Transthoracic echocardiogram for the diagnosis of right ventricular dysfunction in critically ill patients

Acute right ventricular dysfunction (RVD) is one of the hemodynamic alterations in patients with septic shock, pulmonary embolism and ARDS. This condition had previously been diagnosed by pulmonary artery catheters (PAC). This report is on the use of transthoracic echocardiography (TTE) to diagnose RVD in critically ill patients.

To evaluate the use of TTE for the diagnosis of RVD.

A single center, cohort study, was performed in a 12-bed medical ICU. All patients who had had PAC insertions during the period from August 2009 to October 2010 were included in this study. TTE was performed by an investigator (WS. or ST) who was not aware of the patients' diagnoses. The hemodynamic parameters were measured within the hour prior to performing a TTE. The RVD was diagnosed according to the following criteria: Right atrial (RA) pressure > or = 12 mmHg, pulmonary artery occlusion pressure (PAOP) < 18 mmHg, mean pulmonary artery pressure (PAP) > 25 mmHg, and pulmonary vascular resistance (PVR) > 250 dyne*sec*cm(-5).

The PACs were inserted in 59 patients. Of these, 15 had been diagnosed with RVD. A total of 83 TTE examinations, in comparison with hemodynamic parameters measured from PACs, were studied. The TTE parameters; left ventricular (LV) D-shape (sensitivity 61.1%, specificity 84.6%), loss of right ventricular (RV) apical triangle (sensitivity 44.4%, specificity 80%), RV systolic pressure > 40 mmHg (sensitivity 77.8%, specificity 60%) and right ventricular end systolic areas: left ventricular end systolic areas (RVESA:LVESA) > 0.65 (sensitivity 94.4%, specificity 39.1%) were consistent with RVD. The presence of at least 2 out of 4 echocardiograph findings correlated with RVD, with the area under the ROC curve at 0.79, with a sensitivity of 77.8% and a specificity of 67.7%.

TTE is an accurate tool for the diagnosis RVD in critically ill patients with acceptable sensitivities and specificities.