Quantitative measures of right ventricular dysfunction by echocardiography in the diagnosis of acute nonmassive pulmonary embolism

Background: Transthoracic echocardiography (M) is used in the risk assessment of patients with pulmonary embolism (PE), but the incremental diagnostic information from quantitative measures of right ventricular (RV) size, pressure, and function by TTE has yet to be fully evaluated. Methods. In 300 consecutive patients with suspected first nonmassive PE, TTE and ventilation/ perfusion scintigraphy were performed. Results: Among measures of RV anatomy, RV pressure estimates, and estimates of global and regional RV function with significant diagnostic information in a logistic regression analysis, the acceleration time of RV outflow less than 89 milliseconds, the ratio of RV to left ventricular diameter greater than 0.78, RV outflow tract fractional shortening less than 35%, and signs of RV strain on electrocardiogram had independent, incremental diagnostic information (area under the receiver operating characteristics curve = 0.81). If D-dimer greater than 4.1 mmol/L was included, the area under the curve increased to 0.88. The negative and positive predictive values if any 2 of 3 factors in the final model were present were 88% and 70%, respectively. Conclusion: TTE is able to identify differential diagnoses and enhance pretest probability of PE significantly. TTE could therefore be considered as an integral part of the initial diagnostic workup of patients suspected of PE, especially if definitive diagnostic imaging has limited availability.