Cardiovascular Disease of Dogs and Cats

What way do the arteries flow? What happens to the blood carried to the lungs

arteries flow away from the heart (Arteries= Away)

Blood carried to lungs to be oxygenated

What way do veins flow? what happens to the blood?

veins flow towards the heart

oxygenated blood throughout back to the heart to go out to the rest of the body

Filling of the ventricle

Diastole

Contraction of ventricle

systole

how many directions does blood flow

one

What is A

Cranial

What is B

caudal

What is C

Base

What is D

Apex

What is a normal heart sound

“Lub-Dub”

What creates the sound of the heart? where is it best heard

The valves opening and closing within the heart. best heard at apical impulse which can be felt on the left side of the thorax (around 4th-6th intercostal space. always listen to both sides of the chest to fully assess the heart

What are the 3 major cardiac valves auscultated on the left

“PAM lives on the left”

P=pulmonic valve

A=aortic valve

M=mitral valve

What is the major cardiac valve auscultated on the right

tricuspid valve

What are the most common abnormal heart sounds, what do they indicate

heart murmurs is most common

indicates underlying heart disease

Are all heart murmurs bad? how can you tell the difference between ok and bad heart murmurs?

No, cats can have functional heart murmurs caused by stress

can be differentiated with pro-BNP test

What do heart murmurs mean and what sound does it make

Turbulent blood flow in which blood is moving multiple directions which the flow causes vibrations that are heard- make the “whoosh’ sound

How can heart murmurs be described and where are they best heard

based on location, timing, and loudness

best heard at point of maximal intensity (PMI)

What do heart murmurs grades describe

loudness of heart murmur, does not correlate with severity of disease

Mitral valve degeneration (MVD)

most common cardiac disease

degenerative disturbance of the connective tissue of the mitral valve leading to heart disease

leads to mitral valve regurgitation (heart murmur) resulting in cardiac volume overload (eventually heart will not be able to keep up with the high workload and results in congestive heart failure)

prevalence increases with age

breeds affected by mitral valve degeneration

Small breeds, Old dogs

cavalier King Charles spaniels

papillons

miniature poodles

yorkies

chihauhuas

dachshunds

Clinical signs of mitral valve degeneration

left sided apical systolic murmur

± tachypnea (increased respiratory rate) or dyspnea (difficult breathing)

Diagnosis of mitral valve degeneration

auscultation

radiographs

• left atrial enlargement

• cardiomegaly/ increased vertebral heart score (VHS)

echocardiogram

• left atrial and ventricular size increases

treatment of mitral valve degeneration

not indicated for less severe disease

• usually monitor with chest radiographs every 6 months

pimobendan (vetmedin)

• positive ionotrope

• helps heart pump more efficiently

• reduces the rate of change the heart size will increase

monitor for signs of left sided congestive heart failure (CHF)

Dilated cardiomyopathy (DCM)

heart disease in which there is impaired, weakened systolic function of one or both ventricles

causes cardiac enlargement and possible CHF, arrhythmias or both

has been associated with certain diets

what diets has dilated cardiomyopathy been associated with

dogs-grain free

cats- taurine deficiency (before 1987)

who does dilated cardiomyopathy most impact

dogs but can also affect cats

• adult onset disease:4-10 years old

• males>females

breeds affected

• dobermans

• Irish wolfhound

• great dane

  • typically bigger dogs

Clinical signs for dilated cardiomyopathy

may be without clinical signs

cardiac arrhythmias

syncope

• temporary loss of consciousness due to low blood pressure (think fainting goats)

soft grade I-III systolic left and/or right apical murmur

± CHF signs

Diagnosis of dilated cardiomyopathy

suspected based on predisposed breeds with heart murmur or arrhythmias

radiographs

• cardiomegaly

• enlarged atriums

electrocardiogram (ECG)

• sinus tachycardia or ventricular tachycardia

echocardiogram

• ventricular and atrial dilation

  • reduced myocardial systolic function

treatment dilated cardiomyopathy

antiarrhythmics

• digoxin

pimobendan (vetmedin)

ACE inhibitors

• lower blood pressure

Hypertrophic cardiomyopathy (HCM)

Heart disease characterized by increased ventricular wall thickness

• commonly left ventricle

results in altered contractions and relaxation as it pumps blood

common heart disease of older cats

What does hypertrophic cardiomyopathy often increase

often increases risk of thromboembolism

• feline arteriothrombembolism (FATE)

• saddle thrombus causing cats to be unable to use back legs

clinical signs of hypertrophic cardiomyopathy (HCM)

often none, incidentally found on physical exam

systolic murmur

arrhythmias

± CHF signs

Diagnosis hypertrophic cardiomyopathy

Pro-BNP

• assess for heart muscle damage

echocardiogram

• increased inter ventricular septum and/or left ventricular wall thickness

• ± left atrial enlargement

ECG

• possible ventricular premature complexes (VPCs)

Radiographs

• cardiomegaly

Treatment for hypertrophic cardiomyopathy (HCM)

ACE inhibitors

Clopidogrel

• platelet aggregation inhibitor

• decreases risk of clot formation

• Don’t poke jugular

monitor for signs of CHF

patent ductus arteriosus (PDA)

arterial shunt between aorta and pulmonary artery that is present in fetuses but should constrict and close 24 hrs after birth

most common congenital heart defect of dogs

Who is patent ductus arteriosus (PDA) commonly seen with

affects young dogs

breeds:

• maltese

• pomeranian

• shetland sheepdog

• collie

• irish setter

clinical signs patent ductus arteriosus

often found incidentally

continuous heart murmur

exercise intolerance

failure to thrive

±signs of CHF

Diagnosis of patent ductus arteriosus

radiographs

• enlarged aorta

• enlarged left side of the heart

echocardiogram

• visualize patent ductus

patent ductus arteriosus treatment

surgery

• PDA closure with ductal occluder

  • vessel ligation with thoracotomy

Congestive heart failure

sudden onset of clinical signs associated with pulmonary edema or cavitary effusions (fluid retention) due to heart disease

occurs because the pressure within the veins and capillaries draining into the diseased side of the heart increase to the point where the vessels leak

right-sided CHF

ascites(abnormal accumulation of excess fluid within the peritoneal cavity)

pleural effusion

left sided CHF

pulmonary edema

Congestive heart failure clinical signs

tachypnea

dyspnea

cough (esp dog)

pulmonary crackles

decreased breath sounds

exercise intolerance

restlessness

heart murmurs

diagnosis of congestive heart failure

radiographs

• right sided

  • decreased serosal detail

  • pleural effusion

• left sided

  • pulmonary edema in perihilar region

  • left atrial enlargement

treatment for congestive heart failure

furosemide

• diuretic to treat fluid retention

oxygen therapy

ACE inhibitors