3: Chronic Ischemic Heart Disease Flashcards
traditional risk factors for atherosclerotic vascular disease
- age (men > 45; women > 55)
- family history (first degree relative) - males 30)
- sedentary lifestyle
before exam look at this slide
graphs and relative risk increases based on risk factors
what two risk factors, if had together, significantly increase risk of fatal or non-fatal MI?
DM + previous MI
what is metabolic syndrome?
any 3 of the following:
- HTN (>/= 130/85)
- abdominal obesity (waist circumference > 40cm men; >35 cm women)
- HDL /= 150
- fasting plasma glucose >/= 100
what is metabolic syndrome associated with?
inflammation (vasculitis)
coagulation abnormalities
progression to T2DM
manifestations of CAD
- chronic stable angina
- unstable angina
- MI
- ischemic cardiomyopathy (CHF)
- sudden cardiac death
- silent ischemia
what physical findings may appear during periods of ischemia?
an S4 heart sound (not always though)
also may show an S3 if they have CHF/dilated cardiomyopathy
what tests do you get for eval of ischemic heart disease in the office?
- office and ambulatory BP
- fasting lipid profile
- BMI calculation
- fasting plasma glucose (OGTT)
- chemistries
- CBC
- stress testing
- measure of LV function (important prognostic value; tells you how to treat patient)
questions you need to ask for chest pain history
- location
- character
- radiation
- intensity
- duration
- frequency
- associated symptoms
- exacerbating/relieving factors
- pattern over time
presentation of stable angina pectoris (6 things)
- visceral discomfort
- diffuse and sub-sternal pain
- dyspnea, diaphoresis, nausea, light-headed
- provoked by physical exertion, emotional upset, rarely heavy meals, working in cold
- onset over several minutes
- relieved by rest, sublingual NTG
difference between atypical angina and typical angina
missing one of the following:
- substernal pain
- brought on by exertion
- relieved by rest or NTG
less common sites of pain with MI
- right side
- epigastrium
- jaw
- back
where might you see pain referred in angina?
lower jaw (not upper jaw)
Canadian CV society classification of angina
Class I: no angina
Class II: angina on more than usual activity
Class III: angina on less than usual activity
Class IV: angina at rest or on any activity
angina equivalents
- arm/back/lower jaw pain
- dyspnea on exertion
- postprandial symptoms
- nocturnal angina
- nausea
- diaphoresis
- fatigue
why is nocturnal angina really bad?
at night is when the body has the lowest metabolic demand and blood flow should be best - if angina still occurs then, means the patient is critically ill
what other options are there for a chest pain ddx?
- CAD/MI
- aortic: dissection, ulcer, hematoma
- pericarditis
- pulm: embolism, pneumonia, pleurisy
- esophageal: spasm, inflam, stricture, GERD, achalasia
- musculoskeletal
- anxiety
in what group of people is it more common to see TIA sx or claudication pain?
smokers
ddx: how does pericarditis differ?
variable duration sharp positional (relieved by sit up + lean forward) pleuritic worse with inspiration
ddx: how does aortic dissection differ?
excruciating, ripping, sudden pain
anterior
radiates to back
unequal pulse?
ddx: how does PE differ?
sudden onset dyspnea and pleuritic pain
ddx: how does musculoskeletal pain differ?
sudden onset
fleeting
reproduced by palpation
ddx: how does GERD differ?
burning
substernal
epigastric 10-60minutes
related to meals
ddx: how does psychological differ?
tightness aching with dyspnea non-exertional lasts more than 30 min
when do we feel chest pain? aka pathophysiology of ischemia
imbalance between supply and demand:
supply:
- stenosis
- spasm
- anomaly
- anemia
demand:
- tachycardia
- aortic stenosis
- HTN urgency
- LVH
causes of non-atherosclerotic CAD
- coronary vasospasm
- anomalous coronary arteries
- coronary arteritis (Kawasaki)
- coronary dissection
- myocardial bridge
- coronary embolization
what is myocardial bridge?
piece of myocardium over a coronary artery
- incidental finding
- doesn’t normally cause angina
- don’t do anything about it
novel risk factors for atherosclerotic disease
- chronic inflammation (RA)
- elevated hsCRP
- homocys
- chronic kidney disease
- coagulation abnormalities
- chronic infection?
myocardial ischemia: secondary causes
- severe anemia
- hypoxemia
- uncontrolled HTN
- severe LVH
- uncontrolled tachycardia (SVT, WPW)
- thyrotoxicosis
resting EKG in ischemic heart disease
- may be normal in 50%
- most common finding is non-specific ST-T changes
- conduction abnormalities such as LBBB, LAFB (marker for poor prognosis)
importance of pretest probability: what groups do you do stress tests for and which do you not?
