Acute Coronary Syndromes and Sudden Death

Question 1

A 56-year-old man attends the Emergency Department with a six hour history of intermittent severe central chest pain radiating to his throat. The episodes occur at rest and each lasts 10-20 min. He smokes 20cigarettes/day and has type-2 diabetes. Examination is normal. His ECGs and cardiac troponin levels are normal. What is the most likely diagnosis?

a. Stable angina
b. Unstable angina
c. Myocardial infarction
d. Pericarditis
e. Non-cardiac pain

Answer 1

Unstable Angina

Question 2

Elevated Cardiac Markers: troponin:

Answer 2

• troponin complex is where cross-bridging between thick and thin
  filaments
  occurs
• Tn-T binds the complex tropomyosin
• Tn-C binds Ca2+ during excitation-contraction coupling
• Tn-I inhibits cross-bridging tropomyosin heavy chains
• Tn-C is common to all muscle - Tn-T and Tn-I are specific to cardiac muscle

Question 3

Markers of myocardial infarction slide

Answer 3

insert

Question 4

Acute Coronary Syndromes: Unstable Angina Diagnosis/Test Results:

Answer 4

• Cardiac-type chest pain
• +/- ECG changes
• Normal troponin level

Question 5

Acute Coronary Syndromes: Non-ST-elevation MI (NSTEMI) Diagnosis/Test Results:

Answer 5

• Cardiac-type chest pain
• +/- ECG changes
• Elevated troponin level

Question 6

Acute Coronary Syndromes: ST-elevation MI (STEMI) Diagnosis/Test Results:

Answer 6

• Cardiac-type chest pain
• Ischaemic ST elevation

Question 7

Case 2: insert slide:

Answer 7

PCI

Question 8

A 63-year-old comedian collapses on stage during a performance. He is unresponsive, is not breathing and has no palpable pulse. What is the most appropriate immediate action?

a. Ask for help from the audience
b. Call 999 for an emergency paramedic crew
c. Commence cardiopulmonary resuscitation
d. Search for a cardiac defibrillator
e. Video the event on your phone for posterity

Answer 8

c

Question 9

SCD

Answer 9

• sudden coronary death
• unexpected death due to cardiac causes
• (<1 hour of onset)4
• most cases are due to severe ventricular arrhythmias

Question 10

Causes of SCD:

Answer 10

insert slide

Question 11

HCM:

• is
• most common cause of
• type of mutation
• affects how much of population
• anatomy

Answer 11

• hypertrophic cardiomyopathy
• most common cause of SCD age<30
• autosomal dominant
• 1/500 pop
• inappropriate LV hypertrophy: no other cause like hypertension, aortic stenosis
• LV septum > posterior wall (asymmetrical
  LVH)
• LV outflow tract obstruction
• mitral regurgitation (systolic anterior
  motion)

Question 12

HCM presentation:

Answer 12

• chest pain/breathlessness
• palpitations/dizzy/syncope
• murmur: LVOT obstruction, mitral regurg
• abnormal ECG (screening)
• on family screening

Question 13

Cardiac Action Potential Graph:

Answer 13

insert

Question 14

Channelopathies: Long QT syndrome and variants:

Answer 14

• Na+ or K+ channel abnormalities
• Long QT interval on ECG
• swimming, alarm clocks
• all can be associated with deafness!!!!

Question 15

Re-entry and cardiac scarring:

Answer 15

insert slide

Question 16

Re-entry mechanism of arrhythmias:

Answer 16

insert slide

Question 17

Inhomogenity in acute MI:

Answer 17

insert slide

Question 18

Ventricular Tachycardia:

insert ECG

Answer 18

• usually due to re-entry around LV scarring
• typically with established MI
• other structural heart disease:
  - hypertrophic cardiomyopathy
  - dilated cardiomyopathies
  - RV cardiomyopathy
• regular, broad complexes
• may degenerate to ventricular failure (VF)

Question 19

SVT: Supraventricular tachycardia:

Answer 19

• most common in younger patients with normal hearts
• regular narrow complexes
• generally benign

Question 20

Anti-arrhythmic drugs: Insert table:

