COMPLICATIONS OF ACUTE CORONARY SYNDROME

Question 1

DDx: General Categories

Answer 1

Arrythmia
Mechanical Complications
Pericarditis
Congestive Heart Failure
Cardiogenic Shock

Question 2

DDx: Most Important Arrythmias

Answer 2

Atrial Fibrillation
Ventricular Fibrilation
Ventricar Tachycardia
PVCs
Idioventricular Rhythm

Question 3

List the 6 most common arrythmias / conduction disturbances in order of frequency

Answer 3

Ventricular Premature Beats (99%)
Accelerated Idioventricular Rhythm (70%)
Ventricular Tachycardia, non-sustained (69%)
Atrial Premature Contractions (50%)
Sinus Bradycardia (40%)
Sinus Tachycardia (35%)

Question 4

Consequences of post-MI arrythmias on cardiac function

Answer 4

Impaired hemodynamic performance

Compromised myocardia viability due to increased 02 requirements

Predisposition to more serious rhythm disturbance due to diminished ventricular fibrillation threshold

Impaired atrial kick (loss of up to 35% SV in patients with already reduced LV compliance)

Question 5

Indications for Temporary Transcutaneous Pacemaker

Answer 5

Unresponsive sympromatic bradycardia
Mobitz II or higher AV block
New LBBB or bifascicular block
RBBB or LBBB with first degree block
Some cases with stable bradycardia and new or indeterminate-age RBBB

Question 6

Indications for Temporary Transvenous Pacing

Answer 6

Asystole
Unresponsive sympromatic bradycardia
Mobitz II or higher AV block
New or indeterminante-age LBBB
Alternating BBB
RBBB or LBBB with first degree block
Consider in RBBB with left anterior or posterior hemiblocks
Override pacing in unresponsive ventricular tachycardia
Unresponsive recurrent sinus pauses > 3 sec

Question 7

DDx: Mechanical Complications

Answer 7

Ventricular Free Wall Rupture
Intraventricular Septum Rupture
Papillary Muscle Rupture
Ventricular Pseudoaneurysm

Question 8

Ventricular Free-wall rupture: timeline, most common location, cause, complications

Answer 8

MC form of cardiac rupture
Timeline: 1-2 weeks post-MI
Most common location: anterior wall
Complications: tamponade -> profound hypotension & shock -> pulseless electrical activity

Question 9

Interventricular Septal Rupture: timeline, cause, complications

Answer 9

2nd MC form of cardiac rupture
Timeline: 3-5 days post MI
Cause:
Complications: VSD -> left or right shunt

Question 10

Papillary Muscle Rupture: timeline, most common location, cause, complications

Answer 10

Timeline: 2-7 days post MI
MC Location: Posterior Medial Papillary Muscle
Cause: single blood flow from posterior descending coronary artery - common in inferior MI
Complications: acute mitral regurgitation

Question 11

Ventricular Pseudoaneurysm: timeline, most common location, cause, complications

Answer 11

Timeline: 1-2 weeks post MI
Location: Anterior ventricular wall??
Contained free wall rupture
Complications: Impaired CO, risk of mural thrombus formation, risk of arrythmia

Question 12

DDx: Pericarditis

Answer 12

Fibrinous Pericarditis
Dressler’s Syndrome

Question 13

Fibrinous Pericarditis: timeline, cause, clinical features, complications, treatment

Answer 13

Timeline: 1-3 days post-MI
Cause: Inflammatory reaction to cardiac necrosis adjacent to pericardium
Clinical Features: pleuritic chest pain, worse in supine, new friction rub
Complications: Tamponade
Treatment: ASA 650 mg PO q 4-6 hrs, colchicine 0.4 mg PO bid DO NOT USE IBUPROFEN

Question 14

Dressler’s Syndrome: timeline, cause, complications

Answer 14

Timeline: weeks post MI
Cause: autoimmune phenomenon resulting in fibrinous pericarditis
Treatment: ASA 650 mg PO q 4-6 hrs, colchicine 0.4 mg PO bid DO NOT USE IBUPROFEN