CARDIOVASCULAR Flashcards
(109 cards)
1
Q
PHARMACOLOGY
Describe the action of beta blockers
A
Beta 1 specific
Antagonise sympathetic activation and so are negatively chronotropic and inotropic
Myocardial work is reduced and so is myocardial demand = symptom relief
2
Q
PHARMACOLOGY
What drugs that might be use in someone with angina or in someone at risk of angina to improve prognosis?
A
- Aspirin
- Clopidogrel - antiplatelet
- Atovostatin - Statin
- ACEi - ramipril
3
Q
ACS
What might the ECG of someone with unstable angina show?
A
May be normal, or might show T wave inversion and ST depression
4
Q
ACS
A raised troponin is not specific for ACS. In what other conditions might you see a raised troponin?
A
- Gram negative sepsis
- PE
- Myocarditis
- Heart failure
- Arrhythmias
5
Q
ACS
Describe the initial management of ACS
A
- Analgesia - morphine + sublingual GTN
- Oxygen (if SpO2 > 94%)
- dual antiplatelets
- ALL patients = aspirin 300mg
- if PCI = prasugrel or clopidogrel
- if fibrinolysis = ticagrelor or clopidogrel
MONA
6
Q
ACS
What is the overall treatment for STEMI?
A
PCI - if symptom onset within 12 hours and access to PCI within 120 minutes
Thrombolysis e.g. alteplase or tenecteplase - If ineligible for PCI
7
Q
ACS
Describe the secondary prevention therapy for people after having a STEMI
A
- lifestyle changes
- manage CVD risks
- thrombolysis = 12 months aspirin 75mg + ticagrelor
- PCI = lifelong aspirin + 12 months ticagrelor/prasugrel
- ACEi
8
Q
DVT
What investigations might be done in order to diagnose a DVT?
A
- WELLS score
if WELLS >2 DVT likely
- duplex ultrasound of leg within 4 hours (if not within 4 hrs, offer anticoagulation)
- d-dimer
if WELLS <1 DVT unlikely
- D-dimer with results within 4 hrs (if not within 4hrs offer anticoagulation)
- if D-dimer is raised = duplex USS
- if D-dimer normal = no further Ix
bloods - FBC, U&Es, LFTs, PT + APTT
9
Q
PE
What investigations might be done to diagnose a patient with PE?
A
- CXR (typically normal)
- ECG (sinus tachy, S1Q3T3, RBBB + R axis deviation
- if WELLS >4 = CTPA (V/Q scan as alternative in severe renal impairment)
- if WELLS<4 = D-dimer
10
Q
PERICARDITIS
Describe the aetiology of pericarditis
A
IDIOPATHIC
VIRUSES (most common = coxsackie), mumps, EBV, CMV, varicella, HIV
less common
- autoimmune
- TB
- trauma
- uraemia secondary to kidney disease
- post-MI syndrome
- dressler syndrome
- connective tissue disorders
- malignancy
- hypothyroidism
11
Q
PERICARDITIS
What might the ECG look like in someone with acute pericarditis?
A
- Saddle shaped ST elevation
- PR depression
12
Q
PERICARDITIS
How can acute pericarditis be clinically diagnosed?
A
Patient has to have at least 2 of the following:
1. Chest pain
2. Friction rub
3. ECG changes
4. Pericardial effusion
13
Q
PERICARDITIS
What is the treatment for pericarditis?
A
idiopathic/viral
- 1st line = NSAIDs + colchicine
- 2nd line = NSAIDs, colchicine + low-dose prednisolone
bacterial
- IV antibiotics + pericardiocentesis with washout, cultures
14
Q
CARDIAC TAMPONADE
What are the signs of Cardiac tamponade?
A
Beck’s triad:
1. low BP but high HR
2. Increased JVP
3. Quiet S1 and S2
- Pulsus paradoxus = pulses fade on inspiration
- Kussmaul’s sign = rise in jugular venous pressure with inspiration
15
Q
MYOCARDITIS
What can cause myocarditis?
A
most common = coxsackie B
others
Viral infection - coxsackie B, adenovirus, herpes
lyme disease
toxoplasmosis
autoimmune - SLE, dermatomyositis, sarcoidosis
drug-induced - antipsychotics, immunotherapies
hypersensitivity reactions
16
Q
HEART FAILURE
what is the management for chronic HF?
