Congestive Heart Failure

What will happen to CO with HCM?

Decreases, heart walls get thick so the chambers get smaller

What is the equation for CO?

CO = SV x HR

What is the equation for MAP?

MAP = CO x SVR

What is the #1 heart priority?

Maintain normal system arterial pressure

What are the 3 heart priorities?

1. Maintain normal systemic arterial pressure

2. Maintain normal tissue blood flow

3. Maintain normal systemic and pulmonary capillary pressures

What valves open at the end of isovolumetric contraction?

Aortic and Pulmonic

How do hearts usually like to fail and present?

Backwards failure first

Respiratory signs and ascites

What happens later in the heart disease process?

Forward failure when very bad

Low cardiac output

Exercise intolerance, syncope, pre-renal azotemia, cyanosis

What happens to the heart when there is volume overload?

Larger chamber and thinner walls

What happens to the heart when there is pressure overload?

Heart has to fight against a higher pressure —> muscle thickens, smaller chambers

What is an example of a pump failure?

DCM, heart cannot beat

What are some general appearances of an animal with CHF?

Anxious/restless

Open mouth breathing

Orthopnea and elbows abducted

Dyspnea

Tachypnea

Hyperpnea

If you see an animal with dyspnea in CHF what would you be thinking?

Pulmonary edema present, cannot tap it, need to do thoracic xrays

If you see an animal with tachypnea —> short and shallow breaths, what are you thinking?

Restrictive breathing pattern —> THORACOCENTESIS!!

In what animals can you see jugular pulse changes?

Mainly large animals, good monitoring indicator of heart disease

Due to increased venous pressures —> Right sided heart failure

What is an important thing to know about your patient in relation to heart disease?

History!

Vaccination status, travel hx, diet, etc

What clinical signs of heart disease would the owners see?

Syncope, exercise intolerance, cough, dyspnea, abdominal distention, cyanosis

What clinical signs of heart disease would the veterinarians see?

Pulse abnormalities, murmurs, arrhythmias, jugular pulses

What diseases might cause an animal to cough?

Mainstem bronchi compression —> enlarged heart

CHF

Resp + parasitic diseases

Non cardiac diseases

What is this?

Mainstem bronchi compression

What is this?

CHF —> alveoli have fluid in them

What are the clinical signs of syncope?

***Exertion or excitement

***Rear limb weakness

Hypoxia

Fainting

Sudden collapse

Lateral recumbency

Micturition

Vocalization

Stiffening of the forelimbs and opisthotonus

What clinical signs are generally not seen with syncope and align more with seizures?

Tonic/clonic motion

Facial fits

Defecation

Aura

Post-ictal dementia

Neurologic deficits

What are the important aspects of a physical exam for an animal with suspected CHF?

Pay close attention to MM and CRT

Abdominal palpation —> fluid wave

Jugular pulses

Palpate the chest —> precordium

Arterial pulse abnormalities

Palpate thyroid

Retinal exam —> hemorrhage and detachment (hypertension)

What is the equation for determining pulse pressure?

Psystolic - Pdiastolic

What are the different heart sounds categories?

Normal, abnormal, extra, murmers

What are the heart rate and rhythm categories?

Normal, tachycardias, bradycardias, gallops, arrhythmias

What are some abnormal lung sounds you can hear?

Crackles, wheezes, rales, decreased

What’s going on here?

Pulmonary edema, caused by canine or feline left sided backwards heart failure

Would hear crackles, dyspneic, NO thoracocentesis

What’s going on here?

Pleural effusion (more common in cats)

Either left or right sided backwards heart failure

Tachypneic, thoracocentesis!!

What’s going on here?

Hepatic congestion/ascites

Right sided backwards heart failure (any species)

What reason could produce a holosystolic or pansystolic regurgitation or plateau murmer? Sound is flat

Mitral/tricuspid insufficiency

VSD

What reasons could produce a crescendo-decrescendo ejection murmer?

Aortic/pulmonic stenosis

What reasons could produce a diastolic decrescendo?

Rare and quiet

What reasons would cause a continuous (machinery) murmer?

PDA —> tiny puppies common

Murmur grade when it is very soft, intermittent

1

Murmur grade when it is a soft murmur, can hear consistently in a quiet room

2

Murmur grade when it is a moderate intensity mrumur

3

Murmur grade when it is a loud murmur

4

Murmur grade when it is a loud murmur with a precordial thrill

5

Murmur grade when it is a very loud murmur, can hear with stethoscope off of the body wall

6

What is an arrhythmia?

Structural or pathophysiologic remodeling

Conduction abnormalities

Automaticity errors

What are potential causes of arrhythmias?

Genetic factors

environmental stresses

ischemia

modulated by neuroendocrine factors

some expected in athletes —> horses

What are the basics of a cardiac workup?

Thoracic radiographs

Cardiac ultrasound/echo

Arterial BP

EKG

What is the first line cardiac workup in large animals?

Chemistry bloodwork —> lots of electrolyte changes

What does a doppler evaluate?

Systolic pressure

What organs are at risk with an elevated BP?

Brain, kidneys, heart, eyes, vessels

Evidence of target organ damage in the kidney?

Progression of CKD

Evaluate creatinine, proteinuria, GFR

Evidence of target organ damage in the eyes?

Retinopathy

Acute blindness, detachment, vessel tortuosity, perivascular edema, papilledema, hyphema, secondary glaucoma

Evidence of target organ damage in the brain?

Encephalopathy or stroke

Localize to CNS, neuro exam, MRI

Evidence of target organ damage in the heart and vessels?

Left ventricular hypertrophy or cardiac failure

Heart size, rhythm, murmurs, hemorrhage

Auscultation, radiography, US, EKG

What diagnostic will tell us if we have CHF?

