CMPP -- Ischemic Heart Disease 1: Stable Angina

acute coronary syndrome (ACS)

signs and symptoms indicating an active process of atherosclerotic plaque buildup or formation of a thrombus, or spasm within a coronary artery, causing a reduction or loss of blood flow to myocardial tissue; includes unstable angina and other pathological events leading to myocardial infarction (MI); early diagnosis and rapid treatment are critical to avoid or minimize damage to heart muscle

unstable angina; Non-ST segment elevation MI; ST segment elevation MI

clinical presentation ACS

Stable angina

predictable and consistent pain that occurs on exertion and is relieved by rest and/or nitroglycerine

ischemic heart disease/coronary artery disease

what is the most common cause of death?

decreased indigence in smoking, improved lipid management, better care of hypertension/diabetes, medical advances (PCI)

why have we had a drop in mortality form CAD over the past 30 years?

inadequate perfusion to meet myocardial demand

myocardial ischemia results from...

inspired level of oxygen, pulmonary function, hemoglobin concentration, adequate coronary blood flow

what determines myocardial oxygen supply?

heart rate, contractility, wall stress/tension

what determines myocardial oxygen demand?

restrict flow through the coronary vessels (atherosclerosis, vessel spasm, arterial thrombi, coronary emboli), reduce supply or amount of oxygenated blood available (aortic stenosis, anemia, presence of carboxyhemoglobin)

how can we "mess up" myocardial oxygen supply?

oxygen demand (coronary vasculature is able to vary resistance)

what dictates coronary circulation?

increased, decreased, increased

increased demand from myocardium leads to ____ dilation of vessels, which leads to _____ resistance, which leads to _____ perfusions to meet that demand.

diastole

the coronary arteries are perfused during...

large epicardial arteries (right and left coronaries), pre-arteriolar vessels, arteriolar and intramyocardial capillary vessels

3 types of coronary vessels

the left anterior descending artery and the left circumflex artery

left coronary circulation divides from the aortic root into...

the septum and anterior ventricular wall

the left anterior descending artery supplies...

LAD (left anterior descending artery)

what coronary artery supplies the septum and anterior ventricular wall?

the left ventricular wall

the left circumflex artery supplies...

left circumflex artery

what coronary artery supplies the left ventricular wall?

marginal branch, posterior descending

right coronary circulation divides from the aortic root into...

right ventricle

the marginal branch supplies the...

marginal branch

what coronary vessel supplies the right ventricle?

posterior and inferior left ventricle

the posterior descending branch supplies the...

posterior descending artery

what coronary vessel supplies the posterior and inferior left ventricle?

Coronary artery disease (CAD)

thickening and obstruction of coronary vessel from atherosclerotic plaques

Plaque

collection of fat, smooth muscles, and cells; diffusely distributed throughout the vasculature; not uniform in size, shape, or makeup

genetic factors, high fat diets, smoking, sedentary lifestyle

development of plaques is associated with...

obesity, type ii diabetes, insulin resistance

risk factors for development of plaques...

atherosclerosis

plaque built up in the vessels, which causes stenosis of the vessels; can affect coronary, cerebral, and peripheral circulation

coronary, cerebral, and peripheral circulation

atherosclerosis can affect...

elevated LDL, low HDL, smoking, HTN, DM (cause microvascular disease over time)

risk factors for atherosclerosis

disturb the normal function of the vascular endothelium, and this disruption leads to plaque formation

risk factors for atherosclerosis all...

20-75

the AHA says that all patients between ____ and ____ years should receive the 10 year CVD risk assessment

10-year Risk for Atherosclerotic Cardiovascular Disease (ASCVD)

assessment that helps predict your risk over 10 years of heart attack, stroke, or death from cardiovascular disease.

initiate statin therapy and consider aspirin therapy; encourage lifestyle modifications

if one has a 10-year ASCVD risk of 10% or greater

sub-intimal

a plaque is a _____ collection of lipids, smooth muscle, fibroblasts, and intracellular matrix

turbulent flow (branch points of vessels)

plaques tend to develop at points of...

no

are plaques a part of the circulation?

rupture/erosion into the bloodstream

plaques are at risk of...

small thin fibromuscular cap

plaques are covered by a...

there is inflammation and tissue factor release

if a plaque ruptures, what happens first?

platelets, clotting cascade

after the TF release caused by a plaque rupture, _____ aggregate at the site, which initiates the _____

a thrombus

after the activation of the clotting cascade following a plaque rupture, what forms in the BV?

platelets and fibrin join to trap RBCs from the bloodstream

a thrombus forms when...

ischemia/possibly infarction

thrombi further reduce blood flow in vessels, which leads to...

location of plaque, size of obstruction, and presence of collateral circulation

degree of ischemia is dependent upon...

collateral circulation

circulation formed by smaller blood vessels branching off from or near larger, occluded blood vessels

vasospasm (increased sympathetic firing leads to spasm and platelet aggregation; combined effect with thrombus will worsen ischemia)

occlusion of BVs can trigger the release of local mediators that cause...

