Ischemic Heart Disease USMLE EXAMS
WITH COMPLETE ANSWERS.
What is the cause of ischemic heart disease (IHD)? - Answer Syndromes that are due
to an imbalance between myocardial O2 demand and O2 supply from the coronary
arteries
Why is IHD important epidemiologically? - Answer #1 cause of death in the US
What is the most common cause of IHD? - Answer Usually due to atherosclerosis
IHD is usually due to atherosclerosis. What does this mean in terms of risk factors for
IHD? - Answer Same as those for atherosclerosis:
Hypertension
Diabetes
Smoking
Hyperlipidemia
Family History
Men/post-menopausal women (estrogen is protective)
What are the types of IHD? - Answer Stable Angina
Unstable Angina
Myocardial Infarction
Chronic Ischemic Heart Disease
Sudden Cardiac Death
Coronary Blood Flow:
During what stage of the heart cycle are the coronary vessels filled with blood? -
Answer During diastole
Coronary Blood Flow:
Vessels are filled during diastole. What would happen with HR higher than 180? -
Answer Not enough time is spent in diastole, so not even filling of the coronary vessels
would occur
-Can cause ischemia
Coronary Distribution:
What areas of the heart are perfused by the Left Anterior Descending artery? - Answer
Anterior portion of the Left Ventricle
Anterior 2/3 of the Interventricular Septum
Coronary Distribution:
What areas of the heart are perfused by the Right Coronary Artery? - Answer Posterior
portion of the Left ventricle
,Posterior 1/3 of the interventricular septum
Papillary muscle (can lead to mitral prolapse)
Right ventricle
SA and AV nodes
Coronary Distribution:
What areas of the heart are perfused by the Left Circumflex artery? - Answer Lateral
free wall of the Left Ventricle
Coronary Distribution:
What vessel supplies the apex of the heart? - Answer Posterior Descending Artery
-Can branch from RCA or LC, depending on whether the pt has a Right or Left dominant
heart (80% of people are Right dominant)
Stable Angina:
What is the clinical presentation? - Answer Substernal chest pain that arises with
exertion or emotional stress
Stable Angina:
What is the most common cause? - Answer Usually due to atherosclerosis
Stable Angina:
Usually due to atherosclerosis. How much of the vessel must be blocked for symptoms
to arise? - Answer 70% of the vessel must be stenosed
Stable Angina:
What is the reason for symptoms pathophysiological? - Answer Decreased flow through
the stenosed vessel cannot meet the O2 demand of the myocardium during exercise
Stable Angina:
What are some other possible causes?
Can't meet demand of thick wall? Intense vasospasm? - Answer Aortic stenosis/HTN
with LVH
-Can't meet O2 demand of thickened wall
Hypertrophic cardiomyopathy
-Can't meet O2 demand of thickened wall
Cocaine-induced vasospasm
-Blood supply is partially cut off
Stable Angina:
What type of injury is occurring to the myocardium? (reversible/irreversible? - Answer
Reversible injury to the myocytes
Stable Angina:
What are the clinical findings?
Chest pain time? Radiation? Other general symptoms? - Answer Chest pain <30 min
, Radiate to left arm/jaw
Diaphoresis
Shortness of breath
Stable Angina:
What would be seen on an EKG? - Answer ST-depression (subendocardial ischemia)
Stable Angina:
How does it normally resolve? - Answer Normally goes away with rest (reduce the O2
demand of the myocardium)
Stable Angina:
What drug can be given to help relieve symptoms? Mechanism? - Answer Nitroglycerin
-Venodilation -> less venous return to heart -> less preload -> reduce O2 demand
Unstable Angina:
What is the clinical presentation? - Answer Worsening angina - often occurs at rest
Can be:
Less exertion needed for chest pain
Occurring at rest when it wasn't before
Unstable Angina:
What is the most common cause? - Answer Rupture of an atherosclerotic plaque with
incomplete occlusion of the vessel (complete occlusion would cause an MI)
Unstable Angina:
What type of injury is occurring? (reversible/irreversible) - Answer Reversible injury (no
necrosis yet)
Unstable Angina:
What would be seen on an EKG? - Answer ST-depression (subendocardial ischemia)
Unstable Angina:
What drug can be given to relieve symptoms? Mechanism? - Answer Nitroglycerin
- Venodilation -> less venous return -> less preload -> reduce O2 demand of tissue
Unstable Angina:
Why is this more dangerous than stable angina? - Answer Represents worsening
myocardial ischemia
-High risk of progressing to an acute MI
Prinzmetal's Angina (variant angina):
What is the clinical presentation? - Answer Episodic chest pain that is unrelated to
exertion
WITH COMPLETE ANSWERS.
