STEPUP Cardiovascular System: Ischemic Heart Disease - Stable Angina Pectoris

Question 1

What are the different presentations of coronary artery disease?

Answer 1

1) Asymptomatic
2) Stable angina pectoris
3) Unstable angina pectoris
4) MI - either NSTEMI or STEMI
5) Sudden cardiac death

Question 2

What is the LDL goal in a patient with CAD?

Answer 2

Less than 100 mg/dL

Question 3

Describe typical anginal chest pain by location on chest, what makes it worse, and what makes it better.

Answer 3

1) Substernal
2) Worse with exertion
3) Better with rest or nitroglycerin

Question 4

What is coronary ischemia due to? When does stable angina occur?

Answer 4

1) An imbalance between blood supply and oxygen demand, leading to inadequate perfusion
2) When oxygen demand exceeds available blood supply

Question 5

What are the major risk factors for stable angina pectoris? What is the worst risk factor? What is the most common risk factor?

Answer 5

1) Diabetes Mellitus - worst risk factor
2) Hyperlipidemia - elevated LDL
3) HTN - most common risk factor
4) Cigarette smoking
5) Age - Men > 45 years; Women > 55 years
6) Family history of premature CAD or MI in first-degree relative: Men < 55 years; Women < 65 years
7) Low levels of HDL

Question 6

What are minor risk factors for stable angina pectoris?

Answer 6

1) Obesity
2) Sedentary life style (lack of physical activity)
3) Stress
4) Excess alcohol use

Question 7

What are prognostic indicators of CAD found on echocardiogram?

Answer 7

1) Left ventricular ejection fraction:
a) Normal > 50%
b) If < 50%, associated with increased mortality
2) Vessel(s) involved (severity/extent of ischemia)
a) Left main coronary artery - poor prognosis because it covers approximately two-thirds of the heart
b) Two- or three-vessel CAD - worse prognosis

Question 8

Describe the location, duration, feeling, and onset of stable angina chest pain.

Answer 8

Chest pain or substernal pressure sensation:

1) Lasts less than 10 to 15 minutes (usually 1 to 5 minutes)
2) Frightening chest discomfort, usually described as heaviness, pressure, squeezing, tightness; rarely described as sharp or stabbing pain
3) Pain is often gradual in onset

Question 9

What two factors bring on stable angina?

Answer 9

1) Exertion

2) Emotion

Question 10

What is stable angina relieved with?

Answer 10

1) Rest

2) Nitroglycerin

Question 11

Ischemic pain does not change with what two things? What is absent in the chest wall?

Answer 11

1) Ischemic pain does NOT change with breathing nor with body position
2) Patients with ischemic pain do not have chest wall tenderness
If any of these are present, the pain is not likely to be due to ischemia

Question 12

What is metabolic syndrome X?

Answer 12

1) Any combination of hypercholesterolemia, hypertriglyceridemia, impaired glucose tolerance, diabetes, hyperuricemia, HTN
2) Key underlying factor is insulin resistance (due to obesity)

Question 13

What is Syndrome X?

Answer 13

1) Exertional angina with normal coronary arteriogram: Patients present with chest pain after exertion but have no coronary stenoses at cardiac catheterization
2) Exercise testing and nuclear imaging show evidence of myocardial ischemia
3) Prognosis is excellent

Question 14

What are findings of physical examination in a patient with CAD?

Answer 14

Normal

Question 15

What does a resting ECG look like in a patient with stable angina? What do pathologic Q waves represent? How does your diagnosis change if ST segment or T-wave abnormalities are present during an episode of chest pain?

Answer 15

1) Normal
2) Q waves are consistent with a prior MI
3) If ST segment or T-wave abnormalities are present during an episode of chest pain, then treat as unstable angina (USA)

Question 16

What is a stress test useful for?

Answer 16

1) Useful for patients with an intermediate pretest probability of CAD based upon age, gender, and symptoms

Question 17

When does a stress ECG have highest sensitivity? When is the ECG done in reference to the test? What is the sensitivity based on sufficient exercise?

Answer 17

1) Highest sensitivity if patients have normal resting ECG, such that changes can be noted
2) Test involves recording ECG before, during, and after exercise on a treadmill
3) 75% sensitive if patients are able to exercise sufficiently to increase heart rate to 85% of maximum predicted value for age. A person’s maximum heart rate is calculated by subtracting age from 220 (220-age).

