IM EOR - Cardio part 1

Coronary artery vasospasms causing transient ST-segment elevations, not associated with clot

Prinzmetal angina

____________________ is caused by coronary artery vasospasm.

Prinzmetal's angina

____________________ is a class II antiarrhythmic that can exacerbate vasospasm in Prinzmetal's angina.

Propranolol

____________________ due to subendocardial ischemia is an electrocardiogram finding seen in both unstable and stable angina.

ST-segment depression

__________________ is the number one risk factor for Prinzmetal's angina.

Smoking

Predictable, relieved by rest and/or nitroglycerine

Stable angina

_______________ is used to diagnose unstable if a patient has a normal resting ECG and can exercise, exercise stress testing with ECG is done

Stress testing

Exercise stress testing is the most useful and cost-effective noninvasive test for stable angina. An ST-segment depression of ______mm is considered to be a positive test.

1mm

A 47-year-old man comes to the emergency department because of a 40-minute episode of central chest pain that occurred 2 hours ago and has since subsided. This is the first time that the patient has experienced this type of pain. His troponin and CK-MB levels are normal and an electrocardiogram (ECG) shows symmetric, deeply inverted T-waves in V2 and V3. Which of the following types of acute myocardial infarction is the patient at most risk for? A. Anterior wall myocardial infarction B. Inferior wall myocardial infarction C. Lateral wall myocardial infarction D. Posterior wall myocardial infarction E. Septal myocardial infarction

A (Anterior wall myocardial infarction) (Wellens' syndrome is an ECG manifestation that is specific for severe left anterior descending artery stenosis in patients with unstable angina. It is characterized by symmetric, deeply inverted T-waves in V2 and V3) (This patient has Wellens' syndrome, which is an ECG manifestation that is specific for severe left anterior descending artery stenosis in patients with unstable angina. It is characterized by symmetric, deeply inverted T-waves in V2 and V3. A less common variation shows biphasic T-waves in V2 and V3. Additional diagnostic criteria include a history of chest pain with normal to minimally elevated cardiac enzymes, no Q-waves, no ST-elevation, and no loss of precordial R-waves. Research suggests that over 50% of patients with Wellens' syndrome have a complete or near-complete occlusion of the left anterior descending coronary artery and that approximately three-quarters will develop an anterior wall myocardial infarction. Consequently, further evaluation in the form of coronary angiography followed by immediate intervention and revascularization would be likely next steps in management)

A 62-year-old man comes to the emergency department after experiencing an hour of crushing, left-sided chest pain that improved with aspirin and sublingual nitroglycerine tablets. The pain radiated to his left arm and in addition he had shortness of breath and diaphoresis. Cardiac enzyme tests show no abnormalities. An electrocardiogram (ECG) shows symmetrical, deep (>2 mm), T-wave inversions in the anterior precordial leads. Which of the following is the most appropriate next step in the management? A. Anti-coagulation with urgent cardiac catheterization B. Discharge home with a plan for follow-up C. Obtaining a lipid panel test D. Observation to rule out myocardial infarction E. Ordering stress echocardiography

A (Anti-coagulation with urgent cardiac catheterization) (Patients with Wellens syndrome have critical stenosis of the left anterior descending artery (LAD) and require catheterization. They can be identified by characteristic ECG findings including deep (>2 mm) T-wave inversions in the anterior precordial leads) (This patient has Wellens syndrome, a form of unstable angina caused by occlusion of the left anterior descending (LAD) coronary artery and characterized by symmetrical, often deep (>2 mm), T-wave inversions in the anterior precordial leads. 75% of patients with a Wellens-type ECG develop an anterior myocardial infarction (MI) in the subsequent days or weeks. This lesion requires urgent cardiac consultation for a cardiac catheterization with stenting to alleviate the blockage) (Because Wellens syndrome is a sign of a pre-infarction stenosis of the LAD, a stress test has the potential to result in acute MI and severe damage to the left ventricle. Therefore, these patients should generally forego a stress test and instead undergo angiography to evaluate the need for angioplasty or coronary artery bypass surgery (CABG))

A 49-year-old female presents complaining of several episodes of chest pain recently. Initial ECG in the emergency department shows no acute changes. Two hours later, while the patient was having pain, repeat electrocardiogram revealed ST segment elevation in leads II, III, and AVF. Cardiac catheterization shows no significant obstruction of the coronary arteries. Which of the following is the treatment of choice in this patient? A. Nifedipine (Procardia) B. Metoprolol (Lopressor) C. Lisinopril (Zestril) D. Carvedilol (Coreg)

A (Nifedipine [Procardia]) (This patient is most likely having coronary artery spasm. This can be treated prophylactically with calcium channel blockers such as nifedipine)

Unstable angina is closely related to _____________________ and is a common manifestation of cardiovascular disease.

