S1 Q3 T3 pattern
Though EKG changes arenonspecific and with limited value
diagnostically, they are associated with a poorer prognosis (i.e. new
right bundle-branch block, atrial arrhythmias, inferior Q waves, right
axis deviation ST changes or T wave inversions, s1q3t3 pattern). They
are seen in less than 10 percent of pulmonary embolism patients, and
only half of patients with massive pulmonary embolism. This finding is
not sensitive (54%) nor specific (62%). Causes of acute right heart
strain other than pulmonary embolism can also this pattern.
Acute RV strain can cause slow R wave progression and precordial T
wave inversions. It may also be associated with a QR complex in V1/V2 in
which the precise mechanism has not been determined. Acute PE can also
cause ST elevation in right chest leads (rare) and is most likely
related to RV ischemia.
The patient above also had right axis deviation and poor R-wave
progression, and an incomplete right bundle branch block. Additional
testing confirmed a saddle pulmonary embolism. Patient was treated with
unfractionated heparin.
References
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Geibel A, Zehender M, Kasper W, et al. Prognostic value of the ECG on
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2005; 25:843.
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Goldberger, A. (2015, May 12). Pathogenesis and diagnosis of Q waves on the electrocardiogram. Retrieved October 25, 2016, from https://www.uptodate.com/contents/pathogenesis-and-diagnosis-of-q-waves-on-the-electrocardiogram?source=search_result&search=S1Q3T3&selectedTitle=2~3
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Ferrari E, Imbert A, Chevalier T, et al. The ECG in pulmonary
embolism. Predictive value of negative T waves in precordial leads--80
case reports. Chest 1997; 111:537.
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Rodger M, Makropoulos D, Turek M, et al. Diagnostic value of the
electrocardiogram in suspected pulmonary embolism. Am J Cardiol 2000;
86:807.
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Shopp JD, Stewart LK, Emmett TW, Kline JA. Findings From 12-lead
Electrocardiography That Predict Circulatory Shock From Pulmonary
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