Comparison of 3 Ultrasound Methods for Quantifying Left Ventricular Systolic Function: Correlation with Disease Severity and Prognostic Value in Dogs with Mitral Valve Disease

Abstract

Background: End-systolic volume index (ESVI) is a marker of systolic function, which can be assessed by the geometric (GM, based on Teichholz formula) or 2 planimetric methods (PM, Simpson's derived and length area methods).Hypothesis: Systolic dysfunction (SyD) may be observed in dogs with mitral valve disease (MVD) and is better assessed by PM than GM, which does not take into account the longitudinal left ventricular systolic shortening.Animals: Six healthy dogs were used to determine the variability of the tested variables (Study 1). These variables were then prospectively assessed (Study 2) in 101 small breed dogs: 77 dogs with MVD and 24 healthy controls (CD).Methods: ESVI was measured by GM and PM in awake dogs.Results: All within-and between-day coefficients of variation were o11% (Study 1). For Study 2, a nonlinear overestimation of ESVI was observed by GM compared with PM. PM-derived ESVI was significantly increased in ISACHC class 3 dogs compared with ISACHC class 1 dogs and exerted a significant influence on cardiac events at 5 months in dogs with MVD from ISACHC classes 2 and 3 (P o .05).Conclusions and Clinical Importance: ESVI can be calculated by GM and PM with good repeatability and reproducibility. However, GM overestimates ESVI in a nonlinear way. Therefore, PM-derived ESVI should be preferred for the detection of SyD that is present at the late stages of the disease.

Simpson's Method of Discs for Measurement of Echocardiographic End‐Diastolic and End‐Systolic Left Ventricular Volumes: Breed‐Specific Reference Ranges in Boxer Dogs

“…This would indicate, as previously suggested,11 that either ESVI is higher in these 3 breeds compared with other breeds, suggesting intrinsic systolic dysfunction, or the cut‐off value of 30 mL/m² is too low. In contradiction to this study, the range of SMOD‐derived ESVI was below the cut‐off of 30 mL/m² (9.5–25.4 mL/m²) in a previous study including a group of 24 healthy smaller breed dogs (<10 kg) 19. Because of the large overlap between normal and abnormal values in the ESVC guidelines and several studies describing ESVI >30 mL/m²,11, 12 further study in dogs of different breeds is warranted to determine SMOD‐derived ESVI cut‐offs.…”

“…An interesting and unexpected finding in this study was that in healthy Boxer dogs, the volumes calculated by Teichholz measurements and the volumes derived by SMOD were quite comparable. This is in contrast to findings by Tidholm and Serres, which showed that Teichholz measurements overestimated the volumes by a factor of 2 10, 19. Differences between the Teichholz and SMOD estimations of LV volume may be more pronounced in disease states than in healthy dogs 8.…”

“…The intraobserver CVs for repeated measurements of EDVI and ESVI in the right parasternal and left apical views ranged from 4.2 to 5.7%. Although this indicates somewhat higher variability compared with previous studies,11, 19 these CVs still indicate good‐to‐excellent repeatability.…”

“…Although SMOD is the current ASE‐recommended method for measurement of LV volumes in humans and seems to be very accurate compared with other methods in dogs, studies describing reference ranges are scarce 19, 20. Boxer dogs are particularly prone to heart disease and breed‐specific M‐mode and Doppler reference ranges have been generated for this breed 1…”

Electrocardiographic, echocardiographic, and indirect blood pressure evaluation in dogs subjected to different sedation protocols

“…Cardiac output (CO) and the ejection fraction (EF) were calculated using the modified Simpson method, as described byBOON (2011). Fractional shortening (FS) was calculated from left ventricular diameter values obtained during diastole and systole, as described by SERRES (2008).…”