What is the cause of ischemic heart disease (IHD)? - Answer Syndromes that are due
to an imbalance between myocardial O2 demand and O2 supply from the coronary
arteries
Why is IHD important epidemiologically? - Answer #1 cause of death in the US
What is the most common cause of IHD? - Answer Usually due to atherosclerosis
IHD is usually due to atherosclerosis. What does this mean in terms of risk factors for
IHD? - Answer Same as those for atherosclerosis:
Hypertension
Diabetes
Smoking
Hyperlipidemia
Family History
Men/post-menopausal women (estrogen is protective)
What are the types of IHD? - Answer Stable Angina
Unstable Angina
Myocardial Infarction
Chronic Ischemic Heart Disease
Sudden Cardiac Death
Coronary Blood Flow:
During what stage of the heart cycle are the coronary vessels filled with blood? -
Answer During diastole
Coronary Blood Flow:
Vessels are filled during diastole. What would happen with HR higher than 180? -
Answer Not enough time is spent in diastole, so not even filling of the coronary vessels
would occur
-Can cause ischemia
Coronary Distribution:
What areas of the heart are perfused by the Left Anterior Descending artery? - Answer
Anterior portion of the Left Ventricle
Anterior 2/3 of the Interventricular Septum
Coronary Distribution:
What areas of the heart are perfused by the Right Coronary Artery? - Answer Posterior
portion of the Left ventricle
,Posterior 1/3 of the interventricular septum
Papillary muscle (can lead to mitral prolapse)
Right ventricle
SA and AV nodes
Coronary Distribution:
What areas of the heart are perfused by the Left Circumflex artery? - Answer Lateral
free wall of the Left Ventricle
Coronary Distribution:
What vessel supplies the apex of the heart? - Answer Posterior Descending Artery
-Can branch from RCA or LC, depending on whether the pt has a Right or Left dominant
heart (80% of people are Right dominant)
Stable Angina:
What is the clinical presentation? - Answer Substernal chest pain that arises with
exertion or emotional stress
Stable Angina:
What is the most common cause? - Answer Usually due to atherosclerosis
Stable Angina:
Usually due to atherosclerosis. How much of the vessel must be blocked for symptoms
to arise? - Answer 70% of the vessel must be stenosed
Stable Angina:
What is the reason for symptoms pathophysiological? - Answer Decreased flow through
the stenosed vessel cannot meet the O2 demand of the myocardium during exercise
Stable Angina:
What are some other possible causes?
Can't meet demand of thick wall? Intense vasospasm? - Answer Aortic stenosis/HTN
with LVH
-Can't meet O2 demand of thickened wall
Hypertrophic cardiomyopathy
-Can't meet O2 demand of thickened wall
Cocaine-induced vasospasm
-Blood supply is partially cut off
Stable Angina:
What type of injury is occurring to the myocardium? (reversible/irreversible? - Answer
Reversible injury to the myocytes
Stable Angina:
What are the clinical findings?
Chest pain time? Radiation? Other general symptoms? - Answer Chest pain <30 min
, Radiate to left arm/jaw
Diaphoresis
Shortness of breath
Stable Angina:
What would be seen on an EKG? - Answer ST-depression (subendocardial ischemia)
Stable Angina:
How does it normally resolve? - Answer Normally goes away with rest (reduce the O2
demand of the myocardium)
Stable Angina:
What drug can be given to help relieve symptoms? Mechanism? - Answer Nitroglycerin
-Venodilation -> less venous return to heart -> less preload -> reduce O2 demand
Unstable Angina:
What is the clinical presentation? - Answer Worsening angina - often occurs at rest
Can be:
Less exertion needed for chest pain
Occurring at rest when it wasn't before
Unstable Angina:
What is the most common cause? - Answer Rupture of an atherosclerotic plaque with
incomplete occlusion of the vessel (complete occlusion would cause an MI)
Unstable Angina:
What type of injury is occurring? (reversible/irreversible) - Answer Reversible injury (no
necrosis yet)
Unstable Angina:
What would be seen on an EKG? - Answer ST-depression (subendocardial ischemia)
Unstable Angina:
What drug can be given to relieve symptoms? Mechanism? - Answer Nitroglycerin
- Venodilation -> less venous return -> less preload -> reduce O2 demand of tissue
Unstable Angina:
Why is this more dangerous than stable angina? - Answer Represents worsening
myocardial ischemia
-High risk of progressing to an acute MI
Prinzmetal's Angina (variant angina):
What is the clinical presentation? - Answer Episodic chest pain that is unrelated to
exertion
