What is represented by a small square running horizontally on an EKG strip?

On an EKG strip, a small square represents 0.04 seconds. This measurement is critical for interpreting the time intervals between heartbeats and understanding the rhythmic activity of the heart. The EKG graph paper is divided into small squares, typically 1 millimeter in height and 1 millimeter in width. The horizontal axis represents time, and knowing that each small square corresponds to 0.04 seconds allows healthcare professionals to assess heart rates and the duration of various phases of the cardiac cycle accurately.