Heart Disease

1
Heart Disease
An introduction to problems that can occur in the
heart
Partnership for Environmental Education and Rural
Health Texas AM University http//peer.tamu.edu
2
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

3
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

4
The Heart
5
Basic Anatomy

• Arteries Carry blood away from the heart
• Veins Carry blood to the heart
• Capillaries Site of gas exchange

6
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

7
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.
8
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.
9
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?

10
Time OutCheck your pulse
11
Review Questions

• Diagram the flow of blood throughout the body,
  indicating where in the circuit the blood is most
  oxygenated.
• Why do veins have valves?
• How does lung structure promote oxygenation?

12
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
13
Coronary Arteries and Veins
The heart needs blood and oxygen too!! When one
of these arteries gets blocked, a heart attack
can occur
14
Causes of Heart Attacks

• Genetics it can run in families
• Diet too much fat and cholesterol
• Not enough vigorous exercise

15
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?

16
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)

17
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
18
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

19
Risk factors for CHF

• High cholesterol levels in blood
• Diabetes
• Physical inactivity
• Obesity
• Smoking
• Poor diet
• High blood pressure (Hypertension)
• (gt140-160 mmHg or gt90 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

20
Options for Patients with CHF

• Heart transplantation
• Mechanical assistance
• Total artificial heart

21
Review Questions

• What is the difference between a heart attack and
  congestive heart failure?
• What are three main risk factors for heart
  attacks?
• What are three main risk factors for congestive
  heart failure?

22
Heart Valve Problems

Tendon-like cords connect valves (underside at
top) to walls of the heart and help hold the
valves shut during contraction
23
(No Transcript)
24
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.

25
Heart Surgery
26
Open Heart Surgery in a Child
Small white ring is an artificial valve that is
being lowered into heart.
27
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

28
Surgical Removal of Dog Heartworms
29
Review Questions

• What causes the sound of heart murmurs?
• What are some causes of heart murmurs?

30
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

31
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.

32
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.

33
Fetal Blood Flow Is DifferentWhy Does It Have To
Be?
After birth blood must go through lungs
Fetus shunt bypasses lungs
34
Normal versus PDA heart
35
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
36
Time Out Listen to your own heart
37
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

38
Surgical Ligation
Aorta
PDA
Pulmonary Artery
39
Catheter Based Occlusion

• With a surgery called Transarterial Ductal
  Occlusion With Coils
• Very safe procedure
• Very successful procedure (95 success)

40
Transarterial Ductal Occlusion
Aorta (with catheter inside)
PDA
Coil within PDA
Pulmonary Artery
No dye visible in the pulmonary artery anymore!
41
Review Questions

• Why is a PDA necessary in a fetus?
• Why is a PDA undesirable in a newborn?
• Why is the blood in a pulmonary artery in a PDA
  patient a mixture of oxygenated and unoxygenated
  blood?