Transcript Heart Murmurs and Heartworms - PEER

DVM
Heart Disease
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
Heart Failure: The people costs (U.S.)
Myth:
Only men suffer from Heart Failure.
Fact:
Over 50% of sufferers are women.
How many people are affected with
Heart Failure?
5 million (2x a decade ago)
How many people die each year of Heart Failure?
287,000
Heart Failure: The dollar costs (U.S.)
How much money is spent on health
care of patients with Heart Failure?
• direct costs 29.6 billion
• lost productivity 37.2 billion
The Heart
Basic Anatomy
• Arteries – Carry blood away from the heart
• Veins – Carry blood to the heart
• Capillaries – Site of gas exchange
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.
• Question: What is the
function of the valves?
Hint: in the diagram, look
at the direction of blood
flow and how the valves
close
3-D Graphic of a
Beating Dog Heart
Click to View
Courtesy of Odyssey Veterinary Software
http://www.diawebster.com/
This is a spectacular video. You must have
Windows Media Player and linked file must be
in the same folder as this PowerPoint. It may
not run on all PCs.
Blood Oxygenation
Right side
pumps venous
blood into
lungs, which
drains into left
side of heart for
pumping
oxygenated
blood to the
brain and body.
Heart Rate
• A slower rate tends to move more
blood per beat. Why?
• Fast rates tends to move more total
blood. Why?
• But very fast rates are not efficient and
may even be dangerous. Why?
Time Out
Check your pulse
Review Questions
1. Diagram the flow of blood
throughout the body, indicating
where in the circuit the blood is
most oxygenated.
2. Why do veins have valves?
3. How does lung structure
promote oxygenation?
Heart Attacks
Cause: heart arteries get filled with deposits
(“plaques”) that promote clots that block the
artery. See artery cross section below:
narrowed
opening for
blood flow
plaque
Coronary Arteries and Veins
The heart needs
blood and oxygen
too!!
When one of these
arteries gets
blocked, a heart
attack can occur
Causes of Heart Attacks
• Genetics: it can run in families
• Diet: too much fat and cholesterol
• Not enough vigorous exercise
What is Congestive Heart Failure
(CHF)?
The inability of the
heart to pump enough
blood to the rest of the
body.
Why do you suppose it is
called CONGESTIVE heart
failure?
CHF in Dogs
• Causes:
• Birth (congenital) defects of
the heart
• Degeneration of the heart
valves
• Heart muscle disease
(cardiomyopathy)
• Heartworm disease
• Diseases of the pericardium
(the lining around the heart)
• Irregular electrical rhythms
of the heart (arrhythmia)
Symptoms of CHF in Dogs
Some of the symptoms of heart failure are
related to
–increased activity of the nervous system
–increased concentrations of circulating
hormones (and related chemicals).
Symptoms include:
Coughing
Shortness of breath
Difficult breathing
Weight loss
Fatigue
Arrows indicate the presence of fluid in the lungs
The Odds for Getting CHF
• Lifetime risk – 20% (men and women)
• CHF deaths far exceed cancer, HIV
• Life expectancy following CHF
– approximately 5 years
– Overall median survival
•1.7 years in men
•3.2 years in women
Risk factors for CHF
•
•
•
•
•
•
•
High cholesterol levels in blood
Diabetes
Physical inactivity
Obesity
Smoking
Poor diet
High blood pressure (Hypertension)
(>140-160 mmHg or >90 diastolic, or
both) seen in 91% of people with CHF
*** Both women and men are at risk,
especially if they have any of the
above risk factors
Options for Patients with CHF
• Heart transplantation
• Mechanical assistance
• Total artificial heart
Review Questions
1. What is the difference between
a heart attack and congestive
heart failure?
2. What are three main risk factors
for heart attacks?
3. What are three main risk factors
for congestive heart failure?
Heart Valve
Problems
Tendon-like cords connect valves
(underside at top) to walls of the
heart and help hold the valves
shut during contraction
Heart Murmurs
• 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.
Heart Surgery
Open Heart Surgery in a Child
Small white ring is an artificial valve that is being lowered into heart.
Heartworms in Dogs
• Heartworm disease is an
infection of Dirofilaria immitis
of the arteries and right side
of heart
• Heartworms are spread by
mosquitoes
• Dogs usually show no clinical
signs!
• Dogs should be wormed
monthly for heartworms
Surgical Removal of Dog
Heartworms
Review Questions
1.
What causes the sound of
heart murmurs?
2.
What are some causes of
heart murmurs?
Patent Ductus Arteriosus (PDA)
• 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!)
– It is an artery that needs to be
open in the fetus but needs to be
closed in the adult
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.
PDA in Humans
• The estimated incidence is from 6 out of every
100,000 live births up to 20 out of every 100,000
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.
Fetal Blood Flow Is Different
Why Does It Have To Be?
Fetus: shunt bypasses lungs
After birth: blood must
go through lungs
Normal versus PDA heart
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
Time Out
Listen to your own heart
Management Options for PDA
• 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 artery
– Catheter based occlusion
• Placing a “coil” inside the artery to stimulate
closure
Surgical Ligation
Aorta
PDA
Pulmonary
Artery
Catheter Based Occlusion
• With a surgery called Transarterial Ductal
Occlusion With Coils
– Very safe procedure
– Very successful procedure (95% success)
Transarterial Ductal Occlusion
Aorta (with catheter inside)
PDA
Coil within PDA
Pulmonary Artery
*No dye visible in the pulmonary artery anymore!
Review Questions
1. Why is a PDA necessary in a
fetus?
2. Why is a PDA undesirable in a
newborn?
3. Why is the blood in a pulmonary
artery in a PDA patient a mixture
of oxygenated and unoxygenated
blood?