Volumetry Of The Left Atrial Appendage In Healthy Cats By Two-Dimensional And Three-Dimensional Echocardiography

IntroductionWe studied whether monoplane, triplane and real-time three-dimensional echocardiography are feasible for volumetric measurement of the left atrial appendage (LAA) in healthy cats to establish a foundation for further studies on cats with heart disease.Materials and MethodsThe study included 50 healthy cats of various breeds. Left atrial (LA) maximum volume (LAMax), LA minimum volume (LAMin), ejection fraction (EF) and stroke volume (SV) were calculated based on the one-dimensional monoplane Simpson method of discs (SMOD) volumetry, as well as on triplane echocardiography (RTTPE) and on real-time three-dimensional echocardiography (RT3DE) using the TomTec (R) software. Monoplane SMOD was applied in the left apical two-chamber view. All parameters were also measured including the left atrial appendage (LAA) and the volumes of the LA excluding the LAA subtracted from the volumes of the LA including the LAA to obtain the volumes of the LAA (LAAV).ResultsThe monoplane SMOD mean volume for LAAMax (0.97 ml) was nearly twice as high as the value obtained with the RTTPE (0.61 ml) and three times as high as that given by the 4D-TomTec (TM) (0.31 ml). Age, sex and weight had no influence on the results.ConclusionWe have shown the feasibility of monoplane, triplane and real-time three-dimensional echocardiography for LAA volumetry in healthy cats. 4D-TomTecT is the least suitable method, whereas monoplane SMOD and RTTPE appear promising. The results provide the groundwork for further studies in cats with cardiopathies to determine a LAAV cut-off value to commence antithrombotic treatment and reduce the risk of aortic thromboembolism.