Canine Cardiac Dz

What is Frank-Sarling's law?

A short term adaptive response - Increased preload to help push more blood out

What is a neurohormonal response?

A short term adaptive response

-NE, RAAS system - to increase peripheral BP/ vasoconstriction

What is myocardial remolding going to do?

Reduces wall stress by increasing cardiac muscle

How is RAAS going to be a long term maladaptive response?

Na+ retention will cause pulmonary congestion

How will increased vasoconstriction by RAAS and the SNS cause a long term maladaptive response?

Increases the after load - heart now has to work harder to push blood out

How does SNS stimulation cause a long term maladaptive response?

Increases energy use

How does Hypertrophy cause a long term maladaptive response?

Cardiac cells outgrow blood supply and leads to death of the cells

What therapy do we use for increased Na+ retention?

Diuretics - furosemide/ lasix

What therapy do we use for increased vasoconstriction?

Vasodilators

What therapy do we use for increased Activation of RAAS?

ACE inhibitors - Benazipril/ enalapril

What therapy do we use for poor contractility?

Inotropic agents - pimobendan

What therapy do we use for NE tox?

Beta-blockers - not as helpful in vetmed

What two therapies is there no evidence for helping a subclinical B2 animal?

ACE-inhibitors

Spironolactone

What are some criteria that would qualify a dog with stage B2 DVD to start Pimobendan?

LA/Ao ratio aboce 1.6

Elevated VHS (above 10.5)

LVIDdN above 1.7

Murmur intensity above 3/6 systolic

What do ANP/BNP measure?

Atrial stretch - try to find subclinical heart dz

What affect does BNP have on the body?

Natriuretic

Diuretic

Vasoactive effects

What is the biologically inactive for of BNP?

NT-BNP - longer 1/2 life

How can BNP be used clinically?

Help Dif between resp or CHF

Ancillary test - not stand alone

Monitoring therapeutic responses

What aquired heart dz are you most likely to see in a poodle, chihuahua or a bichon?

DVD

What breed are you most likely to see congenital L-R PDA?

Small breeds

What breeds will you mostlikey see Pulmonary stenosis, or Subvalvular aortic stenosis?

Large or small breeds

What breeds are you most likely to see a Tricuspid valve dysplasia?

Large breed -labs

What aquired heart condition would you suspect in bulldogs, retrievers or newfoundlands?

DVD or DCM

What lungs sounds would prompt you to take a radiograph in a heart pt?

Crackles

Wheezes

Bronchial sounds

Pleural friction rub

Do all cardiac pts in congestive heart failure have lung sounds?

No - radiograph anything suspicious based on other clinical signs

What is the MOA of Pimobendan?

Phosphodiesterase inhibitor 3

-inodilator

Calcium sensitization

What does the Phosphodiesterase inhibitor aspect of pimobendan do?

Prevents Cyclic AMP breakdown increasing camp to activate protein kinase which has contractility and vasodilation properties

How is Pimobendan different from other calcium sensitization drugs?

Sensitizes contractile apparatus TnC resulting in less arrhythmias b/c it is not increasing intracellular calcium like other drugs do

What was the outcome of the Quest trial?

Dogs with DVD had an increased survival time on Vetmedin

What was the outcome of the Protect study?

Increased survival time of preclinical DCM in dobermans

Why was the outcome of the Epic trial?

DVD stage B2 dogs benefited from taking Pimobendan and were less likely to get CHF for longer

What is the MOA of Enalapril?

Competitive antagonist for Angiotensin converting enzyme (ACE) so Angiotensin 1 cannot be converted to angiotensin 2

How does Enalipril affect the cardiac system?

Decreases peripheral resistance - decreases BP

Which ACE inhibitor is preferred due to less renal clearance?

Benazepril

what trial might suggest that ACE inhibitors might not have a big effect on survival time of stage C DVD dogs?

The valve trial

What is the MOA of Furosemide?

Loop diuretic - Inhibits Na-K-2CL - decrease Na and Cl absorption and increases K loss

How does Furosemide impact the cardiac system?

Reduces Pre and after loads

What does spironolactone do for the cardiac system

Reduces fibrosis caused by Myxomatous mitral valve dz

What two drugs is cardalis composed of?

Benazepril and spironlactone - combo drug for easier admin

What stage do we use cardalis in?

Stage C

Name two surgical tx for the mitral valve?

Mitral valve repair bypass

Transcatheter edge to edge mitral valve repair

What is diltazem?

A negative inotropic drug that blocks Ca++ channels to convert arrythmias (a-fib)

What dog Breeds are at risk of nutritional DCM with grain free diets?

Golden retrievers

Boxers

American cocker spaniels

What is Cor pulmonale

abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels.