Drugs on the Heart Flashcards
If the ❤️ was an electric pump…
SA node initiates cycle
AV node relays to the ventricle
Purkinje fibres& bundle of his spread implies through the ventricles.
Malfunction- poor pumping / inadequate supply
Lack of coordination of pumping / v fast - turbulence, blood clot, stroke
How is coronary artery disease caused
Lifestyle
Genes
Diet
When blood vessels narrow and blood clots against the plaque
How can you prevent coronary artery disease
Change lifestyle
Reduce BP
Use statins to reduce cholesterol
What is angina
When the ❤️ doesn’t get enough oxygen
The tissues are starved of o2 and this releases potassium&hydrogen protons.
Cardiac ischemia causes the pain
What are the symptoms of angina
Crushing pain in the chest. Can be seen to be down the right arm or neck or jaw.
How do you treat angina
By reducing the o2 demand or increasing the o2 supply
What does glyceryl tritrate (GTN) do
Nitroglycerol
. Reduces Cardiac workout by dilating peripheral b.v.
. ❤️ not have to push as hard, less blood is returned- lower contraction force.
. Increase SA, cardiac blood supply
. Blood is detoured passed the blockage
What does atenolol do
. Slows down HR
. Decreases atria beat / forcibility
. Reduces ventricle beat force
. Decrease Cardiac work rate and o2 demand
. Increase disastole allowing more time for blood to flow in.
What is the cause of a ❤️ attack
Ischaemia- muscle death.
Plaque builds in artery - blood clot
What is a glyceryl titration drug and its action
Propranolol
. Decrease workload and oxygen demand
. Improve blood flow to coronary arteries
. Reduce pain
What does a tissue plasminogen activator do
. Clot busting
. Within a few hours is will destroy a clot
What is an angioplasty
. A stent that is put into a vessel to re open it
What causes ❤️ failure
Heart not efficient at supplying the body.
Can reduce BP to make it easier on the heart or make the heart pump harder.
What’s a treatment for heart failure
Digoxin
What does digoxin do
. Increase CO as its a positive inotropic agent (increase constriction)
. Stops Sodium and potassium and increased calcium stored. This increases the construction of the force without increasing o2 consumption
When do you give digoxin
When there’s heart failure or arterial fibrillation
When sinus rhythm is symptomatic despite ACE / D
What are the strengths and weaknesses of digoxin
😊 improves symptoms and exercises tolerance and decreases likelihood of hospitalisation
😔 not a cure
What are the four classifications of cardiac Dysthrythmia
.Site of origin - arterioles/ junction/ ventricle
. True arrythmias- very disorganised rhythm
. Tachycardia- hb fast
. Bradycardia- hb slow
What are the 5 Dysthrythmic mechanisms
. Ectopic pacemaker- cardiac tissues other than SA node initiates the heart beat.
. Delayed depolarisation- calcium build in cells and cause train action p.
. Re-entry circles- tissue damage/abnormal makes action p travel in circles
. Congenital abnormalities- additional conductory pathways disrupt vent. Signal
. ❤️ block- damage to coronary pathways disrupt AV signals
Who’s at risk of a coronary Dysthrythmia
. Coronary artery disease
. ❤️ valve disorder
. Blood chemistry disorder
. Drugs such as beta blockers, stimulants
What does an ectopic pacemaker do
Increases sinus rhythm
What does aerial ventricular block cause
Depolarised and contraction mean no QRS waves
What is ventricular fibrillation
The development ventricular ectopic failure-entry circuits
The AV stop beating co-ordinatidly
No QRS
fatal
Need DC electric shock
The classification of treatments
1) sodium channels (lidocaine)
2) B 1 adrenoceptor (atenolol)
3) potassium channels (amidarone)
4) calcium channels (verapamil)
5) other (digoxin)
