Myocardial infarction

Question 1

What are the three major risk factors for myocardial infarction in pregnancy

Answer 1

Age > 30 years
Hypertension
Diabetes

Hemorrhage is the leading cause

Question 2

Majority of acute myocardial infarction occurs during which period in pregnancy

Answer 2

80% occur in antepartum or postpartum.

Question 3

List other common findings with myocardial infarction

Answer 3

40% will have atherosclerosis
27% will have coronary artery dissection
21% will have a coronary thrombosis
13 to 29% have normal coronary arteries

Question 4

How is acute myocardial infarction diagnosed

Answer 4

Elevated troponin and or elevated CKMB levels

Abnormal electrocardiogram most associated with ST segment elevation

Question 5

Less recommended work ups for acute myocardial infarction

Answer 5

Echocardiogram to exclude unrecognized structural cardiac abnormality and to evaluate for ventricular function

Electrocardiogram to establish ST segment elevation or depression and Q wave abnormalities

Laboratory work up should include troponin CKMB, CBC, PTINR, APTT, Electrolytes, magnesium, BUN, creatinine, blood glucose and serum lipid profile

Question 6

List potential complications of acute myocardial infarction

Answer 6

Cardiac arrest
Maternal mortality 5 to 7% if in hospital myocardial infarction
Cardiac failure or dysrhythmia

Question 7

What is the initial management of acute myocardial infarction

Answer 7

Goal is to complete MONA therapy in less than 10 minutes of diagnosis:

M is for morphine 2 to 4 mg IV
O is for oxygen via nasal cannula or mask
N is for nitroglycerin 0.5 mg sublingual every five minutes times 3
A is for aspirin 160 mg to 325 mg by mouth and chewed

Question 8

When should an electrocardiogram be repeated if initial electrocardiogram is normal and acute myocardial infarction is suspected

Answer 8

repeat 12 lead electrocardiogram in 5 to 10 minutes after the initial electrocardiogram

Question 9

What is the management of newly discovered ST elevation or new left bundle branch block

Answer 9

Treat as though patient has acute myocardial infarction in consultation with cardiologists
Give the following:
Beta blockers
IV nitroglycerin
IV heparin
Antiplatelet therapy such clopidogrel
Morphine IV to treat pain
Anti-thrombin therapy
Consider reperfusion therapy
Fetal monitoring if viable

Question 10

When should delivery occur post an acute myocardial infarction

Answer 10

Expert opinion recommend postponing delivery for 2 to 3 weeks post infarction to minimize additional cardiac demands

Question 11

What are some labor and delivery considerations for a patient with acute myocardial infarction

Answer 11

If vaginal delivery attempted consider assisted second stage to minimize cardiac workload.
Avoid hypertension or tachycardia
Avoid methergine and prostaglandins as they may cause coronary vasoconstriction

Question 12

How often does MI occur in pregnancy?

Answer 12

Used to be 1 in 20,000 but now 1 in 12,000 deliveries

Question 13

What does ALIVE at 5 stand for?

Answer 13

Activate BLS
Left uterine displacement 
Intubate early/IV placement above diaphragm 
Verify team and equipment for delivery 
Extract the fetus in 5 min

Question 14

What do you do when a pregnant patient codes?

Answer 14

Call a code 
Start chest compression/LUD
Get backboard and code cart
Place AED pad 
Manage airway (jaw thrust) 

Place hand at xyphoid bone location to perform chest compression, same as if not pregnant

No defibrillation for pea or asystole

LUD - two hands pulling uterus towards you or one hand pushing uterus away from you