Week 7 Topic 1 Cardiovascular Medications

1
Week 7 Topic 1Cardiovascular Medications

• Prof. Warren Payne

2
What causes angina pectoris?

• Imbalance between demand for oxygen by the heart
  and supply of oxygen to the heart

3
Estimate of Oxygen Uptake by the Heart

• Myocardial VO2 (MVO2) SBP x HR
• (Double Product or Rate Pressure Product)

4
Control of Angina Pectoris

• Need to ensure that
• MVO2 (demand) is reduced to match supply or
• MVO2 is met by increasing supply
• Demand and supply controlled by HR and SBP

5
Control of Demand and Supply

• Dilate
• Reduce volume
• Reduce pumping rate

6
Medications to Control Demand and Supply

• Dilate
• Nitrates
• Reduce volume
• Diuretics
• Reduce pumping rate
• ? Blockers

7
Medications to Control Demand and Supply

• Dilate
• Nitrates
• Angiotensin Converting Enzyme (ACE) Inhibitors
• Ca Channel Blockers

• Reduce volume
• Diuretics
• Reduce pumping rate
• ? Blockers
• Reduce pumping force
• Ca Channel Blockers
• ? Blockers

8
Mechanisms of ActionDilators

• Nitrates
• Reduce Ca availability by increasing Ca
  uptake by sarcoplasmic reticulum
• ACE Inhibitors
• Reduce the production of the potent
  vasoconstrictor, angiotensin

9
Mechanisms of Action Volume Reducers

• Diuretics
• Affect the loop of Henley to reduce water
  reabsorption by the kidneys

10
Mechanisms of ActionRate Reducers

• ? Blockers
• Block the effect of adrenergic stimulation on
  heart rate and contractility

11
Mechanisms of ActionPumping Force Reducers

• Ca Channel Blockers
• Reduce the influx of Ca during a cardiac action
  potential. Reduce contractility and increases
  smooth muscle compliance.

12
Effect of Medications on Resting and Exercise HR,
BP, ECG and Exercise Capacity
Medications Heart Rate Blood Pressure ECG Exercise Capacity
? Blockers
13
Effect of Medications on Resting and Exercise HR,
BP, ECG and Exercise Capacity
Medications Heart Rate Blood Pressure ECG Exercise Capacity
Nitrates
14
Effect of Medications on Resting and Exercise HR,
BP, ECG and Exercise Capacity
Medications Heart Rate Blood Pressure ECG Exercise Capacity
Ca Channel Blockers
15
Effect of Medications on Resting and Exercise HR,
BP, ECG and Exercise Capacity
Medications Heart Rate Blood Pressure ECG Exercise Capacity
Diuretics
16
Effect of Medications on Resting and Exercise HR,
BP, ECG and Exercise Capacity
Medications Heart Rate Blood Pressure ECG Exercise Capacity
ACE Inhibitors