L12.1 Cardiovascular Pharmacology Flashcards
chronic high blood pressure (hypertension) left untreated can lead to …
stroke, blood vessel damage (arteriosclerosis), heart attack or heart failure, kidney failure
what do beta-blockers do?
- the beta drugs act predominantly on the heart tissue, if they are selective for antagonists for B1-adrenergic receptors
- results: reduce heart rate, reduce ventricular contractility
what is myocardial ischaemia?
reduced blood flow through coronary arteries leading to inadequate oxygenation of heart myocytes leading to chest pain (short term) and to myocyte cell death (long term)
how can we treat angina?
(see notes for diagram)
what is stable angina? how is it treated?
predictable chest pain experienced with exertion due to underlying narrowing of the coronary vessels by atheroma (accumulated fatty deposits and scar vessels).
treat by targeting cardiac work and blood supply (organic nitrates, vasodilators, B blockers); underlying atherosclerosis (statins), anti-thrombotic therapy (aspirin)
what is unstable angina? how is it treated?
pain occuring with reduced exertion, culminating in pain at rest. similar pathology. to an MI (treat with antiplatelet drugs, organic nitrates etc.)
what is myocardial infarction? how is it treated?
sudden occlusion of a coronary vessel leading to death of cardiac tissue due to O2 deprivation. the location and size of the block determines the extent of the damage.
treatment; restore myocardial flow by physical and pharmacological means
describe the emergency management
see notes
what is a coronary artery bypass grafting?
surgical procedure performed to relieve angina and reduce risk of death
arteries or veins from elsewhere in the body are grafted to coronary arteries to bypass atherosclerotic narrowing and improve blood supply to the coronary circulation to the myocardium
what is congestive heart failure?
the inability of the heart to supply adequate nutrients to the metabolising tissues of the body; it simply cannot pump effectively of efficiently
lethal disease with a 5 year survival rate for 25% of patients after the first hospitalisation
what is the difference between left and right heart failure?
left heart failure: blood accumulates in pulmonary circulation, leading to pulmonary congestion and fluid in lungs
right heart failure: blood accumulates in venous circulation, causing organ congestion and peripheral oedema
what is the pathophysiology of heart failure?
- cardiac output decreases in heart failure
- one strategy would be to increase heart function by increasing adrenaline
- long term, through, this is not a great idea as vasoconstriction is increased along with CO, and the workload on the heart is increased
- activation of adrenal medulla leads to activation of renin-anglostensin system (RAS)
- long term, this is not good either as RAS leads to retention of salt and water, leading to congestion and oedema
describe the treatment of heart failure
treatment aims to: improve the ability of the heart muscle to contract or decrease the workload of the heart (vasodilators and diuretics)
- the most successful treatment, defined as improved survival, all reduce cardiac workload
- this usually involves a mixture of medications
what drugs are used in heart failure?
- positive inotropic agents: digoxin
- vasodilators: ACE inhibitors, nitrates
- diuretics
- beta blockers
what are diuretics?
- the use of diuretics simply improves kidney function such that oedema is relieved
- by reducing swelling in the organs and limbs, the work of the heart is reduced significantly
- diuretics are often combined with all other forms of heart failure treatment
