PVR > 2/3 SVR
12
Q
2 types of ASD
A
Secundum (2º ASD)
Primum (1º ASD)
13
Q
What is 1º ASD associated with?
A
Endocardial cushion defects (AVCD)
14
Q
2 conditions that are not true ASD’s
A
Sinus Venosus Defect (superior and inferior)
Patent Foramen Ovale (PFO)
15
Q
Common locations of congenital shunts
A
- Ductus arteriosis
- Foramen ovale
- Ductus venosus
16
Q
Describe the atrial septum formation at 30 days
A
Septum primum extends downwards through the ostium primum towards the endocardial cushion
17
Q
Describe the atrial septum formation at 33 days
A
Septum primum splits, the perforation through which is called the ostium secundum. The septum secundum extends downwards to the right of the septum primum’s upper portion
18
Q
Describe the atrial septum formation at 37 days to birth
A
Bottom portion of the septum secundum from the endocardial cushion extends upwards to eventually form the foramen ovale, which is covered by the “flap valve” of the lower septum primum
19
Q
Direction of atrial septal defect
A
LA –> RA
20
Q
Effect of blood flow due to atrial septal defect on the heart chambers
A
Enlargement of the RA, RV and PA
21
Q
Incidence of ASD
A
1 in 1500 live births
22
Q
Where can ASD occur?
A
Anywhere along the interatrial septum (IAS) but most commonly in the area of the foramen ovale
23
Q
Where does 2º (ostium secundum) ASD occur?
A
In the area of the foramen ovale
24
Q
Most common type of ASD
A
Ostium secundum ASD
25
Causes of ostium secundum ASD (5)
* Inadequate formation of septum secundum
* Too much resorption of septum primum
* A combination of the previous two
* Sporadically (most common) OR Inherited:
* Familial septal defect
* Holt-Oram syndrome
26
Define partial ostium primum ASD
1º ASD usually with a cleft mitral valve
27
Define intermediate ostium primum ASD
1º ASD, VSD and 2 separate AV valves
28
Define complete ostium primum ASD
1º ASD, VSD and common AV valve
29
Location of ostium primum ASD
Inferior portion of the interatrial septum
30
Cause of ostium primum ASD
Failure of septum primum to fuse with the endocardial cushions
31
In what chromosomal disorder is ostium primum ASD often found?
Trisomy 21
32
Why isn't a sinus venosus defect a true ASD?
Interatrial septum is intact (however, it is functionally identical to an ASD)
33
Cause of sinus venosus defect
Abormal development of the sinus venosus located postero-superior (superior defect) or, rarely, postero-inferior (inferior defect) to the oval fossa
34
What is sinus venosus defect often associated with?
Partial anomalous pulmonary venous return (PAPVR)
35
Define partial anomalous pulmonary venous return (PAPVR)
Anomalous connection of the right upper pulmonary vein (most commonly) often associated with a superior sinus venosus defect
36
ASD pathophysiological effects after birth
* Increased RV compliance, decreased RV wall thickness
* L --\> R shunt across IAS
* Volume overload = dilatation of RA and RV
37
ASD symptoms in infants
Asymptomatic
38
ASD symptoms in adults
Palpitations (atrial arrhythmias precipitated by RA enlargement)
Decreased exercise tolerance
39
Important ASD auscultation finding
* Fixed split S2
40
Fixed split S2 manifestations on inspiration
* Increased venous return to RA
* Increased RAP
* Decreased L --\> R shunt
* Non-shunted LA blood keeps LV volume constant
41
Fixed split S2 manifestations on expiration
* Decreased venous return to RA
* Decreased RAP
* Increased L --\> R shunt
* Shunted blood keeps RV volume constant
42
EKG rhythm of ostium secundum ASD
Sinus
Atrial fib/flutter
43
EKG axis of both ASD's
* 2º ASD = right axis deviation
* 1º ASD = left axis deviation
44
EKG conduction pattern for 2º ASD
* Partial/complete right bundle branch block
* Increased PR interval
45
2º ASD R wave behavior
Crochetage of R waves in II, III, AVF with rSr' (bunny ears)
46
CXR manifestations of large ASD with pulmonary hypertension
* RA and RV enlargement
* Prominent pulmonary arteries
* May or may not have increased vascular markings
47
Use of Cardiac Catheterization in ASD
