Triplets and Rwave to Rwave Heart Rate Methods

For a YOUTUBE video explaining the Triplets please CLICK HERE

For a YOUUBE video explaining the Rwave to Rwave Heart Rate Method CLICK HERE
EKG Page
With the Triplets HR technique we obtain a quick 'estimate' of heart rate to get an idea of the rhythm we are interpreting. So, for the HR above we would say it is less than 50 beats per minue. Please note that you always start counting with the '0' using the R wave deflection that is directly on top of a dark line of a large box.
The rhythm below is a REGULAR rhythm. With a REGULAR rhythm you can do the Triplets HR technique starting with '0' using a R wave deflection directly on top of a darkline of a large box (plus or minu one small box). Which of the 14 QRS complexes in the rhythm below could you do a Triplets HR technique? Check answer below.
The following QRS complexes could be used for a Triplets: 2, 4, 7, 9, and 13. The Rwave deflection is right on the dark
line of a large box (within one small box (+ or -). What would this HR be using the Triplets HR method?

(answer: less than150 b/min or you could say between 150 b/min and 100 b/min)
Class, this below is NOT for the Exam. I just want to show you how the EKG Pioneers figured out the Triplets HR method.