MATTERS OF THE HEART

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MATTERS OF THE HEART

• The heart has reasons that reason does not
  understand.
• -Jacques Benigne Bossuel

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DISEASES OF THE CARDIOVASCULAR SYSTEM
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CANINE DILATED CARDIOMYOPATHY
90 of cases occur in Doberman Pinschers and
Boxers
OTHER BREEDS INCLUDE WOLFHOUNDS, GREAT DANES, AND
COCKER SPANIELS
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CANINE DILATED CARDIOMYOPATHY PATHOPHYSIOLOGY

• DECREASED CONTRACTILITY FROM AN UNKNOWN CAUSE
  (viral?, carnitine deficiency?)
• Decreased contractility decreased cardiac output

CO (CARDIAC OUTPUT) SV (STROKE VOLUME) X HR
(HEART RATE)
Amt. of blood ejected with Each cardiac
contraction (affected by afterload, preload, and
inherent contractility)
How often the heart contracts
The amt. of blood that leaves The heart
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CANINE DILATED CARDIOMYOPATHY PATHOPHYSIOLOGY

• THE BODY COMPENSATES BY
• 1. INCREASING THE HEART RATE
• this is done by sympathetic nervous system
  stimulation
• 2. TRYING TO INCREASE STROKE VOLUME BY
  INCREASING PRELOAD (this means that the body
  increases filling of the heart)
• This is done by activation of the
  Renin-angiotensin-aldosterone system which leads
  to sodium and water retention

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THE WALLS OF THE HEART ARE WEAK, FLABBY, AND
DILATED THIS DILATION MAY CAUSE SEPARATION OF
THE MITRAL VALVE LEAFLETS LEADING TO MITRAL
REGURGITATION
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CANINE DILATED CARDIOMYOPATHY CLINICAL SIGNS
LETHARGY, EXERCISE INTOLERANCE, COUGHING, WEIGHT
LOSS, TACHYPNEA, SYNCOPE, SOFT MURMUR
(WHERE?) PLEURAL EFFUSION, ASCITES,
HEPATOMEGALY, WT. LOSS
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CANINE DILATED CARDIOMYOPATHY
Enlarged, round heart
DOBERMANS ARE DEEP CHESTED AND MAY NOT APPEAR TO
HAVE SUCH AN ENLARGED HEART ON RADIOGRAPHS
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CANINE DILATED CARDIOMYOPATHY
PLEURAL EFFUSION
PULMONARY EDEMA
PATIENT MAY SHOW SIGNS OF LEFT-SIDED,
RIGHT-SIDED, OR HEART FAILURE FROM BOTH SIDES
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CANINE DILATED CARDIOMYOPATHY PATHOPHYSIOLOGY

• Constant stimulation of the heart by the
  sympathetic nervous system causes ventricular
  arrhythmias and myocyte death
• Most common arrhythmias VPCs and ventricular
  tachycardia, esp. in boxers Dobies other dogs
  may have APCs and atrial fibrillation

ONE VPC
MULTIPLE VPCs CAUSING TACHY-CARDIA
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CANINE DILATED CARDIOMYOPATHY ECHOCARDIOGRAM
http//www.youtube.com/watch?v7TWu0_Gklzofeature
related
http//www.youtube.com/watch?vNSnh3qN2kR4NR1
PERFORMING AN ECHOCARDIOGRAM IS THE DEFINITIVE
WAY TO DIAGNOSE DILATED CARDIOMYOPATHY
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CANINE DILATED CARDIOMYOPATHY DIAGNOSTICS

• Laboratory tests
• Atrial Natriuretic peptide increase
• Released from atria in response to excess stretch
• Brain natriuretic peptide increase
• released from ventricles in response to excess
  stretch
• Pro-BNP release
• Troponin 1 (cTn1) increased
• Released when heart muscle is damaged

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CANINE DILATED CARDIOMYOPATHY TREATMENT
INCREASES CONTRACTILITY
DIGOXIN
FUROSEMIDE
REDUCES FLUID RETENTION
ENALAPRIL
DIURETIC-ELIMINATES EXCESS FLUID
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CANINE DILATED CARDIOMYOPATHY TREATMENT
L-CARNITINE
TAURINE USED IN COCKER SPANIELS AND CATS, MAINLY
COENZYME Q10
DIETARY SUPPLEMENTS THAT MAY HELP IMPROVE HEART
FUNCTION, ESP IF THERE IS A DEFICIENCY
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CANINE DILATED CARDIOMYOPATHY CLIENT INFO

• DCM is a progressive diseases that is almost
  always fatal
• Most dogs die within 6 months -2 years
• Death may occur suddenly due to arrhythmias

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FELINE DILATED CARDIOMYOPATHY
A globular-shaped heart with severe dilation of
all four chambers. Depressed ventricular
contractile performance occurs. Ventricular
dilation distorts the atrioventricular valves
leading to mitral regurgitation and
atrial enlargement
ABNORMALLY THIN VENTRICULAR WALLS
ATROPHIED PAPILLARY MUSCLES
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FELINE DILATED CARDIOMYOPATHY

• In the 1980s DCM in cats was one of the most
  commonly diagnosed heart diseases. It was
  discovered that this was caused by a deficiency
  of TAURINE, an amino acid.
• Since that time commercial foods have added
  taurine to feline diets, which has significantly
  decreased the number of cases of feline DCM