Ischemic Heart Disease Flashcards
What are the two main causes of ischemic heart disease?
Atherosclerotic and non-atherosclerotic
What are atherosclerotic causes of coronary heart disease?
Angina pectoris and acute coronary syndrome
What are the two branches of acute coronary syndrome?
STEMI (st-elevation MI) and NSTEMI (non-st elevated MI)
Explain ischemia:
Decreased blood supply to the myocardium or increased demand for blood
Explain infarction:
Death or necrosis of tissue with results from prolonged ischemia or total occlusion of blood flow to the tissue
What are the most common causes of ischemia?
Coronary arterial disease (plaque in the vessel which impedes blood flow), and increased metabolic demand:
- Hypertrophic cardiomyopathy
- Aortic stenosis
Describe stable angina:
Predictable, regular chest pain that is manageable
Describe unstable angina:
Non-predictable, intense, medication helps minimally
What are two other types of angina?
Variant angina and microvascular angina
What is variant angina also known as?
Prinzmetals Angina (caused by coronary artery spasm, occurs in between 1-6 am, unrelated to exercise)
What is microvascular angina due to?
Microvascular dysfunction
What is CABG?
Coronary Artery Bypass Graft
What happens in CABG?
GSV or internal mammary artery harvested, one end proximal and other distal to blockage
When is CABG performed?
When angioplasty (balloon and stent) cannot be done:
- When blockage is unreachable percutaneously
- Too many blockages to stent (>3-4)
What is the treatment for ischemia/angina/chest pain?
Nitroglycerine (nitrates) are given (pills/spray/aspirin) to lower cause vasodilation (reduces arterial resistance and causes veinous congestion reducing preload).
What is used to prevent thrombi?
- Antiplatelet drugs: ASA/Aspirin, plavix
2. Anticoagulants: Warfarin/coumadin, pradax
What are the downsides to CABG? (3)
- Higher mortality rates than angioplasty
- Longer recovery time
- Cant be done on weak patients
What do beta blockers do?
Lower HR, BP, and afterload (lowers O2 demand)
What do calcium channel blockers do?
Lower muscle contraction lowering after load
What is the gold standard for IHD diagnosis?
Coronary angiogram
What is the treatment for MI?
MONA (done within 5 mins):
Morphine Oxygen Nitrates (NOT if low BP or viagra) ASA/Aspirin 1. Heparin 2. Thrombolysis 3. Reperfusion (CABG/PCI)
What is TPA?
Tissue plasminogen activator - most effective MI clot busting medications
What are the types of TPA?
- Streptokinase
2. Urokinase (from human and pig urine)
What do TPA (streptokinase and urokinase) do?
Cut the chains of plasminogen which prevents them from forming strands or fibrinogen that cause blood clots.
What is STEMI? (4)
- Transmural (occurring through whole thickness of the myocardium endo to epi)
- Anterior MI (anterior leads)
- ST segment is elevated
- Big Q wave
How will the ST segment appear with STEMI MI?
Elevated
What is NSTEMI? (4)
- Small zone of ischemia/cell death
- Subendocardial MI only
- ST segment is depressed
- no Q wave
NSTEMI is what kind of MI only?
Subendocardial MI only
How will the ST segment appear with NSTEMI MI?
Depressed
What does a big Q wave indicate?
A big heart attack (untreated ST elevation) lead to necrosis
ECG change to peaked T waves indicates what?
Acute MI
Symmetric flat or reversed T waves indicates what?
Chronic ischemia
The left main coronary artery branches to what?
LAD, Cx, and RCA
LAD supplies what walls?
Anterior and septal walls
Cx gives rise to what in a left dominant system?
PDA
RCA usually supplies what?
SA and AV nodes
RCA gives rise to what in a right dominant system?
PDA
Abnormal septal motion may be seen with what?
LBBB, WPW (Wolf-Parkinson white syndrome), or paced rhythms
Define sygmoid septum:
Basal septal focal hypertrophy
Describe the hemodynamic properties of a sygmoid septum:
Subaortic stenosis, LVOT acceleration
Describe the wall motion of a sygmoid septum:
Hypokinetic
IHD/CAD could result in what kind of dysfunction?
Papillary muscle dysfunction
Thrombus formation in the LV is more common with MI’s located where?
Anterior
What are the applications for LV contract enhancement?
- Detect intracardiac shunts
- Enhance Doppler signals
- LV opacification
- Myocardial perfusion
Describe a VSD or wall rupture post MI
- MI damages the wall
- Wall thins and becomes necrotic
- Wall weakens
- Wall ruptures
- Shunt occurs
What is Dressler’s syndrome?
Acute pericarditis post infarct
What are the 3 main features of Dressler’s syndrome?
- Fever
- Pleuritic pain
- Pericardial effusion
- Tamponade: rare
How quickly does the survival rate of MI drop with no pulse?
10% every min
Need CPR and defibrillation (AED)
What does the elevation/depression of the ST segment indicate?
Elevation above TP segment = infarct
Depression lower than TP segment = ischemia
List 2 enzymes released during myocardium injury?
- CKMB
2. Troponin C
What direction would the MR jet aim if there was a large inferior MI. And why?
Anterior
Due to posteromedial papillary muscle dysfunction