  Cardiac motion analysis from B-mode ultrasound sequence is a key task in
assessing the health of the heart. The paper proposes a new methodology for
cardiac motion analysis based on the temporal behaviour of points of interest
on the myocardium. We define a new signal called the Temporal Flow Graph (TFG)
which depicts the movement of a point of interest over time. It is a graphical
representation derived from a flow field and describes the temporal evolution
of a point. We prove that TFG for an object undergoing periodic motion is also
periodic. This principle can be utilized to derive both global and local
information from a given sequence. We demonstrate this for detecting motion
irregularities at the sequence, as well as regional levels on real and
synthetic data. A coarse localisation of anatomical landmarks such as centres
of left/right cavities and valve points is also demonstrated using TFGs.
