Congenital Volume Overloads Flashcards
(71 cards)
1
Q
What is a patent ductus arteriosus?
A
- Persistent opening of the ductus arteriosus after birth
2
Q
Who gets PDA?
A
- Toy breeds
- Herding breeds (Sheltie, Collie, Shepherd, Corgi, etc.)
3
Q
PDA sex predilection
A
- Seen more commonly in female than male dogs
4
Q
Pattern of inheritance for PDA
A
- Inherited
- Polygenic trait
5
Q
How common is PDA?
A
- May be the most common dog defect
6
Q
Ductus arteriosus function in utero
A
- Umbilical vein from the mother and skips liver through ductus venosus
- Comes into the caudal vena cava to right atrium
- Preferentially shunted through foramen ovalis into left atrium and left ventricle through aorta into head and body
- Deoxygenated blood from the head in the baby that mixes with oxygenated blood in the right atrium
- SHunted through tricuspid through pulmonary artery and into ductus arteriosus
7
Q
Where is the ductus arteriosus?
A
- Junction of aortic arch and descending aorta and pulmonary artery
8
Q
What is the point of the ductus arteriosus in the fetus?
A
- Don’t want venous admixure to go to the brain
9
Q
PDA murmur PMI, timing, and quality
A
- PMI: Left heart base
- Timing: continuous murmur
- Quality: Continuous murmur
10
Q
Femoral pulses of PDA
A
- Normal to HYPERKINETIC*
11
Q
Jugular distensions/pulses with PDA
A
- None usually for distensions or pulses
12
Q
Arrhythmias with PDA
A
- Pulse deficits
- Possible
13
Q
What can cause the hyperkinetic or bounding pulses with a PDA?
A
- Pulse pressure = systolic - diastolic
- Diastolic pressures are much lower because it’s leaking backwards during diastole
- Normal is 120/80
- During a PDA can be 110/50
14
Q
Radiographic findings of PDA
A
- Left atrial enlargement
- left ventricular enlargement
- Pulmonary arteries and veins will be enlarged
- Aorta enlarged
- MPA will be enlarged too
15
Q
Why do the structures that get enlarged in a PDA get enlarged?
A
- Going through multiple times
- Aorta –> MPA –> arterioles –> capillaries –> main pulmonary vein
16
Q
What type of hypertrophy occurs with PDA?
A
- Eccentric hypertrophy
- Volume overload
17
Q
Echocardiogram with PDA
A
- Right heart will look small compared to the left heart because the left heart is so big
- Eccentric hypertrophy
- Try to use Doppler
- Continuous flow
18
Q
What determines severity of PDA?
A
- Depends on size of PDA
- Larger hole means larger volume overload and larger workload
19
Q
Surgical treatment of PDA
A
- Surgical ligation with thoracotomy
- Also invterventional closure with vascular access via the femoral artery
20
Q
What other treatment may be necessary for PDA?
A
- Treat left-sided CHF if present
- Furosemide + ACE inhibitors +/- Pimobendan
21
Q
What’s the priority for PDA treatment: Treat CHF or treat the PDA?
A
- Important to treat the left sided CHF FIRST
- No anesthesia, until the pulmonary edema is resolved
22
Q
Description of interventional closure
A
- Track up the femoral artery
- Inject contrast to highlight the ductus
- measure the size of the hole
- Waist of the device expands the ductus
23
Q
What is usually the smallest dog that can have an interventional closure?
A
- 2kg
24
Q
Mortality associated with interventional closure
A
- Pretty significant mortality
- Success rates are surgeon dependent
- If they do a bad job, they could cause an embolism
25
Prognosis for PDA if they close the ductus
- CURATIVE!!!!
- Normal life expectancy
- +/- cardiac meds (usually no meds)
26
Prognosis of PDA without closure
- 50-60% develop CHF and die within 1 year
| - 70-80% develop CHF and die within 2 years
27
VSD definition
- Incomplete formation of the interventricular septum resulting in a communication between the left and right ventricles
28
Who gets VSD?
- Most common congenital heart disease in all species except for the dog
29
Left ventricular pressure compared to right ventricular pressure
- LV: 120/6
| - RV: 20/5
30
Mime the flow of blood from the left ventricle to the right ventricle with a VSD
- Just do it
31
VSD murmur PMI, timing, and quality
- Hear it on the right side better (often basilar)
- Systolic
- Ejection quality
32
What additional murmur can happen with a VSD?
- Aortic regurgitation
33
Aortic regurgitation murmur PMI, quality, and timing
- PMI is left heart base
- Quality is decrescendo
- Timing is Diastolic
34
Femoral pulse quality with VSD
- Normal
35
Jugular distensions or pulses with VSD
- None
36
Arrhythmias with VSD
- Possible
| - Pulse deficits
37
Radiographic findings of VSD
- Left atrial and left ventricular enlargement
- Overcirculation of lungs
- Should not see main pulmonary or aortic involvement with VSD
38
What type of hypertrophy occurs with VSD?
