User Tools

Site Tools


cardio:angina:start

This is an old revision of the document!


Anti-Anginal Therapy

Angina is a mismatch between myocardial oxygen supply and demand.

Therapy targets either:

  • ↓ Myocardial oxygen demand
  • ↑ Myocardial oxygen supply
  • Or both

Cardiovascular Pharmacology


Determinants of Myocardial Oxygen Demand

Oxygen demand is primarily determined by:

  • Heart Rate
  • Contractility
  • Wall Stress (Preload & Afterload)

Wall stress increases with:

  • ↑ Blood pressure
  • ↑ Ventricular volume

Therefore, angina therapy reduces:

  • Heart rate
  • Contractility
  • Preload
  • Afterload

Increase Oxygen Supply

Nitrates

Agents:

Mechanism:

  • ↑ Nitric oxide
  • Venodilation → ↓ preload
  • Coronary vasodilation

Primary acute relief agents.


Reduce Oxygen Demand

Beta-Blockers

Common agents:

Mechanism:

  • ↓ Heart rate
  • ↓ Contractility
  • ↓ Myocardial oxygen consumption

First-line in chronic stable angina.


Calcium Channel Blockers

—- dhp

Primarily reduce:

  • Afterload

—- Non-Dihydropyridines

Reduce:

  • Heart rate
  • Contractility
  • Afterload

Useful when beta-blockers are contraindicated.


Novel / Adjunctive Anti-Anginal Agents

Ranolazine

Mechanism:

  • Inhibits late sodium current
  • Reduces intracellular calcium overload
  • Improves myocardial efficiency

Does NOT significantly affect:

  • Heart rate
  • Blood pressure

Useful as add-on therapy.


Special Situations

Vasospastic (Prinzmetal) Angina:

Avoid pure beta-blockers in vasospasm.


Acute vs Chronic Strategy

Acute Angina:

Chronic Stable Angina:


Clinical Pearls

  • Angina = supply-demand mismatch
  • Reduce heart rate whenever possible
  • Nitrates primarily reduce preload
  • Beta-blockers improve mortality post-MI
  • Ranolazine improves symptoms without lowering BP
  • CCBs preferred in vasospasm

cardio/angina/start.1770944879.txt.gz · Last modified: by andrew2393cns