Cardiac Emergencies Flashcards
What is an acute coronary syndrome?
A medical emergency referring to a range of acute myocardial ischaemic states.
Which conditions come under the category of acute coronary syndromes?
STEMI
NSTEMI
Unstable angina
Why are acute coronary syndromes so important?
Single biggest cause of death in the UK, especially important in premature mortality
Easy one - list as many risk factors for an acute coronary syndrome as you can.
Non-modifiable:
- Increasing age
- Male
- FHx
- Premature menopause
- Structural coronary anomalies
Modifiable:
- Smoking
- DM
- HTN
- Dyslipidaemia
- Obesity
- Physical inactivity
- Cociane use
How do acute coronary syndromes typically present?
- Anginal pain at rest or activity - central, crushing, radiating to (left) shoulder/arm, jaw, or back
- Nausea/vomiting
- Fatigue
- Sense of impending doom
- SoB
- Palpatations
What are some cardiac differentials for an acute coronary syndrome?
- Acute pericarditis
- Myocarditis
- Aortic stenosis
- Aortic dissection
- PE
What are some respiratory differentials for an acute coronary syndrome?
- Pneumothorax
- Pneumonia
Other than cardiac and respiratory, what are the other differentials for acute coronary syndrome?
- Oesophageal spasm
- GORD
- Acuute gastritis
- Cholecystitis
- Acute pancreatitis
- MSK chest pain
A patient presents with central crusing chest pain. What initial investiagtions are essential?
- ECG (continuous monitoring)
- Troponins (at 6 and 12 hours after)
- Baseline bloods
- Blood glucose
- Coronary angiography
What initial therapy should be given for NSTEMI or unstable angina, providing there are no contraindications?
Aspirin and antithrombin therapy.
Aspirin - 300mg loading dose
Also oxygen as per requirements
What immediate pain relief can be given to those with suspected actue coronary syndrome?
GTN and/or IV opioid (with antiemetic)
What can be given to an ACS pt who has an aspirin sensitivity?
Clopidogrel
What is the difference between an NSTEMI and unstable angina in terms of investigations?
NSTEMI has elevated cardiac enzymes, unstable angina does not.
Which groups of patients may have atypical pain with an ACS?
Diabetics
The elderly
Hypertensives
May not feel the pain at all - silent MI.
Does a normal ECG exclude ischaemic origin for chest pain?
NO
How would an ECG of unstable angina differ to an ECG of a STEMI?
In unstable angina there may be T wave inversion or ST segment depression, or may show no chnages if done some time after episode of pain has finished.
When are tropoinins more sensitive than CK-MB?
In the first 3-6 hours following the event.
How long does troponin stay elevated?
Up to 14 days, peaking at 12-24 hours.
Is hyperglycaemia at presentation a good or poor prognostic factor for pateints who have had an ACS?
Poor
Which scoring system is used for post-ACS risk stratification?
GRACE score
Following initial management, what hsould be given to patients with ischaemic ECG changes or elevated troponin?
300mg aspirin if not already been loaded
180mg Ticagrelor loading dose
If a patients GRACE score shows medium to high risk, what should be offered following ACS?
Early in-hospital coronary angiography
What are the benefits of beta blockers for patients post ACS?
Improve outcomes long term and reduce severity and frequency of attacks
When are calcium channel blockers used for patients post-ICS?
If beta blockers are not tolerated
What ebenfit do ACE inhibitors have for patients post-ACS?
Reduce mortality
Inaddition to ACE-I, beta blockers, and calcium antagonists, what medications hsould be started post-ACS?
Statin
What complications can occur post ACS?
Acute MI Cardiogenic shock Ischaemic mitral regurgitation SVT VT AVN blockade
A patient presents with an irregularly irregular pulse. What is this most likely to be?
AF
What are the 2 main complications that occur due to AF?
Thrombus formaiton in atria -> stroke
Reduced CO -> HF
When is AF defined as acute?
Onste within last 48 hours.
When is AF defined as paroxysmal?
AF that stops within 7 days, usually before 48 hours.
When is recurrent AF termed persistent rather than paroxysmal?
If the arrythmia requires electrical or pharmacological cardioversion to terminate
What is permanent AF?
AF present for longer than a year and has not been successfully treated with cardioversion.
What are the common causes of AF?
- Idiopathic
- Coronary artery disease
- HTN
- Valvular heart disease
- Hyperthyroidism
How might a patient with new or undiagnosed AF present?
- Breathless
- Palpitations
- Syncope/dizziness
- Chets pain/discomfort
- Stroke/TIA
What is the gold standard of diagnosis of AF?
ECG except between attacks in paroxysmal AF.
How can paroxysmal AF be diagnosed by ECG?
24 hour tape if episodes suspected to happen less than 24 hours apart.
Which bloods should be done for a pt who is found to be in AF?
Why?
FBC - anaemia can cause HF
U&Es - abnormal K+
LFTs and Coag screen - pre-anticoag and other drug commencement
TFTs - hyperthyroid can cause AF
What investiagtions can be done for a pt who is in new AF in whom structural heart dsease is the suspected culprit?
CXR
Echocardiogram
How should AF be managed in broad terms?
Treat cause.
Treat complications.
Control the arrythmia.
Prevent thromboembolisms.
How can AF arrhythmia be managed?
Either with rate or rhythm control.
When is rhythm control used to treat AF?
Reversible cause of AF found
If the pt has HF secondary to AF
New onset AF
How can rhythm control be achieved?
Cardioversion
Why does a ruptured aortic aneurysm cause death so quickly?
It is a large blood vessel so blood loss is very rapid if it ruptures.
What is the largest risk factor for a ruptured AA?
