SM 128 Ischemic Heart Disease Flashcards
Why do significant reductions in lumen size not occur until Atherosclerosis is well advanced?
Due to “positive remodeling”
Initial growth of the plaque occurs away from the lumen so significant obstruction takes a long time to develop
How does Coronary Artery Bypass Surgery work (CABG)?
Treats angina by using venous or arterial conduits to bypass an occlusion in a stenotic region of a vein and restore bloodflow to ischemic myocardium
How can angina be confirmed?
Stress test and searching for ECG, Echo, or scintigraphic evidence of MI
What kind of EKG alterations are seen in Acute Coronary Disease?
ST depression or elevation
What is the sensitivity and specificity of Exercise stress testing?
Sensitivity = 50 - 80% Specificity = 50 - 90%
High variation because not all patients develop an ECG change, which is used as a readout for stress tests, and patients vary in extent of disease
How does Magnetic Resonance Cardiac Imaging work?
A contrast agent is given after pharmacological vasodilation of the heart is induced, to determine regional variations in myocardial blood flow
Also sees heart size and myocardial viability
What strategies are used to control Angina?
MLP
Myocardial revascularization
Lifestyle changes
Pharmacologic treatments
What changes are expected on an exercise stress test in a patient with Ischemic Heart Disease?
Expect to see flat ST interval on an ECG which indicates Ischemia
ST interval should return to normal with rest
What does uniform uptake of a tracer in both stressed and resting conditions on Stress MPI indicate?
Suggests that myocardial accumulation of tracer and the resulting radioactivity is proportional to blood flow
Results are normal; abnormal would be diminished perfusion/radioactivity during stress
What are some of the advantages of a stress echo?
Stress echo’s can detect wall motion abnormalities using real time information
Do not need a computer to process information
Portable and can be done at at patients bedside
No radiation involved
How does Coronary Angiography work?
In Coronary Angiography, a radiographic contrast is injected into the left ventricle to visualize contractile function through the ejection fraction
How do Calcium channel blockers treat Angina?
Decrease entry of Calcium ions into myocardial cells, reducing heart rate, blood pressure, and contractility
Help prevent vasospasm
What are “anginal equivalents” and where are they found?
Symptoms of myocardial ischemia other than angina, such as dyspnea, nausea, fatigue
Found in women, diabetics, elderly
What does Magnetic Resonance Cardiac imaging primarily visualize?
Myocardial blood flow
How critical is a physical exam for diagnosing Ischemic Heart Disease?
Physical exam is less important because many patients appear normal or do not experience angina unless they are exerting themselves
What is the first event to follow a reduction in myocardial blood flow and how long does it take to manifest?
Abnormalities in regional diastolic relaxation occur, within seconds of a reduction in regional blood flow
What is Coronary Atherosclerosis?
A manifestation of systemic disease involving the arterial system, that leads to the asymptomatic process of atherosclerotic plaque formation
How do Lipid Lowering Agents treat Angina?
By lowering LDL, and raising HDL, statins slow the progression of Atherosclerosis and prevent heart attacks in patients with chronic ischemic heart disease
Used in combination with Ezetimbe, Bile Acid sequestrants, and PCSK9 inhibitors