L4: Ischemic Heart Disease Flashcards
What is the term for pathologic processes affecting the coronary arteries (atherosclerosis)
Coronary Artery Disease (CAD)
What is the term for diagnoses including angina pectoris, MI, silent MI, and mortality resulting from CAD?
Coronary Heart Disease (CHD)
What is the term for the pathologic process affecting the entire arterial circulation, resulting in stroke, TIA, angina, MI, claudication, and critical limb ischemia?
Cardiovascular Disease (CVD)
What is the term for irreversible death of the heart muscle due to prolonged lack of O2?
Myocardial Infarction (MI)
Where are the main arteries of the hard located? When does most perfusion occur?
Epicardial region (opposed to endocardium) Most perfusion occurs during diastole
Atheroscleortic plaques form: (2)
- Sites of increased blood turbulence
- Branching points in the epicardial arteries
What is ischemic heart disease?
Condition in which there is an inadequate supply of blood and oxygen to a portion of the myocardium
O2 demand > O2 supply
What is the leading cause of death in the US? Is it more common in males or females?
Coronary Heart Disease (CHD)
M > F
__________ is the initial coronary event in 15% of patients with CHD.
Sudden Cardiac Death (SCD)
When does atherosclerosis begin?
Childhood
What is the role of nitric oxide in terms of our blood vessels?
- Endothelial cells produce NO
- NO inhibits plaque formation and has anti-inflammatory properties
- NO keeps our blood flowing smoothly, eliminates plaque, and vasodilates
What causes endothelial dysfunction?
LDL and oxidized LDL = leads to atherosclerosis
What has an “atheroprotective” role in our vessels? Why?
HDL: anti-inflammatory and anti-oxidant properties
What are the modifiable risk factors for IHD (7)?
- Diet
- Inactivity
- Obesity
- Cigarette smoking
- HTN
- DM
- Dyslipidemia (high LDL, low HDL, high triglycerides)
At what age are men most at risk for developing IHD? Women?
M > 45 years old
W > 55 years old
Almost 2/3rds of women who die suddenly from CHD have:
NO previous symptoms!
Atypical symptoms associated with IHD are more common in:
- Women
- Elderly
- Patients with diabetes
Why do women often have increased mortality with IHD?
Often present without chest pain!
Delayed dx + delayed tx = increased mortality
In what situations are women more likely to die from IHD?
Greater likelihood of being induced by rest, sleep, and mental stress (rather than activity)
Transient ischemia may result in:
Angina pectoris
Prolonged ischemia may result in:
Myocardial infarction
Which condition may cause sx that urge patients to seek medical care, may be confused with other disorders, and may be completely “silent”?
Myocardial ischemia
What conditions fall under the umbrella of acute coronary syndrome?
- Unstable angina
- MI
- Non-ST elevation MI (NSTEMI)
- ST elevation MI (STEMI)
Define stable angina (angina pectoris).
Exertional or stress-related chest or arm discomfort that resolves with rest and/or the use of sublingual nitroglycerin
How long does stable angina typically last? What is the intensity pattern?
- Usually no greater than 5-10 minutes
- Crescendo-decrescendo pattern
How would patients typically describe their “pain” while experiencing stable angina?
- Typically not called pain*
- Heaviness or pressure (“elephant on my chest”)
- Tightness, squeezing, smothering, choking
What is Levine’s sign and what might this indicate?
- Clenched fist over sternum
- May be indicative of stable angina
Where might patients complain of radiating pain when experiencing angina pectoris?
Shoulders, arm, neck, jaw, teeth, epigastrium, mid-back
What physical exam findings might you find in a patient with stable angina?
Tachycardia
Hypertension
Abnormal heart sounds
What are 4 atypical presentations/symptoms of stable angina? Who commonly presents with atypical sx?
- Dyspnea
- Nausea
- Fatigue
- Faintness
Elderly and DM patients. Dyspnea common in women.
What are some symptoms that are NOT likely to be ischemia or angina?
- Sharp, fleeting stabs of chest pain
- Prolonged, dull ache in the left precordial area
- Any discomfort localized with one finger
- Pain lasting for seconds or constant pain lasting for days
What 3 diagnostic studies would we order for angina?
- EKG 12-lead (aka electrocardiogram)
- Chest XR
- Cardiac biomarkers
What might an EKG show in a patient with angina?
May have ST segment depression during episodes or discomfort (resolution of changes when pain resolves)
What 2 diagnostic studies would we consider ordering in patients presenting with atypical angina sx?
Cardiac stress testing (Exercise EKG or nuclear stress test with imaging) or coronary angiography
What is the Bruce protocol?
Exercise stress test: speed and incline are increased every THREE MINUTES until patient’s HR is at 85% maximum predicted for their age
What are we watching for while a patient is undergoing exercise EKG? (4)
- EKG changes
- Decreased myocardial perfusion seen on nuclear image
- Drop in systolic BP > 10 mmHg
- or any other symptoms
What does a nuclear stress test show us?
Perfusion defect will be seen in areas of hypoperfusion (compare resting to exercise/stress)
What does a stress echocardiogram show us?
