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51 Cards in this Set
- Front
- Back
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What is the anatomical cause of stable angina pectoris?
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Fixed atherosclerotic lesions that narrow the major coronary arteries
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What are the risk factors for stable angina pectoris?
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DM
Hyperlipidemia (elevated LDL) HTN Cigarette smoking Men > 45yo, Women > 55yo Family history of premature CAD or MI in 1st-degree relative (Men < 45, Women < 55) Low HDL Elevated Homocysteine levels |
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What are five clinical presentations of coronary artery disease?
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Asymptomatic
Stable angina pectoris Unstable angina pectoris Myocardial Infarction Sudden cardiac death |
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What are three prognostic indicators of CAD?
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LV function (EF) < 50%
Left main coronary artery involvement 2-3 vessel CAD All make for a worse prognosis |
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What is described by...
- Chest pain or substernal pressure sensation lasting 10-15 minutes, frightening chest discomfort described as heaviness, pressure, or squeezing - Brought on by exertion - Relieved with rest or nitroglycerin |
Stable angina pectoris
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When is a stress ECG used?
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To confirm diagnosis of angina
To evaluate response of therapy in patients with documented CAD To identify patients with CAD who may have a high risk of acute coronary events |
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Can a resting ECG be used to diagnose stable angina pectoris?
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No - you need a stress ECG
You can use a resting ECG to identify prior MI (Q waves), or unstable angina (ST segment or T wave abnormalities during chest pain episode) |
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Describe a stress ECG and significance of positive findings.
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Record ECG before, during and after exercise on a treadmill
75% sensitive if patients are able to exercise sufficiently to increase heart rate to 85% maximum predicted value for age. Exercise-induced ischemia results in subendocardial ischemia, producing ST segment depression Other positive findings include onset of heart failure or ventricular arrhythmia during exercise or hypotension Positive test --> patient should undergo cardiac catheterization |
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What is stress echocardiography?
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Performed before and immediately after exercise. Exercise-induced ischemia is evidenced by wall motion abnormalities (akinesis or dyskinesis) not present at rest
More sensitive in detecting ischemia, can assess LV size and function and can diagnose valvular disease. Positive test --> patient should undergo cardiac catheterization |
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What is Metabolic Syndrome X? Syndrome X?
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Metabolic Syndrome X: Any combination of hypercholesterolemia, hypertriglycideremia, impaired glucose tolerance, diabetes, hyperuricemia, HTN
Key underlying factor is insulin resistance (due to obesity) Syndrome X: exertional angina with normal coronary arteriogram - patients present with chest pain after exertion but have no coronary stenoses at cardiac catheterization. Exercise testing and nuclear imaging show evidence of myocardial ischemia. Prognosis is excellent. |
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What information is obtained via cardiac catheterization?
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Information on hemodynamics, intracardiac pressure measurements, cardiac output, oxygen saturation, etc.
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What are the indications for cardiac catheterization?
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Positive stress test
Angina where noninvasive tests are nondiagnostic, or it occurs despite medical therapy, or soon after MI or any angina that is a diagnostic dilemma If patient is severely symptomatic and urgent diagnosis and management are necessary For evaluation of valvular disease and to determine the need for surgical intervention |
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At what point is coronary stenosis significant?
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>70%
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What is the benefit to doing an enhanced stress myocardial perfusion imaging after IV administration of thallium 201?
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Permits one to see whether ischemia is reversible or not, because if reversible it can be rescued by percutaneous transluminal coronary angioplasty or coronary artery bypass grafts.
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What is the alternative if a patient cannot perform an exercise stress test?
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Pharmacologic stress test, with IV adenosine, dipyramidole, or dobutamine.
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How do IV adenosine and dipyramidole mimic a stress test?
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Cause generalized coronary vasodilation
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How does IV dobutamine mimic a stress test?
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Increases myocardial oxygen demand by increasing heart rate, blood pressure, and cardiac contractility.
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What is holter monitoring?
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Ambulatory ECG - can be useful in detecting silent ischemia
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What is the definitive test for CAD?
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Coronary angiography - indicated for patients being considered for revascularization
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When should you refer a patient for surgical revascularization (CABG) of CAD?
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If CAD is severe - left main, or three vessel disease.
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What are the benefits of quitting smoking on CHD?
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Cuts CHD risk in half by 1 year after quitting
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What are ways of reducing risk of CHD?
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Smoking cessation
Managing HTN Reducing hyperlipidemia Glycemic control in DM Weight loss if obese Exercise Reduced saturated fat intake and cholesterol intake Decreasing homocysteine levels? |
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What are the benefits of treating patients with CAD with aspirin?
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It decreases morbidity by reducing risk of MI
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What are the benefits of treating patients with CAD with a beta blocker?
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They block sympathetic stimulation of the heart, thus reducing HR, BP and contractility, and decreasing cardiac work. Has been shown to reduce the frequency of coronary events.
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What are the benefits of treating CAD with nitrates?
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Nitrates cause generalized vasodilation - relieve angina by reducing preload (therefore the load and oxygen demand)
They may also prevent angina when taken before exertion Effect on prognosis is unknown, primary benefit is symptomatic relief |
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What are the benefits of treating CAD with CCBs?
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Cause coronary vasodilation and afterload reduction - now considered a secondary treatment when beta blockers and/or nitrates are not fully effective
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What is the benefit of revascularization?
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Symptomatic relief - does not reduce incidence of MI
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How do you manage a patient with mild CAD (normal EF, mild angina, single-vessel disease)?
