Module 7: Vascular and Myocardial Disease (C26) Flashcards
C26: Vascular control
C26: Vascular control
CO = BP/SVR
Flow (Cardiac Output) = Change in pressure/ resistance
-> CO = stroke volume x Heart Rate
Stabilize BP in the face of changing CO
Baroreceptor arcs
MAP (Mean arterial pressure) = 1/3 pulse pressure + diastolic pressure
pulse pressure = difference between systolic and diastolic pressure
(T/F) MAP > 60 mm HG = organ perfusion
True
Measurement: non-invasive (or non-direct)
Doppler is more accurate and will only read …
systolic pressure
In _________ mostly invasive measurement are used although routine clinical monitoring can be performed
Large animals
What if your blood pressure cuff is too BIG?
It will underestimate the blood pressure
Definition:
Abnormally low blood pressure
- Mean blood pressure (< 60 mm Hg)
Hypotension
Clinically
- Often measure the systolic (not mean)
- Consider hypotensive if systolic BP < 90 mm HG
- And clinically dull
Hypotension:
- Decreased Inotropy
- Decreased HR
- Severe heart failure
- Decreased Plasma volume
Decreased CO
Hypotension:
- drugs/anesthetics
- sepsis
- acidosis
Excessive vasodilation (Vascular resistance)
Treatment for Hypotension:
- decreased CO
- decreased Inotropy
Pimobendan (Vetmedin)
- Oral calcium sensitizer
- Indicated for CHF
Dobutamine CRI
- Beta-1 adrenergic receptor agonist
- Indicated for cardiogenic shock
Treatment for Hypotension:
- decreased CO
- decreased HR
- Anticholinergics (Atropine)
- Pacemaker
Treatment for Hypotension:
- decreased CO
- decreased Stroke Volume
- Severe Congestive Heart Failure NO FLUIDS
- Decreased Plasma Volume: FLUIDS!
- hemorrhage
- dehydration
- hypoadrenocorticism
Term:
is a loop diuretic (water pill) that prevents your body from absorbing too much salt. This allows the salt to instead be passed into your urine.
Lasix
- Excitement/stress, exercise, hyperthyroidism
- Typically transient (baroreceptor reflexes “auto-corrects”)
Hypertension
- Excessive Cardiac Output (CO)
- Vascular disease, hormonal imbalances, RAAS activation
Hypertension
- Increased vascular resistance
If they are hypertension, most of the time it is secondary to some other condition:
- Kidney disease
- Endocrinopathies
Drug side effects, Idiopathic (or primary or “essential”), Obesity is NOT a cause
Target Organ Damage:
Eyes
Heart (thickening of the left ventricle)
Brain (Vascular)
Kidneys (tricky)
Treatment for Hypertension:
- Reduce the likelihood and risk of target organ damage
- Gradually reduce BP over a couple of weeks
ACE-Inhibitors (ACE-I) (FIRST LINE TX IN DOGS)
- Enalapril, benazepril
Calcium channel blocker (CCB)
- Amlodipine (FIRST LINE TX IN CATS)
Combination therapy (ACE-I + CCB)
Angiotensin receptor blockers (ARB)
- Telmisartan
Hypertension: General Tx Approach
- If BP < 180 mm HG (and no TOD)
- ACE-I alone
- If BP > 180 mm Hg
- ACE-I + Amlodipine
Dogs
Hypertension: General Tx Approach
- If BP < 200 mm Hg
- Amlodipine 0.625 mg/CAT q24h
- If BP > 200 mm Hg
- Amlodipine 1.25 mg/CAT q24h + ACE-I (or other)
Cats
(T/F) Do not give an ACE-I if Dehydrated
True
Definition:
A marked increase in BP with ongoing acute organ damage (TOD)
Hypertensive Crisis
- Aggressive therapy
- Gradual reduction
You are screening for high blood pressure in an anxious 11 YO miniature poodle with degenerative mitral valve disease. You get a systolic blood pressure reading of 165 mm Hg. There is no obvious evidence of target organ damage. What should your next steps be?