- asymptomatic patients with or w/o some risk factors: don’t do
- opposite end of spectrum- already diagnosed CAD: don’t do
- DON’T DO FOR UNSTABLE SYMPTOMS
-only use it for patients in the middle ground gray zone - medium risk category w/ some clinical sx and some risk factors
stress test modalities
- exercise stress EKG
- stress imaging modalities
how is the stress provided in a stress test?
treadmill pharmacologic (dobutamine, vasodilators)
whenever you do a pharmacological stress test, what do you also always have to add?
imaging- chances to see things on EKG with this type of test is low
what imaging modalities are used for stress test?
- echo (treadmill, dobutamine)
- nuclear (treadmill, vasodilators, or rarely dobutamine)
- MRI
stage I of standard Bruce protocol for stress test
- office work
- light housework
- golf (walking with bag)
stage II of standard Bruce protocol for stress test
- light factory work
- stairs
- bicycle riding (10 mph)
stage III of standard Bruce protocol for stress test
- heavy factory work
- running (10min/mile)
stage IV of standard Bruce protocol for stress test
- running (8min/mile)
- stairs with heavy weight
- boxing
at what percent stenosis does a person with CAD get symptoms?
70% occluded- this is when you get a drop in flow
what is the evolution of abnormalities in ischemia?
- decreased relaxation (diastolic dysfxn)
- systolic dysfxn
- decreased filling
- decreased ST
- angina
approximately what percent of patients with angina also experience episodes of silent ischemia?
50%
what do you do in evaluating IHD
- confirm diagnosis of CAD
- assess functional limitations
- assess status of modifiable risk factors
- assess burden of ischemia:
- how much muscle is at risk?
- how many vessels involved?
- how severe is ischemia?
- assess LV function
pros and cons of exercise stress EKG
pros:
- low cost, versatility, validated, no need for IV access, fairly sensitive and specific
cons:
- high false positive in females, unreliable with abnormal resting EKG, false negative (failure to achieve HR)
stress EKG: what counts as ST segment changes
greater than 1mm horizontal or down-sloping ST depression is diagnostic of ischemia
- magnitude: more is worse
- duration: longer is worse
- timing: earlier is worse
- number of leads: more is worse
- associated angina, drop in BP, arrhythmia
greater than 1mm ST elevation
coronary artery disease: high risk groups?
- left main stenosis > 50%
- 3 vessel disease, especially with LV dysfxn
- 2 vessel disease involving proximal LAD
- multi-vessel disease in diabetics
- impaired LV function
stress test findings suggestive of high risk
- inability to complete stage II of Bruce protocol
- angina at a low workload (less than 6 METs)
- failure to achieve 80% of target HR or HR>120
- fall in BP > 10 with progressive exercise (accompanied by other evidences of ischemia)
- ischemic ST depression
- ST elevation more than 1mm (non infarct lead)
- sustained ventricular tachycardia
findings with ischemic ST depression
- greater than or = 2mm (esp downsloping)
- occurring at a low workload or HR (5 min into recovery
grading functional capacity with METs
10 - good capacity
what is 1 MET?
oxygen consumption of a 40 y/o, 70kg man in resting state
indications for stress imaging
- unable to exercise
- abnormal baseline EKG
- known CAD (prior infarct, revascularized/cath)
describe the regadenosan, adenosine or dipyridamole
coronary vasodilatation in normal segments, diseased segment (s) unable to dilate leading to relative hypoperfusion
stress imaging findings suggestive of high risk
- perfusion defects in multiple coronary territories
- large reversible perfusion defect in single territory (LAD)
- transient ischemic LV dilatation
- increased lung uptake (with abnormal perfusion)
- abnormal LV function (EF
indications for coronary angiography in stable CAD
- persistent sx despite medical therapy (min 2)
- non-invasive test results suggesting high risk
- equivocal or non-diagnostic non-invasive test results
- high risk occupation
initial management of IHD
- aspirin 81 mg daily
- sublingual NTG as needed
- lipid lowering therapy
- instructions on healthy lifestyle
- activity dictated by symptoms
- report any change in symptoms immediately