* Rarely required
* Useful to evaluate pulmonary pressures/ vascular resistance
48
When is closure of an ASD necessary? (2)
If shunt is significant or unrestrictive:
* Symptomatic patient: palpitations/ decreased exercise tolerance
* Right sided chamber enlargement
49
Goals of closing the ASD
Prevent right-heart failure and irreversible pulmonary hypertension and improve/stop arrhythmias
50
How to close an ASD
* Percutaneously with a device (preferred is feasible)
* Surgically by direct suture closure
51
Define a patent foramen ovale
An unclosed foramen ovale where the septum primum "flap" is often firmly stuck to the septum secundum since LAP \>\> RAP
52
Consequences of PFO
* Usually of no clinical significance
* Increased risk of paradoxical embolus (i.e. stroke)
* Increased RAP --\> straining, coughing, PHTM, RHF
* Can precipitate a R --\> L shunt
53
Consequence of R --\> L shunt due to PFO
Deoxygenated blood
Thrombus
Air (especially if patient is coughing)
54
Recommended treatment to manage PFO
Air filters on IVs
55
What activities are not recommended for PFO patients?
Scuba diving and space travel
56
Incidence of ventricular septal defect (VSD)
1.5 - 3.5 per 1000 live births
57
4 examples of types of VSD
Based on location in the interventricular septum (IVS)
* Membranous (70%)
* Muscular (20%)
* Subarterial (below aortic/pulmonary valves)
* AV septal VSD (adjacent to AV valves)
58
Which VSD is common in Asians?
Subarterial VSD (below aortic/pulmonary valves)
59
Degree if shunting and hemodynamic effects of VSD are related to:
* Size of VSD
* Pulmonary and systemic vascular resistances
60
Heart sound produced by a small insignificant/restrictive VSD
Small hole = loud systolic murmur
61
Consequence of large significant/unrestrictive VSD
* Volume overload of RV, pulmonary circulation, LA and LV
* Initially, SV is increased (Frank-Starling mech)
* Left-sided structures will dilate with time --\> systolic dysfunction --\> heart failure
* Pulmonary overcirculation --\> pulmonary hypertension by age 2
62
In what type of VSD is RV volume overload seen? Which types do you not typically see it?
Typically only occurs with muscular VSD
Rarely with perimembranous and subarterial VSD
63
Name the clinical manifestation associated with small, restrictive VSD
Asymptomatic
64
Name the clinical manifestatin associated with large, moderately restrictive VSD
Dyspnea
65
Name the clinical manifestation associated with large, non-restrictive VSD
Eisenmenger
66
Heart failure symptoms in infants with large unrestrictive VSDs
* Tachypnea
* Poor feeding
* Failure to thrive (FTT)
* Frequent LRTI (lower resp. tract infection)
67
VSD symptoms if Eisenmenger
Dyspnea
Cyanosis
68
VSD palpation findings
Thrill
69
VSD auscultation findings
If restrictive:
* Harsh, high frequency holosystolic murmur
* Grade 3 - 4/6 at LLSB
If non-restrictive:
* No murmur
70
Small VSD CXR findings
* Normal
* With or without dilated proximal PA's
71
Moderate VSD CXR findings
Central PA enlargement
LV dilation
Vascular markings
72
Large VSD CXR findings
Central PA enlargement
Peripheral pruning
Olligemic lung fields
RV enlargement
73
Effect of VSD on the heart chambers
* Left atrial enlargement (LAE)
* Left ventricular hypertrophy (LVH)
* Right ventricular hypertrophy (RVH) if pulmonary vascular disease is present
74
O2 saturation in R heart chambers in VSD
Increased O2 saturation in the RV compared to the RA
* RA O2 sat = 70%
* RV O2 sat = 92%
75
VSD treatment options (4)
* No treatment: 50% of small and moderate-sized VSD will partially or completely close by age 2
* Surgical closure in infancy: Large VSD with associated heart failure or pulmonary vascular disease
* Correction in later childhood/early adulthood: moderate VSD w/o pulmonary vascular disease but significant L --\> R shunt
* Catheter-based device closure: usually muscular VSD
76
Define coarctation of the aorta
Discretely narrowed aortic lumen
77
Incidence of aortic coarctation
1 in 6000 live births
78
What is aortic coarctation associated with?