Non-ST-segment elevation myocardial infarction

The gold standard for diagnosis of unstable angina is ________________, though it is not always needed for a diagnosis.

Angiography

__________________ is indicated for the diagnosis of unstable angina primarily to locate and assess severity of coronary artery lesions when revascularization (percutaneous intervention [PCI] or coronary artery bypass grafting [CABG]) is being considered.

Angiography

The treatment for stable angina may include:

Aspirin Nitrates β-blockers Ca channel blockers ACE inhibitors Statins Coronary angioplasty Coronary artery bypass graft surgery

Anginal chest pain is most commonly described as which of the following? A. Pain changing with position or respiration B. A sensation of discomfort C. Tearing pain radiating to the back D. Pain lasting for several hours

B (A sensation of discomfort)

A 28-year-old man comes to the emergency department because of persistent chest discomfort for the past 6 hours. He describes pain and pressure in the center of his chest that radiates to his jaw. Painful episodes last 5-15 minutes and are accompanied by nausea, diaphoresis, dyspnea, and dizziness. His medical history is significant for migraine headaches controlled with an sumpatriptan that he cannot currently name. His history is also significant for occasional cocaine use in addition to a 10 pack year tobacco smoking history. His temperature is 36.6°C (98.0°F), pulse is 99/min, respirations are 22/min, blood pressure is 135/93 mm Hg, and oxygen saturation is 97% on room air. Electrocardiogram on arrival shows no abnormalities, but 30 minutes later, during a pain episode, a repeat electrocardiogram shows ST elevation in leads V2-V6. Current troponin-I is 0.01. Which of the following is the most appropriate intervention for this patient? A. Aspirin B. Calcium channel blockers and nitrates C. Heparin D. Non-selective β-blockers E. Percutaneous coronary intervention

B (Calcium channel blockers and nitrates) (Prinzmetal (variant) angina should be suspected in a young patient without cardiovascular risk factors, who may be taking medications which increase the risk of vasospasm (e.g. triptans, cocaine, amphetamines). Treatment is different to that of traditional atherosclerotic STEMI or NSTEMI and involves the use of a calcium channel blocker to decreased vasospasm) (This patient has Prinzmetal (variant) angina. While most other forms of angina are due to atherosclerotic coronary artery disease, this form of angina is due to vasoconstriction. Risk factors include certain medications/drugs like cocaine, marijuana, alcohol, butane, sumatriptan and amphetamines. This patient smokes, admits to cocaine use, and takes an abortive agent for migraine headaches (likely a triptan medication). (This overall presentation is also indicative of variant angina. The patient is young without a significant cardiovascular risk profile. In addition, the cyclical nature of the episodes and ST-elevations only when episodes occur makes variant angina very likely) (The most appropriate initial treatment is a calcium channel blocker. Diltiazem at 240-360 mg/day is most effective. Nitrates can be used to relieve episodes of anginal chest pain. In addition, smoking cessation as well as discontinuation of triptan therapy should be discussed)

A patient with which of the following is at highest risk for coronary artery disease? A. Congenital heart disease B. Polycystic ovary syndrome C. Acute renal failure D. Diabetes mellitus

D (Diabetes mellitus) (Patients with diabetes mellitus are in the same risk category for coronary artery disease as those patients with established atherosclerotic disease)

Which of the following medication classes is contraindicated in a patient with variant or Prinzmetal's angina? A. Calcium channel blockers B. ACE inhibitors C. Beta blockers D. Angiotensin II receptor blockers

C (Beta blockers) (Use of a beta-blocker such as propranolol is contraindicated in Prinzmetal's angina. Beta blockers have been noted to exacerbate coronary vasospasm potentially leading to worsening ischemia)

