20 Feb IHD PPT+Lecture (Exam 2) Flashcards
What are the two most important risk factors for the development of atherosclerosis involving the coronary arteries?
Male gender and increasing age
These factors significantly contribute to the risk of ischemic heart disease.
What percentage of surgical patients have ischemic heart disease (IHD)?
30%
This statistic highlights the prevalence of IHD in the surgical population.
What are the first manifestations of ischemic heart disease?
Angina pectoris, acute MI, and sudden death
These manifestations indicate the severity of IHD.
What major cause of sudden death is associated with ischemic heart disease?
Dysrhythmias
Dysrhythmias can lead to fatal outcomes in patients with IHD.
What causes ischemia that frequently manifests as chest pain?
Imbalance between coronary blood flow (supply) and myocardial oxygen consumption (demand)
This imbalance is a key factor in angina pectoris.
What is stable angina typically associated with?
Partial occlusion or significant (>70%) chronic narrowing of a segment of coronary artery
Stable angina occurs when the heart’s oxygen demand exceeds supply.
What substances stimulate cardiac nociceptive and mechanosensitive receptors involved in angina pectoris?
Adenosine and bradykinin
These substances contribute to the sensation of chest pain.
What is the most common cause of impaired coronary blood flow leading to angina pectoris?
Atherosclerosis
Other causes may include myocardial hypertrophy and valvular diseases.
What characterizes the chest pain associated with angina pectoris?
Retrosternal chest pain, pressure, or heaviness that may radiate to any dermatome from C8 to T4
This description helps in diagnosing angina pectoris.
What can induce angina pectoris?
Physical exertion, emotional tension, and cold weather
These triggers highlight the role of external factors in angina episodes.
What is the difference between chronic stable angina and unstable angina?
Chronic stable angina does not change in frequency or severity over 2 months or longer; unstable angina includes angina at rest or an increase in frequency or severity
Understanding this distinction is crucial for clinical assessment.
What does a 12-lead ECG show in cases of angina pectoris?
ST segment depression, T wave inversion, or ST elevation
These changes are indicative of myocardial ischemia.
What is an Exercise Stress Test used for?
Detecting signs of myocardial ischemia and establishing the relationship between chest pain and exercise capacity
This test is a key diagnostic tool in assessing angina.
What indicates a greater likelihood of significant coronary artery disease during exercise testing?
At least 1 mm of horizontal or downsloping ST-segment depression during or within 4 minutes after exercise
This finding suggests more severe underlying coronary pathology.
What is the role of nuclear stress imaging?
Assess coronary perfusion by measuring tracer activity in perfused vs. ischemic areas
It is more sensitive than exercise testing for detecting ischemic heart disease.
What are the tracers used in nuclear stress imaging?
- Thallium
- Atropine
- Dobutamine
- Pacing
- Adenosine
- Dipyridamole
These tracers help visualize blood flow in the heart.
What are common treatments for angina pectoris?
Cessation of smoking, ideal body weight, low-fat diet, statins, regular aerobic exercise, and treatment of hypertension
These lifestyle changes are essential components of angina management.
What is the primary action of aspirin in the context of angina pectoris?
Inhibits COX-1, leading to inhibition of thromboxane A2 production
This action reduces platelet aggregation and thrombus formation.
What are thienopyridines and name an example?
P2Y12 inhibitors that include Clopidogrel
These medications are essential in managing patients with acute coronary syndrome.
What is the effect of nitrates on angina pectoris?
Decrease the frequency, duration, and severity of angina and dilate coronary arteries
Nitrates also reduce myocardial oxygen consumption.
What is the significance of β-blockers in CAD?
Esmolol vs Metoprolol vs Labetolol?
β-blockers are the only drug class proven to prolong life in CAD patients
* Esmolol=good for HR without much effect on contractility
* Metoprolol=good for contractility but not much effect on HR
* Labetelol=good for both
β-blockers have anti-ischemic and anti-dysrhythmic effects.
What is the role of ACE inhibitors in ischemic heart disease?
Treat hypertension, prevent ventricular remodeling, and reduce myocardial workload
They are cardioprotective and beneficial in heart failure.
