Transcript Heart Murmurs and Heartworms - PEER

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Heartworms and Heart Murmurs
An introduction to problems that can occur in the heart
Partnership for Environmental Education and Rural Health
Texas A&M University
http://peer.tamu.edu
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The Heart
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Basic Anatomy
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Arteries – Carry blood away from the heart
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Veins – Carry blood to the heart
Capillaries – Site of gas exchange
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The Heart as a Pump
• The heart works as a pump,
forcing blood forward into the
arteries.
• Blood returns to the heart in
veins. Veins have valves.
• Valves work to keep the
blood from flowing
backwards, even when the
heart isn’t contracting.
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Blood Flow
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Heartworms
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What are they?
• Parasitic worms that live in the
heart and blood vessels of
animals.
• Heartworms (Dirofilaria
immitis) affect dogs, coyotes,
sea lions, ferrets and cats.
• They are transmitted by
mosquitoes
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Life Cycle of a Heartworm
Microfilaria develop
into larva (L3) in the
mosquito
Microfilaria are
transmitted to a new
mosquito when it bites
the infected dog
Adult heartworms
live in the heart and
mate to produce
microfilaria
Microfilaria are
released into the
bloodstream
Larvae continue
to mature in the
dog until they
become adults
Larvae are
transmitted to
the dog when
the mosquito
takes a blood
meal
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Microfilaria
Seen at 400x magnification
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Adult Heartworms
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Clinical Signs
• Coughing
• Exercise intolerance
• Syncope (Fainting)
• Ascites (Fluid in the
belly)
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Radiographs of Heartworm Disease
Enlarged Right Atrium
Widened Caudal Vena Cava (Caval Syndrome)
Enlarged Pulmonary Arteries
Lung Disease (Heartworm Pneumonitis)
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Prevention
•Prevention products make sure
dogs don’t get heartworms in the
first place
• Include: Heartgard, Interceptor,
Sentinel, Revolution, Filaribits
•As long as the animal is
medicated every month, it prevents
any larvae from maturing and
reaching the heart, thus stopping
heartworm disease.
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Treatment
• Treatment products help cure the animal once it already
has heartworms
– Elimination of heartworms is a two step process
– Must get rid of adult worms and larvae separately
• Consists of two shots in the muscle of Immiticide and 4
weeks of strict cage rest
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Surgical Removal
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Heart Murmurs
• What is a heart murmur?
– A heart murmur is an extra or unusual sound heard
during a heartbeat.
– There are many kinds of murmurs, some that are
insignificant and some that indicate a heart problem is
present.
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Patent Ductus Arteriosus
• Special type of heart problem
• Breakdown the words:
– Patent: to make open
– Ductus: tube or canal
– Arterio: relating to an artery
• Put the words together to see that it
means there is an artery that is open
(that should be closed!)
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PDA in canines
• Most common canine
congenital (present at birth)
heart problem
• Affects 5 out of 1000 dogs,
in any size or breed
• 65% of dogs with this
problem will die by 1 year of
age if it is not fixed
• Most have the problem
diagnosed between 1 month
and 3 ½ years of age
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PDA in humans
• The estimated incidence is from 6 out of every 100,000
live births up to 2 out of every 10,000 live births.
• This incidence is increased in children who are born
prematurely.
• The death rate is very low except in extremely premature
infants.
• It occurs twice as often in girls as in boys.
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Return to Anatomy
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Normal versus PDA heart
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Symptoms
• Can a patient live normally?
– Sometimes there are no symptoms
– In large PDAs, symptoms can include:
• Exercise intolerance
• Sweating
• Dyspnea (difficulty breathing)
• Poor weight gain
Audio of a normal heart
Audio of a PDA murmur
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Management Options
• Observation and monitoring
• Medical Management
– Medications may be prescribed to reduce blood
pressure, maintain normal heart rhythm, and prevent
fluid overload.
• Surgical
– Surgical repair
• Ligating (suturing closed) the patent artery
– Catheter based occlusion
• Placing a “coil” inside the artery to stimulate
closure
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Surgical Ligation
Aorta
PDA
Pulmonary
Artery
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Catheter Based Occlusion
• With a surgery called Transarterial Ductal Occlusion
With Coils
– Very safe procedure
– Very successful procedure (95% need nothing else)
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Transarterial Ductal Occlusion
Aorta (with catheter inside)
PDA
Pulmonary Artery
Coil within PDA
*Notice how no dye is visible in
the pulmonary artery anymore!
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Any Questions?