A 63 year-old male with history of hypertension and tobacco abuse presents complaining of dyspnea on exertion for two weeks. The patient admits to one episode of chest discomfort while shoveling snow which was relieved after five minutes of rest. Vital signs are BP 130/70, HR 68, RR 14. Heart exam reveals regular rate and rhythm, normal S1 and S2, no murmur, gallop, or rub. Lungs are clear to auscultation bilaterally. There is no edema noted. Which of the following is the most appropriate initial diagnostic study for this patient? A. Helical CT scan B. Chest x-ray C. Nuclear stress test D. Cardiac catheterization

C (Nuclear stress test) (In patients with classic symptoms of angina, nuclear stress testing is the most widely used test for diagnosis of ischemic heart disease) (Coronary angiography is indicated in patients with classic stable angina who are severely symptomatic despite medical therapy and are being considered for percutaneous intervention (PCI), patients with troublesome symptoms that are difficult to diagnose, angina symptoms in a patient who has survived sudden cardiac death event, patients with ischemia on noninvasive testings)

a 50-year-old woman with a history of hyperlipidemia and diabetes type 2 complaining of "chest pain attacks." She says that these attacks tend to occur while walking up five flights of stairs to get to her apartment, they last for 15-20 minutes and are relieved by rest. She describes the pain as sharp and substernal. A baseline EKG is unremarkable. Suspecting the diagnosis, you perform an exercise stress EKG and observe transient ST depressions in the anterolateral leads after significant exertion. What is the most likely diagnosis? A. Ludwig angina B. ST-elevation myocardial infarction C. Stable angina D. Unstable angina E. Vasospastic angina

C (Stable angina)

A 56-year-old man comes to the emergency department because of chest pain and pressure he experienced an hour ago while shoveling snow. He has had recurrent bouts of this pain over the past year, and he says that it usually radiates to his jaw and left arm, and goes away when he sits down to rest. Today's episode lasted five minutes, he has come to the ED at the urging of his family. He has a 10-year history of hyperlipidemia and type 2 diabetes mellitus. Current medications include atorvastatin and metformin. His temperature is 37.1°C (98.8°F), pulse is 87/min, respirations are 19/min, and blood pressure is 130/85 mm Hg. Initial laboratory studies show a troponin I level of less than 0.01 ng/mL. Chest X-ray and ECG show no abnormalities. Which of the following is the most likely diagnosis? A. Ludwig angina B. Non-ST elevation myocardial infarction C. Stable angina D. Unstable angina E. Vasospastic angina

C (Stable angina) (Stable angina pectoris, caused by myocardial ischemia most commonly due to atherosclerotic coronary artery disease, presents with chest discomfort that occurs on exertion and is relieved with rest or nitroglycerin) (This patient, who has exertional chest pain relieved by rest, most likely has stable angina pectoris. Stable angina results from myocardial ischemia that occurs predictably at a certain level of exertion, causing a mismatch between myocardial oxygen demand (estimated as the product of heart rate and systolic blood pressure) and oxygen supply. Stable angina typically occurs in the setting of coronary artery disease and occurs over a period of time. In this patient's case, the patient has had bouts of pain over the past year, and he has hyperlipidemia and type 2 diabetes mellitus which are important risk factors for coronary artery disease. An ECG obtained during an anginal episode may show ST-segment depression that resolves upon rest; however, cardiac biomarkers, such as troponins, are not elevated. Nitrates are the therapy of choice for treatment of acute episodes and act by acutely lowering blood pressure. Beta-blockers are first-line treatment for preventing anginal symptoms, and calcium channel blockers may be considered when initial treatment with beta-blockers is unsuccessful)

A 65-year-old male comes into the emergency department because of chest pain and pressure that started about three hours ago. The pain radiates up to his jaw and down his left arm. He says that it has waxed and waned over the past three hours, but has never gone away despite him taking three doses of sublingual nitroglycerin. Chest X-ray shows no abnormalities and electrocardiogram (ECG) shows ST-segment depression in the lateral leads. Troponin measurements are positive, above the upper reference limit. Which of the following medications is least appropriate for the patient at this present time? A. Anti-coagulants B. Anti-platelet agents C. β-blockers D. Thrombolytics E. Venous dilators

