Transcript Coronary Artery Disease

Oxygen Needs
Interference
with
O2 Transport
Case Study
Oxygen Needs
Interference with O2 Transport
Coronary Artery Disease
Complications
Dysrhythmias
Pulmonary Embolism
Hypertension
Complication
Congestive Heart Failure
Peripheral Vascular / Arterial Disease
Oxygen Needs
Interference with O2 Transport
Care of Patients with:
Coronary Artery Disease
Risk Factors
Myocardial Infarction
Alterations in:
Rate & Rhythm (Cardiac Conduction)
Effect on Cardiac Output
Content Approach
Anatomy & Physiology Review
Demographics/occurrence
Pathophysiology
Clinical Manifestation
Medical / Surgical Management
Nursing Process (APIE)
Assessment - Nursing Actions - Education
Anatomy & Physiology
Right Heart
Left Heart
Systole
Valve Closure:
Diastole
Valve Closure:
Cardiac Circulation
Myocardium
Anterior
Posterior
Cardiac Cycle
1. Passive Filling – preload
2. Atrial contraction – Aortic & Pulmonic semilunar
valves close – S2
3. Isovolumetric ventricular contraction – all
valves closed
4. Ejection – ventricular systole – Mitral & Tricuspid
valves close – S1 - afterload
5. Isovolumetric ventricular relaxation – all valves
closed
Cardiac Cycle Phases
Heart Sounds & Stethoscope
Placement
Coronary Arterial System
Physiology: Oxygen Supply
to the Cardiac Muscle during
the Cardiac Cycle
Coronary artery oxygen deficit
during ventricular contraction & ejection (systole)
Coronary artery filling
during ventricular filling (diastole)
What is the impact of heart rate on coronary artery filling?
Oxygen Supply to the Cardiac Muscle
during the Cardiac Cycle
 The actual time available for diastole shortens significantly as the heart rate
increase
% of a Minute
70%
50%
33%
Heart Rate
60
120
188
 Results: Less time for ventricular filling & coronary artery filling + as HR
increases, increased oxygen is needed each minute to eject the same volume of
blood.
Stroke volume: volume ejected in one heart beat
Cardiac Output: volume ejected in one minute
Cardiac Output = Stroke Volume x Heart Rate
Factors
Determining Myocardial Oxygen Needs
 Decreased Oxygen Supply:
 Noncardiac: Anemia, hypoxemia, pneumonia, asthma, COPD, low blood
volume
 Cardiac: Arrhythmias/dysrhythmias, congestive heart failure (CHF), coronary
artery spasm, coronary artery thrombosis, valve disorders
 Increased Oxygen Demand or Consumption:
 Noncardiac: anxiety, cocaine use, hypertension, hyperthermia,
hyperthyroidism, physical exertion
 Cardiac: aortic stenosis, arrhythmias, cardiomyopathy, hypertension,
tachycardia
CAD - Demographics
CAD - Demographics
Comparison of death by CV Disease and
Breast Cancer – by Women’s Age
400
300
Cardiovascular
Disease
Breast Cancer
200
100
0
35-54
55-74
>=75
Coronary Artery Disease (CAD)
Pathophysiology
ASHD, IHD, CVHD = CAD
AHA
1.1 mil Americans will have an MI in 2003
460,000 will die
About half of those deaths occur within 1 hour of the start of
symptoms and before the person reaches the hospital.
Major cause: Atherosclerosis—focal deposit of
cholesterol & lipids
CAD – Risk Factors
Unmodifiable: Age, Gender, Ethnicity, Genetic
predisposition/family history
Modifiable Major: Dyslipidemia--Elevated serum
lipids*, hypertension*, cigarette smoking, obesity—
visceral/central obesity
Modifiable Contributing: Diabetes Mellitus*,
stressful lifestyle
* may have genetic predisposition
CAD – Risk Factors
• Metabolic Syndrome:
–
–
–
–
–
–
Insulin Resistance
Hyperglycemia >110mg/dL
Hypertension - > 130/85
Increased triglycerides >110mg/dL
Decrease HDL <40 men; < 50 women
Central Obesity
• men: waist > 40” women: waist > 35”
Risk Factors
One of the Major Modifiable
Physical Inactivity
Types of Plasma Lipoproteins
 HDL –
 Contain more protein and less lipid
 Carry lipids away from arteries to liver for metabolism
 This process prevents lipid accumulation within arterial walls
 Higher levels are desirable
 LDL –
 Contain more lipids than any other lipoproteins
 Affinity for arterial walls
 Increased levels correlate closely with an increased
incidence of atherosclerosis
 Lower levels are desirable
 VLDL
 Contain of triglycerides
 Correlation with heart disease is uncertain
Plasma Lipoproteins
Atherosclerosis
Elevated serum lipids
Cholesterol > 200mg/dl
Triglyceride > 200mg/dl
HDL
< 35 mg/dl – major risk
45-59 mg/dl – average risk
> 60 mg/dl – negative risk
LDL
< 130 – desirable
130 – 159 mg/dl – borderline risk
> 160 mg/dl – high risk
Progressive Atherosclerosis
Drug Therapy for Dyslipidemia
 Bile Acid Sequestrants (Questran) - Binds with bile salts
 Niacin - Inhibits synthesis of VLDL & LDL
 Fibric Acid Derivatives (Atromid)– Decrease VLDL
 HMG CoA Reductase Inhibitors (Statins - Lipitor, Pravachol,
Zocor) – Block synthesis of cholesterol
 Cholesterol Absorption Inhibitor (Zetia)– Inhibits intestinal
absorption of cholesterol
Natural Lipid Lowering Agents
Niacin - < LDL levels
Omega-3 fatty acids – fish/flaxseed oil <Triglycerides & > HDL levels
Milk thistle – Silymarin - > HDL levels
Fiber - < Cholesterol
Phytosterols - < Cholesterol
Soy - < Cholesterol absorption from GI tract
CoEnzyme Q10 – HMG CoA reductase inhibitors –
natural statins
Coronary Thrombogenesis
During an Acute Coronary Syndrome
Angina
Clinical Manifestations
Angina – Chest Pain
 Stable Angina Pectoris – intermittent, same pattern of onset, duration,
intensity of symptoms - 3-5 mins.
 Silent Ischemia – 80% of patients with ischemia are asymptomatic
 Prinzmetal’s Angina – variant – not precipitated by physical activity – may
be due to spasm
 Nocturnal Angina – occurs at night but not necessarily during sleep or in
recumbent position
 Angina Decubitis – recumbent position – relieved by standing
 Unstable Angina – Unpredictable or may evolve from stable angina –
increasing frequency, duration, intensity
CAD
Clinical Manifestation – Diagnostics
 History & Physical Examination
 EKG / Echocardiogram / Stress Echocardiogram
 Thallium Stress Test (perfusion scanning) cold spots where tissue is
inadequately perfused
 CAT scan- calcium score/CT coronary angiogram
 MUGA (Multiple gated radioisotope scan) – left ventricular function
 MRI of the heart
 PET (Positron emission computed tomography) – evaluate coronary artery
patency