Complications

Question 1

7 most common

Answer 1

1. cardiac arrhthymias
2. heart failure
3. mural thrombus formation
4. cardiac rupture
5. pericarditis
6. aneurysm formation
7. papillary muscle rupture

Question 2

Cardiac arrythmias after MI

Answer 2

90% of cases

Most common:
accelerated idioventricular rhythm

Others:
SVT
sinus tachycardia
ventricular tachycardia
atrial fibrillation
AV block
Ventricular fibrillation w/out preceeding v. tach

Question 3

accelerated idioventricular rhythm

Answer 3

originates in ventricle outside conduction system

spreads more slowly than normal rhythm (QRS is wide and “funny looking”)

accelerated means the idioventricular rhythm is beating w/in normal range, but called accelerated b/c idioventricular rhythm should be slow

Commonly a sign of reperfusion

Question 4

SVT and sinus tachycardia after MI

Answer 4

bad usually only if too fast

Question 5

Ventricular tachycardia

Answer 5

worrisome (can degenerate into ventricular fibrillation)

Question 6

AV block is particularly likely if…

Answer 6

MI was in right coronary artery territory

posterior or inferior wall

Question 7

Heart failure after MI

Answer 7

60% of cases

occurs when 20% or more of LV is infarcted

Question 8

Spectrum of HF after MI

Answer 8

asymptomatic, global LV dysfunction requiring echo or heart cath to detect

TO

40% or more of LV is infarcted, pts in cardiogenic shock

Question 9

4 Classes of HF due to MI

Answer 9

Forrester Classes

Class I
–preserved CO, not too bad LA pressure

Class II
–preserved CO, High LA pressure

Class III
–low CO, lower LA pressure

Class IV
–Low CO, high LA pressure

Question 10

Class II pts

Answer 10

some are benefited by diuretic therapy

must distinguish from Class III pts

Question 11

Class III pts.

Answer 11

some can benefit from volume expansion

must distinguish from Class II pts

Question 12

Mural thrombus formation after MI

Answer 12

20% of cases

Forms on endocardial surface overlying infarct b/c blood is not moving or barely moving

Commonly embolize, especially to brain or kidney

***2nd or 3rd week after MI

Question 13

Cardiac rupture after MI

Answer 13

5% of cases

Women
older
Hx of HTN

Occurs w/ transmural infarcts

usually around 5th day after MI

Question 14

Cardiac rupture of free wall

Answer 14

–>some of systolic output goes into pericardium–>hemopericardium–>develops cardiac tamponade

Question 15

cardiac tamponade

Answer 15

impaired cardiac filling and function b/c something in pericardial sac compressing it (i.e. blood, fluid, fibrous adhesions)

Question 16

Rupture of interventricular septum

Answer 16

sudden shunt of blood from LV to RV

Question 17

Most common site of cardiac rupture

Answer 17

edge of infarct

where adjacent contracting muscle pulling on necrotic muscle

Question 18

Pericarditis after MI

Answer 18

5% or less

occurs over transmural infarcts

USUALLY day 2 - day 4 following MI

sometimes 2 wks to months after MI due to autoimmunity (Dressler syndrome)

less and less common because transmural infarcts are becoming less common

Question 19

Ventricular aneurysms due to MI

Answer 19

5%

thinned, scarred transmural infarcts that move paradoxically outward in systole

late complication

many develop mural thrombi

Question 20

Ruptured papillary muscle due to MI

Answer 20

1%
usually posterior papillary muscle

causes acute mitral regurgitation (although HF more often causes mitral regurg than MI)