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Heart Rate Formula:
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The heart rate calculation from ECG using large boxes is a quick method to estimate heart rate based on the distance between R waves on an electrocardiogram. This formula provides a rapid assessment of cardiac rhythm.
The calculator uses the heart rate formula:
Where:
Explanation: Each large box on standard ECG paper represents 0.2 seconds. The formula calculates heart rate by dividing 300 (number of large boxes in one minute) by the number of large boxes between R waves.
Details: Accurate heart rate calculation is essential for assessing cardiac function, diagnosing arrhythmias, monitoring patient condition, and guiding treatment decisions in various clinical settings.
Tips: Count the number of large boxes between two consecutive R waves on the ECG tracing and enter this value. The value must be greater than zero for accurate calculation.
Q1: Why use 300 in the formula?
A: There are 300 large boxes in one minute of ECG recording at standard paper speed of 25 mm/s, as each large box represents 0.2 seconds.
Q2: What is a normal heart rate range?
A: Normal resting heart rate for adults is typically 60-100 bpm, though athletes may have lower resting rates (40-60 bpm).
Q3: How accurate is this method?
A: This method provides a quick estimate but may be less accurate for irregular rhythms. For precise measurement, averaging over multiple beats is recommended.
Q4: Can this formula be used for all ECG rhythms?
A: It works best for regular rhythms. For irregular rhythms, alternative methods (such as counting beats over 6 or 10 seconds) may be more appropriate.
Q5: What if the R-R interval spans partial boxes?
A: For partial boxes, use decimal values (e.g., 3.5 boxes) for more accurate calculation, or use the small box method (1500/small boxes between R-R).