Download Acute management of myocardial infarction

MYOCARDIAL INFARCTION
CASE 1
• Mr. A: 38 years old
• He smokes 1 pack of cigarettes per day
• He has no other past medical history
• 8 hours ago, he gets sharp central chest pain that is
worse with inspiration. It has not yet resolved.
• He feels short of breath
CASE 2
• Mr. D: 50 years old
• He also smokes 1 pack of cigarettes per day
• His past medical history includes hypertension and
diabetes
• While he was working on the farm, he develops dull
central chest pain that radiates to his neck
• With rest, the pain went away after about 5 minutes
• He also has shortness of breath
WHICH PATIENT IS HAVING AN MI?
WH Y ?
HISTORY
• Pain
• Location
• Exertional
• Other symptoms:
• Shortness of breath
• Nausea
• Sweaty
• Risk Factors
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Family history
Diabetes
Hypertension
Smoking
Hyperlipidemia
Previous MI or stroke
PHYSICAL EXAM
• Vital signs
• BP
• HR
• O2 saturation
• Cardiac exam
• S3 or S4 may be present
• Murmur of mitral regurgitation
• May have heart failure on cardiac and respiratory
exam
ECG: ST ELEVATION MI
ECG
ECG: NON ST ELEVATION MI
ECG
STEMI VERSUS NSTEMI
MANAGEMENT: CASE
When you examine Mr. D, he can talk to you
• BP 110/70 HR 100 O2 93% on room air
• He has normal heart sounds, no murmur, but has S4
• Lungs are clear
• ECG shows ST depression and T wave inversion in
V2- V6.
• What do you want to do next?
MANAGEMENT
• First, ABC’s!
• If you have cardiac monitor, put him on it
• IV access
• Oxygen
• What medications do you want to give him?
• For his pain?
• To prevent further thrombosis (antithrombotics)?
• To prevent arrythmia?
• To treat other cardiac risk factors?
MEDICATIONS: PAIN
• Nitrates
• Vasodilation of coronary arteries
• Decrease preload (venous vasodilation)
• Decrease afterload (arterial vasodilation)
• Be careful of hypotension (aortic stenosis, right ventricular
MI)
• Morphine
• Avoid NSAIDS if you can
MEDICATIONS: ANTITHROMBOTIC
• Aspirin
• 162-325mg Po chewed x 1 then 75mg-100mg daily
• Patient needs to take indefinitely
• Decreases mortality
• Give as soon as you suspect an MI
• Consider clopidogrel
• 300mg PO x 1 then 75mg daily for 1-12 months
• Small additional benefit
MEDICATIONS: ANTICOAGULANTS
• Heparin
• Decreases risk of death and re-infarction
• If using unfractionated heparin IV, monitor PTT
• Duration is at least 48 hours
MEDICATIONS: PREVENTING
ARRYTHMIA
• Beta blockers (eg. Atenolol, propranolol, metoprolol)
• Decreases mortality and ventricular arrythmias
• Start within 24 hours
• Contraindications
• Acute heart failure
• Heart block
• Asthma
• Hypotension
• No role for antiarrythmics such as lidocaine or
digoxin
• No role for calcium channel blockers
MEDICATIONS
• ACE inhibitors (ramipril, enalopril)
• Especially beneficial in those with heart failure
• Start within 24 hours
• Prevents left ventricular remodelling
REPERFUSION
• 2 options
• A) Fibrinolytics
• If symptoms started less than 24 hours ago
• Contraindications: Uncontrolled hypertension, stroke in last 3
months, previous intracranial hemorrhage
• For STEMI patients only
• B) Percutaneous coronary intervention (PCI)
• If symptoms started less than 12 hours ago
• If the “door to balloon” time can be less than 90 minutes
• For STEMI patients. Can consider for NSTEMI patients
REPERFUSION
• Which NSTEMI patients should you think about
sending for reperfusion?
• Chest pain and ischemia not responding to medications
• Unstable patients
• Arrythmias
• Heart failure
COMPLICATIONS
• Heart failure
• Bradycardia from AV (conduction) block
• Arrythmia
• Non sustained ventricular tachycardia (VT)
• Sustained VT and ventricular fibrillation
• New mitral regurgitation
• Ventricular wall rupture
• Cardiogenic shock