D (Thrombolytics) (Non-ST segment elevation myocardial infarction (NSTEMI) can be distinguished from unstable angina (UA) based on the presence of positive cardiac biomarkers in the former. Unstable angina with non-ST-elevation myocardial infarction (UA/NSTEMI) generally does not warrant treatment with thrombolytics) (This patient has chest pain that occurred at rest with classical "cardiac" features and did not abate with nitrates, all of which are indicative of unstable angina (UA). The patient's ECG also showed ST-depressions in the lateral leads, making this a case of unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI). Both unstable angina and NSTEMI are caused by atherosclerotic plaque rupture; however, only NSTEMI is associated with an increase in troponins and other cardiac enzymes) (Current guidelines advise against the use thrombolytic therapy in UA/NSTEMI due to a lack of proven benefit. This is because, in patients with unstable angina, mechanical obstruction in the form of plaque fissure/rupture is more common than a completely occluding thrombus. However, the patient's risk of developing transmural ischemia should be stratified using the TIMI Risk Score. Patients at high risk should be taken for percutaneous coronary intervention within the next 24-48 hours)

A 58-year-old man with a history of coronary artery disease, hypertension, and hyperlipidemia presents to an emergency department for evaluation of chest pain. He reports somewhat suddenly experiencing dull left-sided chest discomfort while at rest at home that was not relieved with taking nitroglycerin. His vital signs are T 37.1, HR 94 beats per minute, BP 133/87, and O2 saturation 97% on room air. His ECG shows no ST-segment changes; serum troponin is not elevated. His chest pain subsequently resolves and he is admitted to the cardiac service for further management. What is the most likely diagnosis? A. Ludwig angina B. ST-elevation myocardial infarction C. Stable angina D. Unstable angina E. Vasospastic angina

D (Unstable angina)

A 55 year-old male is seen in follow-up for a complaint of chest pain. Patient states that he has had this chest pain for about one year now. The patient further states that the pain is retrosternal with radiation to the jaw. "It feels as though a tightness, or heaviness is on and around my chest". This pain seems to come on with exertion however, over the past two weeks he has noticed that he has episodes while at rest. If the patient remains inactive the pain usually resolves in 15-20 minutes. Patient has a 60-pack year smoking history and drinks a martini daily at lunch. Patient appears overweight on inspection. Based upon this history what is the most likely diagnosis? A. Acute myocardial infarction B. Prinzmetal variant angina C. Stable angina D. Unstable angina

D (Unstable angina) ( Pain in unstable angina is precipitated by less effort than before or occurs at rest)

A 50-year-old woman comes to the emergency department because of acute severe chest pain for 30 minutes. She states that the pain woke her from sleep and that she is very concerned she is having a 'heart attack.' She states she has had similar chest pains in the past, usually also at night, but never this severe. Cardiopulmonary examination is noncontributory. An ECG is obtained which shows ST-elevations in leads V1, V2, V3, and V4. Laboratory investigations show her cardiac enzyme marker levels are within normal limits. At angiography, no pathological findings are found. Which of the following is the most likely diagnosis? A. Anterior myocardial infarction B. Anteroseptal myocardial infarction C. Unstable angina pectoris D. Variant angina E. Somatic symptom disorder

D (Variant angina) (Variant angina is a syndrome typically consisting of angina (cardiac chest pain) at rest that occurs in cycles. ECG can capture diffuse ST-elevations. Cardiac enzymes and markers are generally normal levels. The gold standard is coronary angiography) (Variant angina is a syndrome typically consisting of angina (cardiac chest pain) at rest that occurs in cycles. It is caused by vasospasm, a narrowing of the coronary arteries caused by contraction of the smooth muscle tissue in the vessel walls rather than directly by atherosclerosis (buildup of fatty plaque and hardening of the arteries). ECG can capture diffuse ST-elevations. Cardiac enzymes and markers are generally normal. The gold standard is coronary angiography with the injection of provocative agents into the coronary artery.) (Rarely, an active spasm can be documented angiographically (e.g. if the patient receives an angiogram with the intent of performing a primary coronary intervention with angioplasty). Depending on the local protocol, provocation testing may involve substances such as ergonovine, methylergonovine, acetylcholine, and hyperventilation. Characteristically symptoms occur at night as while the patient is sleeping they have higher vagal tone, and therefore increased acetylcholine in their serum)

