ASHD/ACS

Question 1

ASHD: atherosclerotic heart disease is ??

Answer 1

the number one killer in the United States and worldwide

Every minute, an American dies of coronary heart disease

Death rates of coronary heart disease have declined every year since 1968, with about half of the decline from 1980 to 2000 due to treatments (med tech, stents, dx) and half due to improved risk factors

Coronary heart disease is still responsible for approximately one of five deaths and over 600,000 deaths per year in the United States

Coronary heart disease afflicts nearly 16 million Americans

Question 2

risk factors ASHD

Answer 2

Positive family history (the *younger the onset in a first-degree relative, the greater the risk)
Male sex
DM
HTN
Physical inactivity
Abdominal obesity
Cigarette smoking
Psychosocial factors
Diet 

**Hypercholesterolemia is an important modifiable risk factor for coronary heart disease **

Metabolic syndrome

Question 3

metabolic syndrome**

Answer 3

constellation of 3+ the following:

abdominal obesity
triglycerides: 150 mg/dL or higher
HDL cholesterol: less than 40 mg/dL for men and less than 50 mg/dL for women
fasting glucose 110 mg/dL or higher
HTN

Question 4

Atherosclerotic plaques may remain stable or ?? or ??

Answer 4

progress only gradually

Plaques may rupture, often related to the inflammatory process and metalloproteinase activity

Question 5

Increased plaque vulnerability

Answer 5

Higher lipid content
Higher concentration of macrophages
Very thin fibrous cap

Question 6

Precipitants of plaque rupture include

Answer 6

exercise, eating, cold weather, and emotional stress

Question 7

Myocardial ischemia are ?? others are ??

Answer 7

symptomatic, causing angina pectoris

completely silent

Question 8

Myocardial hibernation

Answer 8

Areas of myocardium that are persistently underperfused but still viable may develop sustained contractile dysfunction

Reversible following coronary revascularization (cath)

Question 9

Myocardial stunning

Answer 9

Acute, Persistent contractile dysfunction following prolonged or repetitive episodes of myocardial ischemia

Often seen after reperfusion of acute MI and is defined with improvement following revascularization

Question 10

Angina pectoris due to AHD-5 main history clues (symptoms)

Answer 10

Circumstances that precipitate and relieve angina (rest, nitro -stable)

Characteristics of the discomfort (crushing pain)

Location (substernal, epigastric (inferior/posterior wall)) and radiation

Duration of attacks: last btw 5-30 min

Effect of nitroglycerin

Question 11

change in exercise tolerance implies

Answer 11

switch from stable to unstable angina

Question 12

Angina pectoris is usually due to ??

Answer 12

atherosclerotic heart disease

Question 13

ASHD signs: BP

Answer 13

Significant elevation in systolic and diastolic BP

may be hypotensive: may reflect more severe ischemia or inferior ischemia (especially with bradycardia) due to a Bezold-Jarisch reflex

• acute decompensated CHF (inf/post wall)
• don’t give nitro, B-blocker* (decrease pre-load)

Question 14

ASHD signs: heart rhythms

Answer 14

Gallop rhythm and an apical systolic murmur due to transient mitral regurgitation from papillary muscle dysfunction are present during pain only

Supraventricular or ventricular arrhythmias may be present (CHF) -may be fatal (AEDs)

Question 15

ASHD/ACS labs

Answer 15

Standard laboratory tests to evaluate for acute coronary syndrome (troponin and CK-MB)
*timeline issues

Factors contributing to ischemia

Screen for risk factors that may increase the probability of true coronary heart disease

(used to use LDH : non-sp. muscle breakdown, then CK, now CK-MB)

Question 16

takes about ??? hours for trop and CK-MB to rise

Answer 16

6 hrs

additional for acute phase: myoglobin >900

screen for risk factors

Question 17

EKG

Answer 17

Often normal in patients with angina

Old myocardial infarction, nonspecific ST–T changes, and changes of LVH

Horizontal or downsloping ST-segment depression that reverses after the ischemia disappears, T wave flattening or inversion (NSTEMI, not reciprocal depression)

