Myocardial Infarction

Front 1

What are the immediate complications to be concerned about after an MI?

Back 1

Arrythmias
Heart Block
Cardiogenic shock

Front 2

What is cardiogenic shock?

Back 2

LV pump failure that occurs when 40% of the myocardial mass is involved in the infarct.

Front 3

In addition to having a large infarct, cardiogenic shock can also occur from what other conditions?

Back 3

Atrial fibrillation
Supraventricular arrythmias
Brady arrythmia
Iatrogenic use of B-Blockers (slow heart & pump function)
Mechanical complications that lead to reduced net forward cardiac output

Front 4

Cardiogenic shock is more commonly seen when this vessel is occluded?

Back 4

LAD or the R. coronary if there is RV failure

With smaller MI's due to systolic dysfunction or multi-vessel disease (limits compensatory response)

Front 5

90% of people who have an anterior MI will have an ____________?

Back 5

Arrythmia develop

Front 6

Arrythmias are associated with 90% of these types of infarcts.

Back 6

Anterior MI's

Front 7

The is the most common arrythmia type seen in acute MI's. What other types of these arrythmias occur?

Back 7

Premature ventricular contraction is most common

-other types of ventricular arrythmias that occur following an MI:
-Vent. Tachy
-Vent. Fib
Accelerated Idio-pathic Rhythm (bradycardia)

Front 8

This arrythmia occurs when there is successful reperfusion after an MI.

Back 8

Accelerated Idio-ventricular Rhythm

Front 9

What are the SVT arrythmias that occur after an MI?

Back 9

A-fib
A-flutter
SVT tachy

Front 10

If cardiogenic shock doesn't occur from the decline of LV function, it can also occur from?

Back 10

Ventricular or SVT arrythmias

Front 11

Why does atrial fibrillation & SVT arrythmia cause cardiogenic shock?

Back 11

Loss of atrial contribution to filling = decreased stroke volume

Increase rate of contraction = increased O2 demand = BUT you have a decreased stroke volume

Front 12

This type of MI typically causes changes in atrio-ventricular conduction.

Back 12

Inferior/Posterior AMI's (less common in anterior AMI's; poor prognosis)

Front 13

Ischemia cause by the R. coronary can lead to ischemia of this area and lead to an arrythmia. Why?

What type of infarct is the R. coronary artery associated with?

Back 13

Ischemia of the R. coronary reduces the supply to the AV node, therefore you will have AV node block.

R. coronary ischemia is associated with the inferior portion of the heart because it supplies that area.

Front 14

Ischemia of the AVN is due to what artery being occluded? In this AV block, what type of escape rhythm will you have?

Back 14

The R. coronary supplies the AVN, so occlusion of this vessel will cause decreased flow to the AVN & an AV block.

This will lead to a JUNCTIONAL escapr rhythm

Front 15

What are the characteristics of a junctional escape rhythm?

Back 15

Narrow QRS complex
Rhythm is stable
No hemodynamic compromise

Front 16

This type of heart block rarely needs pacemaker insertion.

Back 16

AV block associated with an Inferior MI with a Junctional Escape Rhythm (usually 2 or 3 degree blocks)
HR: ~50

Front 17

An anterior MI is associated with occlusion of this vessel?

Back 17

-LAD

Front 18

When you occlude the LAD, during an anterior MI, what other structures of the conduction system have compromised flwo?

Back 18

-R. Bundle & superior segment of the L. Bundle

Front 19

What type of escape rhythm is associated with an anterior MI? Describe the characteristics of the rhythm.

Back 19

Ventricular Escape rhythm
-Associated with 3rd degree heart block
-Slow, wide complex (30bpm)

Front 20

A temporary pacemacker is indicated in this type of heart block, which is associated with this type of infarct.

Back 20

-RBBB and L superior BBB
-these are associated with anterior MI's

Front 21

Hemoinstability is associated with this type of heart block, which is associated with this type of infarction.

Back 21

-RBBB and L sup BBB; anterior infarct

Front 22

Lower areas of infarct will give you a ___________ escape beat and are hemodynamically ___________?

Back 22

Ventricular; UNSTABLE

Front 23

What are the later stage complications that we worry about after an MI?

