Three Methods to Calculate the Heart Rate
When we talk about the heart rate, we often mean the ventricular rate.
There are several methods for determining the ventricular rate or heart rate. Below, I share three of them.
Method #1: Identify an R-wave that is on a line. Use that as the start R-wave and then count success big boxes from the start as 300, 150, 100, 75, 60, 50. Below 50, use the formula given in method #2. This method is good for regular rhythms.
Method #2: 300 divided by the number of large squares between the QRS complexes. When the rhythm is regular, the heart rate is 300 divided by the number of large squares between the QRS complexes.
Because there are 5 small boxes in one large box, an alternative, more tedious way is to count the number of small boxes for a typical R-R interval and divide 1500 by this number to determine heart rate.
Method #3: The number of QRS complexes per 6-second strip multiplied by 10. Count the number of QRS complexes over a 6-second interval. Multiply by 10 to determine heart rate. This method works well for both regular and irregular rhythms and for bradycardias. It’s recommended for irregular rhythms and for bradycardias.