What indicates the need for revascularization?
- Failure of medical therapy
- 50% L main coronary artery stenosis
- 70% epicardial coronary artery stenosis
- Impaired EF <40%
These criteria help determine the necessity for surgical intervention.
What characterizes Acute Coronary Syndrome?
An acute or worsening imbalance of myocardial oxygen supply to demand
This condition requires immediate medical attention and intervention.
What are the three types of Acute Coronary Syndrome based on ECG and biomarkers?
STEMI, Non-STEMI, and Unstable angina
This classification aids in the diagnosis and treatment strategy.
What causes STEMI?
Thrombotic occlusion of a coronary artery, coronary emboli, congenital abnormalities, coronary spasm, and inflammatory diseases
Understanding these causes is crucial for effective treatment.
What is the function of Troponin in diagnosing myocardial injury?
Troponin levels increase within 3 hours after myocardial injury and remain elevated for 7 to 10 days
Troponin levels are more specific than CK-MB for assessing myocardial damage.
What is included in the MONA protocol for STEMI treatment?
Morphine (fentanly preferred D/T no histamine release/hypotension), Oxygen, Nitrates, Aspirin
This combination helps to reduce myocardial oxygen requirements.
What is the significance of β-blockers in STEMI management?
They relieve ischemic chest pain, reduce infarct size, and manage life-threatening dysrhythmias
β-blockers are essential in the acute management of myocardial infarction.
What is the role of platelet glycoprotein IIb/IIIa inhibitors in urgent CABG?
Can be used even if urgent CABG is likely
What is frequently used in combination with antiplatelet drugs?
Unfractionated heparin
Especially if thrombolytic therapy or PCI is planned
What effects do β-blockers have?
Relieve ischemic chest pain, reduce infarct size, prevent life-threatening dysrhythmias
Who should receive β-blockers?
Patients in hemodynamically stable condition who are not in heart failure, not in a low cardiac output state, and not at risk of cardiogenic shock
Who should not receive β-blockers?
Those with heart block
What should be avoided in patients with STEMI?
Glucocorticoids and other NSAIDs (except for aspirin)
When should thrombolytic therapy be initiated in STEMI?
Within 30 to 60 minutes of hospital arrival and within 12 hours of symptom onset
What does thrombolytic therapy do?
Restores normal antegrade blood flow in the occluded coronary artery
When is PCI preferable to thrombolytic therapy?
If appropriate resources are available
When should PCI be performed?
Within 90 minutes of arrival at the healthcare facility and within 12 hours of symptom onset
PCI is the treatment of choice in patients with what conditions?
- Contraindication to thrombolytic therapy
- Severe heart failure and/or pulmonary edema
- Symptoms present for at least 2 to 3 hours
- Mature clot
What enhances the chance of achieving normal antegrade coronary blood flow during emergency PCI?
Combined use of intracoronary stents and antiplatelet drugs
What is the benefit of CABG in STEMI?
Restores blood flow in an occluded coronary artery, but reperfusion is faster with thrombolytic therapy or coronary angioplasty
When is emergency CABG reserved for patients?
- Coronary anatomy that inhibits PCI
- Failed angioplasty
- Evidence of infarction-related ventricular septal rupture or mitral regurgitation
What causes Unstable Angina/NSTEMI?
- Rupture or erosion of a coronary plaque
- Nonocclusive thrombosis
- Dynamic obstruction due to vasoconstriction
- Worsening coronary luminal narrowing
- Inflammation
- Myocardial ischemia due to increased oxygen demand
What are the symptoms of Unstable Angina/NSTEMI?
- Angina at rest, lasting >10 minutes
- Chronic angina pectoris with a crescendo pattern
- New-onset angina that is severe, prolonged, or disabling
What does the management of Unstable Angina/NSTEMI consist of?
- Acute phase to decrease myocardial oxygen demand and stabilize lesions
- Longer-term phase to prevent disease progression and plaque erosion
What therapies are recommended for Unstable Angina/NSTEMI?