A 46-year-old man comes to the office because of a four-month history of intermittent episodes of chest discomfort and tightness. His symptoms typically occur only on exertion, such as when gardening or playing with his children, and are relieved by rest. He says the episodes last less than 20 minutes. He has otherwise been healthy and his personal medical history is noncontributory. His father has coronary artery disease, but is alive and well. Physical exam, laboratory studies and ECG are normal. The medication most appropriate for treating his acute episodes acts by which of the following mechanisms? A. Blocking calcium channels B. Controlling coronary artery vasospasm C. Decreasing heart rate D. Venodilation E. Arteriolodilation

D (Venodilation) (Stable angina pectoris results when myocardial oxygen demand exceeds oxygen supply. Nitrates, the first-line therapy for acute episodes and they act principally through smooth muscle relaxation and venodilation which causes blood pooling in the peripheral vasculature with a concomitant reduction in preload. Decreased preload decreases cardiac contractility and oxygen demand) (This patient's symptoms of chest pain and tightness on exertion suggest a diagnosis of stable angina pectoris, caused by insufficient oxygen delivery to the myocardium during times of increased demand. Delivery is usually compromised by a stenotic coronary vasculature. Treatment involves nitrates to manage acute attacks and beta-blockers for prophylaxis; calcium channel blockers can be added if anginal symptoms persist) (This questions ask about the mechanism of the drug used to treat acute angina, i.e. nitroglycerin. Nitroglycerin ameliorates anginal episodes by reducing myocardial oxygen demand via peripheral vasodilation. This effected is principally mediated by venodilation, which results in a peripheral pooling of blood, thereby decreasing venous return and preload with the end result of decreasing myocardial contractility and oxygen demand. At higher doses, arterioles also become dilated , reducing afterload as well, but this is a secondary effect) (Vasodilation is achieved via smooth muscle dilation caused by conversion of nitroglycerin to nitric oxide via mitochondrial aldehyde dehydrogenase. Nitric oxide stimulates guanylyl cyclase which increases cGMP. Increased cGMP inhibits calcium entry into the cell, increases potassium conductance by activating potassium channels, and stimulates a protein kinase that activates myosin light chain phosphatase, all of which which leads to smooth muscle relaxation)

A 58 year-old male who is otherwise healthy presents with chest pain and is found to have left main coronary artery stenosis of 75%. The most important aspect of his management now is A. daily aspirin to prevent MI. B. nitrate therapy for the angina. C. aggressive risk factor reduction. D. referral for coronary artery revascularization.

D (referral for coronary artery revascularization) (Although medical therapy is important, revascularization is indicated when stenosis of the left main coronary artery is greater than 50)

A 65-year old man who presents to the ED at 1 am with 90 minutes of central chest pressure that awoke him from sleep. He says he thinks he has 'indigestion.' The pain is non-radiating, with mild shortness of breath but no nausea, vomiting or diaphoresis. He is an ex-smoker with a 20 pack-year history. There is no previous history of CAD, diabetes, hypertension or high cholesterol. On arrival, he looks well, with normal heart rate (54 bpm), blood pressure (127/86) and oxygen saturation (98% on room air). His pain has improved slightly with sublingual nitrates in the ambulance, although he still has some ongoing chest discomfort. His ECG is shown below. Troponins are positive. He is admitted to hospital and undergoes emergent cardiac catheterization, where he is without obstructive coronary disease, but his symptoms can be provoked with the administration of intravenous ergonovine. What is the most likely diagnosis? A. Ludwig angina B. ST-elevation myocardial infarction C. Stable angina D. Unstable angina E. Vasospastic angina

E (Prinzmetal angina)

A 28-year-old man comes to the emergency department because of intermittent chest discomfort for six hours. He describes chest pain and pressure that radiates to the jaw. Episodes of pain last 5-15 minutes and are associated with nausea, diaphoresis, dizziness, and dyspnea. He has not noticed any precipitating factors. He has a 5-year history of migraines, for which he takes an abortive medication. He has smoked a pack of cigarettes daily for 10 years and uses cocaine occasionally. His temperature is 37°C (98.6°F), pulse is 99/min, respirations are 22/min, and blood pressure is 135/93 mm Hg. Initial ECG shows no abnormalities, but a repeat ECG 30 minutes later during an episode of chest discomfort shows ST-segment elevation in leads V2 through V6. Laboratory studies at that time show a troponin I level of 0.01 ng/mL. Which of the following is the most likely diagnosis? A. Ludwig angina B. ST-elevation myocardial infarction C. Stable angina D. Unstable angina E. Vasospastic angina

