Lecture 4: Canine Cardiac Disease Flashcards
What are the short term adaptive responses to heart failure
- Frank starling law- increase preload
- Neurohormonal responses: increase NE, RAAS- increase BP
- Myocardial remodeling (eccentric vs concentric hypertrophy- decrease wall stress)
what are the long term maladaptive responses to heart failure
- Na+ retention/RAAS= pulmonary congestion
- Vasoconstriction= increase after load
- SNS stimulation- increase energy use
- Hypertrophy- death of cardiac cells
what are the goals of heart failure therapy
- Diuretic for Na+ retention
- Vasodilator for vasoconstriction
- ACE inhibitor for RAAS
- Ionotropic agents for poor cotnractility
- Beta blockers for NE toxicity
what Did the epic trial show with pimobendan vs placebo
pimobendan increased survival time
what are the 4 criteria to qualify for pimobendan
- LA/Ao ratio >1.6
- Murmur >or= 3/6
- LVIDdn> or = 1.7
- VHS >10.5
what bio makers are biologically active
ANP and BNP
what activates ANP and BNP and what is result
atrial stretch activates and results in natruresis, diuresis, and vasodilation
do ANP and BNP have a short or long half life in circulation
short
what are the biologically inactive biomakers and what is there half life in circulation and what is the benefit of that
NT-ANP and NT-BNP- longer half life so better for diagnostic assays
what is the clinical utility of biomarkers
can differentiate respiratory vs CHF (elevated)
t or f: biomarkers are gold standard for dx CHF and can be used as a stand alone test
false- ancillary test, Echo still gold standard
what irregular HR is more of a problem- irregularly fast or irregularly slow and why
irregularly fast—> a-fib
what is MOA of pimobendan
phosphodiesterase III inhibitor and calcium sensitization
Prevent breakdown of cAMP—> increase PK—> increase contractility of cardiac muscles and vasodilation of vascular smooth muscle
which improves mean survival time more with DVD: pimobendan or benazepril
pimobendan
what is MOA of enalapril
prevents formation of Angiotensin II by competing with Angiotensin I for ACE
what are the cardiac effects of enalapril
decrease peripheral resistance/ blood pressure
which is preferred and why: enalapril or benazepril
benazepril- less renal clearance
what is the MOA of furosemide
inhibits NA-K-2Cl symporter in LOH—> decrease reabsorption of Na+ and Cl-, increase K+ loss
what are cardiac effects of furosemide
reduce preload and afterload
what is the side effect for furosemide
kidney effects
what is cardalis
combination therapy of benazepril and spironolactone
case ex: 10yr MN miniature schnauzer with 3 month hx of murmur, mild intermittent cough, good appetite, other PE findings WNL
Murmur: grade 4/6 plateau shaped systolic murmur with PMI over left apex, irregularly slow rhythm, enlarged VHS. Clear lungs
Based on these findings what is the dx. What is tx
Dx: DVD of mitral valve (regurgitation) Stage B2 (cough)
Tx: pimobendan and hydrocodone
case ex: 10yr MN Pomeranian, intermittent cough q3 months, progressively worse over last 24hrs, didn’t eat this AM. Other PE findings WNL
Murmur: grade 4/6 plateau shaped systolic murmur with PMI over left apex, tachycardia, pulmonary crackles
Enlarged VHS, abnormal lung fields
Based on these findings what is dx and tx
DVD mitral valve (regurgitation) stage C (tachycardia) and left sided CHF
Tx: furosemide, vetmedin, spironolactone, benazepril, omega 3- FA
case ex: 6yr MI douge de Bordeaux, reluctance to get up, appeared to be gaining weight in abdominal area
PE: weak femoral pulses, abdominal fluid ballotment, abnormal jugular pulses
Grade 2/6 plateau shaped systolic murmur with PMI over left apex, tachycardia and irregular rhythm, pulmonary crackles
Enlarged VHS, abnormal lung fields
Based on findings what is dx and tx
DCM, stage C, left and right sided CHF
ECG: a-fib
Tx: furosemide, benazepril, vetmedin, spironolactone,
A-fib: dilitazem (CCB/negative ionotropic), digoxin