Answer 20

insert slide

Question 21

Anti-arrhythmic drugs: functional classification:

Answer 21

insert slide

Question 22

Prognosis with anti-arrhythmic drugs:

Answer 22

• reduce arrhythmia frequency
• help with symptoms
• does not improve prognosis
• exception: beta blockers in long QT
  syndrome
• class I and II drugs act on cardiac electrical
  tissue:
  - may be PRO arrhythmic
  - risk related to prolongation of the QT
  interval on the ECG

Question 23

Syncope: diagnosis:

Answer 23

• transient loss of consciousness due to
  cerebral hypoperfusion
• rapid onset, short duration, spontaneous
  complete recovery
• most commonly vasovagal syncope
• common faint: provocation, prodrome,
  postural
• arrhythmias: slow>fast ***
• mechanical problems: aortic stenosis,
  major PE **
• easily confused with seizures

Question 24

Ref flags with syncope:

Answer 24

• sudden onset <10 sec
• exertional or supine
• associated with chest pain or
  breathlessness
• known cardiac disease
• loud murmur
• significant injury
• abnormal ECG

Question 25

A 28-year-old man is seen in clinic following three episodes ofloss of consciousness whilst running. He has no significant familyhistory. Examination is normal. His ECG shows epsilon waves.What is the most likely diagnosis?

a. Arrhythmogenic RV cardiomyopathy
b. Brugada syndrome
c. Hypertrophic cardiomyopathy
d. Ischaemic heart disease
e. Vaso-vagal episodes

Answer 25

A

Question 26

Bradycardia - complete atrio-ventricular block: insesrt ECG

Answer 26

insert

Question 27

Permanent Pacemaker

Answer 27

insert

Question 28

implantable cardioverter defibrillator

Answer 28

insert

Question 29

ICD patient selection:

Answer 29

• survivors of SCD but not if ACUTE MI
• VT poorly treated
• high risk groups:
  - poor LV function
  - coronary disease
  - broad QRS complexes on ECG
• some HCM/long QT/ brugada/CPMVT/
  ARVC

Question 30

A 52-year-old man is discharged home following a non-ST-elevation MI for which he underwent coronary stenting. He is taking aspirin, clopidogrel, perindopril bisoprolol and atorvastatin.

Which is the most important reason for him to take clopidogrel?
a. Minimise atheroma progression
b. Prevent adverse LV remodelling
c. Prevent arrhythmias
d. Prevent recurrent MI
e. Reduce vascular inflammation

Answer 30

d

Question 31

Case 6A 12-year-old girl is admitted after collapsing at home after her alarm clock went off. Her father performed CPR and she recovered over 15 minutes. She wears bilateral hearing aids for sensori-neural deafness.
Her mother died suddenly aged 32.Which is the most likely diagnosis?

a. Brugada syndrome
b. Catecholaminergic ventricular tachycardia
c. Ischaemic heart disease
d. Long QT syndrome
e. Vaso-vagal syncope

Answer 31

d

Question 32

A 12-year-old girl is admitted after collapsing whilst swimming. She wears hearing aids for sensori-neural deafness. She is diagnosed with long QT syndrome and started on bisoprolol. To which class of anti-arrhythmic drugs does bisoprolol belong?

a. Class I (fast channel blockers)
b. Class II (beta-blockers)
c. Class III (K+ channel blockers)
d. Class II (Ca2+ channel blockers)
e. Unclassified

Answer 32

b

Question 33

An 88-year-old man is admitted to hospital following an out-of-hospital cardiac arrest in ventricular fibrillation from which he was successfully resuscitated. Two brothers and one sister had died suddenly. He had a history of hypertension. Examination is normal. His ECG shows left ventricular hypertrophy. What is the most likely diagnosis?

a. Aortic stenosis
b. Arrhythmogenic RV cardiomyopathy
c. Dilated cardiomyopathy
d. Hypertrophic cardiomyopathy
e. Ischaemic heart disease

Answer 33

e

Question 34

Case 9 insert slide

Answer 34

c

Question 35

case 10 insert slide

Answer 35

c