Echocardiographic Diagnosis of Acute Pulmonary Embolism in Patients with McConnell's Sign.

BACKGROUND: "McConnell's sign" (McCS), described as hypo- or akinesis of the right ventricular (RV) free wall with preservation of the apex, is associated with acute pulmonary embolism (aPE). However, the sensitivity of McCS for the detection of aPE is limited. We sought to evaluate in patients with McCS, whether echocardiographic parameters of global and regional RV function could differentiate between patients with and without aPE. METHODS: We reviewed echocardiograms of 81 patients with McCS, who underwent CT or V/Q studies for suspected PE, and 40 normal controls (NL). Echocardiograms were analyzed to measure pulmonary artery systolic pressure (PASP), tricuspid regurgitation (TR) by vena contracta width, conventional indices of RV function, and speckle tracking-derived longitudinal free wall strain. ROC analysis was performed to evaluate the diagnostic accuracy of these parameters for diagnosis of aPE. RESULTS: Fifty-five of eighty-one (68%) had PE (McCS + PE), while 26 of 81 (32%) did not (McCS - PE). Compared to NL, global and segmental RV strain were lower in patients with McCS, contrary to the notion of normal apical function. In McCS + PE, compared to McCS - PE: (1) PASP, fractional area change and TR were significantly lower; (2) strain magnitude was significantly lower globally and in basal and apical segments. Individual parameters had similar diagnostic accuracy by ROC analysis, which further improved by combining parameters. In McCS - PE, 69% of patients had pulmonary hypertension (PH). CONCLUSIONS: McCS and aPE are not synonymous. RV free wall strain may aid in differential diagnosis of patients with McCS evaluated for aPE. Specifically, McCS should prompt an inquiry for evidence of PH, which would indicate that aPE is less likely.