Sbm Cardiology: Ischemia

Front 1

These are conditions that affect oxygen supply that cause myocardial ischemia

Back 1

Atherosclerosis, thrombosis, spasm, low diastolic blood pressure, low PaO2, low hemoglobin, tachycardia

Hint 1

Flow (pressure and area), oxygen, time

Front 2

These are conditions that affect oxygen demand that cause myocardial ischemia

Back 2

Tachycardia, HTN (leading to increased wall tension), increased preload (pulmonary wedge pressure), increased inotropy (eg, sympathetic response)

Front 3

These are clinical syndromes causesd by myocardial ischemia

Back 3

Angina; systolic or dyastolic dysfunction (contractility); heart failure, shock (MI); arrthymias, ST-segment changes (changes in membrane polarity)

Front 4

This is transient angina brought on by increase in O2 demand with existing fixed coronary obstruction.

Back 4

Typical angina

Front 5

This is transient angina brought about most commonly by exercise and anxiety

Back 5

Typical angina

Front 6

This is transient angina brought on at rest by a decrease in coronary blood flow

Back 6

Variant angina (Prinzmetal's)

Front 7

This is transient angina brought on most commonly by coronary spasm

Back 7

Variant angina (Prinzmetal's)

Front 8

These are the factors that cause "unstable" angina to be unstable.

Back 8

Acute plaque rupture in an artherosclerotic vessel, leading to thrombosis; or factors that increase O2 demand (eg, sudden hypotension and tachycardia as in shock)

Front 9

These syndromes are caused by decreased coronary blood flow.

Back 9

Variant angina, acute MI

Front 10

This syndrome is characterized by pain virtually identical to that experienced in variant angina, but of longer duration.

Back 10

Acute MI

Front 11

This is the mechanism of transient LV dysfunction caused by transient ischemia.

Back 11

Decreased ATP available for contraction and relaxation

Front 12

Transient vs. persistent LV dysfunction

Back 12

Persistent LV dysfunction is caused by scarring of tissue caused by a myocardial infarction, which may result in heart failure. Transient LV dysfunction is caused by transient ischemia.

Front 13

This produces ST-segment shifts

Back 13

Depolarization of myocardial cell membranes, due to potassium in the extracellular space as a result of tissue damage in myocardial ischemia

Front 14

These are three clinical syndromes in patients with coronary disease

Back 14

Chronic coronary disease, acute coronary syndrome, sudden cardiac death

Front 15

Chronic coronary disease vs. acute coronary syndrome

Back 15

Stable angina and post-MI are chronic coronary diseases, whereas unstable angina, and NSTEMI and STEMI's constitute acute coronary syndromes.

Front 16

Definition of NSTEMI

Back 16

Non-ST-elevation myocardial infarction. Similar to unstable angina, but the ischemia is severe enough to cause MI. Diagnosed by troponin elevation.

Front 17

Definition of STEMI

Back 17

ST-elevation MI, caused by acute coronary thrombosis in the coronary lesion, leading to transmural (ST-elevation) ischemia

Front 18

This is the most common cause of death in patients with coronary disease.

Back 18

Sudden cardiac arrhytmia leading to ventricular fibrillation (sudden cardiac death).

Front 19

Levine sign

Back 19

Clenched fist held against the anterior chest, used by patients to describe angina

Front 20

T/F: Angina is difficult for patients to localize

Back 20

True.

Front 21

This is the most diagnostic feature of angina

Back 21

Exertional angina (esp. cold weather, after eating, emotional stress) that is relieved by rest.

Front 22

T/F: Typical angina is unrelated to respiration or position.

Back 22

True.

Front 23

Class I severity (dyspnea, angina)

Back 23

Asymptomatic

Front 24

Class II severity (dyspnea, angina)

Back 24

Moderate effort: >2 blocks, >1 flight

Front 25

Class III severity (dyspnea, angina)

Back 25

Minimal effort: <2 blocks, <1 flight

Front 26

Class IV severity (dyspnea, angina)

Back 26

Symptoms at rest

Front 27

This is the typical duration of typical angina

Back 27

2-15 minutes with rest and/or nitroglycerin

Hint 27

Pain lasting less than 30 sec is not angina; pain lasting 1 hr might represent MI, but is not typical angina

Front 28

These are the three clinical questions used to evaluate chest pain

Back 28

1) Is the chest discomfort substernal?
2) Are symptoms brought on predictably by exertion?
3) Are symptoms relieved within 30 minutes by rest or nitroglycerin?