Dx of ischemia related to development of WALL MOTION ABNORMALITY with exercise/stress
How do you calculate someone’s max heart rate?
220 - age
What is the gold standard for diagnosing CAD?
Coronary angiography (aka cardiac catheterization)
What are the indications for a coronary angiography?
- Known or suspected CAD
- Atypical chest pain (stress test showing high risk for CAD)
- Before valve surgery in pts with chest pain or EKG changes
True or false: Coronary angiography demonstrates the presence of a “vulnerable plaque”
False!
What are 4 medications (be very general) that can help treat stable angina?
- Meds that decrease O2 demand
- Meds that increase O2 supply
- Antiplatelet medication
- Statins
What kind of diet would you recommend to a patient with CAD?
Plant-based diet
Name 3 classes of medications that decrease O2 demand.
- Nitrates
- Beta-blockers
- Ca2+ channel blockers
What is the first line treatment for acute angina?
Short acting nitrates
How do nitrates work on the heart?
PRELOAD reduction
How do beta blockers work on the heart?
Decrease HR, NP and contractility = AFTERLOAD reduction
What is the first line tx for chronic angina? What other medication can be used (though not first line)
Beta blockers (can also use long acting nitrates)
What is the only antianginal medication proven to prevent re-infarction and improve survival post MI?
Beta blockers (hence use for tx of chronic angina)
How do CCBs work on the heart?
Decrease BP and contractility = AFTERLOAD reduction
When is the use of CCBs indicated?
For patients who do not respond to nitrates or beta blockers
What are 2 classes of medications that increase oxygen supply?
Nitrates and CCBs
How do nitrates and CCBS work on the heart (to help increase oxygen supply)?
Dilate coronary arteries
How do treat with nitrates?
At onset of pain: 0.3-0.6 mg sublingually or by buccal spray»_space; Repeat every 5 minutes for up to 3 doses»_space; If still no relief, call 911 (or begin IV nitro if already hospitalized)
What are 3 antiplatelet medications we can use to help treat stable angina?
- Aspirin (75-325mg daily)
- Clopidogrel (Plavix)
- Combo of ASA and clopidogrel
Patients with a hx of an MI have a risk of death from CHD that is ______ than those without known CVD
20 times higher :-(
What role do statins play in tx of CHD?
Stabilize plaques»_space; Reduces clinical events, slows progression of coronary atherosclerosis, induces regression of coronary atheroscleorisi
How would you prescribe statins in a patient with CHD?
High intensity dosage independent of baseline LDL-C (monitor this over time though)
What 2 revascularization procedures can we perform to treat someone with stable angina?
Percutaneous Coronary Intervention (PCI) and Coronary Artery Bypass Grafting (CABG)
When is a PCI indicated?
Hx of angina despite medical tx; evidence of ischemia on stress testing
*Can be performed with or without stent placement
When is a CABG indicated?
When patient has left main coronary stenosis, or triple vessel disease
What vessels are typically harvested for a CABG?
Great saphenous vein or internal mammary arteries
What are 4 pathophysiological processes that can lead to Acute Coronary Syndrome?
- Plaque rupture or erosion with a superimposed occlusive thrombus *Most common!
- Dynamic obstruction (spasm)
- Progressive mechanical obstruction (plaque forming over a stent)
- UA secondary to increased myocardial oxygen demand and/or decreased supply
What is Prinzmetal’s Angina?
Ischemic symptoms secondary to vasospasm; causes chest pain
What would you see on an EKG during Prinzmetal’s Angina?
Transient ST-segment elevation
Which population is more likely to experience Prinzmetal’s Angina?
Younger patients with fewer risk factors (20’s, 30’s, 40’s)
What diagnostic test would be helpful in diagnosing in Prinzmetal’s Angina?
Coronary angiography (stress test generally unhelpful)
What is the treatment for Prinzmetal’s angina?
Nitrates and CCB’s
What is the presentation for patients with ACS? (6) Who may have an atypical presentation?
- Ischemic pain
- SOB
- Weakness
- Nausea
- Anxiety
- Sense of doom
-Atypical presentation in women, diabetics and elderly pts (sudden breathlessness)
What is the typical presentation of Unstable Angina?
Ischemic discomfort AND 3 of the following:
- Occurs AT REST (often lasts >10 minutes)
- Severe and of NEW ONSET (within last 4-6 weeks)
- Occurs with a CRESCENDO pattern (more severe, prolonged, and frequent than previously)
What is the typical presentation for a Non ST Elevation MI (NSTEMI)?
Similar symptoms to UA with continued worsening
How can you differentiate between a UA and NSTEMI based on clinical features (tests)?
UA: NO elevation of CK-MB or Troponin, Usually normal EKG (may have ST depression or T wave inversion)
NSTEMI: DEFINITE ELEVATION of CK-MB and/or Troponin (there has been MI!), EKG: typically no ST elevation, may have ST depression or T wave inversion
How do you manage UA/NSTEMI?