A
1st line = BB + ACEi (started one at a time)
If ACEi not tolerated, try ARB or hydralazine with nitrate
2nd line = aldosterone antagonist (SPIRONOLACTONE)
3rd line = cardiac resynchronisation therapy (CRT) or ICD insertion, digoxin (particularly in AF) or ivabradine
other options:
- fluid restriction
- loop diuretics (for symptom management)
- annual flu + pneumococcal vaccine
17
Q
ABNORMAL ECGS
What aspect of the heart is represented by leads II, III and aVF?
A
Inferior aspect
18
Q
ABNORMAL ECGS
What might ST elevation in leads II, II and aVF suggest?
A
RCA blockage
Leads represent inferior aspect of heart, RCA supplies inferior aspect
19
Q
ABNORMAL ECGS
Give 3 effects hyperkalaemia on an ECG
A
GO - absent P wave
GO TALL - tall T wave
GO long - prolonged PR
GO wide - wide QRS
20
Q
ABNORMAL ECGS
Give 2 effects of hypokalaemia on an ECG
A
- Flat T waves
- QT prolongation
- ST depression
- Prominent U waves
U have no Pot and no T, but a long PR and a long QT
21
Q
ABNORMAL ECGS
Give an effect go hypocalcaemia on an ECG
A
- QT prolongation
- T wave flattening
- Narrowed QRS
- Prominent U waves
22
Q
ABNORMAL ECGS
Give an effect of hypercalcaemia on an ECG
A
- QT shortening
- Tall T wave
- No P waves
23
Q
ATRIAL FIBRILLATION
what are the causes of atrial fibrillation?
A
PIRATES
Pulmonary - PE, COPD
Ischaemic heart disease
Rheumatic heart disease
Anaemia, Alcohol, Advancing age
Thyroid disease (hyperthyroid)
Electrolyte disturbance (hypo/hyperkalaemia)
Sepsis, Sleep apnoea
24
Q
ATRIAL FIBRILLATION
Describe the treatment for atrial fibrillation
A
HAEMODYNAMICALLY UNSTABLE
- 1st line = synchronised DV cardioversion
STABLE
onset <48hrs
- 1st line = rate control (BB or CCB)*
- 2nd line = rhythm control (flecanide or amiodarone)
onset >48hrs
- 1st line = rate control (BB or CCB)* + anticoagulation for at least 3 weeks, then offer rhythm control if appropriate
*consider digoxin 1st line in patients with AF + HF, those who do no exercise or other drugs excluded
avoid CCB in HF
avoid non-selective BB (e.g. propranolol) in asthma
25
LONG QT SYNDROME
what are the causes of long QT syndrome?
1. Congenital
2. hypokalaemia,
3. hypocalcaemia
4. Drugs - amiodarone, tricyclic antidepressants
5. bradycardia
6. Acute MI
7. diabetes
26
HEART BLOCK
What are the treatments for heart blocks?
1st = asymptomatic, watch and wait --> atropine
Mobitz 1 = no pacemaker if asymptomatic, pacemaker if symptomatic
Mobitz 2 = pacemaker even if asymptomatic
3rd = transcutaneous pacing followed by permanent pacemaker
27
HEART BLOCK
what are the causes of heart block?
Athletes
Sick sinus syndrome
IHD – esp MI
Acute myocarditis
Drugs
Congenital
Aortic valve calcification
Cardiac surgery/trauma
28
BUNDLE BRANCH BLOCK
What changes would you see on an ECG from someone with a LBBB?
WiLLiaM
slurred S wave in V1 (resembles W)
R wave in V6 (resembles M)
wide QRS with notched top in V6
29
BUNDLE BRANCH BLOCK
What changes would you see on an ECG from someone with a RBBB?
MaRRoW
R wave in V1 (resembles M)
slurred S wave in V6 (resembles W)
wide QRS
RSR pattern in V1
30
AORTIC STENOSIS
what are the signs of aortic stenosis?
MURMUR
- ejection systolic murmur over aortic area
- radiating to carotids and apex
- crescendo-decrescendo
- thrill if severe
- left ventricular heave
ASSOCIATED FEATURES
- diminished S2
- slow rising pulse
- narrow pulse pressure
- S4 heart sound
FEATURES OF HF
- crackles
- raised JVP
- peripheral oedema
31
MITRAL REGURGITATION
What can cause mitral regurgitation?
