VENC-CMR measurements of LAA emptying velocities. LAA flow velocity profiles by VENC-CMR in a patient with SR (Figure 2A) and in a patient with AF (Figure 2B). Transmitral flow velocity profiles (black dotted lines) were superimposed to enable a clear identification of e- and a-waves, respectively. The e-wave was defined by the coincidence with early, passive LA emptying (E-wave, Figure 2A). The a-wave was defined by the coincidence with late, active LA emptying (A-wave, Figure 2A) in patients with SR. Peak e-wave velocity was 23 cm/s and peak a-wave velocity was 62 cm/s in patient A. In patients with AF, a temporal shift between transmitral E-wave and LAA e-wave was observed, that could possibly be related to RR-interval variability or irregular electrical LAA activation. The LAA e-waves were therefore differentiated from f-waves by proximity rather than coincidence to passive diastolic LA emptying (E-wave) in patients with AF (Figure 2B). Peak e-wave velocity was 28 cm/s in patient B. A prominent systolic f-wave was detected in this patient, related to electric activation of the LAA in AF.