E (Vasospastic angina) (Vasospastic angina results from coronary artery vasopasm, not atherosclerotic coronary artery disease as in other types of angina. Patients are characterized by recurrent anginal episodes at rest and transient ECG changes. They tend to be younger individuals with fewer cardiovascular risk factors; however, cigarette smoking is a key risk factor) (This patient's symptoms of recurrent anginal episodes that occur at rest with transient ST-segment elevation on ECG during an episode are most consistent with a diagnosis of vasospastic angina, also known as variant or Prinzmetal angina. While most forms of angina are caused by atherosclerotic coronary artery disease, vasospastic angina is caused by coronary artery vasospasm and vasoconstriction. Patients are typically younger, with fewer cardiovascular risk factors. However, cigarette smoking is a major risk factor, and drugs like cocaine or sumatriptan (which the patient is most likely taking for migraine headaches) can also trigger anginal episodes. Other potential precipitating factors include amphetamines, marijuana, and alcohol. Vasospastic angina typically occurs without significant myocardial ischemia, as confirmed by the normal troponin level in this patient. Nonetheless, prolonged vasospasm may lead to myocardial ischemia and infarction as well as life-threatening arrhythmias)

______________ in the lateral leads I, V5 and V6 (and possibly also in leads II and III) may be observed during attacksof Prinzmetal's angina.

Inverted U waves

________________ is a serious skin infection of the floor of the mouth, under the tongue. It does not relate to cardiac pathology or cause chest pain.

Ludwig angina

Previously stable and predictable symptoms of angina that are more frequent, increasing or present at rest

Unstable angina

_______________ is suspected when the pain is less responsive to NTG, lasts longer, and occurs at rest or with less exertion than previous episodes of angina. Such changes require prompt evaluation and treatment

Unstable angina

_______________ is a form of unstable angina caused by occlusion of the left anterior descending (LAD) coronary artery and characterized by symmetrical, deep (>2 mm), T-wave inversions in the anterior precordial leads

Wellens syndrome

Prinzmetal angina is characterized by cardiac chest pain (angina), that occurs at rest and usually happens (during the day / at night or early morning hours)

at night or early morning hours

Prinzmetal angina is characterized by cardiac chest pain (angina), that occurs (with exertion / at rest) and usually happens at night or early morning hours

at rest

The most common cause of stable angina is ________________ of one or more the coronary arteries.

atherosclerosis

Prinzmetal variant angina is due to transient coronary artery vasospasms within normal coronary anatomy or at site of an __________________.

atherosclerotic plaque

The first-line treatment for Prinzmetal angina are _______________________ (drug class).

calcium channel blockers

Pain from _______________ is described as a pressure like pain in the chest that radiates to the left arm, jaw, or shoulder.

cardiac ischemia

Unstable angina is closely related to non-ST-segment elevation myocardial infarction and is a common manifestation of ___________________.

cardiovascular disease

The gold standard for diagnosis of Prinzmetal angina is __________________ with the injection of provocative agents into the coronary artery.

coronary angiography

The most common cause of stable angina is atherosclerosis of one or more the ____________________.

coronary arteries

On ECG stable angina show ST (elevation/depression) ______________.

depression

The electrocardiogram of someone with unstable angina shows ST-segment (elevation/depression) __________________ due to subendocardial ischemia.

depression

People with stable angina (do/do not) ______________ have pain at rest.

do not

Unlike a non-ST segment elevation myocardial infarction, unstable angina (does/does not) show elevation of cardiac enzyme.

does not

Electrocardiogram findings in Prinzmetal's angina include transient ST segment (elevation/depression) _____________________.

elevation

Unstable angina is usually secondary to ___________________ and causes unpredictable chest pain at rest.

incomplete artery occlusion

Prinzmetal angina (is/is not) related to physical activity, changes to heart rate, and blood pressure.

is not

Increased thickness of the (layer of the heart) __________________ can decrease the amount of blood reaching the endocardium.

myocardium

Pain relief treatment for stable angina includes rest and (medication) ______________________.

nitroglycerin

Unstable angina may not always be completely relieved by rest or (medication) ______________, helping to differentiate it from stable angina.

nitroglycerin

Prinzmetal variant angina is due to transient coronary artery vasospasms within _____________ coronary anatomy or at site of atherosclerotic plaque

normal

Unstable angina is chest pain, usually without exertion, caused by __________________________.

subendocardial ischemia