Systolic Dysfunction Flashcards
1
Q
Rule #1 of the heart
A
- Know normal circulation and oxygenated vs deoxygenated blood
2
Q
Rule #2 of the heart
A
- Heart is a muscle
- Heart will hypertrophy if it has to work harder
3
Q
Rule #3 of the heart: What are the three main functions?
A
- ) Conduct electricity
- ) Systole (contract)
- ) Diastole (dilate)
4
Q
Rule #4 of the heart about blood flow
A
- Water is LAZY!
- Flows from high to low pressure
5
Q
Systemic venous pressure value
A
- 5 mmHg
6
Q
Right atrial pressure
A
- 5 mm Hg
7
Q
Right ventricular pressure
A
- 5 mmHg in diastole
- 20 mmHg in systole
8
Q
Pulmonary artery pressure
A
- 8 mmHg in diastole
- 20 mmHg in systole
9
Q
Pulmonary circulation pressure
A
- 6 mmHg
10
Q
Pulmonary vein pressure
A
- 6 mmHg
11
Q
Left atrial pressure
A
- 6 mmhg
12
Q
Left ventricular pressure
A
- 6 mmHg in diastole
120 mmHg in systole
13
Q
Why is the left ventricle so high pressure during systole?
A
- Has to pump against gravity
14
Q
Aortic pressure
A
- 80 mmHg diastole
- 120 mmHg systole
15
Q
What is the calculation for Blood pressure? Cardiac output?
A
- BP = CO * Systemic vascular resistance
- Cardiac output = Stroke volume * heart rate
16
Q
What three things impact stroke volume?
A
- Preload
- Afterload
- Contractility
17
Q
What are the two morphologic responses to disease for the heart?
A
- Concentric hypertrophy
- Eccentric hypertrophy
18
Q
What diseases lead to concentric hypertrophy?
A
- Diastolic dysfunction
- Pressure overload
19
Q
What diseases lead to eccentric hypertrophy?
A
- Systolic dysfunction
- Volume overload
20
Q
What diseases in the heart do not usually lead to hypertrophy?
A
- Arrhythmias
21
Q
What happens during concentric hypertrophy?
A
- Heart muscle becomes too thick
- Lumen is smaller, and walls get thicker
22
Q
What happens during eccentric hypertrophy?
A
- Walls stay the same, but the lumen gets bigger
- Systolic dysfunction occurs first, and then you get eccentric hypertrophy secondary to that
23
Q
Systolic dysfunction and volume overload
A
- Not as much blood leaving the heart
- Next time you go into diastole, it’s filled more already
- Volume overload secondary to systolic dysfunction
24
Q
What is point of maximal intensity of systolic dysfunction murmur?
A
- on left side below costochondral junction (mitral valve)
- Left apical murmur
25
What is timing of systolic dysfunction murmur?
- Systole
26
What is quality of systolic dysfunction murmur?
- Regurgitant
27
Femoral pulses for systolic dysfunction quality
- Potentially weak
| - May have pulse deficits too if arrhythmias
28
Primary causes of systolic dysfunction
1. Dilated cardiomyopathy
| 2. Arrhythmogenic Right Ventricular Cardiomyopathy
29
Secondary causes of systolic dysfunction
- Toxin/drug
- Dietary deficiency
- Tachycardia-induced cardiomyopathy
- Hypothyroidism
- Inflammation
30
What non-infectious diseases can lead to myocarditis and secondary systolic dysfunction?
- Trauma (HBC)
- Heat stroke
- Systemic inflammatory disorders (septicemia, immune-mediated diseases)
31
What infectious diseases can lead to myocarditis and secondary systolic dysfunction?
- Viral (Parvo, distemper)
- Bacterial (Bartonella, Borrelia)
- Protozoal (Trypanosoma or Chagas; Toxoplasma)
32
Treatment for myocarditis and secondary systolic dysfunction secondary to systemic inflammation?
- Treat underlying disease
33
Prognosis for myocarditis and secondary systolic dysfunction secondary to systemic inflammation?
- Depends on underlying disease
| - Heat stroke is okay if you don't have MODS
34
How can hypothyroidism lead to systolic dysfunction?
- Dysfunction of Hypothalamic-pituitary-thyroid axis (see notes)
- Decreased production of T4 and T3
35
Etiology of hypothyroidism
- Thyroiditis
- Idiopathic atrophy
- Bilateral neoplasia
36
Indirect effects of thyroid hormones on the heart
- Increase metabolic rate
| - Think about what hypothyroidism would do
37
Direct effects of thyroid hormones on the heart
- + Inotropy and + chronotropy
| - Think about what hypothyroidism
38
Ultimate impact of hypothyroidism on the heart due to direct and indirect effects
- Decreased contractility and decreased heart rate
39
Treatment for hypothyroid induced systolic dysfunction
- Treat the hypothyroidism
| - Levothyroxine
40
Prognosis for hypothyroid induced systolic dysfunction
- Good with treatment
| - RARELY a cause of myocardial failure
41
Treatment for tachycardia-induced cardiomyopathy and systolic dysfunction
- Stop the tachycardia
| - Anti-arrhythmic medications: Digoxin, Diltiazem, Beta-blockers, Sotalol
42
Prognosis for tachycardia-induced cardiomyopathy and systolic dysfunction
- Guarded to good
| - Potentially curable
43
Function of taurine
- Amino acid
- Diverse function
- Concentrates in the heart and retina
- Essential amino acid in cats!!!
44
What impact can taurine deficiency have on an animal?
- Central retinal degeneration
| - Cardiac systole dysfunction
45
Who gets taurine deficiency systolic dysfunction?
