Week 9: Special populations:CVD – Coronary Artery Disease and Peripheral Artery Disease Flashcards
What is the Claudication Scale
Scale from 1-5 that describes level of pain
1 = no pain
2 = onset of pain
3 = milkd pain
4 = moderate pain
5 = severe (maximal) pain
What is the formula for RPP/MVO2 (Rate Pressure Product/Myocardial oxygen consumption)? What is the relevance of this formula?
RPP (MVO2) = HR x SBP
RPP is an estimate of MVO2
MVO2 = coronary flow x A-Vo2difference
RPP determintes to worlkload of the heart; it is an indirect index of myocardial oxygen consumption that predicts cardiac function, morbidity and mortality in patients with CVD
What is Claudication
- aching or burning in leg muscles
- reliably reproduced at a set distance of walking
- relieved within minutes on rest
- never present at rest
- not exeacerbated by postion
- site of pain provides an indication of the site of disease
What are the classification of stages of Angina
-
Class I – Ordinary physical activity causes no angina. Angina occurs with strenuous, rapid, or
prolonged exertion.
* Class II – Slight limitation of ordinary activity. Angina occurs when walking >2 blocks and climbing >1 flight of stairs.
* Class III – Marked limitation of ordinary activity. Angina occurs with walking 1 – 2 blocks and climbing one flight of stairs.
*** Class IV **– Inability to carry on any activity without discomfort. Angina at rest.
Differentiate Stable and Unstable Angina
**Stable Angina **
- occurs at a particular rate pressure product
* Results from chronic narrowing of arteries
* Precipitated by oxygen demand
* Predictable pain threshold with exertion, changes in emotional state, etc
* Substernal, jaw, neck, left arm pain * Relieved with rest or medication
**Unstable Angina **
* Onset is unpredictable
* Can occur at rest
* May be a precursor to MI
What are angina signs and symptoms
- Pain in chest, arm, jaw, back
- Usually diffuse
- Described as pressure/ heaviness * Can feel like gastric pain
- Pallor
- Sweating
- Dizziness
- Fatigue and SOB
- Light-headedness
- Face of impending doom
What is the purpose of treatment for HT? How does exercise ahieve this?
The primary purpose of hypertension treatment goes beyond simply lowering the diastolic blood pressure. By reducing diastolic pressure, we aim to ensure** sufficient blood flow through the arteries**. This improved flow allows the body to meet its oxygen and nutrient demands, particularly during physical activity. Consequently, increased activity levels enhance overall quality of life. Furthermore, effectively managing and reducing hypertension and modifying other risk factors can significantly reduce the risk of future complications. Ultimately, these combined efforts can lead to an expanded healthspan and potentially longevity.
Exercise can achieve this by improving endothelial function, enabling the endothelium to become more responsive. Exercise promotes the production of NOS3 (nitrasynthase 3??), the enzyme responsible for nitric oxide synthesis. With more nitric oxide available, blood vessels become more relaxed and compliant. Enhanced comliance of the artery will result in reduced levels of endothelial dysfunction and hence reducing periphery resistance.
Difference between Primary and Secondary Hypertension
Primary HT
- Develops overtime
- Exact cause are unknown
Secondary HT
- Developes from a primary cause
- e.g. acute kidney injury / chronic kidney disease etc
Slide 20 of Week 9
What is the most common site for CAD?
The LAD Artery
Left Anterior Descending
This artery supples the left ventricle –> obviously is really bad for certain reasons
How can you improve Coronary Flow? What happens during exercise?
THINK OF THE FORMULA CF = (DBP / Resis CA) x DT
Can improve CF through:
- Increasing diastolic time –> meaning more time for blood to flow through the CA
- Decrease resistance in the coronary arteries
During Exercise
- Coronary blood flow needs to ↑ therefore resistance needs to ↓
- With ↑ HR, time in diastole ↓ as systolic cannot change
- The demand for oxygen has increased and thus needs to increase coronary flow to supply adequate oxygen to the myocardium
- This can be a problem if you have atheroscleorisis as you have an increase in resistance and thus cannot meet the demand –> leading to potential ischaemia
Slide 32 - 33 of Week 9
CA = Coronary Arteries
What is the formula for Coronary Flow?
CF = (Diastolic BP / Resistance in CA) x Diastolic Time
Slide 32 in Week 9
CF = Coronary Flow, CA = Coronary Arteries
What is the formula for CO?
CO = HR x SV
*is the volume of blood ejected by the left ventrical per minute
SV = EDV - ESV
What happens when blood flow/supply is < MVO2 OR VO2?
You get:
- Oxygen Deprivation (Ischemia)
- Build up of metabolites –> then cellular Acidosis
This then leads to Impared cellular function & impaired force generation
–> leading to changes in ECG, causing claudication, gangrene, ulcers etc
Slide 34 of Week 9
What test is used to diagnose PAD? What does it indicate?
Ankle Brachial Index (ABI)
- Compares the BP measured at the ankle with BP measured at the arm.
- A low ankle-brachial index number can indicate narrowing or blockage of the arteries in the legs
Formula:
Ankle BP / Arm BP
Slide 41 of Week 9
What are the Medications associated with HT?
- Beta Blockers
- Calcium Channel Blockers
- Diuretics
- ACE & ARB’s inhibitors
- Anticoagulants
- Nitrates
