|
| |
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
|