Question 18

What does exercise-induced ischemia result in on an ECG? What are other positive findings for a stress ECG?

Answer 18

1) Exercise-induced ischemia results in subendocardial ischemia, producing ST segment depression. So the detection of ischemia on an ECG stress test is based on presence of ST segment depression
2) Other positive findings include onset of heart failure or ventricular arrhythmia during exercise or hypotension

Question 19

What test should patients with a positive stress ECG result undergo?

Answer 19

Cardiac catheterization

Question 20

When is a stress echocardiography performed? How is exercise-induced ischemia determined?

Answer 20

1) Performed before and immediately after exercise
2) Exercise-induced ischemia is evidenced by wall motion abnormalities (e.g., akinesis or dyskinesis) not present at rest

Question 21

Why is a stress echocardiography favored by many cardiologists over stress ECG?

Answer 21

It is more sensitive in detecting ischemia, can assess LV size and function, can diagnose valvular disease, and can be used to identify CAD in the presence of pre-existing ECG abnormalities

Question 22

What test should patients wit ha positive stress echocardiography result undergo?

Answer 22

Cardiac catheterization

Question 23

What are the types of stress tests and their method of detecting ischemia?

Answer 23

1) Exercise EKG - ST segment depression
2) Exercise or dobutamine echocardiogram - Wall motion abnormalities
3) Exercise or dipyridamole perfusion study (thallium/technetium) - Decreased uptake of the nuclear isotope during exercise

Question 24

How can information gained from a stress test be enhanced?

Answer 24

Stress myocardial perfusion imaging after IV administration of a radioisotope such as thallium 201 during exercise

Question 25

How does a nuclear stress test work?

Answer 25

Viable myocardial cells extract the radioisotope from the blood. No radioisotope uptake means no blood flow to an area of the myocardium

Question 26

What is important to determine when performing a nuclear stress test? Why is this important to determine?

Answer 26

1) It is important to determine whether the ischemia is reversible, that is, whether areas of hypoperfusion are perfused over time as blood flow eventually equalizes
2) Areas of reversible ischemia may be rescued with percutaneous coronary intervention (PCI) or coronary artery bypass (CABG). Irreversible ischemia, however, indicates infarcted tissue that cannot be salvaged

Question 27

What are advantages and disadvantages of performing perfusion imaging (nuclear stress test)?

Answer 27

1) Increases the sensitivity and specificity of exercise stress tests
2) Is more expensive, subjects the patient to radiation, and is often not helpful in the presence of a left bundle branch block

Question 28

If the patient cannot exercise, what test can you perform? What can be used for this test? How does this test work? What can this test be combined with?

Answer 28

1) A pharmacologic stress test
2) IV adenosine, dipyridamole, or dobutamine can be used
3) The cardiac stress induced by these agents takes the place of exercise
4) This can be combined with an ECG, an echocardiogram, or nuclear perfusion imaging

Question 29

What do IV adenosine and dipyridamole cause? How does this affect the heart in CAD?

Answer 29

1) IV adenosine and dipyridamole cause generalized coronary vasodilation
2) Since diseased coronary arteries are already maximally dilated at rest to increase blood flow, they receive relatively less blood flow when the entire coronary system is pharmacologically vasodilated

Question 30

How does dobutamine work for the pharmacologic stress test?

Answer 30

Dobutamine increases myocardial oxygen demand by increasing heart rate, blood pressure, and cardiac contractility

Question 31

What is Holter monitoring useful for?

Answer 31

1) Holter monitoring (ambulatory ECG) can be useful in detecting silent ischemia (i.e., ECG changes not accompanied by symptoms)
2) The Holter monitor is also used for evaluating arrhythmias, heart rate variability, and to assess pacemaker and implantable cardioverter-defibrillator (ICD) function
3) Useful for evaluating unexplained syncope and dizziness as well

Question 32

How does a Holter monitor work?

Answer 32

Continuously examines patient’s cardiac rhythm over 24 to 72 hours during normal activity

Question 33

What is the definitive test of CAD? What is this test often concurrently performed with or for?

