Week 11 Flashcards
What are two causes of non-ischaemic chest pain?
- Aortic aneurysms
- Pericarditis
What is an aortic aneurysm
- dilation or enlargement of the aorta
- >3cm diameter of >150% of normal
what percentage of aneurysms present as AAA?
90%
What are the layers of the Aorta?
Tunica adventitia - strong made of collagen and elastic fibres
Tunica Media - smooth muscle
Tunica Intima
What are the three categories of aneurysms?
True aneurysm - involves all 3 layers
False aneurysm - blood leaks through intima but contained by media and adventitia
Dissecting aneurysm - blood penetrates intima and creates secondary lumen between layers of vessel wall
What could it be if you feel a palpable abdominal mass?
AAA
What are the two types of aneurysms?
ON EXAM
- Fusifrom - buldges on all sides of aorta
- Saccular - buldges on one side only
What are risk factors for aortic aneurysms?
- SMoking
- Hypertension
- High Cholesterol
- Male
- Older age
- Family history
- Female <40 - Pregnancy
- Bicuspid aortic valve - 7-14%
- Marfan syndroms - 5-9%
- Turner syndrome
- Trauma
What is marfans syndrome?
genetic disorder of connective tissue
How would your patient present with a dissecting ruptured AA?
- Pain
- Agitated
- Diaphoretic/Palour
- Hypotension
- High HR (compensation)
- Feeling of impending doom
Abdominal AA:
- Abdominal distension (AAA)
- Femoral pulses
- Cold foot: Clots in lower limb
Thoracic:
- Unequal BP in arms (thoracic AA)
- ACS
What is the patient reported pain associated with AA?
Often asymptomatic until rupture:
Abdominal:
- Pain in chest, abdomen, back or flank or tearing pain
- Not changed with movement
- Deep aching, throbbing and gnawing pain
- Pulsating sensation in abdomen
Thoracic:
- Chest pain - deep aching and throbbing or tearing
- Radiating to back
How do you manage AA in pre-hospital?
- IV access - bilateral large bore - Fluid
- Pain relief
- Oxygen
- MICA/HEMS
- Hypotensive resuscitation - agressive fluids
What is the systolic BP cutoff for giving fluid?
Give fluid below 70SBP
for organ perfusion - which shuts down below 70…
How do you treat someone with Haemorrahgic hypovolaemia with a SBP below 70?
Normal saline 250ml IV bolus
- repeat as required - titrate to > or equal to 70SPB
Max dose 2000mL
What is pericarditis?
Inflammation and swelling of the pericardial sac (around the heart)
What is the cause of pericarditis?
- Viral - 85%
- Bacterial
- Fungal
- Idiopathic
- Autoimmune
- Post surgical
How does pericarditis present?
Chest pain:
- Sharp and pleuritic, improved bu sitting up and leaning forward. Worse lying down. Described as retrosternal
Pericardial friction rub:
a superfiscially scratchy or squeaky sound best heard with the stethoscope over left sternal border.
ECG Changes:
- New widespread ST elevation or PR depression
Pericardial effusion
Infective cause:
- Fever, flu like symptoms
What are the ECG changes associated with pericarditis?
- Concave ST Elevation
- PR depression
What are the 4 stages of ECG changes associated with Pericarditis?
stage 1 - widespread STE and PR depression with reciprocal changes in aVR (first 2 weeks)
Stage 2 - normalisation of ST segment, generalised T wave flattening (1-3 weeks)
Stage 3 - flattened T waves become inverted (3 - several weeks)
Stage 4 - ECG returns to normal
What are 3 STEMI mimics?
- Pericarditis
- Pinzmetal’s angina
- Takotsubo
What is Prinzmetal’s angina?
Vagospastic angina
Vasospasm of coronary arteries leading to intermittent occlusion
Self resolved
What is Takosubo?
NOT ON EXAM
Vast majority of cases are women and most pre-menopausal
Often occurs after bad news
Constant anxiety
- Spasm of heart changes shape
Explain the 4 stages of the cardiac cell action potential graph?
4 - Slow depolarisation - Sodium and calcium channels open
0 - Rapid depolarisation - Voltage gated sodium channels open
1 - voltage gated Potassium channels open and sodium channels close
2- Plateau - Calcium channels open
3 - Repolarisation - calcium channels close, potassium channels remain open
What are CLASS 1 cardiac drugs?
Sodium channel blockers
What do CLASS 1 cardiac drugs do?
- Prolong AP
- Shorten AP (ligocaine)
Slows down phase 0 in both atrial and ventricular arrhythmias
- Helps to treat arrythmias such as AF
What are some CLASS 1 cardiac drugs?
- Procainamide
- Quinidine
- Disopyramide
What are CLASS II cardiac drugs?
Beta blockers
What do CLASS II cardiac drugs do?
“OLOLs”
Blocking B1 receptors decreases responsiveness of SA and AV node
- slows heart rate
What are effects of class 2 overdose?
- Brady
- Hypotension
- Wide QRS
- VT
What are CLASS III cardiac drugs?
Potassium channel blockers
- Effects phase 3
What do CLASS III cardiac drugs do?
Prolongs non refractory period
slows AP in ventricular cells
Can break reentrant circuits allow SA node to take over.
What are CLASS IV cardiac drugs?
Calcium channel blockers
What are Cardiac Glycosides?
- For AF
- inhibit enzyme ATPase associated with Na/K pump
- decreased HR
- Increased contraction force
- Slows condusction through AV node
What are Cardiac Glycosides?
Digoxin
- For AF
- inhibit enzyme ATPase associated with Na/K pump
- decreased HR
- Increased contraction force
- Slows condusction through AV node
What are vitamin K inhibitors?
Warfarin
- stops clotting
Vitamin K used in synthesis of prothrombin
Where do Class 1, 2, 3 & 4 cardiac drugs work on the AP
1 - Phase 0 and phase 4 - sodium blockers
2 - Phase 2 - beta blockers
3 - Phase 3 - Potassium blockers
4 - Phase 2 - Calcium channel blockers
What are some drugs listed as class 1, 2, 3, 4 cardiac drugs and what do they do?
Class I : Ligocaine, Procainamide - Decrease conduction rate - decrease contractility - extend AP duration - Increase effective refractory period
Class II: Beta blockers 'OLOLs' - Decrease conduction - Decrease contractility - Decrease rate
Class III: Amiordarone, Sotalol - Decrease AV conduction - Decrease contractility - Increase AP duration - Increase effective refractory period
Class IV: Verapamil, Diltiazem - Decrease AV conduction - Decrease contractility - Decrease AP duration