Back 23

-Mechanical issues: Rupture of LV free wall, Ventricular septum, papillary muscle

-Pump problems: papillary m. dsyfunction, Ventricular aneurysm, ventricle mural thrombus, RV infarct, percarditis

-Reischemia

Front 24

This is the most common reason for hemopericardium. What does this lead to?

Back 24

Rupture of the LV; leads to tampanade and death

Front 25

Rupture of LV free wall is associated more commonly with this group of ppl, is more common in the presence of this condition, and usually occurs this many days after discharge from a MI.

Back 25

-More common in elderly women
-usually seen more in the presence of HTN
-usually occurs 30 days after MI

Front 26

When a ventricular septum rupture occurs, it leads to this condition. Why?

Back 26

Pulmonary edema due to increased R heart pressures

Front 27

Ventricular septal defects are related to this type of infarction.

Back 27

anterior AMI's (the lower ventricular wall is related to inferior AMI's)

Front 28

Papillary muscle rupture leads to this condition. This is seen in this type of infact and usually involes papillary muscles in this region.

Back 28

-Increased R sided pressures leading to pulmonary edema due to regurgitation that occurs in the LH.

-Associated with inferior infarcts & usually involves the posterolateral m. as opposed to the anterolateral m.

Front 29

Papillary rupture is distinguished from papillary muscle dysfunction by the fact that:

Back 29

Rupture of the muscle is mechanical, while papillary muscle dysfunction is due to loss or diminution of cantractile ability due to ischemia during an MI...This is a functional, as opposed to a structural problem.

Front 30

Papillary muscle rupture AND dysfunction is commonly associated with this papillary muscle in particular.

Back 30

Postero-lateral muscle

Front 31

Dilation of the ventricular free wall is seen in this condition. Is this an acute or longterm finding?

Back 31

Ventricular aneurysm; long-term

Front 32

What is the difference between a true and pseudo anerysm?

Back 32

True: mouth diameter is at lease as large as the aneurysm itself; wall is composed of myocardial tissue

False: mouth is smaller than the maximal diameter of the aneurysm; composed of parietal pericardium (it is a confined LV free wall rupture)

Front 33

Where are false aneurysms typically found in the heart? They often contain this.

Back 33

Apex of the anterior wall
-Frequently contain mural thrombus

Front 34

Mural thrombi are typically seen in this type of infarct.

Back 34

Large/transmural AMI's

Front 35

What is acute coronary syndrome Type 1? What are the consequences of this syndrome?

Back 35

Rapid change in the plaque that causes decreased blood supply (demand stays the same)

-This can lead to symptoms of angina or further develop to a myocardial infarction

Front 36

What is acute coronary syndrome Type 2?

Back 36

This is where the demand increases, but the supply remains the same

-Not involving the rupture of a plaque; plaque is stable

Front 37

A myocardial infaction and angina differ in that?

Back 37

There is necrosis involved in myocardial infarction where angina is involved in reduced myocardial supply but no myocardial necrosis occurs

Front 38

The process of unstable angina begins when this occurs?

Back 38

There is a rupture in the fibrous cap and it exposes the contents of the lipid core & this leads to thrombosis. The degree of occlusion will determine amount of ischemia

Front 39

Compare and contrast transmural and subendocardial infarcts.

Back 39

Transmural = involves the entire thickness of the myocardium

Subendocardial infact = only involves the inner 1/3-1/2 of the myocardium

Front 40

The 2 features on an ECG suggest that a transmural infarct has occurred?

Back 40

Q waves & STEMI

Front 41

What features on an ECG would suggest that there has NOT been myocardial infarction?

Back 41

No Q waves/No STEMI suggest that there has not been a transmural infarct.

May see ST-depression with subendocardial infarct

Front 42

Transmural infarcts usually show this on the ECG, while non-STEMI infacts will show this?

Back 42

STEMI (transmural)
Non-STEMI (non-transmural)

Front 43

Inferior infarcts are usually seen in these leads.

Back 43

2,3, and aVF (if large, may involve V6)

Front 44

Anterior infarcts usually involve these leads.

Back 44

Lead 1 and V2-V4 (V5-V6 in very large infarcts)

Front 45

Anterolateral lesions will involve which leads?

Back 45

I, V5, V6, aVL