Transcript Slide 1

Tuesday Conference
Myocardial Infarction
Diagnosis and management
Objectives
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Define the major types of myocardial
infarction (MI).
Describe the mechanisms leading to
ischemia or necrosis of myocardial cells.
List the major risk factors for acute MI
(AMI).
Identify the common and uncommon signs
and symptoms in AMIs.
Objectives
• Outline the initial diagnostic tests and
therapies, and understand their importance.
• Discuss reperfusion techniques and their
complexities and benefits.
• Describe the long-term benefits of various
medications.
• List other advantageous secondary
prevention therapies and their limitations.
Case 1
• A 48-year-old white man is brought to your
office by his wife, complaining of heartburn
that has been bothering him off and on for the
last several days. As they were driving in, his
pain became much worse than any he’d had
before.
Case 1
• He said the pain was squeezing his chest so
badly that he couldn’t breathe and felt like he
would throw up.
• He has not been a patient of yours, so you
have no past history. He does admit to being
under a lot of stress and smokes several
packs of cigarettes per day.
Case 1
• His initial evaluation including vital signs is as
follows: blood pressure 160/100, pulse 88,
weight and height not done. He is mildly
obese and looks very uncomfortable. He is
not taking any medicines and has no other
complaints.
MCQ 1
• What is the next most important evaluation to
determine the cause of this man’s symptoms?
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Full history and physical examination
Blood tests for CK-MB fraction and troponin I
Echocardiogram
Electrocardiogram (ECG)
Complete blood cell count and chemistry and lipid
profiles
MCQ 2
• If the ECG shows ST elevation in leads V1-V3 and the patient’s
chest pressure continues, all but one of the following is
important in his immediate care:
• Sublingual nitroglycerin (NTG), 0.4 mg every 5 minutes x 3, if he
has not used an erectile dysfunction medication in the last 24
hours
• Non-enteric coated aspirin 162 mg, chewed if he is not allergic
to aspirin
• Arrange for the patient’s wife to drive him to the ER immediately
• Short acting beta-blocker if no contraindications
• Supplemental oxygen
MCQ 3
• If the patient continues to have pain along with the ECG
changes already noted, which of the following would exclude
him from consideration for reperfusion therapy?
• More than 60 minutes from the onset of his pain to ER arrival
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Evidence of dissecting aortic aneurysm
• No cardiologist available
• No catheterization facility with qualified personnel within 30
miles
• A dose of unfractionated heparin on arrival in the ER
MCQ 3
• Which of the following statements is incorrect concerning
fibrinolytic therapy?
• The plasminogen activators as a class show restoration of
coronary blood flow in 50% to 80% of MI patients compared to
over 90% in PCI procedures
• Streptokinase has potential for an allergic response and is less
expensive than other fibrinolytics
• Both unfractionated heparin and LMWH are often used with
fibrinolytics
• Compared to thrombolytics, PCI has a better long term survival
rates
CASE 1 (Part 2)
• Our 48-year-old gentleman has now been
hospitalized for 3 days, has undergone coronary
artery stenting, and is anxious to get home and back
to work. He had minimal myocardial damage due to
early intervention.
• His tests came back showing the following:
cholesterol = 200, high-density lipoprotein cholesterol
= 30, low-density lipoprotein (LDL) cholesterol = 150,
glucose = 120.
MCQ 4
• According to recent Guidelines which LDL level requires
statins for patients presenting with a Myocardial
infarction?
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LDL 130
LDL 100
LDL 70
Every patient with Myocardial infarction should be treated
with a statin regardless of LDL level
Case 1 (Part 2)
• The rest of his chemistry profile and CBC were normal.
The ECG showed normalization of the ST segments with
no obvious Q-wave abnormalities. His chest x-ray was
within normal limits. His blood pressure is now 120/76,
with pulse rate of 64. His weight is 200 lbs, height 5 ft 7
in.
Case 1 (Part 2)
• His medications include metoprolol, enalapril,
atorvastatin, nitroglycerin dermal patch, and entericcoated aspirin. He has received educational materials
on smoking cessation, low-cholesterol and low-fat
diets, weight loss and diabetes prevention, and
activity recommendations, and is scheduled for
follow-up evaluations.
MCQ 5
• All the medications he is on are recommended during
the first hours of an acute MI. Which one is not
recommended for indefinite use?
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Atorvastatin
NTG
Metoprolol
Aspirin
Enalapril
MCQ 6
• Major risk factors, any one of which will double the
risk of atherosclerotic coronary artery disease,
include tobacco use, high cholesterol, diabetes
mellitus, and all but one of following?
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Family history of coronary disease
Diastolic hypertension
Systolic hypertension
Male gender
High LDL cholesterol
Key points
• Quickly reopening the occluded coronary artery is the most important
key to preventing myocardial damage.
• This can be accomplished either by IV infusions with fibrinolytics or
PCI.
• IV fibrinolysis or PCI should be given to every patient with at least
0.1mV ST elevation in 2 contiguous leads or a new bundle branch block
on ECG within the 30- or 90-minute time frame, unless there are
contraindications.
• Although treatment is most effective within this window, treatment
may still beneficial up to 12 hours after pain onset.
Key points
• It is now the expected standard of care that every
patient with signs or symptoms of suspected AMI
should get at least 160 mg of chewable aspirin,
sublingual NTG, and oxygen immediately.
• With ECG or lab evidence of acute myocardial
ischemia, additional immediate treatment with betablockers, unfractionated heparin along with PCI or
Fibrinolytics ( if STEMI), and/or glucoprotein IIb/IIIa
antagonists is beneficial.
Key points
• The indefinite use of beta-blockers, aspirin,
angiotensin-converting enzyme inhibitors, and statins
is considered standard therapy in most post-MI
patients. Nitrates are not recommended for long-term
indefinite therapy.
• Both systolic and diastolic hypertension double the
risk of coronary atherosclerosis and should be
treated along with the other modifiable risk factors of
hypercholesterolemia, diabetes mellitus, and tobacco
use.
Key points
• Transmural and non-transmural MIs are anatomical
definitions and cannot be predicted by Q waves or
ST-segment changes.
• Cardiac stress testing, cardiac rehabilitation with
exercise and dietary recommendations, implantable
cardiac defibrillators in those with ejection fraction
less than 30%, aggressive and long-term lipid
management, and stents at the time of percutaneous
angiography have all been shown to improve the
individual’s long-term outcome following an MI.
Thank You