Isthmic spondylolisthesis is caused by a defect in a part of the vertebra called the pars interarticularis. This defect can cause the vertebra to slip forward.
What's a normal heart rate? Most adults have a resting heart rate of 60-100 beats per minute (bpm). The fitter you are, the lower your resting heart rate is likely to be. For example, athletes may have a resting heart rate of 40-60 bpm or lower. You should contact your GP if you think your heart rate is continuously above 120 bpm or below 40 bpm, although this could just be normal for you.
In other words, it is the minimum possible rate of heartbeat. It can be compared to the idling of a vehicle. The average heart rate in adults ranges from 65 to 80 beats per minute (bpm). Whereas, the normal resting heart rate for adults can be anywhere between 60 to 70 bpm.