Stenotic Diseases Flashcards
(77 cards)
1
Q
Definition of stenosis
A
- Narrowing in the outflow tract
2
Q
What type of hypertrophy occurs secondary to stenosis?
A
- Pressure overload, so it’s a concentric hypertrophy
3
Q
What are the two types of pulmonic stenosis?
A
- Dysplastic
- Hypoplastic
4
Q
Which is preferred for type of stenosis: dysplastic or hypoplastic?
A
- Dysplastic
5
Q
What occurs in dysplastic stenosis?
A
- Fused valve, so it only opens a very small hole
6
Q
What occurs in hypoplastic stenosis?
A
- Too narrow to begin with
7
Q
Who gets pulmonic stenosis?
A
- Small breeds
- TERRIERS (pitbulls)
- Brachiocephalic dogs
8
Q
Where is the PMI for the murmur in PS?
A
- Left heart base
9
Q
Timing of the murmur for PS?
A
- Systolic
10
Q
Quality of the murmur for PS?
A
- Ejection type murmur (crescendo-decrescendo
11
Q
Additional murmur that can happen with PS if progresses?
A
- Tricuspid regurgitation
12
Q
What is the PMI, timing, and quality of a tricuspid regurgitation murmur that occurs secondary to pulmonic stenosis?
A
- PMI (right apex) = tricuspid
- Timing is systolic
- Quality is regurgitant/plateau/band
13
Q
Pulmonic stenosis femoral pulse quality
A
- Normal
- May have pulse deficits
14
Q
Can you have jugular pulses with PS?
A
- Yes, you can
- Possible to have jugular distention and pulses
- Will not always be present
15
Q
Arrhythmias with pulmonic stenosis - are they possible?
A
- Yes
- Can cause pulse deficits
16
Q
Other physical exam findings with PS?
A
- May have ascites secondary to right heart failure
17
Q
Appearance of radiograph for a dog with pulmonic stenosis?
A
- Main pulmonary artery will be enlarged due to post-stenotic dilatation
- Right atrial enlargement
- Right ventricular enlargement
18
Q
Appearance of pulmonic stenosis on echocardiogram
A
- Concentric hypertrophy of the right ventricle
- Right ventricular free will can be much larger than the left ventricular lumen
- Pulmonic valve will be small
- Can see a post-stenotic dilatation
19
Q
What determines severity of pulmonic stenosis?
A
- How wide does it open?
- If it opens just a tiny bit, that’s very severe
- Creates more extra pressure
20
Q
How do you determine how much pressure is on the right heart secondary to pulmonic stenosis?
A
- Pressure ~= velocity
- Can use the modified Bernoulli equation
- ∆P = 4v^2
21
Q
Make sure you can go through the calculations for the right ventricle based on the velocity of flow through the stenotic valve
A
just make sure you can do it
22
Q
Normal pulmonary artery pressure
A
- 20
23
Q
Normal right ventricular pressure
A
- 20 during systole
- 5 during diastole
24
Q
What is considered mild pulmonic stenosis PA velocity and RV-PA gradient?
A
PA velocity: 2.5-3.5 m/s
Gradient: 30-50 mmHg
25
What is considered moderate pulmonic stenosis PA velocity and RV-PA gradient?
PA velocity: 3.5-4.5 m/s
Gradient: 50-80 mmHg
26
What is considered severe pulmonic stenosis PA velocity and RV-PA gradient?
PA velocity: >4.5 m/s
Gradient: >80 mm Hg
27
What is the treatment of choice for most cases of pulmonic stenosis?
- Balloon valvuloplasty
28
Balloon valvuloplasty procedure details
- Catheter in the jugular vein
- Insert it into the heart at the level of the pulmonic valve
- Trying to measure the annulus size
- Can see a little filling defect
29
What size balloon do you pick?
- should be 1.5x the size of the annulus
30
What will cardiac output be as the balloon is inflated?
- Crappy
31
What can happen to the rhythm of the heart as you inflate the balloon?
- Often can go into V-tach
32
Success rate of balloon valvuloplasty?
- 70% success rate
33
What is considered a "procedural success" for balloon valvuloplasty?
- 50-60% reduction in gradient
- NOT CURATIVE
- Palliative, and depends on the degree of severity that the dog comes in with
34
Re-stenosis rate after balloon valvuloplasty?
- About 15-20% of dogs will re-stenose, which can occur at any time
35
What can make a candidate less ideal for balloon valvuloplasty?
- Sub- or supra-valvular stenosis
| - Pulmonary annular hypoplasia (if the artery is tiny to begin with :()
36
Medical management of pulmonic stenosis
- Treatment of diastolic dysfunction with Beta blockers
- Treatment of arrhythmia if present
- Treatment of CHF if present
37
What is the purpose of beta blockers with diastolic dysfunction?
