Limits...
Speckle tracking echocardiography in mature Irish Wolfhound dogs: technical feasibility, measurement error and reference intervals.

Westrup U, McEvoy FJ - Acta Vet. Scand. (2013)

Bottom Line: These were scanned under normal clinical conditions to obtain in one session both standard echocardiographic parameters and STE data.Measurement error was determined separately in 5 healthy mature Irish Wolfhounds.The calculated mean peak torsion of the heart was 11.6 ± 5.1 degrees (n = 45).The measurement error was 24.8%, 26.4%, 11.5%, 6.7%, 9.0% and 10 degrees, for RS-apex, RS-base, CS-apex, CS-base, LS and torsion, respectively.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Small Animal Clinical Sciences, Faculty of Life Sciences, University of Copenhagen, Dyrlaegevej 16, Frederiksberg C DK-1870, Denmark. ulw@sund.ku.dk

ABSTRACT

Background: Two-dimensional strain measurements obtained by speckle tracking echocardiography (STE) have been reported in both humans and dogs. Incorporation of this technique into canine clinical practice requires the availability of measurements from clinically normal dogs, ideally of the same breed, taken under normal clinical conditions.The aims of this prospective study were to assess if it is possible to obtain STE data during a routine echocardiographic examination in Irish Wolfhound dogs and that these data will provide reference values and an estimation of measurement error.

Methods: Fifty- four healthy mature Irish Wolfhounds were used. These were scanned under normal clinical conditions to obtain in one session both standard echocardiographic parameters and STE data. Measurement error was determined separately in 5 healthy mature Irish Wolfhounds.

Results: Eight dogs were rejected by the software algorithm for reasons of image quality, resulting in a total of 46 dogs (85.2%) being included in the statistical analysis. In 46 dogs it was possible to obtain STE data from three scanning planes, as well as to measure the rotation of the left ventricle at two levels and thus calculate the torsion of the heart. The mean peak radial strain at the cardiac apex (RS-apex) was 45.1 ± 10.4% (n = 44), and the mean peak radial strain at the base (RS-base) was 36.9 ± 14.7% (n = 46). The mean peak circumferential strain at the apex (CS-apex) was -24.8 ± 6.2% (n = 44), and the mean peak circumferential strain at the heart base (CS-base) was -15.9 ± 3.2% (n = 44). The mean peak longitudinal strain (LS) was -16.2 ± 3.0% (n = 46). The calculated mean peak torsion of the heart was 11.6 ± 5.1 degrees (n = 45).The measurement error was 24.8%, 26.4%, 11.5%, 6.7%, 9.0% and 10 degrees, for RS-apex, RS-base, CS-apex, CS-base, LS and torsion, respectively.

Conclusions: It is concluded that this technique can be included in a normal echocardiographic examination in large breed dogs under clinical conditions. The usefulness of the reference values reported here, given their wide normal range, will ultimately be determined by the values that are obtained from a large numbers of diseased dogs.

Show MeSH

Related in: MedlinePlus

Schematic representation of the left ventricle. The levels where the measurements were obtained and the direction of rotation. The basal rotation is subtracted from the apex rotation, providing the torsion of the LV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3672081&req=5

Figure 5: Schematic representation of the left ventricle. The levels where the measurements were obtained and the direction of rotation. The basal rotation is subtracted from the apex rotation, providing the torsion of the LV.

Mentions: During systole, radial strain (RS) is expected to be a positive value, (Figures 1, 2 and 3). Circumferential strain (CS) is expected to be negative and longitudinal strain (LS) is normally negative due to a decrease in length of the left ventricle in systole shown in human studies [4] (Figure 4). Calculation of the extent of LV torsion requires short axis speckle tracking data at the level of the apex and at the level of the mitral valves (base) (Figure 5). Software can calculate the rotation at both levels. Viewed from apex to base, counter-clockwise rotation, in degrees, is expressed as a positive value and clockwise rotation, in degrees, as a negative value. Peak LV torsion is then defined as peak systolic basal rotation minus peak systolic apical rotation (Figure 6).