* **Bicuspid aortic valve**
* Turner's syndrome (45, XO)
79
Where does aortic coarctation usually occur?
Region of the ligamentum arteriosum
80
3 types of aortic coarctation and which one is most common?
Post-ductal
Preductal
**Juxta-ductal**
81
3 thoeries behind the cause of aortic coarctation
* "No flow, no grow" = decreased antegrade flow through left heart and ascending aorta during fetal life --\> aortic hypoplasia
* Ectopic muscular tissue from ductus arteriosus extends into aorta during fetal life and constricts at the same time as the ductus closes
* A manifestation of more diffuse aortic disease
82
Pathophysiological changes due to aortic coarctation (3)
* Increased LV afterload
* Decreased blood flow in descending aorta and lower extremities
83
Why is the blood flow to the head and upper extremities preserved in aortic coarctation?
Vessels branch off BEFORE the coarctation site
84
Consequence of leaving aortic coarctation uncorrected (2)
* LVH
* Dilated collateral vessels formed from intercostal arteries to bypass coarctation and supply blood to descending aorta --\> can erode surface of ribs (rib notching on CXR)
85
Aortic coarctation symptoms in infants
Heart failure symptoms
Differential cyanosis if coexistent PDA
86
Coarctation symptoms in older children and adults
Can be asymptomatic
Symptomatic:
* Unexplained HTN or difficult to control HTN
* Epistaxis
* Headache
* Leg weakness on exertion
* Claudication
87
Physical observational findings of coarctation in physical exam
* Less developed lower body (narrow hips, short legs)
* More developed upper body (broad shoulders, long arms)
* Upper extremity hypertension
88
Where to measure BP in coarctation patients
In both arms and one leg
89
BP findings in coarctation
* BP difference \>30 mmHg between R and L arms if coarctation proximal to L subclavian
* Systolic BP difference \<10 mmHg between brachial and popliteal arteries
* Diastolic BP equal in both UE and LE
90
Palpation findings in coarctation physical exam
* Diminished pulse in lower extremities
* Radial/brachial-femoral delay
* Precordium: LVP overload --\> sustained apex
91
Auscultation findings of coarctation
* Bicuspid valve
* Interscapular systolic murmur from coarctation site (more severe = longer murmur)
* Anterior systolic murmurs from intercostal collateral arteries (interclavicular areas, sternal edge, axillae)
92
Coarctation ECG
LVH with or without LAE is most common abnormality
93
Coarctation CXR findings
* "3 sign" prestenotic and poststenotic dilatation
* Rib notching
* On inferior ribs 3 - 8
* From dilated intercostal arteries
* Usually bilateral unless subclavian arises below coarctation
94
Coarctation treatment for neonates
Prostaglandin infusion to keep ductus arteriosus patent
95
Coarctation treatment for younger children
* Elective repair often done to prevent hypertension
* Types of surgery:
* End-toend anastomosis
* Subclavian flap aortoplasty
* Arch augmentation
* Interposed graft
96
Coarctation treatment for older children, adults and those with recoarctation post repair
* Transcatheter balloon dilatation +/- stent preferred
* Surgery:
* End-to-end anastomosis
* Arch augmentation
* Interposed graft
* Jump graft bypassing coarct segment
97
Most common form of cyanotic heart disease
Tetralogy of Fallot
98
Incidence of Tetralogy of Fallot
5 in 10 000 live births
99
Associated cardiac defects with TOF
* Right aortic arch (25%)
* ASD (10%) = pentalogy of Fallot
* Anomalous left coronary anomaly (LAD comes off RCA and crosses over RVOT)
100
15% of TOF cases are associated with what genetic disorder?