Presence of aneurysm
What risk of rupture do aneurysms over 6cm have yearly?
25%
A patient who is unconscious is brought in to A&E following acute abdominal pain and a collapse. What is the most serious pathology that needs to be ruled out?
Ruptured AAA
A patient who is unconscious is brought in to A&E following acute chest pain and a collapse. What are the top 2 differentials we have to rule out?
Acute MI
Thoracic AA
Why are thoracic aortic aneurysms often rapidly fatal?
If they bleed into the mediastinum, cardiac tamponade can occur.
What is the classic triad of ruptured AAA?
- Pain in flank or back
- Hypotension
- Pulsatile abdominal mass
How will a patient with a ruptured AAA appear?
Weak, pale, and unwell, often sweating, and dizzy when they stand up.
O/E of the abdomen of a patient with a ruptured AAA, what might you find?
- Pulsatile mass in central abdomen
- Tender to palpation
- Bruit
What lab studies should be done for a patient with ruptured AAA?
- FBC
- Crossmatch
- Baseline biochemistry
What imaging can confirm the presence of an AAA?
CT angiography
How is a ruptured AAA managed?
Surgically secure aorta, graft placement if possible.
Emergency endovascular aneurysm repair.
What is the prognosis for a ruptured AAA?
Very poor - less than 30% of patients reach hospital alove, and only 80% of those make it to theatre.
What is a cardiac tamponade?
Extra-cardiac compression of heart causing reduced ventricular filling and haemodynamic compromise, due to accumulation of blood/fluid/pus/clots/gas in the pericardial space
What are the most common causes of cardiac tamponade?
Trauma or HIV in young adults
Malignancy or CKD in elderly
A young man who was in a car crash presents with shortness of breath, tachycardia, and cold clammy extremities. What signs on examination would suggest cardiac tmponade had occurred?
- Neck veins distended
- Hypotension
- Muffled heart sounds
- Pericardial friction rub
- Pulsus paradoxus
What is pulsus paradoxus, and what does it signify?
Exaggeration of normal decrease in systemic BP during inspiration. >10mmHg
On ECG, pulse wave amplitude lower on a regular cycle.
What is the investigation of choice for diagnosing cardiac tamponade?
Echocardiogram
How should cardiac tamponade be managed?
Depends if it causes cardiac arrest or not. If yes, ALS.
If no, ITU monitoring, pericardiocentesis, supportive care.
Positive inotropic drugs.
Treat underlying cause.
What is the prognosis associated with cardiac tamponade?
Depends on how quickly it is diagnosed and treated. Good if speedily treated and underlying cause removed.
What are the 2 main types of hypertensive emergency?
- Accelerated hypertension
- Malignant hypertension
What pressure is considered a hypertensive emergency?
Recent increase of BP to 180 systolic or 110 diastolic.
Which organs are damaged in hypertensive emergencies?
Neurological (encephalopathy)
Cardiovascular
Renal
How can we distinguish between accelerated and malignant hypertension?
Presence of papilloedema +/or retinal haemorrhages indicate malignant hypertension over accelerated hypertension.
What pathologies can cause secondary malignant hypertension?
- Renovascular hypertension
- Renal artery stenosis
- Renin-secreting tumours
- Kidney trauma
- Phaeochromocytoma
- Cocaine
- Pre-eclampsia/eclampsia
- Thyroid disease
How may a person with malignant hypertension present?
May be asymptomatic, but:
- Headaches
- Fits
- N&V
- Chest pain
- Neurological symptoms
- Bleeding
How should malignant hypertension be managed?
- Reduced BP over 24-48 hours
- Arterial line can be used for continuous BP monitoring
- IV nitroprusside/labetolol/nicardipine
- Treat underlying cause
If it is suspected that a phaeochromocytoma is the cause of malignant hypertension, what can be given to manage the BP?
Phentolamine
What is Torsades de pointes?
A distinctive polymorphic ventricular tachycardia
How does Torsades de pointes present on an ECG?
QRS amplitude varies, and complexes appear to twist around the baseline.
Is Torsades de pointes life-threatening?
Yes
If Torsades de pointes occurs in a young patient, what is most likely to be the cause?
Congenital long QT syndrome due to CHD
If Torsades de pointes occurs in an older patient, what is most likely to be the cause?
Aquired Long QT syndromes
What are the risk factors a patient can have for acquired long QT syndrome which can lead to Torsades de pointes?
- Acute MI
- Drugs
- Electrolyte disturbance
- AKI
- Liver failure
- Metabolic disturbance
- Bradycardia
- Toxins
A patient presents with episodes of palpitations, dizziness, and syncope. What would the most worrying thing be to see on their ECG?
Torsades de pointes
A young woman who has a FHx of congenital deafness dies suddenly. What cardiac arrythmia might this reflect?
Long QT syndrome -> Torsades de pointes
Jervell and Lange Nielson syndrome
A young woman with palpitations, dizziness, and syncope has an ECG done which shows torsades de pointes. What further investigations should be done?
- Bloods - look for electrolyte disturbance.
- Cardiac enzymes - assess for MI
- CXR and echo - structural heart disease
How should torsades de pointes be managed immediately?
- Resus and defibrillation
- IV Magnesium
How should torsades de pointes be managed once the immediate threat is managed?
- Medication review
- Correct underlying cause
- Temporary transvenous pacing if IV magnesium doesn’t work
- Propranolo long term
- Permenant pacing long term/ICD
What are the consequences of torsades de pointes?
VT
VF
Sudden cardiac death
It’s real bad.
What is the prognosis like for torsades de pointes?
Patients may revert spontaneously or cpnvert to VT/VF. Can cause sudden death, but prognosis is excellent once any precipitating cause is dealt with.
