Changing the PV Loop

What is Preload?

Some say Preload = End-Diastolic Pressure, others say Preload = End-Diastolic Volume, so which one is it? Watch and find out! Rishi is a pediatric infectious disease physician and works at Khan Academy.

What is afterload?

Rishi is a pediatric infectious disease physician and works at Khan Academy.

Increasing the Heart's Force of Contraction

Find out exactly how stretch increases force of contraction in end-diastole, whereas more calcium increased force of contraction in end-systole. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Reimagine the Pressure Volume Relationship

Understand what is happening at the cellular level to cause two identical left ventricular volumes to have such different pressures! Rishi is a pediatric infectious disease physician and works at Khan Academy.

What is Contractility?

Contractility tells us how many myosin heads are working at the end of systole; a number that goes up or down with the level of sympathetic nerve stimulation. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Getting Ea (Arterial Elastance) from the PV Loop

Find out how to use the PV loop to draw the Ea (Arterial Elastance) line, and what it represents. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Arterial Elastance (Ea) and Afterload

First, learn the difference between arterial elastance (Ea) and afterload. Then, understand how Ea is affected by changes in afterload, and in turn, how the PV loop can shift. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Arterial Elastance (Ea) and Preload

Understand how Ea is affected by changes in preload, and in turn, how the PV loop can shift. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Stroke Work in PV Loops and Boxes

Watch how PV loops can be "morphed" into PV boxes to make drawing them and thinking about them much simpler. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Contractility, Ea, and Preload Effects on PV Boxes

See how contractility, Ea (arterial elastance), and preload each have an effect on PV Boxes. Rishi is a pediatric infectious disease physician and works at Khan Academy.