How do you calculate heart rate using the thick lines on an ECG?

The correct approach to calculate heart rate using the thick lines on an ECG is based on the number of large squares between R-waves. The thick lines on an ECG paper typically denote 0.2 seconds in width, which is equivalent to five small squares (each small square representing 0.04 seconds).

To derive heart rate from the ECG, you can use the following methodology: if you count the number of large squares between two consecutive R-waves, you can determine the heart rate with the formula 300 divided by the number of large squares. This method effectively allows a quick estimation of heartbeats per minute.

For instance, if the distance between two R-waves is one large square, the heart rate would be 300 beats per minute; if the distance is two large squares, the heart rate would be 150 beats per minute; for three squares, it would be 100 beats per minute; for four squares, it would be 75 beats per minute, and so forth. Thus, the numbers presented in option B (300, 150, 100, 75) align perfectly with this calculation method, providing a clear and systematic approach to determining the heart rate using thick lines on an ECG.

In contrast, the