A medical apparatus, comprising: a probe, adapted for insertion into a heart, the probe comprising an elongated body, and a mapping electrode disposed on a distal portion of the body; a memory; a display; and a processor linked to the display and being coupled to access the memory, the processor being connectable to receive an input provided by the mapping electrode, wherein the processor is configured to perform the steps of: obtaining electrocardiographic signals from a target in the heart via the mapping electrode; holding a series of the electrocardiographic signals in a buffer; identifying a PVC beat in the buffer indicating a premature ventricular contraction; acquiring a PVC point based on the PVC beat; identifying an SR beat in the buffer, said SR beat representing normal sinus rhythm; acquiring an SR point based on said SR beat; displaying the PVC point and the SR point on an electroanatomic map; associating a local activation time of the PVC point with the SR point, said association being accomplished by assigning the LAT of the PVC point to the SR point; generating an electroanatomic map based on the assigned LAT of the PVC point at the SR point, the electroanatomic map reflecting a geometry of the heart during sinus rhythm and an activation time of the heart while experiencing premature ventricular contraction. a probe, adapted for insertion into a heart, the probe comprising an elongated body, and a mapping electrode disposed on a distal portion of the body; a memory; a display; and a processor linked to the display and being coupled to access the memory, the processor being connectable to receive an input provided by the mapping electrode, wherein the processor is configured to perform the steps of: obtaining electrocardiographic signals from a target in the heart via the mapping electrode; holding a series of the electrocardiographic signals in a buffer; identifying a PVC beat in the buffer indicating a premature ventricular contraction; acquiring a PVC point based on the PVC beat; identifying an SR beat in the buffer, said SR beat representing normal sinus rhythm; acquiring an SR point based on said SR beat; displaying the PVC point and the SR point on an electroanatomic map; associating a local activation time of the PVC point with the SR point, said association being accomplished by assigning the LAT of the PVC point to the SR point; generating an electroanatomic map based on the assigned LAT of the PVC point at the SR point, the electroanatomic map reflecting a geometry of the heart during sinus rhythm and an activation time of the heart while experiencing premature ventricular contraction. obtaining electrocardiographic signals from a target in the heart via the mapping electrode; holding a series of the electrocardiographic signals in a buffer; identifying a PVC beat in the buffer indicating a premature ventricular contraction; acquiring a PVC point based on the PVC beat; identifying an SR beat in the buffer, said SR beat representing normal sinus rhythm; acquiring an SR point based on said SR beat; displaying the PVC point and the SR point on an electroanatomic map; associating a local activation time of the PVC point with the SR point, said association being accomplished by assigning the LAT of the PVC point to the SR point; generating an electroanatomic map based on the assigned LAT of the PVC point at the SR point, the electroanatomic map reflecting a geometry of the heart during sinus rhythm and an activation time of the heart while experiencing premature ventricular contraction.