Download diseases of the cardiovascular system

To understand the heart and
mind of a person, look not at
what he has already achieved,
but at what he aspires to
-Kahlil Gibran
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earning.shtml#fig1
CARDIAC CYCLE
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The atria contract in unison and the ventricles contract in unison
The atria and ventricles ___________ contract at the same time (as one group
contracts, the other relaxes)
ATRIAL contraction sends blood into the ventricles through the _________ and
_______________ valves
– While this is occurring, the __________________ valves close
– The ventricles relax at this time
VENTRICULAR contraction sends blood through the _______________ valves
into the aorta and pulmonary artery
– While this is occurring, the bicuspid and tricuspid valves close
– The atria ___________ at this time and blood enters the atria from the vena
cava and pulmonary veins
SYSTOLE – ________________ of the atria and ventricles
– blood is being _________________ from the heart
DIASTOLE – _______________ of the atria and ventricles -heart is filling with
blood
HEARTBEAT: Lub-dub: S1 and S2
– S1: Beginning of systole
(pulse)
• increase in
_________________
pressure during
contraction exceeds
the pressure within
the atria
• closing ____valves
(mitral first)
• contraction forces
blood semilunar
valves.
– S2: Beginning of
_________ (no pulse)
• ventricles begin to
___________
• pressures within the
heart become
________ than the
semilunar valves,
• causes the semilunar
valves to snap
_________ (aortic
first)
STROKE VOLUME
• Contractility: Contractility is the intrinsic ability of cardiac
muscle to develop force for a given muscle length. It is also
referred to as inotropism.
• Preload: Preload is the muscle length prior to contractility,
and it is dependent of ventricular filling (or end diastolic
volume.) This value is related to right atrial pressure. The
most important determining factor for preload is venous
return.
• Afterload: Afterload is the tension (or the arterial pressure)
against which the ventricle must contract. If arterial pressure
increases, afterload also increases. Afterload for the left
ventricle is determined by aortic pressure, afterload for the
right ventricle is determined by pulmonary artery pressure.
2.5 – 3.5 rib spaces
CANINE WITH CARDIOMEGALY
NORMAL CANINE HEART
Stroke Volume (SV) = EDV – ESV
Cardiac Output (Q) = ____ X ______
MURMURS
• I - Lowest intensity, difficult to hear even by expert
listeners
• II- Low intensity, but usually audible by all listeners
• III - Medium intensity, easy to hear even by
inexperienced listeners, but without a _________thrill
• IV - Medium intensity with a palpable thrill
• V - Loud intensity with a palpable thrill. Audible
even with the stethoscope placed on the ________
with the edge of the diaphragm
• VI - Loudest intensity with a palpable thrill. Audible
even with the stethoscope ___________ the chest.
DISEASES OF THE
CARDIOVASCULAR SYSTEM:
Cardiomyopathies
CHF
Valvular disease
Congenital malformation
Infectious
FELINE HYPERTROPHIC
CARDIOMYOPATHY (HCM)
NEUTERED MALE CATS BETWEEN 1-16 YRS. OF AGE
THE MOST COMMON CARDIOMYOPATHY IN ________!
FELINE HYPERTROPHIC
CARDIOMYOPATHY
• THE PREDOMINANT PATHOLOGY OF
THIS DISEASE IS ____________________
HYPERTROPHY
• CAUSE:
– +/- genetics
– related to abnormal ___________________ or
________________ transport within the muscles
of the heart
FELINE HYPERTROPHIC
CARDIOMYOPATHY
Blood backs up LA enlarged
FELINE HYPERTROPHIC
CARDIOMYOPATHY: DIAGNOSIS
http://www.youtube.com/watch?v=yNj-lQaUBao
http://www.youtube.com/watch?v=KvUFb4qZwmw&feature=related
http://www.youtube.com/watch?v=xlsq5tJpj04&feature=related
FELINE HYPERTROPHIC
CARDIOMYOPATHY: Pathophysiology
PROBLEM #1: The walls lose compliance and resist filling during
diastole! (_________________________)
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 →
___________________!
• PROBLEM #3: The left atrium becomes dilated with
blood → the blood becomes __________→ blood
stasis leads to clot formation → clot becomes
dislodged and trapped elsewhere in the arterial system
→ _____________________!
***90% of thrombi become lodged in the aortic ___________
causing “saddle thrombus”***
FELINE HYPERTROPHIC CARDIOMYOPATHY:
SADDLE THROMBUS
ACUTE, PAINFUL CONDITION CAUSING
PARESIS, ___________
REAR LEGS/FEET!
