Angina pectoris how drugs act

Angina can be viewed as a problem of supply and demand. Drugs used in angina pectoris are those that either increase supply of oxygen and nutrients, or reduce the demand for these — or both.

Supply can be increased by: cardiac work and myocardial oxygen need by:

• dilating coronary arteries

• slowing the heart (coronary flow, uniquely, occurs in diastole, which lengthens as heart rate falls).

Demand can be reduced by:

• reducing afterload, (i.e. peripheral resistance), so reducing the work of the heart in perfusing the tissues

• reducing preload, (i.e. venous filling pressure); according to Starling's Law of the heart, workload and therefore oxygen demand varies with stretch of cardiac muscle fibres

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

Get My Free Ebook


Post a comment