1. Myxomatous degeneration (mitral valve prolapse) - most common cause
2. Ischaemic mitral valve
3. Rheumatic heart disease
4. IE
5. dilating left ventricle
32
MITRAL REGURGITATION
what are the signs of mitral regurgitation?
MURMUR
- Pan-systolic murmur
- Radiates to left axilla
- blowing at apex
- S3 heart sound
- Quiet S1
- displaced apex towards axilla
33
AORTIC REGURGITATION
What causes aortic regurgitation?
acute
- infective endocarditis
- rheumatic fever
- aortic dissection
chronic
- rheumatic disease
- bicuspid aortic valve
- aortic endocarditis
34
AORTIC REGURGITATION
what are the signs of aortic regurgitation?
MURMUR
- early diastolic murmur - decrescendo
- soft, high-pitched
- collapsing (waterhammer) pulse
- wide pulse pressure
- displaced apex
OTHER SIGNS
- austin flint murmur = rumbling mid-diastolic murmur, loudest at apex, suggests severe disease
- corrigans sign = visible distension + collapse of carotid arteries
- millers sign = visible pulsation of uvula
- Quinckes sign = visible pulsations in nail bed when compressed
- De Mussets sign = heartbeat associated with head bobbing
- Traubes sign = pistol shot sound over femoral arteries
- Duroziezs sign = audible systolic + diastolic murmur on compression of femoral artery
35
MITRAL STENOSIS
Name 3 causes of mitral stenosis
1. Rheumatic heart disease
2. IE
3. Mitral annular calcification - rarer
36
MITRAL STENOSIS
what are the symptoms of mitral stenosis?
1. progressive dyspnoea
2. Haemoptysis (coughing up blood)
3. palpitations (AF)
4. chest pain
37
MITRAL STENOSIS
what are the signs of mitral stenosis?
rumbling mid-diastolic murmur with opening snap - decrescendo-presystolic crescendo
1. malar flush
2. AF
3. tapping apex beat
4. low volume pulse
5. loud snapping S1
38
INFECTIVE ENDOCARDITIS
Give the 2 major points in the Duke's criteria that if presence can confirm a diagnosis of infective endocarditis
1. Two positive blood cultures
2. Positive echo showing endocardial involvement
39
PULMONARY STENOSIS
what is the murmur?
- ejection systolic murmur
- heard loudest over pulmonary area (2nd IC space, L sternal edge)
- loudest during inspiration
- radiates to left shoulder/infraclavicular region
40
PULMONARY STENOSIS
what are the causes?
- Turners, Noonans
- tetralogy of fallot
- rheumatic fever
- carcinoid syndrome
41
PULMONARY STENOSIS
How does a patient present with pulmonary stenosis?
Right ventricular failure
Collapse
Poor pulmonary blood flow
right ventricular hypertrophy
Tricuspid regurgitation
42
TRICUSPID REGURGITATION
what is the murmur?
- pansystolic murmur
- heard loudest over tricuspid region
- loudest during inspiration
43
EQUATIONS
Write an equation for mAP
mAP = DP + 1/3PP
44
EQUATIONS
Give the equation for stroke volume
SV = EDV - ESV
45
ANEURYSM
What classifies as an Abdominal aortic aneurysm?
> 3 cm
Dilation affects all 3 layers of the vascular tunic
46
COR PULMONALE
what are the causes of cor pulmonale?
- chronic lung disease
- pulmonary vascular disorders
- neuromuscular and skeletal diseases
47
COR PULMONALE
what are the signs of cor pulmonale?
- cyanosis
- tachycardia
- raised JVP
- RV heave
- pan-systolic murmur due to tricuspid regurgitation
- hepatomegaly
- oedema
48
COR PULMONALE
what is the management for cor pulmonale?
- treat the underlying cause
- oxygen
- diuretics
- venesection if haematocrit >55
- heart-lung transplant in young patients
49
ATRIAL FLUTTER
what are the causes of atrial flutter?
more likely to occur with pulmonary disease:
- COPD
- obstructive sleep apnoea
- PE
- pulmonary hypertension
other causes:
- ischaemic heart disease
- sepsis
- alcohol
- cardiomyopathy
- thyrotoxicosis
50
ATRIAL FLUTTER
what is the management for atrial flutter?
