Ischemic Heart Disease Flashcards
What is ischemic heart disease?
narrowing of one or more coronary arteries due to atherosclerosis
What are the many names for ischemic heart disease?
coronary artery disease (CAD)
coronary heart disease (CHD)
atherosclerotic cardiovascular disease (ASCVD)
What is the most well known outcome of ischemic heart disease?
heart attack
What is the epidemiology of ischemic heart disease?
2nd leading cause of death (after cancer)
leading cause of hospitalization
#1 cause of life-years lost due to premature mortality
What are the main types of cardiovascular diseases caused by atherosclerosis?
ischemic heart disease
cerebrovascular disease
peripheral arterial disease
What is atherosclerosis called when it is present in the following: coronary artery, cerebral arteries, arteries of limbs
coronary artery disease
-major cause of myocardial infarction (heart attack)
cerebrovascular disease
-major cause of cerebrovascular accident (stroke)
peripheral arterial disease
-poor circulation, pain, numbness
What are the three presentations of coronary atherosclerosis?
silent (asymptomatic) disease=most patients
chronic, stable (exertional) angina
acute coronary syndromes (ACS)
-includes: unstable angina, NSTEMI, STEMI
Describe the symptoms of angina.
dull, retrosternal discomfort/ache/heaviness
may or may not radiate to jaw, neck, shoulders, arms
What are the two types of angina?
stable angina: problem of demand exceeding supply
unstable angina: inadequate supply regardless of demand
Describe fixed obstruction angina (stable angina).
an increase in demand that cannot be accommodated with increased supply
“demand” for oxygen increases when cardiac myocytes increase energy expenditure
angina pain that is NOT associated with plaque rupture
What will cause an increased demand for blood?
heart rate
blood pressure
venous return
contractility
exertion, emotion, stress
What are real world examples for triggers of stable angina?
SNS activity: physical exertion, emotion, stress
exertion after a heavy meal (SNS and metabolic demands)
metabolic demands imposed by:
-chills, fever, hyperthyroidism, tachycardia, exposure to cold,
and hypoglycemia
anemia
Which arteries are supplied during diastole?
coronary arteries
When will endocardial vessels be fully dilated under resting conditions?
if epicardial vessels are obstructed over 70-75%
True or false: for a vessel with epicardial vessel plaque that is dilated at rest, it can dilate further during exercise
false
its maximally dilated at rest, thus exercise creates ischemia and thus the symptoms of angina appear
What are some additional issues in fixed obstruction angina?
endothelial dysfunction (decreased NO production)
microvascular dysfunction (poor response to NO)
What is a rare form of angina that is due to vasospasm?
Prinzmetals angina/variant angina
When does the pain occur from stable angina?
during conditions of increased demand
How is stable angina relieved?
rest and nitroglycerin
Describe nitrates.
a class of medications that cause vasodilation
all are prodrugs (not active when administered)
converted to NO
What is nitric oxide?
a paracrine hormone synthesized by endothelial cells to signal to smooth muscle cells next door
relaxes smooth muscle in blood vessel walls
What does nitroglycerin target?
veins
What is preload?
the degree to which the myocardium is stretched before it contracts
increased preload=increased work of the heart
Describe the grading of angina.
class I: ordinary physical activity does not cause angina,
strenuous or prolonged exertion causes angina
class II: slight limitation of ordinary activity, angina occurs on
walking or climbing stairs rapidly
class III: marked limitations of ordinary physical activity
class IV: inability to carry on any physical activity, symptoms
may be present at rest
What is exercise stress testing?
occurs on a treadmill or stationary bike
patient hooked up on a ECG, heart rate and bp monitor
exercise is initiated slowly and slowly builds
it is stopped if chest pain, ST changes, decrease in bp>=10mmHG
What is a classic sign of cardiac ischemia?
ST depression
-common way to establish stable angina
-does NOT indicate if myocardial cell death has occurred
True or false: stable angina is not a medical emergency
true
What is commonly performed to evaluate coronary artery blood flow?
cardiac catherterization and angiography
-identify locations of narrowed vessels due to atherosclerosis
Name the core medication therapy for patients with CAD.
ABCKDE
antiplatelets
blood pressure medications (not necessarily for bp)
cholesterol-lowering medications
K-CKD (CKD often present with CAD)
diabetes medications
exercise/diet/lifestyle changes (stress, alcohol, tobacco)
What is an agent (aside from nitrates) that should be considered in all patients with stable ischemic heart disease?
ACEI
ARBs used in patients with intolerance to ACEI
What are the drugs that have an indication to prevent or reduce the frequency/intensity of stable angina episodes?
beta blockers
non-DHP CCBs
DHP CCBs
nitrates
ranolazine
How do beta blockers work for angina?
prevents angina by reducing contractility to decrease demand
When should beta blockers be used first line for stable angina?
first-line for stable angina in people with another indication for beta blockers:
-systolic heart failure
-post MI
evidence for the above has made it first line in almost all cases of SIHD
How is the dose titrated for beta blockers in stable angina?
dose titrated to a resting heart rate of 55-60bpm
Which beta blockers are used in stable angina?
all BB are effective equally to prevent angina
B1 selective agents preferred due to lower risk of:
-erectile dysfunction (B2-blockade)
-peripheral circulation problems (esp in pts with PAD)
-interaction with B2 agonists
Which beta blockers should be avoided for stable angina?
BB with ISA (e.g., acebutolol)
Describe the monitoring of beta blockers.
decreased heart rate and bp–>AV block or low HR
signs of poor cardiac output–>exercise tolerance or decreased renal perfusion (RAAS/edema etc)
reduced circulation–>caution in Raynaud’s/PAD (esp B2)
respiratory disease (asthma)–>generally safe
diabetes–>can mask hypoglycemia
What are the non-selective beta and alpha blockers?
carvedilol and labetalol
not typically used for stable angina (unless complications exist)
What is the main difference between non-DHP CCBs and beta blockers?
intensity of action
What can non-DHP CCBs inhibit?
3A4 (its also a substrate)
When should non-DHP CCBs be avoided?
systolic dysfunction
already using a beta blocker
bradycardia or AV block
What is the difference between a 1st degree, 2nd degree, and 3rd degree AV block?
1st degree: P-R interval delay
2nd degree: intermittently dropped QRS
3rd degree: P and QRS are independent
What is a 2nd or 3rd degree AV block a contraindication for?
beta blockers and non-DHP CCB
UNLESS A PACEMAKER IS PRESENT
True or false: bradycardia or first degree heart block can occur from non-DHP CCB or BB
true
When are DHP CCBs used for stable angina?
can be safely combined with BB if symptoms persist
good alternative as monotherapy for patients with bradycardia or intolerance to BB
How can nitrates be used for angina?
prn use (treatment): sprays or tablets
prevention: NTG patch
Why are nitrate-free intervals required?
to prevent tolerance
unknown mechanism