- Bed rest
- Oxygen
- Analgesia
- β-blocker therapy
- Sublingual or IV nitroglycerin
- Calcium channel blockers if ischemia persists
- Antiplatelet therapy (aspirin, clopidogrel, etc.)
- Heparin therapy
- Fondaparinux as an anticoagulant
Is thrombolytic therapy indicated in UA/NSTEMI?
No, it is not indicated and can increase mortality
What factors are associated with increased mortality in UA/NSTEMI?
- Older age (>65 years)
- Positive finding for cardiac biomarkers
- Rales
- Hypotension
- Tachycardia
- Decreased left ventricular function (ejection fraction <40%)
What does PCI include?
- Balloon angioplasty
- Bare-metal stent
- Drug-eluting stent
How long does reendothelialization take after balloon angioplasty?
2-3 weeks
What is a major concern after angioplasty and stent placement?
Thrombosis
What does DAPT consist of?
Aspirin (ASA) with a P2Y12 inhibitor
What is the minimum duration of DAPT for balloon angioplasty without stenting?
2 weeks
What is the minimum duration of DAPT for bare-metal stent?
6 weeks
What is the minimum duration of DAPT for drug-eluting stent?
1 year
What should be monitored after PCI?
Continuous ECG monitoring with ST-segment analysis
What is the timing for surgery after PCI?
- Minimum 2 weeks for balloon angioplasty without stenting
- Minimum 6 weeks for bare-metal stent
- Minimum 1 year for drug-eluting stent
What is the ACC/AHA algorithm for patients with functional capacity of 4 or more METs?
Proceed directly to surgery
What are active cardiac conditions that increase risk for surgery?
- Unstable coronary syndromes
- Recent MI
- Unstable or severe angina
- Decompensated heart failure
- Severe valvular heart disease
- Significant dysrhythmias
What are the goals of anesthetic considerations?
- Prevent myocardial ischemia
- Monitor for ischemia
- Treat ischemia
What should be avoided in patients due to its effect on coronary artery vasoconstriction?
Hyperventilation
What is the preferred drug to treat tachycardia in anesthetic considerations?
Esmolol
What is the preferred drug for bradycardia treatment?
Glycopyrrolate
What is the standard for ECG monitoring?
Leads II and V5
What does the Revised Cardiac Risk Index (RCRI) estimate?
The risk of cardiac complications after surgery
What are the components of RCRI?
- High-risk surgery
- History of ischemic heart disease
- History of congestive heart failure
- History of cerebrovascular disease
- Diabetes mellitus requiring insulin
- Preoperative creatinine > 2.0 mg/dL
What is associated with poor functional capacity?
Increased perioperative risk
What is the definition of emergency surgery? How about urgent and time-sensitive?
- Required when life or limb would be threatened if surgery did not proceed within 6 hours or less
- Life or limb 6-12 hours
- 1-6 weeks needed
What should be continued throughout the perioperative period?
β-blockers
What is the risk of discontinuing antiplatelet therapy?
Increases the risk of stent thrombosis
What is the recommended action for patients with any angina and a stent?
Prompt evaluation to rule out AMI
How does the number of risk factors affect the probability of perioperative cardiac complications?
The greater the number of risk factors, the greater the probability of complications.
List two components of RCRI.
- High-risk surgery
- History of ischemic heart disease
- History of congestive heart failure
- History of cerebrovascular disease
- Diabetes mellitus requiring insulin
- Preoperative creatinine > 2.0 mg/dL
What is the preoperative creatinine level that is a component of RCRI?
Preoperative creatinine > 2.0 mg/dL.
What does the ACC/AHA algorithm recommend for a patient with a functional capacity of 4 or more METs?
The patient should proceed directly to surgery.
When is preoperative coronary angiography most suitable?
For patients with stress test results suggesting significant myocardium at risk.
What are some active cardiac conditions that are risk factors?
- Unstable coronary syndromes
- Acute MI ≤ 7 days
- Severe valvular heart disease
What is the ideal time frame post-MI before undergoing noncardiac surgery?
> 60 days post MI is ideal.
What are the goals of anesthetic considerations for patients with ischemic heart disease?
- Prevent myocardial ischemia
- Monitor for ischemia
- Treat ischemia
Fill in the blank: The risk of ischemic heart disease increases with _______.
