Acute Coronary Syndromes and Sudden Death Flashcards
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
Unstable Angina
Elevated Cardiac Markers: troponin:
- 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
Markers of myocardial infarction slide
insert
Acute Coronary Syndromes: Unstable Angina Diagnosis/Test Results:
- Cardiac-type chest pain
- +/- ECG changes
- Normal troponin level
Acute Coronary Syndromes: Non-ST-elevation MI (NSTEMI) Diagnosis/Test Results:
- Cardiac-type chest pain
- +/- ECG changes
- Elevated troponin level
Acute Coronary Syndromes: ST-elevation MI (STEMI) Diagnosis/Test Results:
- Cardiac-type chest pain
- Ischaemic ST elevation
Case 2: insert slide:
PCI
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
c
SCD
- sudden coronary death
- unexpected death due to cardiac causes
- (<1 hour of onset)4
- most cases are due to severe ventricular arrhythmias
Causes of SCD:
insert slide
HCM:
- is
- most common cause of
- type of mutation
- affects how much of population
- anatomy
- 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)
HCM presentation:
- chest pain/breathlessness
- palpitations/dizzy/syncope
- murmur: LVOT obstruction, mitral regurg
- abnormal ECG (screening)
- on family screening
Cardiac Action Potential Graph:
insert
Channelopathies: Long QT syndrome and variants:
- Na+ or K+ channel abnormalities
- Long QT interval on ECG
- swimming, alarm clocks
- all can be associated with deafness!!!!
Re-entry and cardiac scarring:
insert slide
Re-entry mechanism of arrhythmias:
insert slide
Inhomogenity in acute MI:
insert slide
Ventricular Tachycardia:
insert ECG
- 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)
SVT: Supraventricular tachycardia:
- most common in younger patients with normal hearts
- regular narrow complexes
- generally benign
Anti-arrhythmic drugs: Insert table:
insert slide
Anti-arrhythmic drugs: functional classification:
insert slide
Prognosis with anti-arrhythmic drugs:
- 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
Syncope: diagnosis:
- 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
Ref flags with syncope:
- sudden onset <10 sec
- exertional or supine
- associated with chest pain or
breathlessness - known cardiac disease
- loud murmur
- significant injury
- abnormal ECG
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
A
Bradycardia - complete atrio-ventricular block: insesrt ECG
insert
Permanent Pacemaker
insert
implantable cardioverter defibrillator
insert
ICD patient selection:
- 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
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
d
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
d
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
b
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
e
Case 9 insert slide
c
case 10 insert slide
c
