Can what I eat help prevent future kidney stones? You may be able to prevent future kidney stones by making changes in how much sodium, animal protein, calcium, or oxalate you consume. A dietitian who specializes in kidney stone prevention can help you plan meals. You can make changes to what you eat based on the type of kidney stone you had.
Here are some simple steps on how to measure the PR interval: 1  Find the P-wave on the EKG strip. 2  Determine where the PR interval is, and to do this you start measuring at the beginning of the p-wave until the beginning of the QRS complex. 3  Count the SMALL boxes between there measurements.  Remember each box represents 0.04 seconds.
The P-R Interval. The first measurement is known as the P-R interval and is measured from the beginning of the upslope of the P wave to the beginning of the QRS wave. This measurement should be 0.12-0.20 seconds, or 3-5 small squares in duration.The second measurement is the width of the QRS which should be less than 3 small squares, or less than 0.12 seconds in duration. Image: Normal Intervals. 1  P-R interval = 0.12 - 0.20 sec (3 - 5 small squares).2  QRS width = 0.08 - 0.12 sec (2 - 3 small squares). 3  Q-T interval 0.35 - 0.43 sec. P-R interval = 0.12 - 0.20 sec (3 - 5 small squares). 2  QRS width = 0.08 - 0.12 sec (2 - 3 small squares). 3  Q-T interval 0.35 - 0.43 sec. * 4  The PR interval should really be referred to as the PQ interval; however it is commonly referred as the PR interval.