Ischemic Heart Disease Flashcards
What is Myocardial ischemia?
refers to angina pectoris
disorder usually caused by a critical coronary artery obstruction/ atherosclerotic coronary artery disease (CAD).
occurs when blood flow to the heart muscle (myocardium) is obstructed by a partial or complete blockage of a coronary artery by a buildup of plaques (atherosclerosis). This narrows the artery causing a temporary lack of oxygen-rich blood to the heart.
What is myocardial infarction?
Refers to a heart attack.
Is caused when a plaque ruptures forming a blood clot that can get trapped in narrowed arteries and completely cut off blood flow.
What are the symptoms of Myocardial ischemia/Angina?
The sudden severe, pressing chest pain occurs, starting from substernal and radiate to left arm and back of the neck.
Describe the process of plaque formation.
A plaque develops is arteries wall.
It grows/builds up over time.
Eventually it ruptures.
A clot forms around the rupture blocking blood flow.
The harder the heart is working the more oxygen & nutrients it needs.
T/F
True
There are 4 types of acute coronary syndrome.
- Stable angina
- Unstable angina
- NSTEMI
- STEMI
Explain Stable angina.
Remember this type is predictable.
pain occurs when increased myocardial demand is required but vessel is unable to dilate to allow adequate blood flow.
Atherosclerotic plaque is stable
ECG and troponins are normal.
Explain Unstable Angina.
Remember this type has no relief with GTN.
pain even at rest and it progresses rapidly over a short period of time.
Plaque partially ruptures and thrombus forms causing partial occulsion of the vessel.
Does not cause permanent heart damage.
Troponins are normal
But ECG can be normal, T waves can be inverted or ST depression.
Explain NSTEMI.
Remember this is the most common type and intermediate type of ACS.
Plaque ruptures and thrombus forms causing partial occulsion of the vessel causing injury and subendocardial myocardium infracts.
Troponins elevate and
ECG can be normal, T waves can be inverted or ST depression.
Explain STEMI.
Remember this type refers to the worst scenario and refers to a classic heart attack.
Complete occlusion of vessel lumen causing transmural injury and myocardium infracts.
causes extensive heart damage.
Troponins elevate and
ECG shows hyperacute T waves and ST elevation.
What are Principal Goals of Therapy for ACS?
- Correct O2 demand vs supply imbalance.
- reduce pre-load on the heart.
- improve coronary artery circulation.
- reduce ionotropic and chronotropic activity of myocardium which lowers O2 demand.
- Stop the formation of fibrin clots and progression of thrombus.
- Prevent myocardial infarction
What is preload?
What is ionotropic force?
What is chronotropic rate?
What is Afterload?
amount of blood returning to be pumped out.
force of heart contraction.
speed of heart rate
How much resistance the heart has to pump against
What are the types of angina pectoris?
1.Classical/ Stable: due to atherosclerosis
2. Unstable: due to progressive occulsion, rupture of atheromatous plaque and platelet aggregation at plaque.
3. Variant or Prinzmetal’s : due to coronary vasospasm.
What are the Conditions that decrease O2 supply?
- Coronary Artery Disease
Accumulation of plaques, Platelets aggregation
as well as Stenosis/spasm/constriction all narrow or block blood vessels. - vessel constriction can reduce blood flow to heart. (not due to plaques)
- Decrease Hb levels in anaemic conditions or Normal blood flow and supply but a decrease in O2 carrying capacity.
What are the signs and symptoms of myocardial infraction?
Remember some people especially females can experience silent ischemia with no symptoms.
Chest pain (left-side)
Neck or jaw pain
Shoulder or arm pain
Clammy skin
Nausea & vomiting
What causes Myocardial infraction (MI)
Coronary artery diseases
Blood clot
Coronary spasm
What factors increase the risk of MI?
Tobacco use
diabetes
High B.P
High blood cholesterol or triglyceride levels
Lack of physical activity
Obesity
Family history
What are some Further treatment or Surgical procedures for treating MI
- Angioplasty and stenting (Percutaneous Coronary Intervention PCI)
- Coronary artery by-pass surgery
With stenting, use antiplatelet therapy for 1-2 years to prevent platelets from adhering to stent.
Acute Treatment for Heart Attack
(On the Way to the Hospital & In the Emergency Room)
On route to hospital
1. 1-3 s/l GTN tablets or sprays every 5 mins - coronary dilation & reduce workload heart
2. Aspirin 300/325mg - inhibits platelet aggregation
3. Clopidogrel 300mg- inhibits platelet aggregation
clopidogrel is a prodrug so it needs to be broken down to use. 1/3 of people in Trinidad and Tobago don’t have enzyme to break it down so it becomes useless.
At emergency (Hospital Treatment)
1. Morphine and antiemetic
2. Oxygen
3. IV GTN / GTN patch
4. Enoxaparin- a low molecular weight heparin/anticoagulant.
5. Tenecteplase- fibrin-specific tissue-plasminogen activator.
How does Tenecteplase work?
It binds to fibrin-rich clots and cleaves the Arg/Val bond in plasminogen to form plasmin. Plasmin in turn degrades the fibrin matrix of the thrombus, thereby exerting its thrombolytic action.
How does arachidonic acid regulating platelet activity?
Prostacyclin (PGI2) and Thromboxane (TXA2) are key Products Formed from Arachidonic Acid.
PGI2: made by vascular endothelium lining of vessels.
acts as a vasodilator and inhibits platelet aggregation.
Helps protect against arterial thrombosis (blood clots)
TXA2 :Is a vasoconstrictor.
inhibits adenylyl cyclase and lowers the cAMP concentration which accelerates platelets aggregation
Both regulate the platelet’s ability to aggregate.
When a blood vessel is damaged, collagen in the sub-endothelial matrix is exposed, which triggers platelet attachment and they release TXA2. This starts clotting.
Dyspepsia:
Erosive Gastritis:
Peptic Ulcers with Bleeding & Perforation:
Dyspepsia (Indigestion) – Mild stomach discomfort, bloating, or nausea.
Erosive Gastritis – Inflammation of the stomach lining, which can cause pain and irritation.
Peptic Ulcers with Bleeding & Perforation –
Ulcers (sores) form in the stomach or intestines due to acid damage.
In severe cases, ulcers can bleed (internal bleeding) or perforate (create a hole) in the stomach, which is a medical emergency. 🚨
Myopathy
Myositis
Rhabdomyolysis
Myopathy (muscle pain)
Myositis (muscle weakness)
(Severe Muscle Breakdown)