Transient ST-segment elevation (STEMI)

Question 18

how to read posterior MI

Answer 18

flip around, depression that’s actually elevation

leads to acute decompensated CHF

Question 19

Pretest probability**

know likelihood of getting a + or - test

Answer 19

History/Physical
Laboratory and ECG
Age
Sex

• Pts with low to intermediate pretest probability for CAD should undergo noninvasive stress
• Pts with high pretest probability are generally referred for cardiac catheterization*** (don’t stress out high risk pt)

26 yo should get EKG, troponins, not stress test

Question 20

slide 14

Answer 20

algorithm for stable CHD
when to give ASA
give nitro when anginal symptoms
don't give nitro for post/inf wall
don't get B-blocker for inf.  wall or decompensated HF

ASA and clopidogrel

Question 21

TIMI risk score **

Answer 21

slide 15

1: age >=65
1: >= 3 CAD risk factors (HTN, DM, smoking, fam hx, elev. cholesterol)
1: known CAD (sten. >50%)
1: ASA use in past 7 days (CP despite doing right thing! -concerning)

presentation:

1: recent severe angina(less than 24 hrs ago)
1: elevated cardiac markers
1: ST deviation more than/= 0.5 mm

total: 0-7 pts

Question 22

Precautions and risks of Exercise Stress

Answer 22

Risk of exercise testing is about one infarction or death per 1000 tests

Individuals who have pain at rest or minimal activity are at higher risk and should NOT be tested

pt must be stable and ambulatory

Question 23

Indications for Exercise Stress test

Answer 23

To confirm the diagnosis of angina

To determine the severity of limitation of activity due to angina

To assess prognosis in patients with known coronary disease

To evaluate responses to therapy (rarely)

• if can do ex. stress test, you should
• get to 85% max HR

Question 24

Interpretation of ex. stress test

Answer 24

Positive test is 1 mm (0.1 mV) horizontal or downsloping ST-segment depression (beyond baseline) measured 80 msec after the J point

60–80% of patients with anatomically significant coronary disease will have a positive test

10–30% of those without significant disease will also be positive

False positives are uncommon when a 2-mm depression is present

Additional information is inferred from the time of onset and duration of the ECG changes, their magnitude and configuration, BP and heart rate changes, the duration of exercise, and the presence of associated symptoms

Question 25

when can't do ex. stress test

Answer 25

do Myocardial Stress Imaging

Question 26

Myocardial Stress Imaging (MSI) indications

Answer 26

When the resting ECG makes an exercise ECG difficult to interpret Confirmation of the results of the exercise ECG when they are contrary to the clinical impression To localize the region of ischemia To distinguish ischemic from infarcted myocardium To assess the completeness of revascularization following bypass surgery or coronary angioplasty Prognostic indicator in patients with known coronary disease

Question 27

MSI: Myocardial perfusion scintigraphy (radionuclide imaging)

Answer 27

Provides images in which radionuclide uptake is proportionate to blood flow at the time of injection Scintigraphic defects indicate a zone of hypoperfusion that may represent either ischemia or scar If the myocardium is viable, as relative blood flow equalizes over time or during a scintigram performed under resting conditions, these defects tend to "fill in" or reverse, indicating reversible ischemia many false + compare rest and stress images, if same, normal (- test) if at rest fills in, but during stress "chunks missing", then + test Brown does if higher risk

Question 28

MSI: Radionuclide angiography (Multi Gated Acquisition Scan, or MUGA scan)

Answer 28

Uses radionuclide tracers to image the LV and measures its EF and wall motion In coronary disease, resting abnormalities usually represent infarction, and those that occur only with exercise usually indicate stress-induced ischemia used for monitoring patients exposed to cardiotoxic therapies (such as chemotherapeutic agents)

Question 29

Stress echocardiography

Answer 29

Echocardiograms performed during supine exercise or immediately following upright exercise may demonstrate exercise-induced segmental wall motion abnormalities as an indicator of ischemia High-dose dobutamine (20–40 mcg/kg/min) can be used as an alternative (inc. HR)