Answer 33

1) Cardiac catheterization with coronary angiography

2) Often performed with concurrent PCI or for patients being considered for revascularization with CABG

Question 34

How is cardiac catheterization with coronary angiography done? What is the most accurate test for detecting (presence and severity of) CAD? What do you do if the CAD is severe (e.g., left main or three-vessel disease)?

Answer 34

1) Contrast is injected into coronary vessels to visualize any stenotic lesions. This defines the location and extent of coronary disease
2) Angiography is the most accurate test for detecting CAD
3) If CAD is severe, refer patient for surgical revascularization (CABG)

Question 35

What information does cardiac catheterization provide?

Answer 35

Information on hemodynamics, intracardiac pressure measurements, cardiac output, oxygen saturation, etc.

Question 36

What are some indications for cardiac catheterization?

Answer 36

It is generally performed when revascularization or other surgical intervention is being considered

1) After a positive stress test
2) Acute MI with intent of performing angiogram and PCI
3) In a patient with angina in any of the following situations: When noninvasive tests are nondiagnostic, angina that occurs despite medical therapy, angina that occurs soon after MI, and any angina that is a diagnostic dilemma
4) If patient is severely symptomatic and urgent diagnosis and management are necessary
5) For evaluation of valvular disease, and to determine the need for surgical intervention

Question 37

What is the most accurate method of determining a specific cardiac diagnosis?

Answer 37

Cardiac catheterization

Question 38

What is the main purpose of coronary arteriography (angiography) and when can this be done?

Answer 38

1) To identify patients with severe coronary disease to determine whether revascularization is needed
2) Revascularization with PCI involving a balloon and/or a stent can be performed at the same time as the diagnostic procedure

Question 39

When is coronary stenosis usually significant?

Answer 39

Coronary stenosis >70% may be significant (i.e., it can produce angina)

Question 40

What are 4 ways to treat patients with CAD?

Answer 40

1) Risk factor modification
2) Medical therapy
3) Revascularization
4) Management decisions (general guidelines) - risk factor modification and aspirin are indicated in all patients. Manage patients according to overall risk

Question 41

What are risk factor modifications for CAD?

Answer 41

1) Smoking cessation cuts coronary heart disease (CHD) risk in half by 1 year after quitting
2) HTN - vigorous BP control reduces the risk of CHD, especially in diabetic patients
3) Hyperlipidemia - reduction in serum cholesterol with lifestyle modifications and HMG-CoA reductase inhibitors (statins) reduce CHD risk
4) DM - Type 2 diabetes is considered to be a cardiovascular heart disease equivalent, and strict glycemic control should be strongly emphasized
5) Obesity - weight loss modifies other risk factors (diabetes, HTN, and hyperlipidemia) and provides other health benefits
6) Exercise is critical; it minimizes emotional stress, promotes weight loss, and helps reduce other risk factors
7) Diet: Reduce intake of saturated fat (<7% total calories) and cholesterol (<200 mg/day)

Question 42

What are medical therapy options for patients with CAD?

Answer 42

1) Aspirin
2) Beta blockers
3) Nitrates
4) Calcium channel blockers
5) ACE inhibitors and/or diuretics in the setting of congestive heart failure (CHF)

Question 43

When is aspirin therapy indicated for CAD? What does it help to decrease?

Answer 43

1) Indicated in all patients with CAD

2) Decreases morbidity - reduces risk of MI

Question 44

What are beta blockers used for in CAD? What does it help to reduce?

Answer 44

1) Block sympathetic stimulation of heart. First-line choices include atenolol and metoprolol
2) Reduce HR, BP, and contractility, thereby decreasing cardiac work (i.e., beta blockers lower myocardial oxygen consumption)
3) Have been shown to reduce the frequency of coronary events

Question 45

How do nitrates help treat CAD? What may they prevent? What is the main benefit? How are they administered?

Answer 45

1) Cause generalized vasodilation. Relieve angina; reduce preload myocardial oxygen demand
2) May prevent angina when taken before exertion
3) Effect on prognosis is unknown; main benefit is symptomatic relief
4) Can be administered orally, sublingually, transdermally, intravenously, or in paste form. For chronic angina, oral or transdermal patches are used. For acute coronary syndromes, either sublingual, paste, or IV forms are used

Question 46

How do calcium channel blockers work in the setting of CAD? Are they considered primary or secondary treatment? Do they show any change in mortality?

