left ventricular isovolumetric contraction time calculated left ventricular isovolumetric relaxation time left ventricular ejection time myocardial performance index TEI-Doppler index LV performance index CMO:0002556 jsmith A calculated measurement comprised of the sum of left ventricular isovolumetric contraction time and isovolumetric relaxation time divided by the left ventricular ejection time. (IVCT+IVRT)/ET VT:2000009 Tei Index 2014-08-18T13:54:20Z MPI clinical_measurement_ontology left ventricular isovolumetric contraction time and isovolumetric relaxation time to ejection time ratio