Will simultaneous measurement of E/e' index facilitate the non-invasive assessment of left ventricular filling pressure in patients with non-valvular atrial fibrillation?

The ratio of early transmitral flow velocity (E) to early diastolic mitral annular velocity (e') was applied as a non-invasive index to assess left ventricular filling pressure (LVFP). However, the reliability of E/e' was undermined in patients with atrial fibrillation (AF). Recently, a novel method entitled 'dual Doppler' was established, which allows simultaneous recording and display of E and e'. Our study investigates whether the dual-Doppler method improves the reliability of E/e' in AF patients.