Count all heart sounds via stethoscope or all QRS complexes on an ECG strip.
0 BPM
Understanding Heart Rate in Bigeminy
Ventricular bigeminy is a cardiac rhythm where every normal heartbeat (sinus beat) is followed by a Premature Ventricular Contraction (PVC). This "paired" beat pattern can make manual pulse checking at the wrist very deceptive.
Why Radial Pulse is Often Inaccurate
In many patients with bigeminy, the PVC (the second beat in the pair) happens so quickly after the first beat that the heart hasn't had enough time to fill with blood. As a result, the PVC may not produce a strong enough pulse wave to be felt at the wrist (radial pulse). This creates a pulse deficit, where the felt pulse rate is exactly half of the actual heart rate.
Example Calculation:
If you listen to the heart with a stethoscope for 30 seconds and hear 44 beats (22 normal + 22 PVCs):
Formula: (44 beats / 30 seconds) × 60 = 88 BPM. Note: At the wrist, you might only feel 44 pulses per minute.
How to Calculate Heart Rate Correctly
Use Auscultation: Listen directly to the heart using a stethoscope rather than feeling the pulse at the wrist.
Count Every Beat: Count both the normal beat and the premature beat as individual events.
Time the Duration: Count for at least 30 seconds (then multiply by 2) or a full 60 seconds for maximum accuracy.
ECG Method: On a standard ECG strip, count the total number of QRS complexes in a 6-second strip and multiply by 10.
Interpretation of Results
A "normal" resting heart rate is typically between 60 and 100 BPM. However, in bigeminy, even if the rate is numerically normal, the rhythm itself requires medical evaluation to determine the underlying cause of the ventricular irritability.
Disclaimer: This calculator is for educational purposes only. If you are experiencing palpitations, chest pain, or shortness of breath, seek immediate medical attention.
function calculateBigeminyHR() {
var beats = document.getElementById("totalBeats").value;
var seconds = document.getElementById("observationTime").value;
var resultBox = document.getElementById("hrResultBox");
var bpmOutput = document.getElementById("bpmOutput");
var interpretation = document.getElementById("bpmInterpretation");
if (beats > 0 && seconds > 0) {
var hr = (beats / seconds) * 60;
var finalHR = Math.round(hr);
bpmOutput.innerHTML = finalHR + " BPM";
resultBox.style.display = "block";
var text = "Based on a count of " + beats + " beats over " + seconds + " seconds, the actual heart rate is " + finalHR + " beats per minute.";
if (finalHR 100) {
text += " This indicates Tachycardia (fast heart rate).";
} else {
text += " This falls within the normal resting heart rate range.";
}
text += "Note: If you only feel a pulse of " + Math.round(finalHR / 2) + " at the wrist, this confirms a significant pulse deficit common in bigeminy.";
interpretation.innerHTML = text;
} else {
alert("Please enter valid positive numbers for both beats and seconds.");
}
}