Front 29

These are the three categories of chest pain

Back 29

1) Definite (or "typical") angina -- all 3 features
2) Probably (or "atypical") angina -- any 2 features
3) Nonanginal pain (none or 1 feature)

Front 30

These are physical findings suggestive of coronary heart disease

Back 30

Decreased LV compliance during anginal attack with S4 gallop or murmur of mitral regurgitation; HTN; type A behavior; obesity; hyperlipidemia (arcus senilis, xanthelasma, etc.).

Front 31

These are nine (9) noncoronary causes of chest pain

Back 31

Aortic stenosis, hypertrophic cardiomyopathy, aortic dissection, pericarditis, pleural pain, esophageal pain, GI pain, musculoskeletal pain, anxiety-hyperventilation syndrome.

Front 32

Respirophasic

Back 32

Describes pain that is worsened by inspiration.

Front 33

This is the established test for diagnosing coronary artery disease

Back 33

Coronary arteriography (angiography)

Front 34

These are some of the problems with coronary arteriography

Back 34

Observer variability, underestimation of disease, definition of "significant" disease (>70% obstruction), cost, morbidity and mortality (1/1000 death rate; complications: acute MI, cerebral thrombosis, allergic rxn, arterial trauma).

Front 35

Indications of coronary angiogram

Back 35

Diagnosis (if hx and noninvasive eval. is inconclusive) and treatment planning (CABG vs. angioplasty)

Front 36

This is the most common cause of anterior wall transmural ischemia

Back 36

Occlusion of the LAD

Front 37

Transient spasm

Back 37

Variant angina (Prinzmetal's)

Front 38

Characterization of "pathological Q wave"

Back 38

0.04 seconds wide, and at least 1/4 the magnitude of the remaining R wave

Hint 38

Transmural infarction

Front 39

ST-segment depression may indicate these conditions.

Back 39

Subendocardial ischemia, LVH ("strain pattern"), electrolyte abnormalities (e.g., hypokalemia), hyperventilation syndrome (resp. alkalosis w/ or w/o hypokalemia)

Hint 39

Segment shifts are due to shifts in membrane polarity. NEWLINE NEWLINE Even in LVH, it is because of decreased blood flow to subendocardium leading to some tissue damage releasing K+ into the EC space.

Front 40

This diagnostic tool is used to detect "hot" and "cold" spots in the myocardium

Back 40

Myocardial perfusion scan, with IV thallium-201, which acts like potassium

Front 41

T/F: A "cold" spot in a myocardial perfusion scan denotes absolute decrease in flow

Back 41

False. It is underperfused, but not necessarily completely cut off.

Front 42

T/F: A positive thallium scan almost always indicates coronary artery disease

Back 42

True.

Front 43

T/F: Electrocardiograms are more specific for coronary disease than thallium scans

Back 43

False. Thallium scans are more sensitive and specific (90% and 95%) for coronary disease than ECG, since ST-segment depression seen on ECG may be a variety of other conditions

Front 44

Stress echocardiograms are conducted in this way

Back 44

Dobutamine is infused, increasing inotropy and heart rate and therefore "exercising" the heart

Front 45

Submaximal stress test

Back 45

Patient is stopped at a target HR, marked change in BP, dangerous arrhythmia, extreme ST-segment shift

Front 46

J-point

Back 46

Junction between QRS complex and ST-segment

Front 47

These are the data derived from stress tests

Back 47

ST-segment shifts, exercise tolerance, HR and BP responses, exercise-induced arrhythmias, "soft" data (symptoms), thallium scan "cold" spots

Front 48

In a stress test, "shortness of breath" may actually indicate this symptom

Back 48

Angina

Front 49

Indications of stress test

Back 49

Diagnosis (not great, only 70% sensitivity and 85% specificity) and prognosis (better predictor than the severity of angina)

Front 50

Definition of positive ST-segment depression

Back 50

Any amount of flat or down-sloping ST-segment depression greater than 1 mm at 0.08 seconds after the J-point

Front 51

Stress-testing for coronary artery disease is most useful for persons in whom pre-test probability is low, intermediate, or high?

Back 51

Intermediate. Highs make false negatives likely, and lows make false positives likely.

