Ischemic Heart Disease Flashcards
What are the risk factors for ischemic heart disease?
30% surgical pts
Angina pectoris, acute MI, and sudden death
Dysrhythmias
The two most important risk factors for the development of atherosclerosis involving the coronary arteries are _____ and increasing ______
male gender; increasing age
Angina pectoris is caused by ____
Imbalance between coronary blood flow (supply) and myocardial oxygen consumption (demand)
Stable angina typically develops in the setting of _____ occlusion or significant (>70%) chronic narrowing of a segment of coronary artery.
partial
_______ is the most common cause of impaired coronary blood flow resulting in angina pectoris, but it may also occur in the _____ of coronary obstruction as a result of myocardial hypertrophy, severe aortic stenosis, or aortic regurgitation
atherosclerosis ; absence
What can induce angina?
Physical exertion, emotional tension, and cold weather may induce angina
Which statement best describes chronic stable angina?
Chronic stable angina refers to chest pain or discomfort that does not change appreciably in frequency or severity over 2 months or longer.
chronic angina pectoris that becomes more frequent and more easily provoked
Describe unstable angina
angina at rest (typically lasting >10 minutes unless interrupted by antianginal medication),
Do patients with typical ECG evidence of AMI need an echo?
no
Troponin levels remain elevated for bumps in ___ hours, elevated for up to 2 weeks
3-4 hours
Cardiac labs
Troponin levels remain elevated for: bumps in 3-4 hours, elevated for 7-10 days
Greater the level of troponin the larger the MI
The greater the degree of _________ , the greater the likelihood of significant coronary artery disease.
ST-segment depression
Look at Picture
:) you can do it
What results in sudden cardiac death
overdose, cardiomyopathy, atherosclerosis
What results in coronary bloodflow being decrease?
reduction in lumen size, MI, hypotension
- we cause hypotension
What are signs you’ll see during anesthesia that they are having low coronary blood flow?
EKG changes
Stable angina is chest pain that ____ _____ with rest
goes away
When you have angina you’ll see slow ___ _____ and _____ cardiac contractility
What causes these changes?
AV conduction; decrease
Adenosine and bradykinin release
There are weird presentations of cardiac pain in ___ and _____
diabetics and women
How to differentiate cardiac from other pain?
touch it, give GI cocktail, if its pericarditis they will feel better with sitting up
- could be PE and you will see it on a blood gas. They could be confused and air hungry
- AAA: tearing pain in the back and chest
Unstable angina
Chest pain increasing in frequency and/or severity without increase in cardiac biomarkers
- no increase in CKP
-chronic angina pectoris that becomes more frequent and more easily provoked
- new-onset angina that is severe, prolonged, or disabling
chronic stable chest pain can be caused by
- distal occlusions
After a EKG and labs are done for a chest pain patient, what else would you do?
Stress test
- ____ stress test is more accurate because it provides nuclear imaging
- The greater the size of perfusion abnormality = ??????
- What does a nuclear stress test show us?
- Chemical
- Size of perfusion abnormality = significance of CAD detected
- Assesses coronary perfusion
Tracer activity in perfused vs ischemic areas
Size of perfusion abnormality = significance of CAD detected
Estimates LV systolic size and function
Differentiates new perfusion abnormality vs. “old” MI
what abnormality can you see on an ultrasound with chest pain?
- valve function
- wall motion abnormalities
gold standard for looking at coronary blood flow is
angiography
- can see little. occlusions that result in hypoperfusion
How do we treat stable angina?
- reverse reversible factors (DM, weight, get off the couch, GLP-1)
- treatment of HTN
What is the dose for daily aspirin?
75-325mg/day
“Baby aspirin” is 81mg/day
What is the life span of a platelet
7-14 days
Platelet glycoprotein IIb/IIIa receptor antagonists (abciximab, eptifibatide, tirofiban) work by…..
Inhibit platelet activation, adhesion, and aggregation
- given IV
Clopidogrel is _____
irreversible
- just like the other drugs
How do you assess platelet function?
Platelet function panel and TEG (thromboelastagram)
Effient is very ___
predictable
- cardiologist will use this pre or post intervention for a cath
Patients who take chronic nitrates ____________ respond well to doses
do not
- they wont respond
what is the only medication that prolongs life span with CAD?
beta blockers
- when you induce anesthesia you will see an induced hypotension
With beta 2 blockers we would worry about what complications?
pulmonary
propranolol is used for __ and ____
anxiety and tremors
describe the difference in metoprolol, esmolol, and labetolol
metoprolol is more for contractility and esmolol is more for HR
labetolol is in the middle
When do you start a patient on a CCB?
when the BB doesn’t work
ACE inhibitors are very ____
cheap
- patients will be put on this early because it isnt expensive
Why do we put patients on statins
Small reduction in mortality in patients undergoing surgical procedures
- coronary plaque stabilization
2 primary interventions for revascularization are
CABG and PCI
- over 50% LAD occlusion = CABG
- over 70% epicardial coronary artery = CABG
- impaired EF < 40% = CABG
What do we do in PCI?