- Cardioversion
- Give a LMWH
- Shock with defibrillator
- Catheter ablation = definitive treatment – creates a conduction block
- IV Amiodarone – restore sinus rhythm
51
AORTIC DISSECTION
what are the risk factors of aortic dissection?
Hypertension- most common risk factor
Trauma
Vasculitis
Cocaine use
Connective tissue disorders- Turners + noonans
52
AORTIC DISSECTION
what are the clinical features of aortic dissection?
-Sudden and severe tearing pain in chest radiating to back
-Hypotension
-Asymmetrical blood pressure
-Syncope
- Aortic regurgitation, coronary ischaemia, cardiac tamponade
- Peripheral pulses may be absent
53
AORTIC DISSECTION
what are the investigations of aortic dissection?
-ECG/cardiac enzymes - rule out MI
-Chest x-ray - widening mediastinum
-CT scanning- definitive imaging
- echo - TTE/TOE
- bloods - FBC, U&Es, group and save, crossmatch
- gold standard = CT angiography
54
BUNDLE BRANCH BLOCK
what are the causes of RBBB?
- normal variant (more common with increasing age)
- right ventricular hypertrophy
- PE
- MI
- Atrial septal defect
- cardiomyopathy or myocarditis
55
BUNDLE BRANCH BLOCK
what are the causes of LBBB?
A new LBBB is always pathological
IHD
Aortic valve disease
56
AORTIC ANEURYSM
what is the management for abdominal aortic aneurysm?
- ruptured = urgent repair (do not wait for imaging)
- symptomatic = repair indicated regardless of diameter
- asymptomatic AAA = surveillance until high risk of rupture - 5.5cm in men and 5.0cm in women
57
ENDOCARDITIS
what antibiotics are used for endocarditis?
INITIAL BLIND THERAPY
- native valve = amoxicillin (consider gentamicin)
- pen allergy = vancomycin + gentamicin
NATIVE S.AUREUS
- flucloxacillin
- pen allergy = vancomycin + rifampicin
PROSTHETIC VALVE S.AUREUS
- flucloxacillin + rifampicin + gentamicin
- pen allergy = vancomycin + rifampicin + gentamicin
FULLY SENSITIVE STREP (S.VIRIDANS)
- benzylpenicillin
- pen allergy = vancomycin + gentamicin
LESS SENSITIVE STREP
- benzylpenicillin + gentamicin
- pen allergy = vancomycin + gentamicin
58
MI ECG
ECG changes in which regions indicates a lateral MI?
lead I
aVL
V5
V6
59
MI ECG
ECG changes in which regions indicates an inferior MI?
lead II
lead III
aVF
60
MI ECG
ECG changes in which regions indicates a septal MI?
V1
V2
61
MI ECG
ECG changes in which regions indicates an anterior MI?
V3
V4
62
MI ECG
ECG changes in lateral regions are caused by which artery in an MI?
lateral = circumflex
63
MI ECG
ECG changes in inferior regions are caused by which artery in an MI?
inferior = RCA
64
MI ECG
ECG changes in anterior regions are caused by which artery in an MI?
anterior = LAD
65
MI ECG
A blockage in the LAD will cause ECG changes in which regions?
anterior - V3, V4
septal - V1, V2
66
MI ECG
A blockage in the RCA will cause ECG changes in which regions?
inferior - leads II, III, aVF
67
MI ECG
A blockage in the circumflex artery will cause ECG changes in which regions?
lateral - lead I, aVL, V5, V6
68
PERCARDITIS
What are the side effects of colchicine?
Diarrhoea and nausea
69
DVT
what are the components of the WELLS score?
- active cancer
- bedridden or recent major surgery
- calf swelling >3cm compared to other leg
- superficial veins present (non-varicose)
- entire leg swollen
- tenderness along veins
- pitting oedema of affected leg
- immobility of affected leg
- previous DVT
- alternative diagnosis likely (-2)
all score +1
70
PE
what are the components of the WELLs two level score?
- clinical signs + symptoms of DVT (+3)
- PE is no.1 diagnosis (+3)
- tachycardia <100 (+1.5)
- immobilisation for >3 days
- previous PE/DVT (+1.5)
- haemoptysis (+1)
- malignancy with treatment in last 6 months (+1)
71
CARDIAC TAMPONADE
what are the causes?
idiopathic
pericarditis
iatrogenic (cardiothoracic surgery)
malignancy
aortic dissection
rheumatological - SLE, RA, scleroderma
72
MYOCARDITIS
what are the clinical features?
