IHD Flashcards
(29 cards)
What diseases are classified as ischaemic?
Angina and MI
what is the severity of IHD dependent on?
Duration of the ischaemia
The rate at which blood flow is reduced
The extent of blood flow decrease
What conditions can lead to IHD
Atherosclerosis and thrombosis
What factors increase the risk of formation of plaques?
*BAD HEART
Bmi
Age
Diabetes
Hypertension
Ethnicity
An increase in ldl decrease in hdl
Relatives
Tobacco
What is the physiological cause of IHD?
- Reduction in oxygen supply e.g
Atherosclerosis
Thrombosis
Vasopasm
Vessel inflammation - Increase in demand e.g
Tachycardia
Thick myocardium
Over exertion
What is mild transient ischaemia?
Angina pectoris
What is prolonged ischaemia
Myocardial infarction.
Irreversible damage leading to cardiac necrosis
What is stable angina
- When there is an obstruction in the artery so less blood flow
- Has a fibrous plaque so it does not rupture
- It is exercise induced
- Symptoms relieved by resting
What is unstable angina
-Caused by either a rupture of an atherosclerotic plaque which causes a plug formation or a thrombus
- induced at rest
- requires urgent treatment as it can lead to m.i
What is a Subendocardial infarction (NSTEMI)?
-caused by a rupture of a plaque or atherosclerosis
- developed at rest
- blood flow reduction is to the extent that cells can die
-PARTIAL OCCLUSION OF LUMEN
-30 minutes + of ischaemia
What is a transmural infarction (STEMI)?
- caused by rupture of atherosclerosis plaque or a thrombus
-develops at rest
-blood flow reduced entirely - the ruptured plaque then blocks the whole lumen
What are the two treatment strategies of angina
- Drugs to reduce atherosclerosis i.e statins
- Drugs for pain and prophylaxis
What is the treatment aim of angina
- Increasing oxygen supply
- Decrease the demand
How do beta blockers help IHD
- block the effect of catecholamines (noradrenaline and adrenaline) on the heart
- reduce cardiac work so slower heart rate
-reducing oxygen demand
Types of beta blockers
Atenelol
Metoprolol
Propanalol
What are beta blockers contraindicated in?
Asthma because of the b2 receptor activity
What do organic nitrates do?
Vasodilators that act on the peripheral circulation
Reduce oxygen demand and preload increase supply
What is the MOA of organic nitrates ie.GTN (DACPPV)
Danny Always Calls Puny Patrick Vile
Decompose to form NO
Activating guanlyl cyclase
CGMP is increased
Protein kinase G is activated
Proteins are phosphorylated
Vasodilation occurs
What are common nitrates used
GTN (glyceryl trinitrate or nitroglycerin
isosorbide dinitrate/mononitrate
When is GTN or isosorbide used?
GTN is used during an attack
Isorbide to prevent an attack
A patient takes nitrate and is still experiencing pain why is that and how can this be solved
Anginal pain can become unresponsive to nitrates especially during prophylaxis so to combat this make sure the patient has drug free periods without GTN
What do potassium channel openers do? E.g nicorandil
- Activates KATP channels
- Hyperpolarizes the membrane and reduces electrical excitability
What is the secondary prevention of arterial thrombus formation?
75mg aspirin daily
What is the management of unstable angina and MI
300mg aspirin
GTN
