Clinical update no. 288
20 September 2012
An ECG finding of simultaneous T-wave
inversions in the anterior and inferior leads
may be found in pulmonary embolus, and
should be distinguished from changes in acute
coronary syndrome. Among several other ECG
63yr-M with syncopal episode followed by
abnormalities tested, only sinus tachycardia
chest pain and diaphoresis. No cardiac history,
and the S1-Q3-T3 pattern distinguished PE
previously well. Hypotensive with CDA, BP
from ACS. Simultaneous T-wave inversions in
110/70 in ED, HR 80 bpm. Progress ECG
anterior and inferior leads are associated with
PE and are seen in 4–11%.
There had been some resolution of ST
depression, seen previously in V3-V5. Serial
Previous studies have also shown that
troponin 80. Admitted under cardiology as
patients with PE frequently had simultaneous
NSTEMI. Coronary angiogram showed minor
disease only in LAD. Subsequently had CT-PA
showing extensive bilateral PE
T-wave inversions in anterior/inferior leads,
especially lead III. In contrast, only 1% of
patients with ACS had simultaneous T-wave
inversions in anterior/inferior leads.
The current study confirms that this finding is
more prevalent in PE than in ACS. Although it
is an infrequent finding in PE with a sensitivity
of <10% it is quite specific, especially when
present in four leads (V1, V2, III, aVF).
The classic S1-Q3-T3 pattern was reported in
1935. It is uncommon. The specificity
reported here seems too high, and may be
inflated due to inclusion bias in the study.
Other ECG findings associated with acute PE,
including sinus tachycardia, rightward axis
shift, P-pulmonale pattern, complete or
incomplete right bundle branch block, T-wave
inversions, and non-specific ST-segment/Twave abnormalities. Other ECG findings have
been reportedly associated with PE but do not
distinguish PE from patients with ACS or noncardiac chest pain.
Of ECG changes studied, only three were both
reliable and statistically associated with PE:
•
sinus tachycardia;
•
S1-Q3-T3 pattern (large S-wave in lead I,
Q-wave in lead III, and T-wave inversion
in lead III),
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•
The described TIII-V1 pattern.
To produce ECG changes, a PE must be large,
The following patient did not have PE –
S1Q3T3 is not specific.
and is presumed to produce ECG changes by
causing acute pulmonary hypertension, giving
a change in cardiac position due to right heart
dilatation, right ventricular ischemia, intraventricular conduction disturbances due to
ischaemia, and increased sympathetic
stimulation.
Other factors producing negative T waves
include hypoxemia and the release of chemical
mediators within the right ventricle. V1 faces
the anterior region of the right ventricle and
Following ECG after collapse 3 days post hip
replacement shows new right axis deviation,
new RBBB with R wave in V1, and acute right
heart strain. Normal pre-op ECG also shown
lead III faces the inferior region of the right
ventricle, giving the observed pattern.
Changes with PE are acute, though chronic
pulmonary hypertension can produce similar
findings. A new ECG findings of pulmonary
hypertension suggest acute PE.
T-wave inversions may lead to a workup for
ACS which if negative may lead to discharge
without consideration of PE.
Conversely, many findings traditionally
described for PE are simply not worth
remembering because they are unreliably
measured and are no more prevalent in
patients with PE than in other populations.
Cases: the following in an unstable patient
with clinically suspected PE.
New onset right axis changes are from acute
PE, Na channel blocking drug toxicity (e.g.
TCAs), hyperkalaemia, or artefact from lead
misplacement.
ECG findings with right ventricular
hypertrophy are: tall R wave > 6 mm in V1,
right axis deviation, and right atrial changes
(P wave >2.5mm in II and > 1.5 mm in V1)
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