1 Most episodes of acute lower back pain are caused by muscle strain, such as from lifting a heavy object, a sudden movement or a fall. 2  The low back pain can be very severe and last for several hours, several days or even a few weeks.
3. Characteristics of the Normal ECG. It is important to remember that there is a wide range of normal variability in the 12 lead ECG. The following normal ECG characteristics, therefore, are not absolute. It takes considerable ECG reading experience to discover all the normal variants.
The 12-lead EKG gives more detailed record of the heartâs electrical activity from many different angles. As we stared earlier, this chapter is just an introduction to the 12-lead EKG. You will need to take a more advanced course in EKG in order to interpret the results of an EKG tracing in all 12 leads. We hope you have enjoyed this course and gained a practical knowledge of interpreting the EKG.