AV Valve Disease Flashcards
RULE #1 of the heart
Arteries flow away from the heart,
Veins throw away towards the heart
RULE #2 of the heart
The heart is a muscle. More pressure on the heart makes it bigger.
RULE #3 of the heart
The heart has 3 main functions:
- Conduct electricity to stimulate contraction
- Systole
- Diastole
RULE #4 of the heart
water is LAZY! It flows from high pressure to low pressure
RULE #5 of the heart
BP = CO x SVR
CO = SV x HR
SV depends on Preload, Afterload, Contractility
RULE #6 of the heart
The heart has limited responses to disease.
- Systolic dysfunction, Volume overload ECCENTRIC HYPERTROPHY
- Diastolic dysfunction, Pressure overload CONCENTRIC HYPERTROPHY
systolic dysfunction means:
failure to eject all of the blood from the ventricle
Mitral Regurgitation PMI: ? Timing: ? Quality: ? Femoral pulse quality: ?
PMI: Left Apex
Timing: systole
Quality: regurgitant/plateau/band/flat
Femoral pulse quality: can be weak
2 types/causes of Primary Systolic Dysfunction?
Dilated Cardiomyopathy (DCM) Arrhythmic Right Ventricular Cardiomyopathy (ARVC)
Processes/conditions that are causes of Secondary Systolic dysfunction? (5)
Toxin/Drug Dietary deficiency Tachycardia-induced cardiomyopathy Hypothyroidism Inflammation (leads to myocarditis)
Effects of Thyroid hormones on the heart:
indirect effects?
direct effects?
Indirect effects: increase metabolic rate, thus increasing the oxygen demand of tissues (including the myocardium itself!)
direct effects: + intropy, + chronotropy
Arrhythmias that occur with Tachycardia-induced cardiomyopathy? (2)
supraventricular tachycardia, atrial fibrillation
Treatment for tachycardia-induced cardiomyopathy?
Stop the tachycardia! Antiarrhythmic meds: Beta-blocker, sotalol, diltiazem, digoxin.
Dietary deficiencies that causes systolic dysfunction?
Taurine deficiency, L-carnitine deficiency.
Cats and cocker spaniels are susceptible to ____ deficiency.
taurine
treatment for taurine deficiency
Treat the CHF: furosemide, pimobendan, ACE inhibitors.
Give Taurine: Cat 250 mg/kg; dog 500 mg/kg
taurine deficiency causes ___ and ____
secondary systolic dysfunction and central retinal degeneratoin
who gets L-carnitine deficiency?
American Cocker Spaniel, Golden retrievers, boxers
treatment for L-carnitine deficiency
Treat CHF: furosemide, pimobendan, ACE- inhibitor,
Give L-carnitine! 50-100mg/kg PO TID
what nutritional deficiency can lead to systolic dysfunction in large animals? What is the disease called in horses/cows vs. pigs?
Selenium deficiency.
White muscle dz/ mulberry dz
chemotherapeutic agent that can cause systolic dysfunction
doxorubicin
who gets DCM?
DOBERMANS, irish wolfhounds, great danes, boxers, Cocker spaniels
Treatment for DCM
mild/no CHF: drugs not necessary, monitor
moderate/severe, no CHF: pimobendan, +/- ACE inhibitor
Fulminant DCM with CHF: furosemide, pimobendan, ACE inhibitor, +/- spironolactone, +/- antiarrhythmics
DCM -> CHF -> ? (Think RULE #1)
pulmonary edema
arrhythmogenic right ventricular cardiomyopathy (ARVC) causes ___ and can lead to _____ &_____
arrhythmias. can lead to syncope and sudden death.
histologic changes in the myocardium secondary to ARVC?
fibro-fatty replacement of myocytes
how do you diagnose ARVC?
Holter monitor for 24hr, count the number of arrhythmias.
echocardiogram
treatment for ARVC
treat CHF if present: furosemide, pimobendan, ACE inhibitors, +/- spironolactone
ARVC -> CHF -> ?
Pleural effusion