Answer 46

1) Cause coronary vasodilation and afterload reduction, in addition to reducing contractility
2) Now considered a secondary treatment when beta blockers and/or nitrates are not fully effective. None of the calcium channel blockers have been shown to lower mortality in CAD. In fact, they may increase mortality because they raise heart rates. Do not routinely use these drugs in CAD

Question 47

When is revascularization preferred? What are the two methods? Does it change in the incidence of MI?

Answer 47

1) May be preferred for high-risk patients, although there is some controversy whether revascularization is superior to medical management for a patient with stable angina and stenosis > 70%
2) Two methods - PCI and CABG
3) Revascularization does not reduce incidence of MI, but does result in significant improvement in symptoms

Question 48

What is the management for mild CAD?

Answer 48

Mild disease (normal EF, mild angina, single-vessel disease)

1) Nitrates (for symptoms and as prophylaxis) and a beta blocker are appropriate
2) Consider calcium channel blockers if symptoms continue despite nitrates and beta blockers

Question 49

What is the management for moderate CAD?

Answer 49

Moderate disease (normal EF, moderate angina, two-vessel disease)
1) If the nitrates + beta blocker +/- calcium channel blockers do not control symptoms, consider coronary angiography to assess suitability for revascularization (either PCI or CABG)

Question 50

What is the management for severe CAD?

Answer 50

Severe disease (decreased EF, severe angina, and three-vessel/left main or left anterior descending disease)
1) Coronary angiography and consider for CABG

Question 51

What is the best initial test for all forms of chest pain?

Answer 51

ECG

Question 52

In what situations is stress testing used?

Answer 52

1) To confirm diagnosis of angina
2) To evaluate response of therapy in patients with documented CAD
3) To identify patients with CAD who may have a high risk of acute coronary events

Question 53

What is a ideal initial stress test due to ready availability and inexpensive cost?

Answer 53

Exercise stress ECG is ideal initial test if able to exercise and normal resting ECG (readily available and relatively inexpensive)

Question 54

When is a stress test generally considered positive?

Answer 54

1) ST segment depression
2) Chest pain
3) Hypotension
4) Significant arrhythmias

Question 55

What is the standard of care for stable angina?

Answer 55

Aspirin and a beta blocker (only ones that lower mortality), and nitrates for chest pain

Question 56

What are side effects of nitrates?

Answer 56

1) Headache
2) Orthostatic hypotension
3) Tolerance
4) Syncope

Question 57

What did the COURAGE trial show?

Answer 57

It showed essentially no difference in all cause mortality and nonfatal MIs between patients with stable angina treated with maximal medical therapy alone versus medical therapy with PCI and bare metal stenting

Question 58

What is another name for PCI?

Answer 58

Angioplasty

Question 59

What does percutaneous coronary intervention (PCI) consist of? When should it be considered? What is the only difference in outcomes of patients between PTCA with stenting and CABG?

Answer 59

1) Consists of both coronary angioplasty with a balloon and stenting
2) Should be considered in patients with one-, two-, or three-vessel disease
3) Even with three-vessel disease, mortality and freedom from MI have been shown to be equivalent between PTCA with stenting and CABG. The only drawback is the higher frequency of revascularization procedures in patients who received a stent

Question 60

What type of lesions is PCI best used for? What is a significant problem with PCI?

Answer 60

1) Proximal lesions
2) Restenosis is a significant problem (up to 40% within first 6 months); however, if there is no evidence of restenosis at 6 months, it usually does not occur. New techniques and technologic improvements such as drug-eluting stents are attempting to reduce this problem

Question 61

What did the PRECOMBAT and SYNTAX trials show? In which patients is CABG still used as a primary method of revascularization? When else may CABG be indicated?

Answer 61

While CABG remains the standard of care at some institutions for patients with high-risk disease, the PRECOMBAT and SYNTAX trials have shown that PTCA with stenting may be as good as CABG even in patients with left main CAD

2) CABG is still used as the primary method of revascularization in a small number of patients with STEMI
3) It may be indicated in patients with cardiogenic shock post-MI, after complications with PCI, in the setting of ventricular arrhythmias, and with mechanical complications after acute MI

Question 62

What are main indications for CABG?

Answer 62

1) Three-vessel disease with > 70% stenosis in each vessel

2) Left main coronary disease with > 50% stenosis, left ventricular dysfunction