Ischemic Heart Disease Flashcards
Results from an imbalance between the heart’s blood supply and its requirement for oxygen, i.e., inadequate perfusion
ischemic heart disease/coronary artery disease
compromises the ability to provide nutrients, remove waste products
ischemic heart disease/coronary artery disease
__% of ischemic heart disease cases is due to _______ coronary blood flow due to coronary artery _________ (with or without ________)
90% of ischemic heart disease cases is due to reduced coronary blood flow due to coronary artery atherosclerosis (with or without thrombosis)
what are some other causes of IHD
- reduced blood supply
- severe anemia
- pulmonary disease
2 major epicardial coronary arteries
- right coronary artery
- left common coronary artery
Supplies the right wall, posterior wall, posterior septum (80% people)
right coronary artery
Supplies the apex, left anterior wall, anterior septum
left anterior descending artery (LAD)
Supplies the lateral left (80% people)
left circumflex artery
What does the left common coronary artery branch into?
- left anterior descending artery
- left circumflex artery
Smaller branches off of the coronary arteries perfuse the myocardium
intramural arteries
When the left ventricle contracts, the aortic valve _____. The valve cusps ______ filling of the coronary arteries.
When the left ventricle contracts, the aortic valve opens. The valve cusps prevent filling of the coronary arteries.
When the left ventricle relaxes, aortic pressure ____ the aortic valve, allowing the coronary arteries to ____.
When the left ventricle relaxes, aortic pressure closes the aortic valve, allowing the coronary arteries to fill.
Conditions that aggravate IHD include:
- conditions that increase cardiac energy demand
- conditions that reduce availability of blood or oxygen to the myocytes
examples of conditions that increase cardiac energy demand
- hypertrophy
- increased rate i.e. via epinephrine, activity, cold
examples of conditions that reduce availability of blood or oxygen to the myocytes
- reduced blood pressure i.e. anemia, shock
- low oxygen tension
IHD is generally related to ________ chronic ________ of _______ arteries
IHD is generally related to atherosclerotic chronic inflammation of coronary arteries
What are results of atherosclerotic chronic inflammation of coronary arteries?
- stenosis - narrowing of coronary arteries
- increases risk of thrombus formation and total vessel occlusion and/or embolus formation
What is increased risk of thrombus formation and total vessel occlusion and/or embolus formation associated with?
- rupture of fibrous cap of unstable plaques
- erosion through fibrous cap
- hemorrhage into plaque
manifestations of IHD
acute coronary syndrome (ACS)
examples of acute coronary syndromes
- Chronic ischemic heart disease
- Angina pectoris
- Acute coronary syndrome
- Acute myocardial infarction (AMI) – myocardial death resulting from a period of ischemia
- Sudden cardiac death
chronic restriction of blood flow to cardiac tissue resulting in ischemia
(chronic) ischemic heart disease/coronary artery disease
What is the most common cause of chronic ischemic heart disease?
result of atherosclerotic plaque formation in coronary arteries
most common symptom of acute ischemia
angina
What are some things IHD can result in?
- myocardial cell death
- dilated cardiomyopathy
- myocardial infarction
- arrhythmias
Weakening of cardiac muscle, resulting in stretch and reduced cardiac output
dilated cardiomyopathy
A collection of symptoms resulting from coronary blood flow that does not meet current oxygen demand of the heart tissue (i.e., chronic ischemic heart disease)
angina pectoris
symptoms of angina pectoris
- paroxysmal (sudden onset)
- recurrent substernal or precordial/retrosternal discomfort
3 types of angina pectoris
- stable angina
- unstable angina
- prinzmetal angina
Associated with reduction of coronary perfusion to a critical level by chronic stenosing coronary atherosclerosis
stable angina
when oxygen demand exceeds available what is delivered by the blood supply, therefore myocardium becomes temporarily ischemic
stable angina
Is angina pectoris associated with myocyte death?
not necessarily
Is stable angina associated with plaque disruption?
NO
What are typical symptoms for patients with stable angina?
REVERSIBLE with rest, oxygen, vasodilators
A pattern of angina pain which changes progressively over a short period of time
unstable angina
increased frequency, duration, pain level, precipitated by less effort or occurs at rest
unstable angina
Is unstable angina associated with plaque disruption?
YES
What are some subsequent conditions follow plaque disruption?
- thrombosis
- embolization
- coronary vessel spasm
What is often a program to MI?
unstable angina
Caused by reduction of coronary perfusion due to coronary artery spasm
prinzmetal angina
type of angina NOT associated with increased activity, heart rate, blood pressure
prinzmetal angina
Can EKG changes associated with ischemia be seen with prinzmetal angina?
yes
type of angina where Symptoms occur more commonly at rest and in younger patients
prinzmetal angina
refers to the signs and symptoms associated with acute ischemia of the myocardium
acute coronary syndrome (ACS)
What is the initial stage of acute myocardial infarction associated with?
acute thrombus formation
What may result in minimal permanent cardiac damage? (e.g., angioplasty, thrombolytics)
rapid tissue reperfusion
What may be associated with ACS?
- EKG changes including ST elevation or depression
- unstable angina
- characteristic symptoms including chest pain/pressure, radiation to the left arm or jaw, diaphoresis, nausea
Results from irreversible ischemia-related injury to myocardial tissue
acute myocardial infarction
2 types of AMI
- subendocardial
2. trasmural
involves the innermost 1/3 to 1/2 of the thickness of the heart wall at the affected area
subendocardial infarct
Blood supply to subendocardial region is most limited due to what?
normal narrowing of intramural arteries
What may result from subencocardial infarct?
- reduced blood pressure
- severe anemia
involves the full thickness of the heart wall at the affected area
transmural infarct
What is transmural infarct associated with?
thrombus blocking blood flow
Acute myocardial infarction progresses from ______ infarct to ______ infarct
Acute myocardial infarction progresses from subendocardial infarct to transmural infarct
consequences of AMI
- contractile dysfunction
- conduction disturbances
- myocardial remodeling
- pericarditis
- infarct expansion
- mural thrombus formation
related to loss of contractile myocardium and replacement with fibrotic tissue, resulting in weak and/or poorly coordinated contraction
contractile dysfunction
due to infarction of conductive tissues resulting in arrhythmia or “myocardial instability”
conduction disturbances
increased likelihood to change to uncoordinated rhythms such as fibrillation, bundle branch blocks
conduction disturbances
remodeling with ventricular walls and septum thinning (aneurysm), and detachment of papillary muscles
myocardial remodeling
associated with new post-AMI systolic murmur
detachment of papillary muscles
causing inflammatory fluid accumulation in the pericardial space
pericarditis
types of pericarditis
- serous
- fibrinous
- fibrohemorrhagic
stethoscope finding for pericarditis
friction rub
expansion around an area of recent infarct due to further compromise of blood flow
infarct expansion
Where does a mural thrombus form?
on wall of affected chamber
What is the risk for mural thrombus formation?
thromboembolism - usually going to CNS
unexpected death from cardiac causes early after symptom onset, or without onset symptoms
sudden cardiac death
What is SCD usually related to?
lethal arrhythmia
possible causes of SCD
- Congenital structural or conduction abnormality
- Aortic valve stenosis or mitral valve prolapse
- Myocarditis
- Dilated or hypertrophic cardiomyopathy
- Pulmonary hypertension
