A novel approach is presented for modeling the complex activity pattern of the heart in echocardiogram videos. In this approach, the heart is represented by the constellation of its chambers, where the constellation is modeled by pictorial structure at each instance in time. Pictorial structure is then extended to the temporal domain to simultaneously capture the evolution pattern of the appearance of each chamber, the evolving spatial relationships between them, and the topological transformations in their constellation due to phase transitions. Inference and learning algorithms are presented for the model. The problem of correspondence is solved at each stage of the inference process, by matching the evolving model of the complex activity pattern to the observed constellations. The model, which is trained using examples of normal echocardiogram videos is shown to be efficient in temporal segmentation of the content of echocardiogram videos into different phases during one cycle of heart activity.