Thoracic radiographs!!!!

What can we see on thoracic radiographs?

Cardiomegaly —> chamber enlargement

Vascular abnormalities

CHF

Lungs

Pleural space

What is the VHS?

Vertebral heart score

VHS for normal dogs 8.7-10.7

What is the VLAS?

Vertebral left atrial size

Ventral central carina to the caudal border of the LA

Should be <2.3 vertebral bodies

What is the VLAS used for?

MMVD in dogs

Why do we see LA enlargement in dogs with MMVD?

Insufficiency enlarges the atria due to increased fluid flowing back into the atria from the ventricle

What can we see here?

Cardiomegaly

What can we see here?

Pleural space

If you have a dog in respiratory distress with B-lines and LA enlargement what are you doing?

Treat for CHF

If you have a dog in respiratory distress with ascites and RA enlargement what are you doing?

Treat for CHF

If you have a dog with ascites and RV hypertrophy what are you thinking?

Pulmonary hypertension

If you have a cat in respiratory distress that has B-lines, LA enlargement, pleural/pericardial effusion what are you doing?

Treat for CHF

What do the B-lines represent?

Wet lungs

What will an EKG help us assess?

PQRST complexes

evaluation of wave forms and patterns

rhythm disturbances

Measurements may help with disease estimation

What are the 5 questions you must ask yourself when evaluating an EKG?

1. rate

2. rhythm

3. P in front of every QRS? QRS after every P?

4. Morphology

   1. Measurements

What is the benefit of doing an echo?

Non-invasive imaging of the heart chambers, vessels, and valves

Measurements

Doppler —> evaluates flow and pressure and valves

What are some serum test cardiac markers?

NT-pro-BNP and Cardiac troponins

What does the NT-pro-BNP test assess?

Ventricular stretch

CATS better

may help you rule OUT cardiac disease in a dog

What does the cardiac troponins test assess?

High sensitivity tropnonin I

Myocardial damage

Monitor over time

What would you use cardiac catheterization and cardiac CT for?

Diagnostic: Complicated congenital abnormalities, evaluating pressures

Therapeutic: Pre-surgical/ballooning, pulmonic stenosis in bulldogs

Research: cardiac therapeutics

What are the basic concepts to remember about cardiac disease?

Bad hearts get big just in different ways

You can pace a heart to death, Increased rate = sooner death

Hearts like to fail BACKWARDS

What happens to the heart when there is increased PRESSURE?

Concentric hypertrophy

Fibers added in parallel

ex: HCM

What happens to the heart when there is increased volume?

Eccentric hypertrophy

Fibers added in series

Ex: DCM

What are the neurohormonal activation compensatory mechanisms?

Increased sympathetic tone

Decreased parasympathetic tone

Activation of RAAS and ADH/VP

What are the different anatomic diagnosis of cardiac disease that can all progress to CHF?

Pericardial, myocardial, valvular, endocardial, vascular, electrical

What are the physiological diagnosis for cardiac disease?

CHF, shock, hypotension, syncope, arrhythmia, shunting, valvular disease (regurgitation and stenosis), hypertension, myocardial failure (systolic or diastolic failure)

What is a systolic failure?

Hard time for the heart to squeeze —> need positive inotropic drug

What is a diastolic failure?

Hard time for the heart to relax —> need increased lucitropy —> B-blocker

What are the general therapeutics for CHF?

Controlling edema and effusions, opposing the effects of neuroendocrine activation

Improving cardiac output

Reduce cardiac workload

Supporting myocardial function

managing arrhythmias

Frequent reassessment****

What emergency therapy option is good for low stress?

Oxygen

What emergency therapy option would you use if a restrictive breathing pattern is observed?

Thoracocentesis

What drug would you use to decrease preload?

Diuretic drug —> Furosemide (2 mg/kg IV)

What drugs would you use if you need an anxiolytic/sedative?

Opioids ± ace

Diazepam

What drugs would you use if you needed volume redistribution?

Venodilators —> Nitroglycerin ointment, nitroprusside ICU

What drugs would you use to decrease afterload?

Vasodilators —> ARBs, ACE inhibitors (enalapril, benazapril), Amlodipine (antihypertensive), hydralazine

What drugs would you use to increase contractility if myocardial failure?

PIMOBENDAN!!!!

Dobutamine —monitor ECG

InAmrinone

What drugs would you use for HCM in cats?

Calcium channel blocker —> Diltiazem

B-blockers

What chronic therapies need to be implemented for a patient with CHF?

Regular mild to moderate activity —> no strenuous or burst exercise

Diet and weight management —> WSAVA approved diets

Diuretics —> Furosemide, Spironolactone

What must be done 3 days after putting a patient on furosemide?

Recheck!! Renal parameters must be checked

What is the purpose of adding spironolactone to therapy?

Potassium sparing drug, aldosterone antagonist

What positive inotropic drug is used for chronic therapy?

Pimobendan!! —> phosphodiesterase III inhibitor, ionodilator

Digoxin —> less commonly used, anti- and pro-arrhythmic

What would you use ACE inhibitors for?

Enalapril and benazapril

Mainly for neuroendocrine modulating effects

Arterial dilator

Caution in renal failure

What are examples of vasodilators?

Angiotensin receptor blockers

Hydralazine —> arterial effects

Amlodipine —> calcium channel blocker

Where does amlodipine work?

Periphery

Anti-hypertensive, hits receptors in the vasculature —> great for primary hypertension

Where does diltiazem work?

Centrally hits receptors in the AV node

Slows conduction at the AV node —> great for supraventricular tachycardia

When would you use B-blockers?

HCM/HOCM

Arrhythmias

Afib

ARVC/Boxers

What is a good calcium channel blocker?

Diltiazem —> great for cats, tells AV node to chill out