Recheck the blood pressure in about 1-2 weeks in a less-stressful environment and look for target organ damage again
A 10 YO Doberman is presented to you after a collapsing episode. On presentation, the patient is in respiratory distress. You suspect the patient is in left-sided congestive heart failure. You check your blood pressure and get a systolic blood pressure reading of 70 mm Hg. What should your next step be?
Give a dose of IV Lasix and start a dobutamine CRI
A 12 YO cat is presented to you after the owner noticed a dull mentation and the cat bumping into objects at home. Upon exam, you suspect complete or partial blindness and get a systolic blood pressure reading of 200 mm Hg. What should your next steps be?
Hospitalize and start antihypertensive medications
C27: Hypertrophic Cardiomyopathy - CATS
C27: Hypertrophic Cardiomyopathy - CATS
(T/F) Cats usually do not cough with cardiac disease
True
- Heartworm
- Bronchial
CAT INFO
- Gallops and Murmurs are sensitive (murmur) and specific (gallop) of cardiac dz in cats
- Heart rate is not a good indicator of cardiac disease
- Cats tend to have *high sympathetic tone8 during PE
- Medical treatment is technically more difficult in cats
Feline Myocardial Diseases:
Primary Cardiomyopathies:
- Hypertrophic CM
- Dehydration
- Hypertension
- Acromegaly
- Hyperthyroidism
- Restrictive CM
- Dilated CM
- Dietary taurine deficiency
- Tachycardia-induced cardiomyopathy
- Arrhythmogenic RV CM
- Cardiomyopathy of non-specific phenotype
Feline Myocardial Diseases:
Secondary:
- Hyperthyroidism
- Hypertension
- Ischemia
Definition:
A primary, myocardial disease of unknown origin characterized by concentric hypertrophy (pressure overload) and diastolic dysfunction (filling) of the LV and rarely the RV
Feline HCM
- very common
- Maine coon (4-7 years), Ragdolls (early onset (6-24 mo))
- Male»_space; females
A disease of abnormal myocardial growth of (most likely) genetic origin
HCM
- Genetic abnormality
- Mutation – Impaired structure | sarcomere assembly
- Poison peptides or haploinsufficiency
- Mutation – Impaired structure | sarcomere assembly
- Left side has higher pressure
- live a long healthy life
- clinical Heterogeneity
- No signs
- Young - old age
Auscultation finding for Feline HCM:
- Systolic murmur (dynamic auscultation (raise cat up and down)
- Gallop sounds (use bell of stethoscope) = are never normal!
- Arrhythmia
- systolic click
** Abnormal in 90% **
heart murmurs also in about 50% of healthy cats
Feline HCM - Electrocardiography
- Highly variable
-> Increased R amplitude > 0.9 mV
- LV enlargement pattern
-> increased P
- Atrial enlargement pattern
Radiography Findings :
- LV elongation (LVH)
- LA enlargement
Echocardiography:
LV hypertrophy (increased diastolic thickness)
Serum NTpro-BNP:
- Useful as a confirmatory test for cats with murmurs for justification of an echocardiogram
- helpful in the workup of respiratory distress
- normal cats: < 100 pmol/L
- Cats with CHF often Increased
- Many false negative
Genetic testing;
- Only for Maine coon cats, ragdolls, and sphynx cats
LV hypertrophy:
- Systemic hypertension
- Feline Hyperthyroidism
Management:
Acute CHF, FATE - Uniform therapeutic approach
- FONST = Furosemide, Oxygen, Nitroglycerine paste (ear pinnae), Sedation, Tap (pleural effusion)
Treatment Asymptomatic or post-symptomatic cats - Tailored therapy according to key problems or Risks
cat is hypothermia and hypotension -> Cardiogenic shock ->
RUN