- angioplasty: balloon into the plaque and pushing it against the wall
- placement of a stent and then use the balloon to open the stent
- transluminal interventions: grinds the plaque off the walls of the vessels
ACS is
Acute or worsening imbalance of myocardial oxygen supply to demand
ACS chart
STEMI Diagnosis
How do you know if the patient has a new LBBB?
must have an old 12 lead
Troponin is more specific for ____ than CK-MG
cardiac damage
Troponin
Increase within ___ hours after myocardial injury
3
Drug therapy for ACS
MONA????
Oxygen
Aspirin
Morphine causes hypotension – fentanyl is starting to be used
Torodol – decreased ???
Nitrates
P2Y12 inhibitors (clopidogrel, prasugrel, or ticagrelor)
Platelet glycoprotein IIb/IIIa inhibitors
Unfractionated heparin
β blockers
RAAS
What medications are in reperfusion drug therapy
TPA, streptokinase, reteplase, tenecteplase
What is the time frame for thrombolytics
should be initiated within 30 to 60 minutes of hospital arrival and within 12 hours of symptom onset. Thrombolytic therapy restores normal antegrade blood flow in the occluded coronary artery.
indications for PCI
Indications
Contraindication to thrombolytic therapy
Severe HF and/or pulmonary edema
Symptoms present for 2 - 3 hours
Mature clot
Causes of unstable angina
chronic angina patients will have very ____ blood flow through their vessels
litte
Do we use thrombolytics for NSTEMI?
no
What is DAPT therapy
Dual antiplatelet therapy
ASA and P2y12 inhibitor
if a patient has had coronary intervention you dont want to take them to the OR for ____ to a _____
6 months to a year
Reendothelialize after balloon angioplasty - 2–3 weeks
bare-metal stent placement - 12 weeks
drug-eluting stent - a full 1 year or longer
You can give a 1:1 ratio of glycopyrrolate and neostigmine to reduce ____
reduce the bradycardia with neostigmine
RCRI test
What are the active cardiac conditions we worry about?Unstable coronary syndromes
- Acute (MI ≤ 7 days) or recent MI (>7 days but ≤ 1 month ago) with evidence of important ischemic risk
- > 60 days post MI ideal
Unstable or severe angina
Decompensated heart failure
Severe valvular heart disease
- Severe aortic stenosis or severe mitral stenosis
Significant dysrhythmias
- High-grade atrioventricular block, Mobitz type II atrioventricular block, third-degree heart block, and symptomatic supraventricular and ventricular tachydysrhythmias
Age
How do you prevent ischemia in the OR?
Prevent
- Persistent tachycardia
- Systolic HTN
- SNS stimulation
- Arterial hypoxemia
- Hypotension
Etomidate will be induction of choice
May want an arterial line before induction
What is the first manifestations of ischemic heart disease? (there are 3)
angina pectoris
acute MI
sudden death
explain how adenosine and bradykinin release cause chest pain?
These substances stimulate cardiac nociceptive and mechanosensitive receptors whose afferent neurons converge with the upper five thoracic sympathetic ganglia and somatic nerve fibers in the spinal cord and ultimately produce thalamic and cortical stimulation that results in the typical chest pain of angina pectoris.
Describe EKG changes associated with ischemic heart disease?
12 lead ECG – GOLD standard
ST segment depression
Associated T wave inversion
ST elevation
ST-segment depression (characteristic of subendocardial ischemia) that c
**resting electrocardiogram (ECG) may be normal in patients with angina, or it may show nonspecific ST–T-wave changes or abnormalities related to an old MI.
Patients with chronically inverted T waves resulting from previous MI may show a return of the _____ to the normal upright position (pseudonormalization of the T wave) during myocardial ischemia
T waves
during an exercise stress test how would you know the patient have IHD?
At least 1 mm of horizontal or downsloping ST-segment depression during or within 4 minutes after exercise. The greater the degree of ST-segment depression, the greater the likelihood of significant coronary artery disease.
what are the tracers involved in a nuclear stress test?
how do the tracers work?
Tracers - thallium and technetium
- A significant coronary obstructive lesion causes a reduction in blood flow, and thus less tracer activity is present in that area.
- Exercise increases the difference in tracer activity between normal and underperfused regions because coronary blood flow increases markedly with exercise except in those regions distal to a coronary artery obstruction
Administration of atropine, infusion of dobutamine, or institution of artificial cardiac pacing produces a rapid heart rate to create cardiac stress.
cardiac stress can be produced by administering a coronary vasodilator such as adenosine or dipyridamole. These drugs dilate normal coronary arteries but evoke minimal or no change in the diameter of atherosclerotic coronary arteries.
The _____ of the perfusion abnormality is the most important indicator of the significance of the coronary artery disease detected. in nuclear imaging
size
what are the indications for cardiac angiography?
