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Question
79 y.o. male lung cancer patient with tachypnea, tachycardia, and normal blood pressure. Click here: http://vimeo.com/27973006
Possible diagnosis?
Answer
Answer: Right ventricular (RV) dysfunction secondary to submassive pulmonary embolism (PE).
Ultrasound for suspected PE
Consider bedside echo with PE and elevated troponin or BNP.
Recall the classes of PE:
- Non-massive PE: Normal RV function with normotension
- Submassive PE: RV dysfunction (see below) with normotension
- Massive PE: RV dysfunction with hypotension
- Cardiac arrest (Pulseless electrical activity)
Ultrasound “clues” of submassive / massive PE:
- Right ventricular enlargement: RV diastolic volume is >60% of the LV; normally RV is 60% the size of the LV.
- Interventricular septal shift ("D-sign"): The normally concentric LV cavity will now look like the letter “D” from diastolic septal flattening; "D" sign indicates elevated pulmonary pressure (e.g., pulmonary embolism)
- McConnell’s sign: Hypokinesis in RV free wall with normal apical motion; originally though to be specific for PE, but sensitivity and specificity have been questioned because other disorders also have a "McConnel'-type" appearance (severe pulmonary hypertension, RV infarction); can still help add to pre-test probability.
- Free-floating thrombus: clot visualized in pulmonary artery and/or in right-side of heart (rare)
References
Lodato JA, Parker Ward RP, Lang RM. Echocardiographic Predictors of Pulmonary Embolism in Patients Referred for Helical CT. Echocardiography 2008;25:584-590.
McConnell MV, Solomon SD, Rayan ME, et. al. Regional Right Ventricular Dysfunction Detected by Echocardiography in Acute Pulmonary Embolism. Am J Cardiol. 1996; 78: 469-473.
ACEP. Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Suspected Pulmonary Embolism. http://www.acep.org/content.aspx?id=30060. [July 24, 2011].
John Griffiths. Respiratory: Management of small, submassive and massive pulmonary embolism. http://www.frca.co.uk/article.aspx?articleid=100750. [July 24, 2011].
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