SIGNS
tachycardia
fever
displaced apex beat
S3 gallop
peripheral oedema
SYMPTOMS
chest pain - worse lying flat, improved by sitting forward
shortness of breath
fatigue
syncope
palpitations
73
PVD
what classification is used?
fontaine classification for different stages of PVD
74
PVD
what is the site of the disease when the claudication is at the following sites?
1. unilateral buttock
2. unilateral thigh
3. unilateral calf
buttock = common iliac
thigh = common femoral
calf = superficial femoral
75
ARTERIAL ULCER
what are the features?
- symmetrical shape
- well-defined borders
- punched out appearance
- loss of hair surrounding (shiny)
- pale, dry, gangrenous with cool surrounding skin
- minimal bleeding when knocked/touched
- painful, particularly at night
76
VENOUS ULCERS
what is the appearance?
- shallow
- irregular borders
- oedema, erythema + brown pigment
- warm skin surrounding
77
CRITICAL LIMB ISCHAEMIA
what is aortoiliac disease?
also known as Leriche syndrome
triad of:
- claudication of buttocks and thighs
- absent or decreased femoral pulses
- erectile dysfunction
78
ACUTE LIMB ISCHAEMIA
how can you tell if the cause is embolic or thrombotic?
EMBOLIC
- sudden onset
- cardiac history
- arrhythmia (AF)
- cold mottled skin
- clear demarkation
THROMBOTIC
- progressive onset
- no cardiac history
- peripheral artery disease
- no arrhythmias
- cool and cyanotic
- no clear demarkation
79
ACUTE LIMB ISCHAEMIA
what is the classification?
rutherford classification
1 = viable
2= threatened
3 = irreversible
80
ACUTE LIMB ISCHAEMIA
what is the management?
initially LMWH
based on rutherford classification
I (viable) = catheter-directed thrombolysis/thrombectomy (within 6-24hrs)
IIa = catheter-directed thrombolysis or percutaneous thromboembolectomy
IIb = percutaneous/open thromboembolectomy, bypass surgery
III = amputation
81
HEART FAILURE
what are the causes of HF with reduced ejection fraction (systolic dysfunction)?
damage to myocytes e.g. ischaemic heart disease
82
HEART FAILURE
what are the causes of HF with preserved ejection fraction (diastolic dysfunction)?
increased ventricular stiffness e.g. HTN
reduced relaxation e.g. constrictive pericarditis
83
ATRIAL FIBRILLATION
which medications are used for rate control?
1st line = beta-blocker (bisoprolol) or CCB (diltiazem/verapamil)
consider digoxin 1st line when AF + HF
2nd line = combination therapy with any two
- beta-blocker (bisoprolol)
- diltiazem
- digoxin
84
ATRIAL FIBRILLATION
what medications are used for rhythm control?
if no structural/ischaemic heart disease = flecainide or amiodarone
if structural/ischaemic heart disease = amiodarone
85
INFECTIVE ENDOCARDITIS
which bacteria is associated with IV drug use?
staph aureus
86
INFECTIVE ENDOCARDITIS
which bacteria are associated with prosthetic valves?
s. aureus
s. epidermidis
87
INFECTIVE ENDOCARDITIS
which bacteria are associated with colon cancer?
strep bovis
88
INFECTIVE ENDOCARDITIS
which bacteria is associated with infection of native valves?
strep viridans
89
INFECTIVE ENDOCARDITIS
which bacteria is associated with poor dental hygiene and infection following dental procedures?
strep viridans
90
INFECTIVE ENDOCARDITIS
what is the minor criteria for Modified Dukes criteria?
- predisposing heart condition or IVDU
- fever >38
- immunological phenomenon (glomerulonephritis, osler nodes, roths spots, rheumatoid factor)
- microbiological evidence not meeting major criteria
- vascular abnormalities
91
ACS
what is the management of an NSTEMI?
- anticoagulation = fondaparinux to most patients, unfractionated heparin if renal failure
- use GRACE score to work out if patient requires PCI
92
AORTIC DISSECTION
what is the classification system for aortic dissections?
