It is interesting to note that the Well's criteria for diagnosing a
A 23-year-old woman is on the combined oral contraceptive
PE use tachycardia rather than tachypnoea.
pill and has just returned from holiday in Japan. She reports
that she is feeling very short of breath. You suspect a
2012 NICE guidelines
pulmonary embolism and perform an ECG.
All patients with symptoms or signs suggestive of a PE should
Which one of the following is the most common ECG finding
have a history taken, examination performed and a chest x-
in pulmonary embolism?
ray to exclude other pathology.
A. S1, Q3, T3 pattern
If a PE is still suspected a two-level PE Wells score should be
B. Tall, tented T waves
C. Prolonged QT interval
D. Sinus tachycardia
E. Sinus bradycardia
Clinical signs and symptoms of DVT (minimum of leg swelling and
pain with palpation of the deep veins)
An alternative diagnosis is less likely than PE
Heart rate > 100 beats per minute
Immobilisation for more than 3 days or surgery in the previous 4
The most common ECG finding in patients with pulmonary
embolism is sinus tachycardia. The S1, Q3, T3 pattern is often
quoted in textbooks but is rarely seen.
Malignancy (on treatment, treated in the last 6 months, or palliative) 1
The October 2014 AKT feedback stated
Clinical probability simplified scores
• PE likely - more than 4 points
Some candidates found interpretation of ECGs difficult. This
• PE unlikely - 4 points or less
is an area in which we will continue to test regularly. ECGs
are increasingly performed routinely in practice (eg in
If a PE is 'likely' (more than 4 points) arrange an immediate
relation to blood pressure management or QT interval
computed tomography pulmonary angiogram (CTPA). If there
is a delay in getting the CTPA then give low-molecular weight
heparin until the scan is performed.
PULMONARY EMBOLISM: INVESTIGATION
If a PE is 'unlikely' (4 points or less) arranged a D-dimer test. If
We know from experience that few patients (around 10%)
this is positive arrange an immediate computed tomography
present with the medical student textbook triad of pleuritic
pulmonary angiogram (CTPA). If there is a delay in getting the
chest pain, dyspnoea and haemoptysis. Pulmonary embolism
CTPA then give low-molecular weight heparin until the scan is
can be difficult to diagnose as it can present with virtually any
cardiorespiratory symptom/sign depending on it's location
If the patient has an allergy to contrast media or renal
impairment a V/Q scan should be used instead of a CTPA.
So which features make pulmonary embolism more likely?
CTPA or V/Q scan?
The PIOPED study1 in 2007 looked at the frequency of
different symptoms and signs in patients who were diagnosed
The consensus view from the British Thoracic Society and NICE
with pulmonary embolism.
guidelines is as follows:
• computed tomographic pulmonary angiography (CTPA) is
The relative frequency of common clinical signs is shown
now the recommended initial lung-imaging modality for
non-massive PE. Advantages compared to V/Q scans
• Tachypnea (respiratory rate >16/min) - 96%
include speed, easier to perform out-of-hours, a reduced
• Crackles - 58%
need for further imaging and the possibility of providing
• Tachycardia (heart rate >100/min) - 44%
an alternative diagnosis if PE is excluded
• Fever (temperature >37.8°C) - 43%
• if the CTPA is negative then patients do not need further
investigations or treatment for PE
• ventilation-perfusion scanning may be used initially if
appropriate facilities exist, the chest x-ray is normal, and
there is no significant symptomatic concurrent
ECG of a patient with a PE. It shows some of the ECG features that may be
associated with PE (sinus tachycardia, S1, T3 and T wave inversion in the precordial
leads). Other features such as the left axis deviation are atypical.
• sensitivity = 98%; specificity = 40% - high negative
predictive value, i.e. if normal virtually excludes PE
• other causes of mismatch in V/Q include old pulmonary
embolisms, AV malformations, vasculitis, previous
• COPD gives matched defects
Labelled CTPA showing a large saddle embolus
• peripheral emboli affecting subsegmental arteries may be
• the gold standard
• significant complication rate compared to other
Clinical Characteristics of Patients with Acute Pulmonary
Embolism(Data from PIOPED II) Am J Med. Oct 2007; 120(10):
Further CTPA again showing a saddle embolus
A 45-year-old female develops pleuritic chest pain following
Some other points
a hysterectomy 10 days ago. You admit her to the acute
medical unit and a CTPA confirms a pulmonary embolism.
