Cardiac cycle: Difference between revisions

In an [[electrocardiogram]], electrical systole initiates the atrial systole at the P wave deflection of a steady signal; and it starts contractions (systole).

 

[[File:Wiggers Diagram 2.svg|thumb|right|upright=2.2|A [[Wiggers diagram]] illustrate events and details of the cardiac cycle with electrographic trace lines, which depict (vertical) changes in a parameter's value as time elapses left-to-right. The ventricular "Diastole", or relaxation, begins with "Isovolumic relaxation", then proceeds through three sub-stages of inflow, namely: "Rapid inflow", "Diastasis", and "Atrial systole". (During the "Diastole" period, the "Ventricular volume" increases (see red-line tracing), beginning after the vertical bar at ''"Aortic valve closes"'' and ending with the vertical bar at R in the QRS complex). + The ventricular "Systole", or contraction, begins with "Isovolumic contraction", i.e., with the vertical bar at ''"A -V valve closes"''; it ends with completing the "Ejection" stage at the bar at ''"Aortic valve closes"''. During "Ejection" stage, the (red-line) tracing of "Ventricular volume" falls to its least amount (see [[ejection fraction]]) as the ventricles pump blood to the pulmonary arteries and to the aorta.]]