Wu VCC, et al. - In patients with atrial fibrillation (AFib), researchers extensively studied the optimal number of heartbeats (defined as the minimum number of heartbeats showing coverage probability ≥95%) needed for representing left heart chamber function. In order to determine the optimal number, an automated quantification analysis of three- dimensional echocardiography (3DE) datasets were performed in 93 AFib patients for whom 10-20 consecutive full-volume 3DE data sets were obtained twice. Using 3DE automated quantification software, the optimal number of heartbeats needed to obtain representative chamber volumes and function was six to nine heartbeats randomly selected in patients with AFib.