Question 30

alternative stress test

Answer 30

-use low-dose adenosine: vasodilates coronary vessels (ragidenosine)

Question 31

Positron emission tomography

Answer 31

Demonstrate either perfusion or metabolism of myocardium Can accurately distinguish transiently dysfunctional (“stunned”) myocardium from scar tissue

Question 32

CT scanning can image the heart and, with contrast medium and multislice technology, the coronary arteries

Answer 32

High sensitivity for excluding significant CAD Electron beam CT (EBCT) can quantify coronary artery calcification

Question 33

Cardiac MRI

Answer 33

Excellent assessment of pericardial disease, neoplastic disease of the heart, myocardial thickness, chamber size, and many congenital heart defects rare, tertiary care centers

Question 34

*coronary angiogram*(cath lab)

Answer 34

Life-limiting stable angina despite an adequate medical regimen Clinical presentation (unstable angina, postinfarction angina, etc) or noninvasive testing suggests high-risk disease (see Indications for Revascularization) Concomitant aortic valve disease and angina pectoris, to determine whether the angina is due to accompanying coronary disease Asymptomatic older patients undergoing valve surgery so that concomitant bypass may be done if the anatomy is propitious Recurrence of symptoms after coronary revascularization to determine whether bypass grafts or native vessels are occluded (door to balloon time of 60-90 min) acute event: go after offending vessel ONLY

Question 35

coronary angiogram 2

Answer 35

Cardiac failure where a surgically correctable lesion, such as LV aneurysm, mitral regurgitation, or reversible ischemic dysfunction, is suspected Survivors of sudden death, symptomatic, or life-threatening arrhythmias when CAD may be a correctable cause Chest pain of uncertain cause or cardiomyopathy of unknown cause Emergently performed cardiac catheterization with intention to perform primary PCI in patients with suspected acute myocardial infarction

Question 36

Coronary vasospasm

Answer 36

Cocaine can induce myocardial ischemia and infarction by causing coronary artery vasoconstriction or by increasing myocardial energy requirements and contribute to accelerated atherosclerosis and thrombosis Ischemia in Prinzmetal (variant) angina usually results from coronary vasoconstriction Patients with chest pain associated with ST-segment elevation should undergo coronary arteriography If significant lesions are not seen and spasm is suspected, avoid precipitants, such as cigarette smoking and cocaine Treat with nitrates and calcium channel blockers (don't use B-blockers w. cocaine use) -unopposed alpha will cause problems make sure not underlying STEMI

Question 37

NSTEMI/UA

Answer 37

Unstable angina (UA): Change in nature of pain Change in response to meds (no cardiac enzyme elevation) NSTEMI: Cardiac enzyme elevation (demand ischemia: sepsis, ESRD) Can have EKG changes, however not ST segment elevation *urgent not emergent cath (w.in 24-48 hrs)

Question 38

STEMI

Answer 38

Sudden but not instantaneous development of prolonged (more than 30 minutes) anterior chest discomfort (sometimes felt as “gas” or pressure). Sometimes painless, masquerading as acute heart failure, syncope, stroke, or shock. ECG: ST-segment elevation or left bundle branch block. (NEW LBBB)

Question 39

STEMI tx

Answer 39

Immediate reperfusion treatment is warranted. Primary PCI within 90 minutes of first medical contact is the goal and is superior to fibrinolytic therapy. Fibrinolytic therapy within 30 minutes of hospital presentation is the goal, and reduces mortality if given within 12 hours of onset of symptoms. get tPA if outside 45 min drive of cath lab (but many complications!)

Question 40

slide 35 EKG

Answer 40

anteriolateral MI | left main?

Question 41

complications

Answer 41

``` Postinfarction ischemia Arrhythmias Acute LV failure RV infarction Mechanical defects (papillary muscles) Myocardial rupture ```

Question 42

if have anterior wall MI, have ST elevation in ?? have reciprocal changes in ??

Answer 42

V1-V4 II, III, aVF (inferior)

Question 43

if looking at inferior MI, also need to look at ??

Answer 43

posterior leads depression that is actually elevation in V1 (flip EKG around) -may lead to CHF