[age].
What diagnostic tool is essential for identifying underlying cardiac abnormalities? What tool is most specific?
12-Lead EKG.
Echo
What is the gold standard for evaluating coronary vessels?
Cardiac Angiography.
What medication is used to prevent platelet clumping in ischemic heart disease?
Aspirin.
What is the first-line intervention for revascularization?
PCI (Percutaneous Coronary Intervention).
What are the indications for CABG?
- Significant Coronary Artery Disease
- Epicardial Coronary Artery Occlusion
- Multi-Vessel Disease
What is the initial management step in acute coronary syndromes?
Oxygenation.
What are contraindications for thrombolytics?
- Severe Heart Failure
- Recent Surgery
- Existing Coagulopathy
What is a widely used tool for evaluating cardiac risk in patients undergoing non-cardiac surgery?
RCRI Score.
Fill in the blank: Opioids like _______ can be used for pain management while maintaining cardiac stability.
[fentanyl]
What is Etomidate commonly used for in cardiac patients?
Induction agent due to its cardiac stability
Important for minimizing hemodynamic instability.
What is the purpose of gradual induction in anesthesia?
Minimize sympathetic surges and hemodynamic instability
Critical for maintaining patient stability.
What is the recommended monitoring method for cardiac patients during surgery?
Continuous blood pressure monitoring with arterial lines
Ensures timely detection of hemodynamic changes.
What are the benefits of regional anesthesia for cardiac patients?
Effective pain control with less hemodynamic impact
What is the drug of choice for treating hypotension and bradycardia in regional anesthesia? What is a critical aspect of this drug you need to think about when administering? (The second part is more of a pharm question)
Ephedrine
- Tachyphylaxis
What does aspirin do in the context of ischemic heart disease?
Inhibits platelet aggregation by irreversibly inhibiting COX enzymes
Reduces risk of thrombus formation.
What is the action of glycoprotein IIb/IIIa inhibitors?
Block the binding of fibrinogen to platelets
Prevents platelet aggregation.
What do nitrates accomplish in cardiac treatment?
Cause vasodilation by releasing nitric oxide
- This improves coronary blood flow and reduces myocardial O2 demand.
- Ensure you patient can tolerate a reduced preload.
What should be done with ACE inhibitors before surgery?
Discontinue 24 hours before surgery
Minimizes the risk of hypotension.
Fill in the blank: It is generally safe to continue _______ perioperatively.
[statins]
What is the purpose of tailored interventions in anesthesia management?
To meet individual patient needs and hemodynamic responses
Ensures optimal care for each patient.
What are the common cardiac monitoring leads for patients with ischemic heart disease?
Lead II and lead V5
Important for effective monitoring during surgery.
What factors does the RCRI score consider?
- History of Ischemic Heart Disease
- High-Risk Surgery
- Diabetes Mellitus
- Functional Capacity
- Congestive Heart Failure
- Abnormal EKG
Each factor contributes to the overall risk assessment.
What is the significance of the MET score?
Indicates the patient’s ability to perform physical activities
A lower MET score suggests reduced functional capacity.
What is the role of monitoring in postoperative management of cardiac patients?
Closely monitor vital signs, EKG, and cardiac biomarkers
Essential for detecting postoperative complications.
What is Ischemic Heart Disease (IHD)?
Condition caused by reduced blood flow to the heart muscle
Can lead to damage or dysfunction of the heart.
What is the definition of angina?
Chest pain caused by reduced blood flow to the heart muscle
Indicates underlying cardiac issues.
What is the difference between stable and unstable angina?
- Stable Angina: Predictable and relieved by rest or nitrates
- Unstable Angina: Unpredictable, occurs at rest, or worsening
Important for clinical assessment and management.
What are the book definitions of chronic stable vs unstable angina?
- Chronic Stable= chest pain that does NOT change in frequency or severity in a 2-month period.
- Unstable= chest pain increasing in frequency and/or severity WITHOUT increase in cardiac biomarkers
If there is a change in biomarkers (CK/Trops/etc.) with no ST elevation then NSTEMI.
