Submassive pulmonary embolism

A submassive pulmonary embolism refers to an acute pulmonary embolism with evidence of myocardial necrosis or right ventricular dysfunction in the absence of systemic hypotension. An elevation in troponin I or T provides evidence of myocardial necrosis. Right ventricular dysfunction is defined by the presence of any of the following:

• echocardiographic evidence of right ventricular dilation or systolic dysfunction
• an RV/LV diameter ratio >0.9 on CT
• biomarker elevations
  • brain natiuretic peptide (BNP) > 90 pg/mL or pro-BNP >500 pg/mL
• characteristic electrocardiographic abnormalities
  • right bundle branch block
  • anteroseptal ST-T wave abnormalities

Differential diagnosis

• massive pulmonary embolism
  • acute pulmonary embolism with either right ventricular dysfunction or evidence of myocardial necrosis with systemic hypotension, pulselessness or bradycardia