Featured Image: A Wiggers diagram, showing the cardiac cycle events occuring in the left ventricle.
In the atrial pressure plot: wave “a” corresponds to atrial contraction, wave “c” corresponds to an increase in pressure from the closed mitral valve bulging into the atrium during ventricular systole, and wave “v” corresponds to passive atrial filling.
In the electrocardiogram: wave “P” corresponds to the onset of atrial depolarization, waves “QRS” (aka QRS complex) correspond to the onset of ventricular depolarization, and wave “T” corresponds to ventricular repolarization.
In the phonocardiogram: The sound labeled 1st contributes to the S1 heart sound and is the reverberation of blood from the sudden closure of the mitral valve (left A-V valve) and the sound labeled “2nd” contributes to the S2 heart sound and is the reverberation of blood from the sudden closure of the aortic valve. CREDIT: DanielChangMD revised original work of DestinyQx. SOURCE: wikipedia Commons. (This file is licensed under the Creative Commons Attribution-Share Alike 2.5 Generic license. – Public Domain).