• sensitivity = 95-98%, but poor specificity
There is no previous history of venous thromboembolism.
How long should the patient be warfarinised for?
• the classic ECG changes seen in PE are a large S wave in
A. Not suitable for anticoagulation
lead I, a large Q wave in lead III and an inverted T wave in
B. 3 months
lead III - 'S1Q3T3'. However this change is seen in no
C. 6 months
more than 20% of patients
D. 4 weeks
• right bundle branch block and right axis deviation are also
associated with PE
• sinus tachycardia may also be seen
3 months EXPLANATION:
As this patient has a temporary risk factor for a
thromboembolic event the recommended period of
anticoagulation is 3 months.
ECG from a patient with a PE. Shows a sinus tachycardia and a partial S1Q3T3 -
the S wave is not particularly convincing.
PULMONARY EMBOLISM: MANAGEMENT
Recent NICE guidelines advise to 'offer a VKA* beyond 3
The NICE guidelines of 2012 provided some clarity on how
months to patients with an unprovoked PE'.
long patients should be anticoagulated for after a pulmonary
embolism (PE). Selected points are listed below.
*vitamin K antagonsist, i.e. warfarin
Low molecular weight heparin (LMWH) or fondaparinux
Please see Q-2 for Pulmonary Embolism: Management
should be given initially after a PE is diagnosed. An exception
to this is for patients with a massive PE where thrombolysis is
being considered. In such a situation unfractionated heparin
A 60 year old man presents with palpitations. You carry out
should be used.
an electrocardiogram which confirms atrial fibrillation. He
• a vitamin K antagonist (i.e. warfarin) should be given
has no past medical history of cardiovascular or
within 24 hours of the diagnosis
cerebrovascular disease and recent bloods which included a
• the LMWH or fondaparinux should be continued for at
random glucose were within normal limits. His BMI is 28
least 5 days or until the international normalised ratio
kg/m² and today his blood pressure is 135/82 mmHg. What
(INR) is 2.0 or above for at least 24 hours, whichever is
is his CHA2DS2VASc score for stroke risk?
longer, i.e. LMWH or fondaparinux is given at the same
time as warfarin until the INR is in the therapeutic range
• warfarin should be continued for at least 3 months. At 3
months, NICE advise that clinicians should 'assess the
risks and benefits of extending treatment'
• NICE advise extending warfarin beyond 3 months for
patients with unprovoked PE. This essentially means that
if there was no obvious cause or provoking factor
(surgery, trauma, significant immobility) it may imply the
patient has a tendency to thrombosis and should be given
treatment longer than the norm of 3 months
• for patients with active cancer NICE recommend using
ATRIAL FIBRILLATION: ANTICOAGULATION
LMWH for 6 months
NICE updated their guidelines on the management of atrial
fibrillation (AF) in 2014. They suggest using the CHA2DS2-VASc
score to determine the most appropriate anticoagulation
• thrombolysis is now recommended as the first-line
strategy. This scoring system superceded the CHADS2 score.
treatment for massive PE where there is circulatory
failure (e.g. hypotension). Other invasive approaches
should be considered where appropriate facilities exist
C Congestive heart failure
H Hypertension (or treated hypertension)
A2 Age >= 75 years
A 57-year-old female presents after being discharged from
Age 65-74 years
the acute medical unit two weeks ago, following an
admission with shortness of breath and pleuritic chest pain.
S2 Prior Stroke or TIA
During her admission a pulmonary embolism was diagnosed
V Vascular disease (including ischaemic heart disease and 1
and warfarin commenced. She has no past medical history of
peripheral arterial disease)
note and enjoys good health. What is the recommended
S Sex (female)
length of warfarinisation for this patient?
The table below shows a suggested anticoagulation strategy
A. 6 weeks
based on the score:
B. 3 months
C. 6 months
D. 12 months
Males: Consider anticoagulation
Females: No treatment (this is because their score of 1 is only reached due to
There are no transient risk factors for venous
thromboembolism therefore the patient should be
anticoagulated for 6 months.