- Eccentric hypertrophy
39
VSD echocardiogram findings
- Aortic regurgitation can happen
40
What determines severity of VSD?
- Size
| - Larger hole = more volume overload = larger workload
41
For murmur with a VSD, will it be louder when it's smaller or bigger?
- Louder when it's smaller
| - Again, severity does not correlate very well with the loudness of the murmur
42
Treatment and prognosis for a small VSD
- No treatment needed
| - Normal quantity and quality of life
43
Treatment and prognosis for a large VSD
- May develop Left sided CHF at some point
| - If they develop left sided heart failure, furosemide + ACE-inhibitor +/- Pimobendan if CHF develops
44
Surgical options for severe VSD
- Pulmonary artery banding (palliative)
- Open heart failure (people only)
- Interventional closure
45
What determines prognosis for VSD?
- Size of the defect
| - Development of CHF
46
What is prognosis if an animal goes into stage C with VSD?
- ~ 1 year
47
Eisenmengers Physiology with VSD/PDA - initially
- Pulmonary overcirculation, resulting in pulmonary vascular hypertrophy and fibrosis
- Increased pulmonary pressures
- As long as systemic pressures are higher than pulmonary pressures, blood will go to the lungs first
- Make sure you can mime out where blood will go
48
Physiology of no shunt with a PDA or VSD
- Pulmonary pressures = systemic pressures
49
Right to left shunting pathophysiology of VSD and PDA
- Pulmonary overcirculation
- Pulmonary vascular hypertrophy and fibrosis
- Increased pulmonary pressures
- Eventually, pulmonary pressures > systemic pressures
- Right --> left shunting leading to deoxygenated blood in your body (AKA hypoxemia)
50
What secondary condition can occur with hypoxemia?
- Polycythemia
51
Pathophysiology of polycythemia secondary to right to left shunting
- Deoxygenated blood to systemic circulation
- Hypoxia
- Increased EPO secretion by the kidneys
- Polycythemia
- Hyperviscosity
52
What causes R--> L PDA?
- Reversal happens EARLY in life
- 1st couple of months
- Not a result of an uncorrected left to right PDA
- If you have a left to right, it will often just go into CHF
53
Findings for a R--> L shunt: murmur, jugular distension, and mucous membranes?
- Murmur: usually none, as blood is too viscous
- Jugular distension and pulsation: +/+
- Mucous membranes cyanotic, especially with exercise
54
On a PE, what would be different about the distribution of cyanosis for a R-->L PDA vs a R-->L VSD?
- THINK ABOUT IT
55
Treatment for right to left PDA
- CLOSURE IS CONTRAINDICATED (right heart failure because it has to work against an increased pressure)
- Treat polycythemia
56
How to treat polycythemia
- Phlebotomy (~20mL/kg q4-6 weeks)
| - Medical treatment: sildenafil, hydroxyurea (bone marrow suppressor)
57
Prognosis for R--> L VSD or PDA
- Long term prognosis is guarded to poor
- Better with control of polycythemia
- Acceptable quality of life for ~5-10 years, but often quite high maintenance
58
Breeds that get tricuspid dysplasia?
- Lab!!!!!!****
- Danes
- Borzoi
- German Shepherd Dog
- Boxer
- Shih Tzu
- Mastiff
59
Breeds that get mitral valve dysplasia?
- Cats
- Bull Terrier*
- Labs
- Danes
- German SHepherd Dogs
60
Murmur PMI, timing, and quality for tricuspid dysplasia?
- Right apex
- Systolic
- Regurgitant
61
Murmur PMI, timing, and quality for mitral valve dysplasia?
- Left apex
- Systolic
- Regurgitant
62
Femoral pulses, jugular distension/pulses, and arrhythmias for tricuspid dysplasia?
- Femoral pulses: Normal
- Jugular distension/pulses: +/+
- Arrhythmias: pulse deficits
63
Femoral pulses, jugular distension/pulses, and arrhythmias for mitral valve dysplasia?
- Femoral pulses: Normal to weak
- Jugular distension/pulses: -/-
- Arrhythmias: pulse deficits
64
Severity of AV Valve dysplasia
- Varies greatly
| - worse with larger regurgitant volume or of stenosis is also present
65
Treatment of AV valve dysplasia
- Treat CHF if present
- Treat arrhythmias
- Surgery not really an option for these guys
66
How to treat CHF for AV valve dysplasia?
- For either, furosemide + ACE inhibitors +/- Pimobendan
| - For tricuspid valve dysplasia, abdominocentesis +/- thoracocentesis
67
What is the common arrhythmia with AV valve dysplasia?
- Atrial fibrillation
68
How to treat atrial fibrillation?
- Diltiazem (calcium channel blocker)
| - +/- digoxin
69
Prognosis for AV valve dysplasia if mild
- Normal quantity/quality of life
70
Relative prognosis for TVD vs MVD
- TVD often fare better than MVD
71
Prognosis once you hit CHF
- ~ 1 year
| - May be worse with atrial fibrillation