FELINE HYPERTROPHIC CARDIOMYOPATHY:
SADDLE THROMBUS
FELINE HYPERTROPHIC CARDIOMYOPATHY:
CLINICAL SIGNS and DIAGNOSIS
• Soft, sytolic murmur (grade 2-3/6)
• Gallop rhythms or other arrhythmias
– ECG: ↑ p wave duration, ↑ QRS width, sinus tachycardia
• Echo: shows ↑ ventricular wall thickness, dilated left
atrium
• _____________ onset of heart failure
• Acute onset of systemic
__________________________
– Hindlimb paresis
– Cold rear legs
– Painful rear legs
FELINE HYPERTROPHIC
CARDIOMYOPATHY: TREATMENT
FUROSEMIDE (DIURETIC)
ASPIRIN
ANTICOAGULANT
OR
PROPRANOLOL (B-BLOCKER)
__________________________
Relax so
Time to
fill
DILTIAZEM (CALCIUM CHANNEL BLOCKER)
Inhibits contractility: low BP and cardiac ________
FELINE HYPERTROPHIC
CARDIOMYOPATHY: TREATEMENT
• LASIX (furosemide): a diuretic used to treat
___________________
• DILTIAZEM: a calcium channel blocker used to
inhibit cardiac and vascular smooth muscle
____________; reduces blood pressure and cardiac
afterload; overall improvement in ______________
– Or Propranolol: a beta-blocker to decrease heart rate and
myocardial oxygen demand
• ASPIRIN: an anticoagulant used to thin blood and
help prevent __________ formation in HCM
• TPA (Activase): serves as a ____________ 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
FELINE HYPERTROPHIC
CARDIOMYOPATHY: CLIENT INFO
• There is no ____________!
– 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 >200 beats/min
CANINE HYPERTROPHIC
CARDIOMYOPATHY:
• An _____________ 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
DISEASES OF THE
CARDIOVASCULAR SYSTEM:
Cardiomyopathies
CHF
Valvular disease
Congenital malformation
Infectious
CONGENITAL DEFECTS: PATENT
DUCTUS ARTERIOSUS
CHIHUAHUAS, MALTESE, POODLE, POMERANIAN, SHELTIE
PUPPIES COMMONLY AFFECTED (Table 1-1)
CONGENITAL DEFECTS: PATENT DUCTUS
ARTERIOSUS
Normally, the ductus arteriosus carries blood from the _______________
to the _________ during fetal development. It bypasses the lungs of
the fetus.
CONGENITAL DEFECTS: PATENT DUCTUS
ARTERIOSUS
The duct should close in the first
12-24 hours after birth. If it does
not, the blood begins to shunt
from the aorta into the pulmonary
artery and _______________ the
lungs.
The left side of the heart will
have an increase in blood return
and become volume overloaded.
________________________
THIS IS CALLED A ___________________SHUNT
CONGENITAL DEFECTS: PATENT
DUCTUS ARTERIOSUS (PDA)
CONGENITAL DEFECTS: PATENT DUCTUS
ARTERIOSUS
• CLINICAL SIGNS:
– A loud murmur best heard over the left base
– Sometimes called a “machinery” murmur or a continuous
murmur (btw S1 and S2)
– If the shunt is small some animals may be asymptomatic
– In large shunts the animal will develop
____________________
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Pulmonary edema
Cough
Exercise intolerance
Tachypnea
Weight loss
– ECG: wide range of arrhythmias including APCs and VPCs
– Echocardiography (ultrasound)
– Radiographs: _____________ and ventricular enlargement
PATENT DUCTUS ARTERIOSUS: TREATMENT
EXCELLENT _____________ WITH SURGICAL CORRECTION:
LIGATION OF THE DUCTUS ARTERIOSUS
PATENT DUCTUS ARTERIOSUS:
TREATMENT
• CLIENT INFO:
– 64% OF ANIMALS WILL DIE WITHIN _____
YEAR IF NOT TREATED SURGICALLY
– Dogs with this condition should not be used for
_______________
ATRIAL AND VENTRICULAR SEPTAL DEFECTS
~ Cats
Atrial Septal Defect
During fetal life, the _____________________ is an openingi n the interatrial septum,
allowing shunting of blood from the right atrium to the left atrium in order to bypass
the nonfunctioning fetal lungs. It should close at birth. If it doesn’t, after birth, the
blood will shunt from left to right resulting in overload of the right side of the heart.
CONGENITAL DEFECTS: ATRIAL AND
VENTRICULAR SEPTAL DEFECTS
• CLINICAL SIGNS: ATRIAL SEPTAL
DEFECTS
– Result in overload of the right side of the heart
→ dilation and hypertrophy of the right-sided
chambers
– Systolic murmur
– _____________________ failure
– Radiographs: right ventricular enlargement
– Echo: right ventricular dilatation
CONGENITAL DEFECTS: ATRIAL AND
VENTRICULAR SEPTAL DEFECTS
Blood is shunted from the oxygen-rich left ventricle into the right ventricle. The blood
goes through pulmonary circulation and right back into the left atrium and ventricle
resulting in volume overload of the left side of the heart. The right ventricle may dilate
as well.
CONGENITAL DEFECTS: ATRIAL AND
VENTRICULAR SEPTAL DEFECTS
• CLINICAL SIGNS: VENTRICULAR SEPTAL
DEFECTS:
– Animals with small defects may have minimal or no signs
– Larger defects may result in acute ________________ ,
usually by 8 weeks of age
– A harsh holosystolic murmur
• CLIENT INFO:
– Repair of these defects requires open-heart surgery or
cardiopulmonary bypass. These procedures are uncommon in
the dog and cat
– Most of these animals will eventually experience development
of congestive heart failure
VSD - Treatment
• There are 2 current surgical options available.
– Before right-to-left shunting has developed,
__________________________
• decrease the blood flow across the defect
• reducing the overload on the lungs and the left heart.
– Repair of the defect, but this requires open heart
surgery and carries a high risk.