22q11 deletion (AD) (DiGeorge Syndrome, CATCH-22)
101
Etiology of TOF
Abnormal anterior and cephalad displacement of the infundibular (outflow tract) portion of the IVS
102
4 anomalies of the TOF
* Malalignment VSD
* Subvalvular +/- valvular pulmonary stenosis
* RVH
* Overriding aorta
103
ToF pathophysiology (2)
* Increased R by pulmonary stenosis --\> increased deoxygenated blood shunting R --\> L through VSD --\> systemic hypoxemia and cyanosis
* Magnitude of shunt flow across VSD = function of severity of pulmonary stenosis. Acute changes in systemic and pulmonary vascular R can also have effect
104
Why doesn't pulmonary hypertension occur in ToF?
Pulmonary stenosis protects against pulmonary overcirculation
105
Define tet spell and associated symptoms (5)
Children have dyspnea on exertion
* Irritability
* Cyanosis
* Hyperventilation
* Syncope
* Convulsions
106
Cause of tet spells
After an activity that results in systemic vasodilation such as physical exertion, crying or feeding = increased R --\> L shunt
107
How children alleviate tet spell. Explain why this works
Squatting
* Increased systemic vascular R by kinking the femoral arteries
* Decrease R --\> L shunt through VSD so blood will preferentially be directed towards lungs
108
Inspection findings in ToF physical exam
Mild cyanosis (lips, mucus membranes, digits)
Digital clubbing
109
ToF palpation findings
RV heave at LLSB
110
Auscultation findings in ToF
* Single S2 (P2 soft and inaudible)
* SEM at LUSB
* No VSD murmur
111
What causes SEM at LUSB in ToF
Turbulent flow thruogh stenotic RVOT
112
Why is there not VSD murmur in ToF?
VSD is large and non-restrictive
113
ToF CXR findings
* Boot-shaped heart (RV enlargement, decreased MPA segment)
* Decreased pulmonary vascular markings
114
ToF ECG findings
RVH and right axis deviation
115
ToF Catheterization details the... (5)
* RV outflow tract anatomy
* Malaligned VSD
* Aortic relationship with ventricles
* RVH
* Associated defects
116
When is definitive repair of ToF usually done?
By 6 - 12 months
117
3 general procedures that ToF surgical repair involves
* VSD closure
* Repair associated defects
* Relieve RVOT obstruction
118
7 ways to relieve RVOT obstruction
* Resection of infundibular muscle
* Transannular patch
* RV subannular outflow patch
* RV to PA conduit
* Pulmonary valve replacement
* Pulmonary valvotomy
* Pulmonary arterioplasty
119
ToF surgical repair procedures in the past (2)
* Right ventriculotomy appraoch (increase incision)
* Generous transannular patch augmentation
120
ToF Surgical repair complications in adults due to procedures performed before
Severe free PR --\> decreased RV function, arrhythmias, sudden cardiac death
121
ToF surgical repair procedures today
* Transatrial/transpulmonary approach
* Limited RV incision for patch augmentation of the RVOT +/- PV annulus
122
Goal of today's approach to ToF surgical repair
Avoid PR at the expense of some residual PS
123
Incidence of congenital heart disease in population
0.8%
124
Frequent result of acynotic lesions on the dynamics of the ventricle(s)
Volume or pressure overload of the ventricles
125
Consequence of large L --\> R shunts
Pulmonary overcirculation --\> PHTN
Shunt reversal and cyanosis = Eisenmenger Syndrome
