S2: Ch1 Cv 1-0

Front 1

1. Stable Angina Pectoris-cause?

Back 1

a. Due to fixed atherosclerotic lesions that narrow the major coronary arteries.
b. Coronary ischemia is dur to an imbalance between blood supply and oxygen demand, leading to inadequate perfusion.
c. Stable angina occurs when oxygen demand exceeds blood supply.

Front 2

2. Risk factors for angina?

Back 2

1. DM
2. Hyperlipidemia- elevated LDL.
3. HTN
4. Cigarette smoking
5. Age (men>45 yrs; women >55)
6. Family hx of premature coronary artery disease (CAD) or MI in 1st-degree relative: men < 45 yo; women < 55 yrs.
7. Low levels of HDL.
8. Elevated homocysteine levels.
3. Prognostic indicators of CAD?
a. L. Ventricular function (ejection fraction EF)
i. Normal >50%
ii. If <50%, associated with increased mortality.

Front 3

4. Vessels involved (severity/extent of ischaemia)?

Back 3

a. Left main coronary A-poor prognosis bc it covers approximately 2/3 of the heart.
b. 2 or 3-vessel CAD-worse prognosis.

Front 4

5. Clinical features of stable angina pectoris?

Back 4

a. Chest pain or substernal pressure sensation.
i. Lasts <10-15 minutes (usually 1-5 minutes)
ii. Frightening chest discomfort, usually described as heaviness, pressure, squeezing; rarely described as frank pain.
b. Brought on by exertion or emotion
c. Relieved w/rest or nitroglycerin.

Front 5

6. How does the Resting ECG appear in stable angina?

Back 5

a. Usually normal in pts w/stable angina.
b. Q waves are consistent w/a prior MI.
c. If ST segment or T wave abnormalities are present during an episode of chest pain, then tx as for unstable angina.
d. For pts w/normal resting ECG, determine whether the pt is capable of performing treadmill exercise. If so, proceed to an exercise stress test.

Front 6

7. quick note: possible presentations of CAD?

Back 6

a. Asymptomatic
b. Stable angina pectoris
c. Unstable angina pectoris (USA)
d. MI
e. Sudden cardiac death.

Front 7

8. When is stress testing used?

Back 7

a. To confirm dx of angina
b. To evaluate response of therapy in pts w/documented CAD
c. To ID pts w/CAD who may have a high risk of acute coronary events.

Front 8

9. Stress ECG?

Back 8

a. Test involves recording ECG before, during, and after exercise on a treadmill.
b. 75% sensitive if pts are able to exercise sufficiently to increase HR to 85% of maximum predicted value for age.
c. Exercise-induced ischaemia results in subendocardial ischaemia, producing ST segment depression.
d. Other positive findings include onset of heart failure or ventricular arrhythmias during exercise or hypotension

Front 9

10. When is a stress test considered positive?

Back 9

a. If the pt develops:
1. ST depression
2. Chest pain
3. Hypotension
4. Significant arrhythmias

Front 10

11. What should you for pts w/positive stress tests?!?

Back 10

a. They should undergo cardiac cath.

Front 11

12. Stress echocardiography?

Back 11

a. Performed before and immediately after exercise.
i. Exercise-induced ischaemia is evidenced by wall motion abnormalities (e.g., akinesis or dyskinesis) not present at rest.
ii. Favoured by many cardiologists over stress ECG bc it is more sensitive in detecting ischaemia, can assess LV size and function, and can diagnose valvular disease.
b. Again, pts w/positive test should undergo cardiac cath.

Front 12

13. Cardiac cath?

Back 12

a. Most accurate method of determining a specific cardiac dx.
b. Provides information on hemodynamics, intracardiac pressure measurements, cardiac output, oxygen saturation, etc.
c. Coronary angiography is almost always performed as well for visualization of coronary arteries!

