Calculate the Cardiac Output of the Heart Rate is 90

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Cardiac Output (CO) is the amount of blood the heart pumps per minute. It is calculated using Heart Rate (HR) and Stroke Volume (SV).







function calculateCardiacOutput() { var heartRate = parseFloat(document.getElementById("heartRate").value); var strokeVolume = parseFloat(document.getElementById("strokeVolume").value); var resultDiv = document.getElementById("result"); if (isNaN(heartRate) || isNaN(strokeVolume) || heartRate <= 0 || strokeVolume <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for Heart Rate and Stroke Volume."; return; } // Cardiac Output = Heart Rate * Stroke Volume var cardiacOutput = heartRate * strokeVolume; // mL/min // Convert mL/min to Liters/min for a more common unit var cardiacOutputLiters = cardiacOutput / 1000; // L/min resultDiv.innerHTML = "

Cardiac Output Result

" + "Heart Rate: " + heartRate + " beats/min" + "Stroke Volume: " + strokeVolume + " mL/beat" + "Cardiac Output: " + cardiacOutput.toFixed(2) + " mL/min (" + cardiacOutputLiters.toFixed(2) + " L/min)"; }

Understanding Cardiac Output

Cardiac Output (CO) is a vital physiological measurement that quantifies the efficiency of the heart's pumping action. It represents the volume of blood pumped by the heart (specifically, by each ventricle) in one minute. This metric is crucial for maintaining adequate blood supply to the body's tissues and organs, ensuring they receive the necessary oxygen and nutrients.

How Cardiac Output is Calculated

Cardiac Output is determined by the product of two key factors:

  • Heart Rate (HR): This is the number of times the heart beats per minute. A typical resting heart rate for an adult is between 60 and 100 beats per minute. Factors like exercise, stress, or illness can influence heart rate.
  • Stroke Volume (SV): This is the volume of blood ejected from the left ventricle with each heartbeat. Normal stroke volume for a healthy adult at rest is typically around 70 milliliters (mL) per beat. Stroke volume is influenced by factors such as the contractility of the heart muscle, the amount of blood returning to the heart (preload), and the resistance the heart has to pump against (afterload).

The formula for Cardiac Output is:

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

Units of Measurement

Cardiac Output is commonly expressed in milliliters per minute (mL/min) or liters per minute (L/min). A common healthy resting cardiac output for an adult is approximately 4 to 8 liters per minute.

Factors Affecting Cardiac Output

Several physiological conditions can alter cardiac output:

  • Physical Activity: During exercise, both heart rate and stroke volume increase, significantly raising cardiac output to meet the increased demand for oxygen by the muscles.
  • Autonomic Nervous System: The sympathetic nervous system increases heart rate and contractility (thus stroke volume), while the parasympathetic nervous system slows heart rate.
  • Hormones: Hormones like adrenaline can increase both heart rate and contractility.
  • Blood Volume: Changes in blood volume can affect preload and therefore stroke volume.
  • Pathological Conditions: Heart failure, arrhythmias, and severe blood loss can drastically reduce cardiac output.

Example Calculation

Let's consider an individual with a resting heart rate of 90 beats per minute and a stroke volume of 70 mL per beat.

  • Heart Rate (HR) = 90 beats/min
  • Stroke Volume (SV) = 70 mL/beat

Using the formula:

Cardiac Output = 90 beats/min × 70 mL/beat = 6300 mL/min

To express this in liters per minute:

6300 mL/min ÷ 1000 mL/L = 6.3 L/min

Therefore, this individual's cardiac output is 6300 mL/min, or 6.3 L/min.

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