Front 52

"met"

Back 52

A unit of measure of activity in stress tests. 1 "met" is metabolic activity at rest.

Front 53

This is the classification scheme of exercise tolerance

Back 53

Poor: inability to exceed 4 mets
Excellent: ability to exceed more than 10 mets

Front 54

This is how ST-segment depressions are quantified

Back 54

Depth (1 mm, 2mm, or greater), extent (number of leads it appears in) and duration.

Front 55

These are criteria for a "markedly positive" stress test

Back 55

Poor exercise tolerance (<4 mets), extensive ischemia (marked ST-segment depression in many leads), prolonged ST-segment depression, exertional hypotension

Front 56

Pain is typically maximal at onset and tends to migrate (eg, from anterior chest wall to upper back to lower back)

Back 56

Aortic dissection

Front 57

Pain is usually related to respiration and/or position

Back 57

Pericarditis

Hint 57

Worsened by lying flat, relieved by sitting up

Front 58

Pain is usually worsened on inspiration

Back 58

Pericarditis, pleural pain

Front 59

Pain may be precipitated by swallowing hot or cold liquids

Back 59

Esophageal pain

Front 60

Pain is usually more subdiaphragmatic, with radiation through or around back

Back 60

GI pain

Front 61

Pain is reproduced by pressing on the chest wall

Back 61

Musculoskeletal pain

Front 62

These are the behavorial components of CAD treatment

Back 62

Exercise (20 min 3 x/week), diet (sat. fat, cholesterol, caloric intake, carb restriction), smoking cessation, counseling to increase compliance with drug therapy

Front 63

Drug therapy for CAD

Back 63

Anti-HTN, cholesterol-lowering drugs

Front 64

These are two effects that statins have

Back 64

Cholesterol reduction, anti-inflammatory (?)

Front 65

Types of cholesterol lowering drugs

Back 65

HMG CoA reductase inhibitors (statins), bile acid sequestrants, nicotinic acid, fibric acids

Front 66

Side effects of statins

Back 66

Myopathy, increased liver enzymes

Front 67

Side effects of bile acid sequestrants

Back 67

GI distress, constipation, decreased absorption of other drugs

Front 68

Side effects of nicotinic acid

Back 68

Flushing, hyperglycemia, hyperuricemia (gout), hepatotoxicity

Front 69

Side effects of fibric acids

Back 69

Dyspepsia, gallstones, myopathy

Front 70

Gemfibrozil

Back 70

Fibric acid (cholesterol lowering)

Front 71

Cholestyramine

Back 71

Bile acid sequestrant (cholesterol lowering)

Front 72

Colestipol

Back 72

Bile acid sequestrant (cholesterol lowering)

Front 73

Statins

Back 73

HMG CoA reductase inhibotors (cholesterol lowering)

Front 74

Mechanism and side effects of nitrates

Back 74

Venodilation lowers preload and therefore also O2 demand; coronary artery dilation increase O2 supply; hypotension can cause reflex tachycardia; headaches

Hint 74

Includes nitroglycerin and isosorbide dinitrate

Front 75

Mechanism and side effects of beta-blockers

Back 75

Reduces HR and BP and therefore also O2 demand; side effects include HF, bradyarrhythmias, fatigue, depression

Hint 75

Includes propranolol, metoprolol, atenolol

Front 76

Mechanism and side effects of calcium channel blockers

Back 76

Prevents spasm to increase O2 supply (useful against variant angina); verapamil and diltiazem reduce HR, BP and inotropy to decrease O2 demand; side effects include headache and edema

Hint 76

Includes verapamil, diltiazem, nifedipine, amlodipine

Front 77

Mechanism and side effects of late Na channel blockers

Back 77

Indirect Ca channel blocker--decreases Na influx into ischemic cells, thereby reducing Ca uptake via the Na/Ca exchanger; similar to verapamil and diltiazem

Hint 77

Includes ranolazine

Front 78

Survival benefit of CABG has been demonstrated for these two subgroups

Back 78

1) Patients with left main coronary disease
2) Patients with 3-vessel disease and poor LV function

Front 79

Risks and side effects of CABG

Back 79

1% to 5-10% mortaility depending on LV function; acute MI, infections, arrhythmias, mental deterioration

Front 80

PTCA / PCI

Back 80

Percutaneous transluminal angioplasty/coronary intervention