S2: Ch1 Cv 1-2

Front 1

56. Diagnosis of MI?

Back 1

a. ECG
b. Cardiac enzymes
c. Troponins (I and T)

Front 2

57. ECG markers for MI?

Back 2

a. Peaked T waves: Occur very early and may be missed.
b. S-T segment elevation
c. Q waves
d. T wave inversion
e. S-T segment depression.

Front 3

58. S-T segment elevation?

Back 3

a. Indicates transmural injury and can be diagnostic of an acute infarct.

Front 4

59. Q waves?

Back 4

a. Evidence of necrosis (Specific) - Q waves are usually seen late; typically not seen acutely.

Front 5

60. T wave inversion?

Back 5

a. Sensitive but not specific.

Front 6

61. S-T segment depression?

Back 6

a. Subendocardial injury.

Front 7

62. ST Segment elevation infarct?

Back 7

a. Transmural.

Front 8

63. Non-ST segment elevation infarct?

Back 8

a. Subendocardial (involves inner 1/3-1/2 of the wall).
b. Tend to be smaller
c. Presentation is similar to unstable angina- cardiac enzymes differentiate the two.

Front 9

64. Diagnostic gold standard for MI?

Back 9

a. Cardiac enzymes: CK-MB and Troponins.

Front 10

65. When does CK-MB increase, for how long does it remain elevated, and when does it peak?

Back 10

a. Increases w/in 4-8 hours.
b. Returns to normal in 48-72 hours.
c. Peaks w/in first 24 hours.
d. When measured w/in 24-36 hours of onset of chest pain, has greater than 95% sensitivity and specificity.

Front 11

66. How often should total CK and CK-MB be measured?

Back 11

a. On admission and q8 thereafter for 24h.

Front 12

67. When do Troponins increase, for how long does it remain elevated, and when does it peak (Most important enzyme test to order)?

Back 12

a. ↑ w/in 3-5 hours
b. Return to normal in 5-14 days.
c. Reach a peak in 24-48 hours.
d. Greater sensitivity and specificity of MI than CK-MB.

Front 13

68. How often should troponins be measured?

Back 13

a. Obtain serum levels of either troponin T or I on admission and Q8 every 24 hours.

Front 14

69. In whom can troponin I be falsely elevated?!?

Back 14

a. Pts w/renal failure.

Front 15

70. Note: Cardiac enzymes are drawn serially- once on admission and every 8 hours until 3 samples are obtained.

Back 15

a. The higher the peak and the longer enzyme levels remain elevated, the more severe the myocardial injury and worse the prognosis.

Front 16

71. What does the combination of substernal chest pain persisting for longer than 30 minutes and diaphoresis strongly suggestive of?

Back 16

a. Acute MI.

Front 17

72. How will Right ventricular infarct present?

Back 17

a. W/inferior ECG changes, hypotension, elevated jugular venous pressure, hepatomegaly.
b. CLEAR LUNGS.

Front 18

73. What should be monitored in a pt w/an acute MI?

Back 18

a. BP and HR: HTN increases afterload and thus oxygen demand, whereas hypotension reduces coronary tissue perfusion. Both nitrates and morphine can cause hypotension!!!
b. Rhythm strip w/continuous cardiac monitor.
c. Auscultate heart
d. Hemodynamic monitoring (CVP,PCWP, SVR, cardiac index [CI] w/a pulmonary artery catheter is indicated if the pt is hemodynamically unstable. Monitoring is helpful is assessing the need for IV fluids and/or vasopressors.

Front 19

74. What do you monitor in the rhythm strip in a pt who had an acute MI?

Back 19

a. Watch for dysrhythmias. Note that PVCs can lower stroke volume and coronary artery filling time.
b. A high frequency of PVCs may predict Vfib or Vt.

Front 20

75. What should you auscultate the heart for in a pt who has had an acute MI?

Back 20

a. 3rd and 4th heart sounds
b. Friction rubs, etc.
c. Lungs- Crackles may indicate LV failure, pulmonary edema.

