A Doppler Echocardiographic Pulmonary Flow Marker of Massive or Submassive Acute Pulmonary Embolus

Abstract

To date, echocardiography has not gained acceptance as an alternative imaging modality for the detection of massive pulmonary embolism (MPE) or submassive pulmonary embolism (SMPE). The objective of this study was to explore the clinical utility of early systolic notching (ESN) of the right ventricular outflow tract (RVOT) pulsed-wave Doppler envelope in the detection of MPE or SMPE. Two hundred seventy-seven patients (mean age, 56±16years; 52% women), without known pulmonary hypertension, who underwent contrast computed tomographic angiography for suspected pulmonary embolism (PE) and underwent echocardiography were retrospectively studied. Extent of PE was categorized using standard criteria. ESN identified from pulsed-wave spectral Doppler interrogation of the RVOT was analyzed, as were other echocardiography parameters such as McConnell's sign, the "60/60" sign, and acceleration and deceleration times of the RVOT Doppler signal. Analysis was conducted using probability statistics and receiver operating characteristic curve analysis. Of the 277 patients studied, 100 (44%) had MPE or SMPE, 87 (38%) had subsegmental PE, and 90 (39%) did not have PE. ESN was observed in 92% of patients with MPE or SMPE, 2% with subsegmental PE, and in no patients without PE. Interobserver assessment of early systolic notching demonstrated 97% agreement (κ=0.93, P<.001). Compared with more widely recognized echocardiographic parameters, the area under the receiver operating characteristic curve (AUC) of 0.96 (95% CI, 0.92-0.98) for ESN was superior to that for McConnell's sign (AUC, 0.75; 95% CI, 0.68-0.80), the 60/60 sign (AUC, 0.74; 95% CI, 0.68-0.79), and RVOT acceleration time≤87 msec (AUC, 0.84; 95% CI, 0.79-0.88), as well as other study Doppler variables, in patients with computed tomography-confirmed MPE or SMPE. The pulmonary Doppler flow pattern of ESN appears to be a promising noninvasive sign observed frequently in patients with MPE or SMPE. Future prospective study to ascertain diagnostic utility in a broader population is warranted.