The calculation for cardiac output is:
a. Stroke volume x blood pressure
b. Heart rate x blood pressure
c. Heart rate x stroke volume
d. Heart rate x end diastolic volume
The correct answer and explanation is:
The correct answer is: c. Heart rate x stroke volume.
Explanation:
Cardiac output refers to the amount of blood the heart pumps per minute. It is a vital measurement used to assess how effectively the heart is delivering blood to the body’s tissues and organs. The formula for calculating cardiac output is:
Cardiac Output (CO) = Heart Rate (HR) x Stroke Volume (SV)
- Heart Rate (HR): This is the number of times the heart beats per minute. It varies based on factors such as activity level, health status, and age. The heart rate determines how often the heart pumps blood.
- Stroke Volume (SV): This refers to the amount of blood pumped by the left ventricle of the heart with each beat. Stroke volume is influenced by factors like venous return, myocardial contractility, and afterload. It represents how much blood the heart sends into circulation during each contraction.
Cardiac output is a crucial parameter in understanding the circulatory system. It ensures that the body’s tissues receive adequate oxygen and nutrients to function properly. If either heart rate or stroke volume decreases, cardiac output will drop, which may lead to insufficient blood supply to organs and tissues, resulting in symptoms like fatigue, dizziness, or even organ failure in severe cases.
While blood pressure is an important parameter in cardiovascular health, it is not directly included in the cardiac output formula. Blood pressure depends on both cardiac output and peripheral resistance (the resistance of the blood vessels), but it is not part of the basic cardiac output equation.
This formula helps healthcare professionals evaluate the overall functioning of the heart and make decisions about treatment for various cardiovascular conditions.