Clincal Presentation And Evaluation Of CAD And Acute MI Flashcards
Stable angina
A predictable episodic chest pain associated w/ particular levels of exertion. Caused by stable fixed plaques in coronary vessels
- myocardial demand exceeds myocardial supply
- the pain lasts less then 20 minutes and has a gradual onset and decline
- pain is usually relieved by rest or by nitroglycerin
- key here is that there is a noticeable pattern that can be determined, if it is a new pattern, then it is unstable angina*
Signs of chest pain
(+)Levine sign: clenched fist to the chest
Pain/discomfort may be anywhere on the chest (anterior/posterior/left/right)
Radiation of pain to the neck jaw or arm
Upper GI pain w/ associated nausea
What two catagories of people often present with atypical angina?
Older Women and diabetic patients
- can often be silent ischemia/asymptomatic ischemia, or present with angina in a atypical location
Women also have higher incidence of prinzmetal angina
Tests for ischemic heart disease
Exercise stress test
Stress echo
Stress radionuclide myocardial perfusion scans
CT for calcium scoring
Angiography (CT coronary or coronary)
- this is the gold standard
Exercise stress test
75% sensitivity
Requires exercise on treadmill to 85% of the maximum heart rate
Has a 12 lead ECG and BP monitoring through out
Normal responses = increase HR and BP
Abnormal responses (all good mean CAD)
- decreased in systolic BP >10mmHg
- chest or referred pain
- ST depression (2mm)
- ventricular tachyarrhythmias
Limitations of the exercise stress test
Cannot use if:
1) the patient has LBBB, early repolarization, ST abnormalities (abnormal ECG’s will be produced) at rest
2) patient is unable to exercise (in which case use dobutamine/adenosine to increase the HR)
* this is called a chemical stress test*
Stress echo test
Similar to stress test except it is monitoring the wall motion while exercising using ultrasounds
- if the muscle is ischemic, the ischemic part will not be in sync with the rest of the heart
Still monitor for ST depression, chest pain
- if cant exercise use chemical agent*
Angiography
Medical imaging technique used to visualize the lumen of the blood vessels
Often uses a contrast agent in combination w/ CT, x ray or MRI
Coronary angiography
Same as a normal angiography except uses a catheter to directly implant the contrast into the coronary vessels
The following is measured:
- ejection fraction
- plaque characteristics (fixed, stable/unstable)
- degree of stenosis (>70% is dangerous)
CT calcium scan of coronary arteries
Evaluates the amount of calcium present in the coronary arteries
- if high calcium, it does correlate w/ CAD
however not all atherosclerotic plaques are calcified, so its not very specific at all
Non pharmacological Treatment for stable angina
1) explain and reassure patient
2) identify aggravating conditions and fix this 1st
- usually revolves around adaption of activity (lower exertion)
3) treat risk factors
4) provide medication (usually nitroglycerin)
* note 1-4 are always done*
5) if for someone 1-4 combined doesn’t work, use revascularization
Possible pharmacological treatment for angina
1) BBs: improves symptoms of angina and reduces mortality and re-infarction rates after an MI
- 1st line unless you cant use it
2) CBBs: reduces myocardial oxygen demand by inhibiting increased HR and arterial pressure
- 2nd line, use BBs first unless you cant
3) Nitrates: systemic venodilation (increase preload) and dilation of coronary arteries/collateral vessels
- short acting = nitroglycerin spray/tablets
- long acting = nitroglycerin patches or high dose tablets
* NOTE: DONT use if patient is taking viagra or hypotensive patinets*
- causes even more hypotension
4) antiplatlets: aspirin or clopidogrel (“Grels”)
* DONT use ibuprofin or aleve (actually increases risk for MI incidents) *
Revascularization
Coronary artery bypass graft surgery (CABG)
Not 1st line therapy, is only used if failing medications (Angina remains constant or gets worse), have >70% coronary artery blockage, or has impaired function on left ventricles/ unstable angina.
- usually uses very large veins or the left internal mammary artery
- arteries are less likely to be blocked (have greater latency rates) compared to veins. So preferred artery’s over veins*
coronary artery bypass graft (CABG) vs percutaneous coronary intervention (PCIs)
PCI
- faster recovery and less costly
- lower acute mortality rates
- needs duel platelets therapies for 1 year
- does not increase lifespan or decrease late stage mortality
CABG
- slower recovery and more costly
- acute mortality rate is higher but still pretty low (2%)
- does show it increases lifespan and decreases late stage mortality
- only really used if 3 vessel CAD is present, the patient is diabetic or the patient has impaired left ventricular function (low ejection fraction)
Unstable angina (crescendo)
Increased frequent pain that is progressively getting worse w/ exertion
CARDINAL signs are:
1) pain is prevalent at rest w/out exertion
2) new onset angina
Unstable angina is the prime harbinger of potential MI (10-25% chance if not treated)
This is often associated with plaque thrombi being developed
- is an acute problem and must be fixed immediately
- often shows ST depression on ECGs, but can be normal
