Agreement between echocardiographic techniques in assessment of the left ventricular myocardial performance index in rabbits

摘要: Objective—Toreportreferencevaluesandexaminetheagreementinthemyocardial� performance�(Tei)�indexoftheleftventricle�(LVTI)�asmeasuredbytissueDopplerimaging� (TDI),� pulsed-waveDopplerimaging� (PWD),� andM-modeechocardiographyinclinically� normalrabbits. Animals—26�clinicallynormalmaleNewZealandWhiterabbits. Procedures—EchocardiographicexaminationsthatincludedTDI,�PWD,�andM-modeecho- cardiographywereperformed.�RabbitsweresedatedbySCadministrationofketamineand� midazolam.�Intraclasscorrelationcoefficients� (ICCs)�wereusedtomeasureabsoluteagree- mentamongthe�3�echocardiographictechniques.�Intraclasscorrelationcoefficientswere� computedforvaluesaandbandfortheequation�(a�-�b)/busedtodetermineLVTI;�value� aequalsthesumofisovolumiccontractiontime,�ejectiontime,�andisovolumicrelaxation� time,�andvaluebequalstheleftventricularejectiontime.�ValuesofICC�>�0.75�indicated� goodagreementbetween�2�echocardiographictechniques. Results—Forvaluea,�Pearsoncorrelationcoefficientsbetweenpairsoftechniqueswere� allhigh�(rr �0.7).�However,�onlytheseptalTDIandthelateralwallTDIhadgoodagreement� (ICC,�0.86).�Forvalueb,�correlationsweregenerallylowwiththeexceptionofthecorrela- tionbetweentheseptalandthelateralwallTDI.�Forvalueb,�TDIwastheonlytechnique� withgoodagreement�(ICC,�0.77).�ForLVTI,�onlyTDItechniqueshadasignificantlypositive� correlation.�Alltheothercorrelationswereclosetozerowithaparadoxicmoderatenegative� correlationbetweenPWD-determinedLVTIandlateralwallTDI-determinedLVTI. Conclusions and Clinical Relevance—ForLVTI,�theabsoluteagreementwaspoorbetween� allpairsoftechniques.�(Am J Vet Res�2009;70:464-471)