- Cats
- American Cocker Spaniels
- MAY be a link with grain free and high legume diets
46
Diagnosing systolic dysfunction secondary to taurine deficiency
- Diet history
| - Taurine blood levels
47
Treatment for systolic dysfunction secondary to taurine deficiency
- Treat CHF: Furosemide, pimobendan, ACE inhibitor
| - Taurine supplementation
48
Prognosis for systolic dysfunction secondary to taurine deficiency
- Guarded to good
| - Potentially curable
49
L-carnitine role
- Fatty acid metabolism and energy production
| - Concentrated in skeletal and cardiac muscles
50
What happens with L-carnitine deficiency potentially?
- Cardiac systolic dysfunction
51
Who gets L-carnitine deficiency?
- American Cocker Spaniels
- Golden Retrievers
- Boxers
52
Diagnosis of systolic dysfunction secondary to L-carnitine deficiency?
- Diet history
- Myocardial levels (myocardial biopsy)
- Response to supplementation
53
Treatment for systolic dysfunction secondary to L-carnitine deficiency?
- Treat CHF: Furosemide, pimobendan, ACE-inhibitor
| - L-carnitine supplementation
54
Prognosis for systolic dysfunction secondary to L-carnitine deficiency?
- Guarded to good
| - May be curable
55
What nutritional deficiency can lead to systolic dysfunction in large animals or food animals?
- Selenium and Vitamin E
56
What is Vitamin E/Selenium deficiency called in horses/cows vs pigs?
- White muscle disease
57
Which drug is most commonly implicated for causing systolic dysfunction?
- Doxorubicin (Adriamycin)
| - Chemotherapeutic agent
58
Doxorubicin cardiotoxicity
- Dose dependent (will happen with a higher dose)
- Arrhythmias
- Severe systolic dysfunction
59
Treatment for doxorubicin induced systolic dysfunction
- No direct treatment
60
Prognosis for for doxorubicin induced systolic dysfunction
- Poor
| - Severe systolic dysfunction is irreversible
61
Primary dilated cardiomyopathy how to diagnose?
- Diagnosis of exclusion
| - Rule out toxin/drug, dietary deficiency, tachycardia, hypothyroidism, and inflammation
62
Etiology of primary DCM
- Idiopathic
| - Suspected genetic disorder
63
Who gets DCM: Age?
- Adults
64
Who gets DCM: Breed?
- Two-handed dogs!
- Irish Wolfhounds, Great Danes, Boxers
- American Cocker Spaniels
- Dobermans!
65
Treatment for Stage B1 (mild) DCM
- No treatment
| - Monitor
66
Treatment for Stage B2 (moderate/severe) DCM
- Pimobendan
| - +/- ACE Inhibitor
67
Treatment for Stage C (post-CHF) DCM
- Furosemide
- Pimobendan
- ACE inhibitor
- +/- Spironolactone
- +/- Anti-arrhythmics
68
What happens to blood flow with DCM?
- Not enough blood going forward (systolic dysfunction)
- Most often a disease of the left side of the heart
- Blood will go back to the lungs (left sided CHF)
69
Prognosis for B1 DCM
- Year to never
| - Can take a VERY long time to get to stage C
70
Prognosis for B2 DCM
- Months to year to never depending on age at diagnosis
71
Prognosis for Stage C DCM Dobermans
- 3-6 months
| - Less with atrial fibrillation
72
Prognosis for Stage C DCM Breeds besides Dobermans
- 6-12 months
73
Monitoring for DCM
- Ideally monitor with echocardiogram
| - Ideally at least yearly, possibly more if very severe (up to 6 months)
74
Arrhythmogenic right ventricular cardiomyopathy breed
- Boxers
75
Arrhythmogenic right ventricular cardiomyopathy - which side of the heart is most often impacted?
- Right sided disease
76
Arrhythmogenic right ventricular cardiomyopathy - features of dsisease
- Arrhythmias (most often ventricular)
| - Syncope and/or sudden death
77
Etiology of Arrhythmogenic right ventricular cardiomyopathy
- Idiopathic, suspect genetic
78
Histologic characterization of Arrhythmogenic right ventricular cardiomyopathy
- Fibro-fatty replacement of myocytes
79
Pathophysiologic effects of Arrhythmogenic right ventricular cardiomyopathy
- Systolic and diastolic dysfunction
- Cannot conduct electricity as well
- Likely due to fat replacement of myoctes
80
Diagnosis of Arrhythmogenic right ventricular cardiomyopathy
- Holter monitor
| - Echocardiogram
81
Normal amount of VPCs in 24 hours for regular dogs and Boxer dogs
- <50 VPCs in 24 hours
| - Boxer should have <100 VPCs
82
Treatment for Arrhythmogenic right ventricular cardiomyopathy if just arrhythmias
- Mexiletine
| - Sotalol
83
Arrhythmogenic right ventricular cardiomyopathy Treatment if just CHF/Systolic dysfunction
- Furosemide
- Pimobendan
- ACE inhibitor
- +/- Spironolactone
84
Arrhythmogenic right ventricular cardiomyopathy Treatment if CHF and arrhythmias
- Mexiletine
- Sotalol
- Furosemide
- Pimobendan
- ACE inhibitor
- +/- spironolactone
85
Prognosis for Arrhythmogenic right ventricular cardiomyopathy if just arrhythmias
- Guarded
| - Syncope and sudden death
86
Prognosis for Arrhythmogenic right ventricular cardiomyopathy if systolic dysfunction and CHF
- Guarded
- 3-6 months
- Often will get ascites