>95%

at rest, ischemia will develop with ___ stenosis

>60%

at exertion, ischemia will develop with ___ stenosis

quantity of ischemia (how MUCH of the heart is affected), severity and clinical manifestations (depending on where the heart is damaged, patients can present differently)

location of obstruction determines...

proximal

if obstruction in the heart is more ____, more tissue is affected

muscle won't contract properly due to lack of oxygen supply (cells cannot work correctly) which will lead to decreased CO

how does lack of oxygen lead to disturbances in mechanical functioning?

there will be abnormal labs due to lack of oxygen going to the tissues

how does lack of oxygen lead to disturbances in biochemical functioning?

cells are not getting enough oxygen, and then this will result in arrhythmias

how does lack of oxygen lead to disturbances in electrical functioning?

LV failure, angina, infarction and necrosis

ischemia of the LV leads to...

mitral regurgitation

ischemia of the papillary muscles of the LV leads to...

anaerobic, lactate, decreases

without oxygen, the tissues of the heart progress from aerobic to ______ metabolism, and glucose is covered to ______ and the pH ______

leaks out, is absorbed into

during the transition form aerobic to anaerobic metabolism when the heart is ischemic, potassium ______ of the cells, and sodium ______ the cells.

repolarization abnormalities

when the heart lacks oxygen, there are ________ seen on EKG

Subendocardial ischemia

there is ischemia within the endocardium itself; indicated on EKG by ST segment depression

St segment depression

what are the findings on EKG associated with subendocardial ischemia?

Transmural ischemia

occur when the whole thickness of the myocardium is schema; indicated on EKG by ST segment elevation

premature beats, ventricular tachycardia, ventricular fibrillation

what are some ways in which ischemia can manifest as electrical instability?

unstable angina, NSTEMI, STEMI, sudden cardiac death

what conditions constitute acute coronary syndrome?

Angina

pressure or discomfort centrally located in the chest; choking, suffocating, heaviness

"tightening"

when people talk about angina, they are actually referring to...

Stable angina

transient episodic chest discomfort that is typically predictable and reproducible, frequency of attacks are consistent over time, resolves over a constant and predicable period of time with rest or meds (nitroglycerine)

physical stress (exertion, exercise, sexual intercourse), psychological stress, anemia, dysrhythmias,

stable angina triggers

men over 50 y/o and women over 60 y/o

stable angina is prominent in what populations?

episodes of sternal pain described classically as heaviness, pressure, squeezing, choking

common complaint of those with stable angina

2-5 minutes

stable angina episodes typically last...

crescendo-descrescendo

what is the pattern of stable angina pain?

within 1-5 minutes or slowed/decreased activity; sublingual nitroglycerin

stable angina is typically relieved with...

Levine's sign

the global position of heart attack; a fist clenched over the chest

left shoulder, both arms, back, neck, jaw, teeth, epigastric area

in stable angina, pain can radiate to any of the following...

increased HR, dyspnea, elevated BP, diaphoresis, new/changed murmur, abnormal precordial pulsations

during a stable angina event, what are some signs for look for during physical exam?

obesity, nicotine stained fingers, AV nicking/cotton wool spots in the eyes, displacement of PMI, murmur, carotid/aortic bruits

what are some common findings on physical exam for one with stable angina and no active symptoms?

AAA pulsation, carotid bruits, decreed peripheral pulses

signs of atherosclerosis

xanthelasmas and xanthomas

what are some MAJOR signs of high cholesterol?

Xanthelasmas

cholesterol deposits in the eyelids

Xanthomas

yellow deposits of cholesterol in tendons and soft tissues

EKG (can be completely normal!!)

what is the first test you do on someone with a complaint of stable angina?

J point and ST segment depression (subendocardial ischemia)

what would the EKG of one with symptomatic stable angina look like?

signs of a previous infarct, Q waves, non-specific ST segment, T wave changes, LVH

non-specific signs of stable angina on EKG

outpatient

bloodwork for stable angina is done in what setting?

CBC, CMP, HgbA1C, fasting cholesterol panel

what would a provider order on bloodwork for a pt with stable angina

assess for anemia which may be triggering angina

why would a provider order a CBC on a pt with stable angina?

to assess electrolyte, kidney, and liver function

why would a provider order a CMP on a pt with stable angina?

so we can get a longer view of blood sugar control

why would a provider order a HgbA1C on a pt with stable angina?

dyslipidemia

why would a provider order a fasting cholesterol panel on a pt with stable angina?

cardiomegaly, pulmonary congestion, widened mediastinum, pulmonary issue, pneumothorax, pneumonia

what can (potentially) be seen on a chest x-ray on one with stable angina?

Stress testing

method for evaluating cardiovascular fitness

to confirm the suspicion of ischemic heart disease and determine the extent of that ischemia; helps to est. the patient's relationship to chest discomfort

why do we perform stress tests?

8 hours

stress testing can be done in an acute setting for a patient pain free for at least...

treadmill/bike; dobutamine

how are stress tests administered?

injected with dobutamine to reproduce physical stress

what if a pt cannot go on a bike/treadmill for a stress test?

to compare EKG from rest to the EKG from stress

what is the end goal of the stress test?

Stress ECHO

stress test plus ECHO looking at structural changes in the heart secondary to stress

Nuclear stress test

stress test that uses a radioisotope to evaluate coronary blood flow; higher sensitivity than a regular stress test

Tc-99 Sestamibi

what is the radioactive tracer used in a nuclear stress test?