It is indicated in patients with
- known or possible angina pectoris who have survived sudden cardiac death
- those who continue to have angina pectoris despite maximal medical therapy,
- those who are being considered for coronary revascularization,
- those who develop a recurrence of symptoms after coronary revascularization,
- those with chest pain of uncertain cause, and those with a cardiomyopathy of unknown cause
provides the best information about the condition of the coronary arteri
Does NOT measure stability of plaque
The most vulnerable plaques are those with a ____ core and lots of _____
lipid; macrophages
Vulnerable plaques (i.e., those most likely to rupture and form an occlusive thrombus) have a thin fibrous cap and a large lipid core containing a large number of macrophages. The presence of vulnerable plaque predicts a greater risk of MI regardless of the degree of coronary artery stenosis. Indeed, AMI most often results from rupture of a plaque that had produced less than 50% stenosis of a coronary artery. Currently there is no satisfactory test to measure the stability of plaques.
how does HTN increase the risk of IHD?
Hypertension increases the risk of coronary events as a result of direct vascular injury, left ventricular hypertrophy, and increased myocardial oxygen demand
when is drug treatment for IHD reccomended?
strongly recommended in patients with clinical atherosclerosis or when the low-density lipoprotein (LDL) cholesterol level exceeds 160 mg/dL (goal is >50% reduction or <70 mg/dL).
what does TXA2 do?
it stimulates activation of new platelets as well as increases platelet aggregation
Thromboxane A2 (TXA2) is a type of thromboxane that is produced by activated platelets during hemostasis and has prothrombotic properties:.
list all the possible drug therapy for IHD
* 8 were listed in lecture
- Aspirin
- Platelet glycoprotein IIb/IIIa receptor antagonists (abciximab, eptifibatide, tirofiban)
- P2Y12 inhibitors (clopidegrel and Effient)
- nitrates
- beta blockers (B1 and B2 specific)
- CCB
- ACE inhibitors
- Statins
Tell me about clopidogrel?
- prodrug
- irreversible affect to platelets
- Inhibits ADP (activates the platelets and makes them sticky) receptor P2Y12 and platelet aggregation
Effient poses a higher risk of ____ than plavix
bleeding
Prasugrel (Effient)
Similar mechanism
More predictable pharmacokinetics
Higher risk of bleeding
Nitrates are contraindicated in what two diseases?
Contraindicated with aortic stenosis and hypertrophic cardiomyopathy
What do nitrates do? How do they help the angina?
Decrease frequency, duration, and severity
Increase exercise to produce ST-segment depression
Dilate coronary arteries and collaterals
Decrease peripheral vascular resistance, which reduces left ventricular afterload and myocardial oxygen consumption.
Decreases preload —> decrease stress on LV
Potential anti-thrombotic effects
antianginal effects of nitrates are greater when these drugs are used in combination with______ or _____
BB or CCB
What drugs block only beta 1?
What does that produce?
atenolol, metoprolol, acebutolol, or bisoprolol
decrease in:
Heart rate
Diastolic time
Myocardial contractility
Myocardial oxygen demand
propranolol & nadolol activate beta 1 and _____
beta 2
watch for pulmonary complicatio
what do CCB do for IHD patients? 5 things
decrease:
Vascular smooth muscle tone
Contractility
Oxygen consumption
Systemic BP
and dilate coronaries
statins decrease what 4 things
Decreases: Lipid oxidation, Inflammation, Matrix metalloproteinase, Cell death
Reduces mortality noncardiac surgery and vascular surgery
describe what is happening in this picture
Acute or worsening imbalance of myocardial oxygen supply to demand
Atheromatous plaque —> Coagulation cascade—-> Thrombin generation—-> Arterial occlusion
Coronary angiography has documented that the majority of STEMIs are caused by ______ occlusion of a coronary artery.
thrombotic
In rare cases STEMI may be due to coronary occlusion caused by coronary emboli, congenital abnormalities, coronary spasm, or inflammatory diseases.
Which substances contribute to thrombogenesis?
Collagen, ADP, epinephrine, serotonin, Thromboxane A2, Glycoprotein IIb/IIIa receptors, Fibrin deposit
A platelet monolayer forms at the site of ruptured plaque, and various chemical mediators such as collagen, ADP, epinephrine, and serotonin stimulate platelet aggregation.
The potent vasoconstrictor thromboxane A2 is released, which further compromises coronary blood flow.
Glycoprotein IIb/IIIa receptors on the platelets are activated, which enhances the ability of platelets to interact with adhesive proteins and other platelets and causes growth and stabilization of the thrombus. Further activation of coagulation leads to strengthening of the clot by fibrin deposition. This makes the clot more resistant to thrombolysis
Contemporary studies using MRI suggest that the development of a Q wave on the ECG is more dependent on the ____ of the infarcted tissue than the transmurality of the infarction.
volume
The primary goal in management of STEMI is to reestablish ____ in the obstructed coronary artery as soon as possible
blood flow
what is the time frame for PCI
angioplasty should be performed within 90 minutes of arrival at the healthcare facility and within 12 hours of symptom onset
_____ __________ discontinuation is the most significant independent predictor of stent thrombosis
P2Y12 inhibitor
This _______ myocardial ischemia usually occurs at a heart rate and blood pressure substantially lower than that present during exercise-induced ischemia.
silent
Some patients can have ischemia but it doesnt cause pain
know it
