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

• CARIOMYOPATHIES

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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?)
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CANINE DILATED CARDIOMYOPATHYDIAGNOSIS
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 DIAGNOSIS
PULMONARY EDEMA
PLEURAL EFFUSION
PATIENT MAY SHOW SIGNS OF LEFT-SIDED,
RIGHT-SIDED, OR HEART FAILURE FROM BOTH SIDES
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CANINE DILATED CARDIOMYOPATHY PATHOPHYSIOLOGY,
DIAGNOSIS

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

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DISEASES OF THE CARDIOVASCULAR SYSTEM

• CARDIOMYOPATHIES

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PATIENT PRESENTATION
http//www.youtube.com/watch?vX-wLIoYTpOU
http//www.youtube.com/watch?vZp7CiC7SXjk
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FELINE HYPERTROPHIC CARDIOMYOPATHY
NEUTERED MALE CATS BETWEEN 1-16 YRS. OF AGE
THE MOST COMMON CARDIOMYOPATHY IN CATS!
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FELINE HYPERTROPHIC CARDIOMYOPATHY CLINICAL
SIGNS and DIAGNOSIS

• Soft, sytolic murmur
• Gallop rhythms or other arrhythmias
• ECG ? p wave duration, ? QRS width, sinus
  tachycardia
• Echo shows ? ventricular wall thickness, dilated
  left atrium
• Acute onset of heart failure
• Acute onset of systemic thromboembolism
• Hindlimb paresis
• Cold rear legs
• Painful rear legs

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FELINE HYPERTROPHIC CARDIOMYOPATHY

• THE PREDOMINANT PATHOLOGY OF THIS DISEASE IS LEFT
  VENTRICULAR HYPERTROPHY
• CAUSE
• Genetics
• Related to abnormal myocardial myosin or calcium
  transport within the muscles of the heart

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FELINE HYPERTROPHIC CARDIOMYOPATHY
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FELINE HYPERTROPHIC CARDIOMYOPATHY DIAGNOSIS
http//www.youtube.com/watch?vyNj-lQaUBao
http//www.youtube.com/watch?vKvUFb4qZwmwfeature
related
http//www.youtube.com/watch?vxlsq5tJpj04feature
related
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FELINE HYPERTROPHIC CARDIOMYOPATHY
Pathophysiology
PROBLEM 1 The walls lose compliance and resist
filling during diastole! (diastolic failure)
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FELINE HYPERTROPHIC CARDIOMYOPATHY
Pathophysiology

• PROBLEM 2 If the left ventricle cannot fill
  adequately with blood, the blood backs up into
  the left atrium (enlargement) ? pulmonary veins ?
  pulmonary edema!
• PROBLEM 3 The left atrium becomes dilated with
  blood ? the blood becomes static ? blood stasis
  leads to clot formation ? clot becomes dislodged
  and trapped elsewhere in the arterial system ?
  thromboembolism!

90 of thrombi become lodged in the aortic
trifurcation causing saddle thrombus
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FELINE HYPERTROPHIC CARDIOMYOPATHY SADDLE
THROMBUS
ACUTE, PAINFUL CONDITION CAUSING PARESIS, COLD
REAR LEGS/FEET!
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FELINE HYPERTROPHIC CARDIOMYOPATHY SADDLE
THROMBUS
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FELINE HYPERTROPHIC CARDIOMYOPATHY TREATMENT
FUROSEMIDE (DIURETIC)
ASPIRIN
ANTICOAGULANT
OR
DILTIAZEM (CALCIUM CHANNEL BLOCKER)
PROPRANOLOL (B-BLOCKER)
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FELINE HYPERTROPHIC CARDIOMYOPATHY TREATEMENT

• LASIX (furosemide) a diuretic used to treat
  pulmonary edema
• DILTIAZEM a calcium channel blocker used to
  inhibit cardiac and vascular smooth muscle
  contractility reduces blood pressure and cardiac
  afterload overall improvement in diastolic
  function
• Or Propranolol a beta-blocker to decrease heart
  rate and myocardial oxygen demand
• ASPIRIN an anticoagulant used to thin blood and
  help prevent clot formation in HCM
• TPA (Activase) serves as a fibrolysin resulting
  in the breakdown of clots that have already
  formed
• Or Heparin, Warfarin acts on the coagulation
  factors to inhibit the formation of a stable clot

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FELINE HYPERTROPHIC CARDIOMYOPATHY CLIENT INFO

• There is no cure!
• Cats with HCM may experience heart failure,
  arterial embolism, or SUDDEN DEATH!
• Cats whose heart rates stay below 200 beats/min
  have a better prognosis than those whose heart
  rate is gt200 beats/min

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CANINE HYPERTROPHIC CARDIOMYOPATHY

• An UNCOMMON canine disease, but the cause
  appears to be heritable
• CLINICAL SIGNS
• Fatigue
• Sudden death
• Tachypnea
• Syncope
• Cough
• BREEDS German Shepherds, Rottweilers, Cocker
  Spaniels, and others