- Slow heart rate
- Promotes right ventricular filling and perfusion
- Decreased contraction against obstruction
38
What can occur secondary to concentric hypertrophy if severe?
- Myocardial ischemia
| - Can result in some arrhythmias or death
39
How to treat CHF for PS?
- Furosemide and an ACE inhibitor
| - +/- abdominocentesis (remember that it is right sided heart failure)
40
Anomalous left coronary artery
- Can occur with pulmonic stenosis
- Basically, some animals never have a left coronary artery and get abnormal growth of it
- Unpredictable location, so these are at greater risk
41
Who is at risk for an anomalous left coronary artery?
- English bulldogs, French bulldogs, boxers
42
What is a risk that can occur with an anomalous left coronary artery?
- Balloon valvuloplasty may rupture coronary artery
| -
43
Prognosis for PS
- Depends on severity of disease
44
Prognosis for mild to moderate PS
- May live normal lives
45
Prognosis for severe PS without treatment
- 3 years
46
Prognosis for severe PS with treatment
- Depends on post-balloon gradient
47
What can worsen the prognosis for severe PS?
- Congestive heart failure
- Arrhythmias (sudden death!)
- Concurrent congenital heart diseases
48
What happens in subaortic stenosis?
- The valve is normal, but there is a narrowing below it
49
Who gets subaortic stenosis?
- Golden retrievers, large breeds, Newfoundlands, Rottweilers, Boxers, German Shepherd dogs
50
Point of maximal intensity, timing, and quality of SAS murmur?
- Left heart base
- Systolic
- Ejection quality murmur
51
Radiation murmur with subaortic stenosis
- Can occur due to radiation to the carotid arteries
| - Listen to the thoracic inlet
52
What are your top two differentials for a left heart base murmur?
- Sounds similar to pulmonic stenosis
| - Differentiate by looking at the breed and exam findings
53
What additional murmur can occur with SAS?
- Aortic regurgitation
54
Aortic regurgitation murmur PM, quality, and timing?
- Left heart base
- Diastolic
- Decrescendo murmur
55
Femoral pulse quality with SAS
- Normal to weak and late
56
Jugular distensions or pulses with SAS
- SHould be none
57
Arrythmias with SAS
- Pulse deficits
| - Definitely possible
58
Radiographic findings with SAS
- Left auricular bulge
- Thoracic aorta has a bulge
- Bulge in the left atrium
- Backpack in left atrium on the lateral view
59
What type of hypertrophy occurs with SAS?
- Concentric hypertrophy
60
Echocardiogram findings with SAS
- Mushroom
- Interventricular septum will be thickened
- Left atrium narrower
- Dilation in the region below the aortic valve
- Blood flow will be really fast below the valve
61
How to determine severity of the subaortic stenosis?
- Again, has to do with the modified Bernoulli equation
- ∆P = 4v^2
- Aortic flow = 5 m/s
62
Normal aortic pressures
- Systole: 120
| Diastole: 80
63
Normal left ventricular pressures
Systole: 120
Diastole: 6
64
Ao velocity and LV-Ao gradient for mild disease
Ao velocity: 2.5-3.5 m/s
LV-Ao gradient: 30-50 mmHg
65
Ao velocity and LV-Ao gradient for moderate disease
Ao velocity: 3.5-4.5 m/s
LV-Ao gradient: 50-80 mmHg
66
Ao velocity and LV-Ao gradient for severe disease
Ao velocity: >4.5 m/s
LV-Ao gradient: >80 mmHg
67
Treatment for SAS: Surgical
- Not effective
| - Fibromuscular ridge below the valve rather than a problem with the valve itself
68
Medical management of SAS
- Treat diastolic dysfunction
- Treat arrhythmias if present****
- Treat left-sided CHF if present
69
How to treat diastolic dysfunction?
- Beta-blockers
70
What function do beta-blockers have for SAS treatment?
- Slows HR
- Promotes LV filling and perfusion
- Decrease contraction against an obstruction
71
How to treat left sided heart failure if present in SAS?
- Furosemide
| - ACE inhibitors
72
What are animals with SAS at increased risk for?
- Endocarditis
73
What should you do for patients with SAS considering the disease they are at increased risk for?
- Aggressive treatment of infections
| - Perioperative antibiotics for procedures that cause bacteremia
74
Prognosis for mild SAS
- Probably live a normal life
75
Prognosis for moderate to severe SAS
- ~2-4 years
76
What will worsen prognosis of moderate to severe SAS?
- CHF
- Concurrent congenital heart diseases
- Endocarditis
- Arrhythmias - SUDDEN DEATH!
77
What can occur because of the concentric hypertrophy with SAS?
- Ischemic injury
- Oxygen starved heart
- Can get VPCs, Ventricular tachycardia, and SYNCOPE or sudden death