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Nitrates (for symptoms and prophylaxis) and a BB as appropriate
Consider CCBs if symptoms continue even with nitrates and BBs. |
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How do you manage a patient with moderate CAD (normal EF, moderate angina, two-vessel disease)?
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Nitrate and BB
if no relief, consider CCB If no relief, consider coronary angiography to assess suitability for revascularization (either PTCA or CABG) |
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How do you manage a patient with severe CAD (decreased EF, severe angina, and three-vessel/left-main or LAD disease)?
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Coronary angiography and consider for CABG
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When would you consider percutaneous transluminal coronary angioplasty?
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Should be considered in patients with 1-2 vessel disease - best if used for proximal lesions.
Restenosis is a significant problem (up to 40% in first 6 months) however if there is no evidence of that by 6 months it usually wont happen. Stents - significantly reduce the rate of restenosis |
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When would you consider CABG?
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It is the treatment of choice in patients with high-risk disease
Indicated in patients with left main disease, three-vessel disease with reduced left ventricular function, two-vessel disease with proximal LAD stenosis, or sever ischemia for palliation of symptoms. |
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What is the pathophysiology of unstable angina?
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Oxygen demand is unchanged but supply is decreased secondary to reduced resting coronary flow - indicates stenosis that has enlarged via thrombosis, hemorrhage, or plaque rupture - it may lead to total occlusion of a coronary vessel.
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What indicates that a patient has USA?
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Patient with chronic angina with increasing frequency, duration, or intensity of chest pain
Patients with new-onset angina that is severe and worsening Patients with angina at rest |
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What is acute coronary syndrome?
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Clinical manifestations of atherosclerotic plaque rupture and coronary occlusion - term generally refers to unstable angina or acute MI.
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What differentiates unstable angina and non-ST segment elevation MI?
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The MI is more likely to have elevated cardiac enzymes
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How do you treat a patient presenting with unstable angina?
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Hospital admission on a floor with continuous cardiac monitoring - establish IV access, give supplemental oxygen, provide pain control with nitrates and morphine
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What drugs are used to treat unstable angina?
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Aspirin
Beta blockers - first line if there are no contraindications LMWH or unfractionated heparin - at least 2 days, keep PTT at 2-2.5 times normal if using unfractionated heparin, PTT not followed with LMWH. Enoxaparin is the DOC based on clinical trials (ESSENCE) Nitrates are first-line therapy Glycoprotein IIbIIIa inhibitors (abciximab, tirofiban) - helpful adjuncts in unstable angina, especially if patient is undergoing PTCA or stenting. |
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What is the ESSENCE trial?
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A clinical trial that showed that USA and non-ST segment elevation MI have decreased risk of death, MI or recurrent angina if treated initially with enoxaparin compared to traditional heparin at 14 days, 30 days, and 1 year. There was also decreased need for revascularization in the enoxaparin group.
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How many patients with unstable angina improve with a purely medical regimen?
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90% - within 1-2 days
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Are thrombolytic therapy drugs or CCBs indicated in unstable angina?
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No, there is no evidence they are beneficial
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What are the criteria in the Thrombolysis in Myocardial Infarction Risk? (TIMI)
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One point for each of the following:
Age > 65 More than 3 risk factors for CAD Known CAD (stenosis > 50%) At least two episodes of severe angina in the past 24 hours Aspirin use in the past 7 days Elevated serum cardiac enzymes ST changes > 0.5mm Risk at 14 days is based on the number of points... 0-1 = 5%; 2 = 8%; 3 = 13%; 4 = 20%; 5 = 26%; 6-7 = 41% |
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Describe conservative management for unstable angina.
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If patient responds to medical therapy (nitrates, aspirin, BB, enoxaparin/heparin/LMWH, abciximab/tirofiban) then perform a stress ECG to establish need for catheterization/revascularization - many patients with controlled unstable angina will eventually require revascularization.
If medical therapy fails to improve symptoms and/or ECG changes indicative of ischemia persist after 48 hours, then proceed directly to catheterization/revascularization |
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After acute treatment for unstable angina, how do you manage it?
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Continue aspirin (or clopidogrel, abciximab, tirofiban), beta blockers, nitrates
Work on reducing risk factors - such as smoking, obesity, DM, HTN, hyperlipidemia, hyperhomocystinemia |
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What is the best drug for treating hyperlipidemia and reducing cardiac risk in patients with unstable angina?
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The CARE trial demonstrated that statins, compared to placebo, decreased risk of death by 24%, reduced risk of stroke by 31%, and reduced need for CABG or coronary angioplasty by 27%
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What is Prinzmetal's/Variant Angina?
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Involves transient coronary vasospasms that are usually accompanied by a fixed atherosclerotic lesion (in 75% of cases) - though it can also happen in normal coronary arteries
Angina at rest is associated with ventricular dysrhythmias |
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What is the hallmark for Prinzmetal's/Variant angina?
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Transient S-T segment elevation on ECG during chest pain, representing transmural ischemia
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What is the definitive test for Prinzmetal's/Variant angina?
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Coronary angiography - displays coronary vasospams when the patient is given IV ergonovine/ergometrine (to provoke chest pain)
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What is the best medical treatment for Prinzmetal's/Variant angina?
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Vasodilators - CCBs and nitrates have been shown to be helpful
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What is Ergonovine/Ergometrine?
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It is an ergot alkaloid that activates alpha-adrenergic, dopaminergic and serotonergic receptors.
It is used for facilitating placenta delivery and minizing bleeding, AND to diagnose prinzmetal's angina by inducing spasm of the coronary arteries. |
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What mortality rate is associated with MI? What proportion of the deaths are pre-hospital?
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30% mortality rate
50% of deaths are pre-hospital |
