Analysis of Poincaré plot derived from 5-min electrocardiography in dogs with myxomatous mitral valve disease.

Abstract

BACKGROUND: Evaluation of heart rate variability (HRV) is used for risk assessment in a variety of cardiac diseases including myxomatous mitral valve degeneration (MMVD). OBJECTIVES: To compare the geometric analysis of HRV using visual patterns of Poincar&#xe9; plot among different classes of MMVD in dogs and to analyse the differences in beat-to-beat variability using tachograms and sequential Poincar&#xe9; plots among different shapes. ANIMALS AND METHODS: Healthy and MMVD dogs were retrospectively reviewed. Five-minute ECG data was used to create Poincar&#xe9; plots and shapes were compared among groups. Furthermore, a sub-analysis of 50 consecutive R-R intervals was performed. Pearson Chi-square with adjusted standardized residuals was used to compare the categorical data between groups. RESULTS: Fifteen healthy dogs and 157 dogs with MMVD were included in the study. Normal and B1 groups showed a predominance of triangular shape (73% and 60% respectively;&#x2009;<&#x2009;0.05). In B2 group the predominant shape was comet (40%;&#x2009;<&#x2009;0.05) while comet and torpedo were predominant in Ca group (41% and 36% respectively;&#x2009;<&#x2009;0.05). Visual geometric analysis revealed a lower dispersion of the cloud clustering towards the left lower corner of the plot with MMVD progression. Diamond and triangle revealed a lower mean heart rate compared to comet and torpedo shapes (&#x2009;<&#x2009;0.01). Interclass correlation between 3 observers was 0.906 (95% CI of 0.8&#x2009;-&#x2009;0.96). CONCLUSIONS: Poincar&#xe9; plot shape changes with MMVD progression suggesting that geometrical analysis of HRV in dogs with cardiac conditions could be a useful tool in the risk assessment and further studies are warranted.