ECG Heart Rate Calculator
This calculator helps you determine your heart rate directly from an Electrocardiogram (ECG) trace. The heart rate is typically calculated by measuring the time between consecutive R-waves (the tallest peak in the QRS complex) or by counting the number of QRS complexes within a specific time frame.
Method 1: Using RR Interval
Enter either RR Interval in seconds or milliseconds. The other will be calculated.
Method 2: Using QRS Count (over 10 seconds)
Default duration is 10 seconds. You can change this value.
Understanding ECG and Heart Rate Calculation
An Electrocardiogram (ECG or EKG) is a medical test that records the electrical activity of the heart over a period of time. It is performed using small sensors attached to the skin. The ECG machine traces the electrical signals as waves on a graph, showing how fast the heart is beating and whether the electrical activity is regular or irregular.
Key Components of an ECG Waveform
- P wave: Represents atrial depolarization (contraction of the atria).
- QRS complex: Represents ventricular depolarization (contraction of the ventricles). This is usually the most prominent part of the ECG.
- T wave: Represents ventricular repolarization (recovery of the ventricles).
- RR interval: The time between two consecutive R-waves. This is a crucial measurement for calculating heart rate.
Methods for Calculating Heart Rate from ECG
There are several ways to calculate heart rate from an ECG trace. The most common methods are:
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Using the RR Interval:
This is the most accurate method when the heart rhythm is regular. The heart rate (in beats per minute, BPM) can be calculated using the following formulas:
- If RR interval is in seconds: Heart Rate (BPM) = 60 / RR Interval (seconds)
- If RR interval is in milliseconds: Heart Rate (BPM) = 60,000 / RR Interval (milliseconds)
A normal resting heart rate for adults is typically between 60 and 100 beats per minute.
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Counting QRS Complexes:
This method is useful when the rhythm might be irregular, or as a quick estimation. You count the number of QRS complexes within a specific duration (commonly 6 seconds or 10 seconds) and then extrapolate to a full minute.
- Heart Rate (BPM) = (Number of QRS Complexes / ECG Duration in seconds) * 60
For example, if you count 15 QRS complexes in a 10-second strip, the heart rate is (15 / 10) * 60 = 90 BPM.
Interpreting Heart Rate
The calculated heart rate gives valuable insights into a person's cardiovascular health. Deviations from the normal range can indicate various conditions, such as bradycardia (slow heart rate) or tachycardia (fast heart rate), and should be evaluated by a healthcare professional.
Example Scenarios:
Example 1 (RR Interval): If the RR interval on an ECG is measured to be 0.8 seconds, the heart rate is 60 / 0.8 = 75 BPM. If the RR interval is measured as 800 milliseconds, the heart rate is 60,000 / 800 = 75 BPM.
Example 2 (QRS Count): If you count 12 QRS complexes in a 10-second ECG strip, the calculated heart rate is (12 / 10) * 60 = 72 BPM. If you count 18 QRS complexes in a 6-second strip, the heart rate is (18 / 6) * 60 = 180 BPM (indicating tachycardia).