Stanford
- type A - ascending aorta +/- aortic arch
- type B - descending aorta only
93
HYPERTROPHIC CARDIOMYOPATHY
what are the examination findings?
- ejection systolic murmur at lower left sternal border
- 4th heart sound
- thrill at lower left sternal border
94
CARDIOMYOPATHY
what are the different types?
- hypertrophic
- dilated
- restrictive
- arrythmogenic right ventricular
95
VARICOSE VEINS
what is the management?
1st line = endothermal ablation
2nd line = foam sclerotherapy
3rd line = surgery
conservative
- compression hoisery
- lifestyle (wt loss, exercise, leg elevation when resting)
96
ATRIAL FIBRILLATION
what are the risk factors?
- increasing age
- DM
- hyperthyroidism
- HTN
- congestive heart failure
- valvular heart disease
- coronary artery disease
- dietary + lifestyle (excessive caffeine, alcohol, smoking, medication use (thyroxine or beta-agonists))
97
SVT
what are the risk factors?
- increasing age
- female
- hyperthyroidism
- smoking
- excessive caffeine or alcohol
- stress
- medication (salbutamol, atropine, decongestants)
- recreational drug use (cocaine, methamphetamines)
98
SVT
what is the management?
UNSTABLE
- synchronised DC shock (up to 3 attempts)
- if unsuccessful, 300mg amiodarone IV + repeat shock
STABLE
- 1st line = vagal manoeuvres (Valsalva, carotid sinus massage)
- 2nd line = adenosine 6mg, if unsuccessful give 12mg then 18mg
- 3rd line = verapamil or BB
- long term = catheter ablation
99
WPW
what are the investigations?
12 LEAD ECG
- delta waves (slurred upstroke in QRS)
- short PR interval (<120ms)
- broadened QRS
if a re-entrant circuit has developed, there will be narrow complex tachycardia
BLOODS
- TFTs
IMAGING
- echocardiogram
- cardiac catheterisation
100
VENTRICULAR TACHYCARDIA
what are the risk factors?
- electrolyte abnormalities (hypokalaemia, hypomagnesaemia)
- structural heart disease (previous MI, cardiomyopathies)
- drugs causing QT prolongation (clarithromycin, erythromycin)
- inherited channelopathies
101
VENTRICULAR TACHYCARDIA
what is the management of pulsed VT?
IF ADVERSE FEATURES PRESENT (HF, MI, shock syncope)
- 1st line = synchronised DC cardioversion (up to 3 attempts)
- 2nd line = amiodarone 300mg IV over 10-20 mins
IF NO ADVERSE FEATURES PRESENT
- 1st line = amiodarone 300mg IV
- 2nd line = synchronised DC cardioversion
if drug therapy fails
- ICD implanted
102
TORSADES DE POINTES
what are the causes?
- congenital
- antiarrhythmics (amiodarone, sotalol)
- tricyclic antidepressants
- antipsychotics
- chloroquine
- erythromycin
- electrolyte abnormalities (hypocalcaemia, hypokalaemia, hypomagnesaemia)
- myocarditis
- hypothermia
- subarachnoid haemorrhage
103
MI COMPLICATIONS
what type of MI most commonly causes acute mitral regurgitation?
infero-posterior MI
104
MI COMPLICATIONS
how does acute mitral regurgitation after MI present?
- acute hypotension
- pulmonary oedema
- early-to-mid systolic murmur
105
MI COMPLICATIONS
how does a ventricular septal defect following MI present?
usually occurs in first week following MI
- pansystolic murmur
- acute heart failure
106
MI COMPLICATIONS
how does a left ventricular free wall rupture present?
occurs 1-2 weeks after
- acute HF
- cardiac tamponade (raised JVP, pulsus paradoxus, diminished heart sounds)
107
MI COMPLICATIONS
which MI region most commonly causes atrioventricular blocks and bradyarrhythmia?
inferior MI
108
ANGINA
what is the long term management?
- 1st line = beta blocker or CCB
- 2nd line = combination of BB + CCB (nifedipine, or amlodipine)
- 3rd line = long acting nitrate, ivabradine, nicorandil or ranolazine
all patients should be given aspirin + statin unless contraindicated
109
CARDIAC TAMPONADE
what is the most common ECG finding in cardiac tamponade?
electrical alternans
