Cardiac cycle -reduced ejection

    Cardiovascular Physiology Concepts
                                    Richard E. Klabunde, Ph.D.

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Arrhythmias

Cardiac Valve Disease

Coronary Artery Disease

Edema

Heart Failure

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Peripheral Artery Disease

Click here for information on Cardiovascular Physiology Concepts, published by Lippincott Williams & Wilkins (200 5)

Cardiac Cycle - Reduced Ejection (Phase 4)

Aortic and Pulmonic Valves Open; AV Valves Remain Closed

Approximately 200 msec after the QRS and the beginning of ventricular contraction, ventricular repolarization occurs as shown by the T-wave of the electrocardiogram. Repolarization leads to a decline in ventricular active tension and therefore the rate of ejection (ventricular emptying) falls. Ventricular pressure falls slightly below outflow tract pressure; however, outward flow still occurs due to kinetic (or inertial) energy of the blood.
Left atrial and right atrial pressures gradually rise due to continued venous return from the lungs and from the systemic circulation, respectively.

Jump to other phases:

Phase 1 - Atrial Contraction

Phase 2 - Isovolumetric Contraction

Phase 3 - Rapid Ejection

Phase 5 - Isovolumetric Relaxation

Phase 6 - Rapid Filling

Phase 7 - Reduced Filling

RK Revised 04/05/07

DISCLAIMER: These materials are for educational purposes only, and are not a source of medical decision-making advice.