A clinical evaluation of Heart Failure in animals, under veterinary clinical cardiology.

1. HEART FAILURE
CLINICAL EVALUATION
OMKAR SUNIL PHADTARE
V/15/191
FOURTH YEAR (2018-19)
CLINICAL CARDIOLOGY TRACKING
PROGRAMME
(DEPT. OF VETERINARY PHYSIOLOGY)

2. DEFINITION
• 2013 ACC/ AHA DEFNITION-
– Heart Failure is defined as “ a complex clinical
syndrome that results from any structural or
functional impairment of ventricular
filling(diastole) or ejection of blood (systole). ”

3. CLASSIFICATION (BY DEFINITION)
• SYSTOLIC HEART FAILURE
– Characterized by reduced ejection
fraction and enlarged ventricle size.
– Clinically present with left
ventricular
failure and marked cardiomegaly.
• DIASTOLIC HEART FAILURE
– Characterized by increased
resistance to filling due to increased
filling pressures.
– Clinically present with pulmonary
congestion with normal or slightly
enlarged ventricles .

4. Congestive Heart Failure
It is complex clinical syndrome
characterized by abnormalities of
left ventricular function and
neurohormonal regulation, which are
accompanied by effort intolerance,
fluid retention, and reduced
longevity.

5. BASEDON
Amountof cardiac
output Positionof heartfailure
Congestiveheartfailure
Highcardiac
output
failure
Lowcardiac
output
failure
Left side
cardiac
failure
Rightside
Cardiac
failure
Classification of CHF
5

6. Based on Amount of Cardiac Output
Low cardiac output failure High cardiac output failure
Most frequent Very rarely
Metabolic demands of the body organs for
oxygen are normal and within limits
Metabolic demands of the body for
oxygen
is very high
Myocardial fraction is prominent factor
leading to the failure of systolic & diastolic
function of the ventricles, ultimetly results
in low cardiac output failure
Hyperthyroidism, anaemia, arteriovenous
shunt causes high cardiac output failure.

7. Based on Position of Heart Failure
LEFT -SIDED CHF
Most commonly results in pulmonary
edema (fluid accumulation within the
lungs).
Common clinical signs include:
i. Increased respiratory rate or difficulty
breathing
ii. Coughing
iii. Exercise intolerance
iv. Fainting

8. Based on Position of Heart Failure
RIGHT-SIDED CHF
Most commonly results in ascites (fluid
accumulation within the abdomen) or
pleural effusion (fluid accumulation
around the lungs).
Common clinical signs include:
i. Abdominal distention
ii. Increased respiratory rate or difficulty
breathing
iii. Exercise intolerance
iv. Fainting

9. NYHA
Class I
(Mild)
Asymptomatic; Heart disease present but no CS
Class II
(Mild)
CS present with strenuous activity; Comfortable at rest
Class III
(Moderate)
CS with routine daily activities and mild exercise;
Comfortable at rest
Class IV
(Severe)
CS severe, even at rest; Requires hospitalization

10. Etiologies
oCoronary Artery Disease (Infarction/Ischemia)
oChronic Pressure Overload (Hypertension/Valvular Heart Disease - Stenotic)
oChronic Volume Oveload (Valvular Heart Disease- Regurgitant/ Intracardiac shunting)
oNon ischemic DCM (Familial/ Infiltrative/Endocrine/ Toxic/ Inflammatory/ Peripartum/Stress)
oHypertrophic Cardiomyopathy
oRestrictive Cardiomyopathy(Amyloidosis /Sarcoidosis / Hemochromatosis)
oFibrosis / Endomyocardial Disorders / Aging
oNutritional – Beriberi
oAnemia
oHeartworm disease

11. Mechanisms
5 Mechanisms of CHF
◦ Volume overload
◦ MR, PDA
◦ Pressure overload
◦ SAH, SAS, PS
◦ Myocardial failure
◦ DCM
◦ Diastolic dysfunction
◦ HCM
◦ Arrhythmias
◦ AFib, SVT, VT

12. CHF - CV System Priorities
Priorities of the CV System
◦ Maintain normal systemic BP
◦ Maintain normal tissue blood flow
◦ Maintain normal systemic and pulmonary capillary pressures
Why does the CV system have priorities?
◦ 3 critical vascular beds in the body (brain, heart, kidneys) have high
innate resistance to blood flow
◦ ie. They need high pressures to force blood through them

13. CHF - Consequences
•CHF results in reduction of cardiac output - triggers cascades of
physiologic events to restore BP
(CV System 1st priority)
– Sympathetic stimulation of the heart
– Vasoconstriction
– Redistribution of blood flow
• SNS
• RAAS
• Vasopressin
• Vascular endothelial systems
– Na/H2O Retention
• Changes in RBF
• Aldosterone
• Vasopressin
• Inhibition of natriuretic hormones

14. CHF - Systems altered…
What’s the harm?
So, if these events are beneficial, why do we try to block them with
medications?
◦ No permanent harm if systems return to normal
◦ Chronic activation - physiologic balance shifts toward
◦ Vasoconstriction
◦ Na retention
◦ Mediators of inflammation
◦ Mediators of tissue growth
◦ Remodeling/fibrosis
-Structural and functional damage to heart muscle

15. Diagnosis
Based on clinical signs
Radiography
• X-Ray
• USG

16. Treatment Goals
#1. Reduce Congestion, Edema, Effusions
I. Reduce vascular volume (preload)
a. Diuretics – Lasix (Furosemide)
Cats - 1-3 mg/kg IM/IV q1-2hr initially
Dogs - 2-4mg/kg IM/IV q1-2hr initially
Cattle – 1-2 mg/kg IM/IV
II. Reduce venous tone (vasodilators - increase venous capacitance)
a. Pimobendan - 0.2-0.3 mg/kg PO BID
III. Invasive procedures
a. Thoracocentesis
b. Abdominoceentesis

17. Treatment Goals
#2. Improve Cardiac Output
I. Arterial vasodilators
Hyralazine
II. Balanced vasodilators
Nitroprusside - 1-10 mcg/kg/min
III. Increase Contractility
Dobutamine
Pimobendan

18. Treatment Goals
#3. Normalize HR and Rhythm
I. Stick to medications that do NOT significantly worsen cardiac function
Digoxin - 0.003-0.005 mg/kg of LBW PO BID
II. Beta-blockers are contraindicated in active CHF

19. Prognosis
Unfortunately, no drugs have proven effective in either preventing or slowing down
progression of heart disease in animals.
Should heart disease progress to CHF, the prognosis is poor with an average
survival time of 6-12 months.
However, most animals are able to be managed with medications and can enjoy a
good quality of life during that period of time.

20. References
WEBSITES
www.slideshare.net
https://www.msdvetmanual.com/circulatory-
system/heart-disease-and-heart-failure/heart-
failure#
www.google.co.in/images
BOOKS
Veterinary Medicine: A textbook of the diseases of cattle,
horses, sheep, pigs and goats.
– Peter D Constable, Kenneth William Hinchcliff, Walter
Gruenberg
ARTICLES
Congestive Heart Failure in Dogs and Cats
Mark Rishniw, BVSc, PhD, DACVIM (SA-IM), DACVIM (CA)
Date Published: 04/06/2018
PennVet
Ryan Hospital
VER 7/24/2013