Cardiac Output (CO) and Stroke Volume
Cardiac Output and Stroke Volume Cardiac Output (CO)- the average volume of blood the heart’s left ventricle ejects into the systemic circulation each minute, measured in liters per minute (L/min); equals Stroke Volume times Heart Rate. CO = Stroke Volume (SV) x Heart Rate (HR) • Typical CO Range: 5 - 8 L/min • Atypical CO Range: <2 and > 10 L/min • Clinical Relevance: indicates increased risk for cardiovascular complications and failure. • Interpretation: CO varies by patient parameters and is used to calculate AF/ CO ratio. SV is determined by a heart’s preload, afterload and contractility. Preload is the filling volume of left ventricle at diastole. Preload is used to assess the fluid conditions that help clinicians make proper decisions on whether or not to infuse fluids. Preload depends on the amount of myocardial fiber stretch at the end of diastole (heart is full of blood and ready to contract). It is the pressure stretching the ventricle of the heart, after pas