Transthoracic echocardiography for pulmonary embolism in the ICU: finding the "right" findings

Use of transthoracic echocardiography (TTE) in documenting cardiac disorders is well accepted. This study reviews institutional experience with TTE in the clinical setting of pulmonary embolism (PE).

Retrospective review of surgical ICU patients who underwent TTE within 72 hours of diagnosis of PE, from January 2005 to March 2007. Collected data included symptoms, clinical suspicion of PE, preexisting conditions, operative procedures, TTE findings, presence of deep venous thrombosis, and treatments used for PE. Preexisting TTEs, when available, were compared with those obtained after acute PE. TTEs subsequent to the first post-PE study were analyzed for change in severity of findings.

Thirty-one patients (12 men, 19 women, mean age 66 years, APACHE II 18.1) were included. Twenty-two had high, and nine had moderate, clinical suspicion for PE. Radiographic diagnosis of PE was made by computed tomography (25 of 31) and by ventilation-perfusion scans (6 of 31). Twelve of 31 patients had extremity deep venous thrombosis by duplex ultrasonography. Tricuspid regurgitation was the most common TTE finding (28 of 31), followed by pulmonary hypertension (24), dilated right ventricle (23), right heart strain (19), and underfilled, hyperdynamic left ventricle (17). Seventeen patients had previous or "baseline" echocardiograms, and when compared with the post-PE TTE, all patients demonstrated worsening in at least one TTE finding.

This study identified findings that can be used in prospective evaluation of TTE for suspected PE. The importance of baseline TTE has also been emphasized. Additional prospective evaluation of TTE in diagnosis of suspected PE in the ICU is warranted.