Atherosclerosis and Ischemic Heart Disease Patho Flashcards
Risk factors of atherosclerosis
Non-modifiable
- Male >45 years
- Female >55years
- Family History of premature CAD–>Male <55,Female<65
Risk factors of Atherosclerosis
Modifiable
- Smoking
- Hypertension
- Dyslipidemia
- Diabetes
- Obesity
- Physical inactivity
What is ischemia?
Inadequate blood supply to an organ or tissue–> tissue damage and necrosis
How do arteries respond to ischemia?
They vasodilate to increase oxygen delivery to the tissue
What are the coronary arteries?
- They lay on the outside of the heart
- They supply oxygen to the myocardium
- Start just above the aortic root
Development of coronary artery disease
- Atherosclerotic plaque build up in the coronary aeteries
- Vessels vasodilate to continue bring blood to the myocardium
- When oxygen demand increases above baseline, the vessels can’t vasodilate further
- Demand>supply = Ischemia + chest pain
Oxygen demand and supply in the myocardium
- Oxygen supply
1. Coronary blood flow
2. Arterial blood O2 content - Oxygen demand
1. Heart Rate
2. Contractility
3. Ventricular Wall tension(Preload and Afterload)
When oxygen and demad are equal the heart is working normally and there is no ischemia
When oxygen supply is less than demand what happens?
The coronary arteries vasodilate to meet demand
If the oxygen demand keeps increasing due to factors such as exercise, emotional stress,med or diseases that increase BP, what happens?
The coronary arteries can not vasodilate nay further an as such results in ischemia
What are the characteristics of chest pain(angina)?
- Quality—>Pressure or heavy weight on chest,crushing, burning, tightness
- Location–>substernal, may radiate , but not common
- Duration–>0.5-20mins
- Precipitating Factors–>Exercise,cold weather, postprandial,emotional stress
- Relieving factors—>resting, sublingual nitroglycerin
Types of angina
- Typical angina(meets all of the characteristics)
- Atypical angina(meets 2/3 of the characteristics)
- Non-cardiac angina(meets 1 or none of the characterstics)
Where can angina radiate to ?
- Neck
- Jaw
- Chest
- Shoulder
- Arm
- Upper abdomen
Atypical angina characterisitic equivalents
Present in women,older adults and pts w/diabetes
- Anxiety
- Shortness of breath
- weakness
- fatigue
- indigestion
Presentations of Ischemic Heart Disease(IHD)
- Chronic Coronary disease(CCD)
- Acute Coronary Syndromes(ACS)
Presentation of patients with Chronic Coronary diesease(CCD)
- Stable angina
- Patients discharged after Acute coronary syndrome(ACS)
- Patients diagnosed with CCD based on screening
Presentations of patients with Acute coronary syndrome(ACS)
- Unstable angina
- NSTEMI
- STEMI
What are the charateristics of Chronic Coronary Disease?
- Stable Angina—>chronic angina precipitated by activity or upset, relieved at rest
- Patient discharged after ACS—>Patients are considered to have CCD after they are discharged for an acute coronary syndrome
- Patient diagnosed with CCD—> patients may have risk factors of or symptoms consistent with CCD for which a screening test is completed(ex: stress test) and CCD is identified
What are the charateristics of Acute Coronary Syndrome(ACS)?
- Unstable angina—>Increased frequeny or duration of angina episodes produce at a lower level of exertion or at rest
- NSTEMI—>Myocardial necrosis resulting from prolonged interruption of the blood supply,generally results from an acute thrombus, but NO ECG changes
- STEMI—>Myocardial necrosis resulting from prolonged interruption of the blood supply, generally results from an acute thrombus, with ECG changes
Plaques and Plaque ruptures
- Angina–>non thrombotic plaque(partially occluded)
- NSTEMI–>thrombotic plaque(partially occluded)
- STEMI–>thrombotic plaque(fully occluded)
Coronary anatomy
- Left coronary anatomy–> supplies left side of the heart
- Right coronary artery–>supplies the right side of the heart
- Circumflex artery–> supplies back of the heart
Cardiac biomarkers that help to recognise cell necrosis
- Myoglobin and ck isoforms—>creatine kinase released when muscle tissues necrosize
- Troponin—>Gold standard for ACS, draw q6H, until they peakn then stop
Levels of troponin equals size of cardiac arrest
Testing and diagnosis of CAD/IHD
- Functional Testing
1. Exercise stress test
2. Pharmacological stress test - Anatomical testing
1. Coronary CT Angiography(Gold standard)
2. Coronary Artery Calcium scoring
What entails an exercise stress test vs a nuclear exercise stress test?
- Exercise stress test
1. Vitals are taken at rest
2. Patient begins to walk on treadmill
3. Vitals recorded evry 3 mins as treadmill intensity increases
4. Exercise until reaching or nearing max heart rate
5. Gradually cool down - Nuclear exercise stress test
1. Electrodes placed on chest for ECG. IV line started
2. Begin walking on treadmill
3. Vitals recorded every 3 minutes as treadmill intensity increases
4. Near max HR, radioactive tracer delivered through IV
5. Lie under gamma camera for 15-20 mins while images are taken of blood flow to heart
If there are any abnormalities on either tests then patient is sent to do a Coronary Angiogram
What is a Coronary Artery Calcium testing?
Looking for calcification of the coronary arteries
- Used for ASYMPTOMATIC patients to determine if there is build-up within the coronary arteries
- Uses CT scan(w/out dye)
- Calculates the mass of calcium
- Score per page