Front 13

14. Indications for cardiac catheterization?

Back 13

a. Generally performed when revascularization or other surgical intervention are being considered.
1. Apres positive stress test
2. When non-invasive tests are nondiagnostic, angina that occurs despite medical therapy, angina that occurs soon after MI, and any angina that is a diagnostic dilemma.
3. If pt is severely symptomatic and urgent diagnosis and management are necessary.
4. For evaluation of valvular disease, and to determine the need for surgical intervention.

Front 14

15. Coronary arteriography (angiography)?

Back 14

a. Most accurate method of identifying the presence and severity of CAD; the standard test for delineating coronary anatomy.
b. Main purpose is to identify pts w/severe coronary disease to determine whether revascularization is needed.
c. Coronary stenosis > 70% may be significant (i.e., it can produce angina).

Front 15

16. How can information from a stress test be enhanced?

Back 15

a. W/stress myocardial perfusion imaging after IV administration of a radioisotope such as thallium 201 during exercise.
b. Viable Myocardial cells extract the radioisotope from the blood. No radioisotope uptake means no blood flow to an area of the myocardium.

Front 16

17. How can you determine if ischaemia is reversible (It is important to determine whether the ischaemia is reversible!!!).

Back 16

a. This is determined by whether or not areas of hypoperfusion are perfused over time as blood flow eventually equalizes.
b. Areas of reversible ischaemia may be rescued w/percutaneous transluminal angioplasty (PTCA) or coronary artery bypass graft (CABG).
c. Areas of irreversible ischaemia, however, indicated infarcted tissue that cannot be salvaged.
d. Perfusion imaging increases the sensitivity and specificity of exercise stress tests, but is almost more expensive.

Front 17

18. What chemicals are used in a pharmacologic stress test?

Back 17

a. IV adenosine, dipyridamole, or dobutamine can be used.
b. The cardiac stress induced by these agents takes the place of exercise. This can be combined w/an ECG, echo, or nuclear perfusion imaging.

Front 18

19. How is a pharmacologic stress test performed?

Back 18

a. IV adenosine and dipyridamole cause generalized coronary vasodilation.
b. Because diseases 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.
c. Dobutamine increases myocardial oxygen demand by increasing heart rate, BP, and cardiac contractility.

Front 19

20. Use of Holter monitoring (ambulatory ECG)?

Back 19

a. Useful in detecting silent ischaemia (i.e., ECG changes not accompanied by symptoms).

Front 20

21. Cardiac catheterization w/coronary angiography?

Back 20

a. Coronary angiography-definitive test for CAD. Indicated for pts being considered for revascularization (PTCA or CABG).
b. Contrast is injected into coronary vessels any stenotic lesions. This defines the location and extent of coronary disease.
c. If CAD is severe (e.g., left main or 3-vessel disease), refer pts for surgical revascularization (CABG).

Front 21

22. Treatment of angina? part 1

Back 21

a. Smoking cessation cuts CHD risk in half by 1 year after quitting.
b. HTN- vigorous BP control reduces the risk of CHD, especially in diabetic pts.
c. Hyperlipidemia-reduction in serum cholesterol w/lifestyle modification and HMG-CoA reductase inhibitors reduces CHD risk.

Front 22

22. Treatment of angina? part 2

Back 22

d. DM- strict glycemia control is thought to have less effect on Macrovascular disease risk than microvascular disease risk but should still be emphasized.
e. Obesity- wt. loss modifies other risk factors (DM, HTN, and hyperlipidemia) and provides other benefits.
f. Exercise is critical; it minimizes emotional stress, promotes wt. loss, and helps reduce other risk factors.
g. Diet: reduce intake of saturated fat (<7% total calories) and cholesterol (<200 mg/day).
h. Hyperhomocysteinemia- value of treating yet to be established.

Front 23

23. Medical therapy for stable angina/CAD?

Back 23

a. Aspirin
b. β-blockers
c. Nitrates
d. Calcium channel blockers
e. If CHF, is also present, tx w/ACE inhibitors and/or diuretics may be indicated as well.