Isovolumetric Relaxation

ISOVOLUMETRIC RELAXATION

The beginning of diastole

Heart:

At the beginning of this phase the AV valves are closed.

Pressures & Volume:

Throughout this and the previous two phases, the atrium in diastole has been filling with blood on top of the closed AV valve, causing atrial pressure to rise gradually (yellow).

The "v" wave is due to the back flow of blood after it hits the closed AV valve. It is the second discernible wave of the jugular venous pulse.

The pressure in the ventricles (red) continues to drop.

Ventricular volume (white) is at a minimum and is ready to be filled again with blood.

ECG:

Heart sounds:

The second heart sound (S2, "dup") occurs when the semilunar (aortic and pulmonary) valves close. S2 is normally split because the aortic valve closes slightly earlier than the pulmonary valve.

Previous phase

Next phase

	Heart: At the beginning of this phase the AV valves are closed.
	Pressures & Volume: Throughout this and the previous two phases, the atrium in diastole has been filling with blood on top of the closed AV valve, causing atrial pressure to rise gradually (yellow). The "v" wave is due to the back flow of blood after it hits the closed AV valve. It is the second discernible wave of the jugular venous pulse. The pressure in the ventricles (red) continues to drop. Ventricular volume (white) is at a minimum and is ready to be filled again with blood.
	ECG:
	Heart sounds: The second heart sound (S2, "dup") occurs when the semilunar (aortic and pulmonary) valves close. S2 is normally split because the aortic valve closes slightly earlier than the pulmonary valve.