Front 21

76. Care trial for statins?

Back 21

a. Pts w/a prior hx of MI were randomized to tx w/statins or placebo.
b. The statin group has a reduced risk of death by 24%, reduced risk of stroke by 31%, and a reduction in need for CABG or coronary angioplasty by 27%.

Front 22

77. Thrombolytic therapy?

Back 22

a. Early tx if crucial to salvage as much of the myocardium as possible.
b. Administer as soon as possible up to 24 hours after the onset of chest pain.
c. Outcome is best if given w/in first 6 hours.

Front 23

78. Indications for thrombolytic therapy?!?

Back 23

a. S-T segment elevation in 2 contiguous ECG leads in pts w/pain onset w/in 6 hours who have been refractory to nitroglycerin.

Front 24

79. First choice and alternatives in thrombolytic therapy?

Back 24

a. t-PA is the first choice in many centre.
b. Alternatives include:
1. Streptokinase
2. anisoylated plasminogen-streptokinase activator complex, and urokinase.

Front 25

80. Contraindications to thrombolytic therapy?

Back 25

a. Uncontrolled HTN (>180/110): first control HTN.
b. Trauma: recent head trauma or traumatic CPR
c. Active peptic ulcer disease
d. Previous stroke
e. Recent invasive procedure or surgery
f. Dissecting aortic aneurysm.

Front 26

81. Percutaneous Transluminal Coronary angioplasty (PTCA)?

Back 26

a. Alternative to thrombolytic therapy. At most medical centres, PTCA is the 1st-line tx for MI>
b. Preferred in pts w/contraindications for thrombolytic therapy; no risk of intracranial haemorrhage.
c. PAMI trial showed that PTCA reduces mortality more than t-PA.

Front 27

82. What are the only agents shown to reduce mortality in MI?

Back 27

1. Aspirin
2. β-blockers
3. ACE inhibitors.

Front 28

83. Aspirin for MI?

Back 28

a. Antiplatelet agent reduces coronary reocclusion by inhibiting platelet aggregation on top of the thrombus.
b. Has been shown to reduce mortality and should be part of maintenance therapy long-term!

Front 29

84. β-blockers for MI?

Back 29

a. Block stimulation of HR and contractility
b. Reduce afterload.
c. Have been shown to reduce mortality and should be part of maintenance therapy!

Front 30

85. ACE inhibitors?

Back 30

a. Initiate w/in hours of hospitalization if there are no contraindications.
b. Has been shown to reduce mortality and should be part of maintenance therapy long-term!

Front 31

86. Statins?

Back 31

a. Reduce risk of further coronary events!
b. Stabilize plaques and lower cholesterol
c. Should be part of maintenance therapy!

Front 32

87. Oxygen?

Back 32

a. May limit ischaemic myocardial injury.

Front 33

88. Nitrates?

Back 33

a. Dilate coronary arteries (increase supply)
b. Venodilation (decrease preload and thus demand)
c. Reduce chest pain, although not as effective as narcotics.

Front 34

89. Morphine sulfate?

Back 34

a. Analgesia
b. Cause venodilation, which decreases preload and thus oxygen requirements.

Front 35

90. Heparin?

Back 35

a. Initiate in all patients w/MI; prevents progression of thrombus; however, Has NOT been shown to decrease mortality.
b. LMWH, specifically, enoxaparin (Lovenox), is preferred over unfractionated heparin.

Front 36

91. Revascularization?

Back 36

a. Benefit highest when performed early; time is more important than type of reperfusion.
b. Should be considered in all patients.
c. 2 forms of revascularization exist; thrombolysis or PTCA.

Front 37

92. Rehabilitation for MI?

Back 37

a. Cardiac rehab is a physician-supervised regimen of exercise and risk-factor reduction after MI.
b. Shown to reduce symptoms and prolong survival!

Front 38

93. Capricorn trial results for β-blockers?

Back 38

a. Showed that the β-blocker carvedilol reduces the risk of death in pts w/post-MI LV dysfunction.