Cardiac Output is Calculated by Multiplying Heart Rate by

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Cardiac Output Calculator

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.cardiac-output-calculator { font-family: sans-serif; border: 1px solid #ccc; padding: 20px; border-radius: 8px; max-width: 500px; margin: 20px auto; } .cardiac-output-calculator h2, .cardiac-output-calculator h3 { text-align: center; margin-bottom: 20px; } .input-group { margin-bottom: 15px; } .input-group label { display: block; margin-bottom: 5px; font-weight: bold; } .input-group input[type="number"] { width: calc(100% – 22px); padding: 10px; border: 1px solid #ccc; border-radius: 4px; } .cardiac-output-calculator button { width: 100%; padding: 12px; background-color: #4CAF50; color: white; border: none; border-radius: 4px; cursor: pointer; font-size: 16px; } .cardiac-output-calculator button:hover { background-color: #45a049; } #result { text-align: center; margin-top: 20px; font-size: 1.2em; font-weight: bold; } function calculateCardiacOutput() { var heartRate = document.getElementById("heartRate").value; var strokeVolume = document.getElementById("strokeVolume").value; var resultDiv = document.getElementById("result"); var numericHeartRate = parseFloat(heartRate); var numericStrokeVolume = parseFloat(strokeVolume); if (isNaN(numericHeartRate) || isNaN(numericStrokeVolume) || numericHeartRate <= 0 || numericStrokeVolume <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for Heart Rate and Stroke Volume."; return; } var cardiacOutput = numericHeartRate * numericStrokeVolume; resultDiv.innerHTML = "Cardiac Output: " + cardiacOutput.toFixed(2) + " mL/min"; }

Understanding Cardiac Output

Cardiac output (CO) is a fundamental measure of cardiovascular function. It represents the volume of blood pumped by the heart per minute. This vital metric indicates how effectively the heart is supplying oxygenated blood to the body's tissues and organs. A healthy cardiac output is crucial for maintaining adequate oxygen delivery and supporting metabolic demands.

How Cardiac Output is Calculated

Cardiac output is primarily determined by two key physiological parameters:

  • Heart Rate (HR): This is the number of times the heart beats in one minute. It's typically measured in beats per minute (bpm).
  • Stroke Volume (SV): This is the volume of blood ejected from the left ventricle of the heart during one contraction (heartbeat). It's usually measured in milliliters (mL) per beat.
The relationship between these two is expressed by the formula:

Cardiac Output (CO) = Heart Rate (HR) × Stroke Volume (SV)

Therefore, if your heart rate is 70 beats per minute and your stroke volume is 70 milliliters per beat, your cardiac output would be:

CO = 70 bpm × 70 mL/beat = 4900 mL/min, or 4.9 Liters per minute (L/min).

Factors Affecting Cardiac Output

Several factors can influence both heart rate and stroke volume, and consequently, cardiac output. These include:

  • Physical Activity: During exercise, heart rate and stroke volume increase to meet the higher demand for oxygen by the muscles.
  • Body Size and Composition: Larger individuals generally have higher cardiac outputs.
  • Age: Cardiac output tends to decrease slightly with age.
  • Autonomic Nervous System: The sympathetic nervous system can increase heart rate and contractility (affecting stroke volume), while the parasympathetic system slows heart rate.
  • Hormones: Hormones like adrenaline can significantly impact cardiac output.
  • Fluid Status: Dehydration can reduce blood volume, potentially lowering stroke volume.
  • Pathological Conditions: Diseases affecting the heart (e.g., heart failure, valve problems) or blood vessels can impair cardiac output.

Clinical Significance

Monitoring cardiac output is essential in various clinical settings, particularly in intensive care units and during surgery. Abnormal cardiac output can indicate underlying cardiac issues, fluid imbalances, or other serious medical conditions. Understanding and calculating cardiac output allows healthcare professionals to assess a patient's hemodynamic status and make informed treatment decisions.

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