Understanding Cardiac Physiology

Stroke Volume is the blood ejected by one ventricle in one single heartbeat.

Think of your heart like a water pump. What is ejected is your stroke

volume. Cardiac Output is stroke volume times heart rate, measuring total flow

per minute. Cardiac Index accounts for body size, ensuring heart performance fits the individual.

Preload follows Frank Starling Law. More stretch means a stronger contraction, like a rubber

band. Afterload is the resistance. High blood pressure makes it harder

for the heart to pump. Guyton says venous return determines output. Master these for

your exams.