Tissue Doppler waveforms of the left atrio-ventricular groove (circumflex artery) at low (left) and high (right) heart rate. Coronary motion occurs throughout systole (S’). At the end of systole there is a short period of relative stasis between the closing of the aortic valve and the opening of the mitral valve (isovolumic relaxation time, IVRT), shown in red. This period varies little with heart rate. The period of minimal cardiac motion (yellow band) occurs between the E’ and A’ waves. The PMCM shortens with increasing heart rate. Images have been resized and edited for clarity.
Otton et al. BMC Medical Imaging 2013 13:5 doi:10.1186/1471-2342-13-5