- Bedrest
- Cardiac monitoring
- IV access
- Labs
- Possible oxygen
- Medication
- Risk stratification, angiography, and revascularization with PCI or CABG if indicated
When would you supply oxygen during management of a UA/STEMI?
Utilized only if arterial O2 < 90%, hypoxia, or acute respiratory distress
What medications would you prescribe during management of a UA/STEMI? (7)
- Sublingual nitroglycerin x 3 at 5 minute intervals
- Morphine (avoided unless pain unacceptable and then with caution)
- Beta blockers (metoprolol or atenolol started within 24 hours)
- CCB as second line (if sx not relieved by nitrates or beta blokers)
- High intensity statin therapy (atorvastatin 80mg/day)
- Antiplatelet therapy in all NSTEMI pts if no contraindications (clopidogrel)
- Anticoagulation (ASA, heparin)
What are the risk factors for patients with UA/NSTEMI progressing to a STEMI? (Thrombosis In MI for Risk Stratification)
1 point each:
- 65 years or older
- > /= 3 risk factors for CHD
- Prior coronary stenosis of >/= 50%
- ST segment deviation on admission EKG
- > /= 2 anginal episodes in prior 24 hours
- Increased serum cardiac biomarkers
- Aspirin use in prior 7 days
What is the difference between an NSTEMI and STEMI?
NSTEMI: Non-occlusive thrombus
STEMI: Occlusive thrombus and transmural infarcation
When is an acute MI (STEMI) most likely to occur (time of day)?
Common within a few hours of awakening in the morning
What are the identifiable precipitating factors for a STEMI seen in 50% of cases? (3)
- Vigorous exercise
- Extreme emotional stress
- Medical or surgical illness
What are 2 primary causes of a STEMI? Which is most common?
- Rupture of vulnerable plaque (most common) = results in COMPLETE OCCLUSION of a coronary artery
- Slowly developing stenosis of coronary artery (less common; collateral vessels usually develop to get BF to affected areas)
What is the onset, peak, and duration of CK enzymes post MI?
Onset: 3-12 hours
Peak: 18-24 hours
Duration: 36-48 hours
What is the onset, peak, and duration of Troponins enzymes post MI?
Onset: 3-12 hours
Peak: 18-24 hours
Duration: Up to 10 days
What does an ST elevation indicate? What about a depression?
Elevation=cell death
Depression=ischemia
A patient presents with no ST-segment elevation with (+) markers. They likely have:
NSTEMI
A patient presents with +/- ST-segment elevations with (-) makers. They likely have:
UA
A patient presents with ST-segment elevations and (+) markers. They likely have:
STEMI
How do you manage a STEMI?
- Bed rest
- Cardiac monitoring
- IV access
- Labs (enzymes, electrolytes, CBC, Coags)
- ACLS protocol when indicated*
- Medication
- Fibrinolysis*
- Select reperfusion strategy*
*different than NSTEMI
What medications would you prescribe during management of an NSTEMI? (7)
- ASA 325mg chewed and swallowed*
- Sublingual nitro
- Beta blockers if no contraindications (metoprolol)
- High intensity statin therapy if possible before PCI*
- Anticoagulation therapy + antiplatelet therapy (in addition to ASA)
Which reperfusion strategy is preferred in management of an NSTEMI?
Primary PCI strongly preferred (over CABG)
-Activate cardiac cath team or surgical team when indicated
*****Risk stratification!
When would you provide fibrinolysis during management of an NSTEMI?
- PCI not available within 120 minutes of first medical contact
- Symptoms <12 hours
- No contraindications
What are the absolute contraindications to thrombolytic (fibrinolytic) therapy? (5)
- Hx of intracranial hemorrhage
- Hx of stroke in past year
- Poorly controlled HTN (SBP > 180 and/or DBP > 110)
- Suspected aortic dissection
- Active internal bleeding
What are some relative contraindications to thrombolytic therapy?
- Current anticoagulant use (INR > 2)
- Recent invasive procedure
- Prolonged CPR
- Known bleeding diathesis
- Pregnancy
- Active peptic ulcer disease
- Hemorrhagic ophthalmic condition
- Hx of severe HTN that is currently well controlled
- Use of streptokinase in preceding 5 days-2 years
- Concern for possible allergic rxn
What are 7 potential post MI complications?
- Recurrent ischemia
- Pump failure (may lead to inpatient death)
- Ventricular arrhythmias
- Pericarditis/Dressler’s syndrome
- Mural thrombus (thrombi attached to the vessel wall)
- Cardiac rupture/LV aneurysm
- Depression
What is Dressler’s Syndrome?
Chest pain due to pericardial inflammation following MI, CABG, or traumatic injury to heart
What are 4 post MI management techniques?
- Risk stratification
- Treat risk factors
- Meds
- Specialists if indicated
What medications may be prescribed/continued post MI?
- Beta blockers
- Aspirin
- If LV dysfunction, consider ACE-I or ARB
Regular exercise and physical fitness can decrease risk of ______ post MI?
Recurrent events
What are the goals of cardiac rehabilitation?
- Increase exercise tolerance and functional capacity
- Decrease cardiovascular mortality
- Decrease emotional stress