Speckle tracking echocardiography in mature Irish Wolfhound dogs: technical feasibility, measurement error and reference intervals.

Westrup U, McEvoy FJ - Acta Vet. Scand. (2013)

Schematic representation of the left ventricle. The levels where the measurements were obtained and the direction of rotation. The basal rotation is subtracted from the apex rotation, providing the torsion of the LV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672081&req=5

Figure 5: Schematic representation of the left ventricle. The levels where the measurements were obtained and the direction of rotation. The basal rotation is subtracted from the apex rotation, providing the torsion of the LV.
Mentions: During systole, radial strain (RS) is expected to be a positive value, (Figures 1, 2 and 3). Circumferential strain (CS) is expected to be negative and longitudinal strain (LS) is normally negative due to a decrease in length of the left ventricle in systole shown in human studies [4] (Figure 4). Calculation of the extent of LV torsion requires short axis speckle tracking data at the level of the apex and at the level of the mitral valves (base) (Figure 5). Software can calculate the rotation at both levels. Viewed from apex to base, counter-clockwise rotation, in degrees, is expressed as a positive value and clockwise rotation, in degrees, as a negative value. Peak LV torsion is then defined as peak systolic basal rotation minus peak systolic apical rotation (Figure 6).

Bottom Line: These were scanned under normal clinical conditions to obtain in one session both standard echocardiographic parameters and STE data.Measurement error was determined separately in 5 healthy mature Irish Wolfhounds.The calculated mean peak torsion of the heart was 11.6 ± 5.1 degrees (n = 45).The measurement error was 24.8%, 26.4%, 11.5%, 6.7%, 9.0% and 10 degrees, for RS-apex, RS-base, CS-apex, CS-base, LS and torsion, respectively.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Small Animal Clinical Sciences, Faculty of Life Sciences, University of Copenhagen, Dyrlaegevej 16, Frederiksberg C DK-1870, Denmark. ulw@sund.ku.dk

ABSTRACT

Background: Two-dimensional strain measurements obtained by speckle tracking echocardiography (STE) have been reported in both humans and dogs. Incorporation of this technique into canine clinical practice requires the availability of measurements from clinically normal dogs, ideally of the same breed, taken under normal clinical conditions.The aims of this prospective study were to assess if it is possible to obtain STE data during a routine echocardiographic examination in Irish Wolfhound dogs and that these data will provide reference values and an estimation of measurement error.

Methods: Fifty- four healthy mature Irish Wolfhounds were used. These were scanned under normal clinical conditions to obtain in one session both standard echocardiographic parameters and STE data. Measurement error was determined separately in 5 healthy mature Irish Wolfhounds.

Results: Eight dogs were rejected by the software algorithm for reasons of image quality, resulting in a total of 46 dogs (85.2%) being included in the statistical analysis. In 46 dogs it was possible to obtain STE data from three scanning planes, as well as to measure the rotation of the left ventricle at two levels and thus calculate the torsion of the heart. The mean peak radial strain at the cardiac apex (RS-apex) was 45.1 ± 10.4% (n = 44), and the mean peak radial strain at the base (RS-base) was 36.9 ± 14.7% (n = 46). The mean peak circumferential strain at the apex (CS-apex) was -24.8 ± 6.2% (n = 44), and the mean peak circumferential strain at the heart base (CS-base) was -15.9 ± 3.2% (n = 44). The mean peak longitudinal strain (LS) was -16.2 ± 3.0% (n = 46). The calculated mean peak torsion of the heart was 11.6 ± 5.1 degrees (n = 45).The measurement error was 24.8%, 26.4%, 11.5%, 6.7%, 9.0% and 10 degrees, for RS-apex, RS-base, CS-apex, CS-base, LS and torsion, respectively.

Conclusions: It is concluded that this technique can be included in a normal echocardiographic examination in large breed dogs under clinical conditions. The usefulness of the reference values reported here, given their wide normal range, will ultimately be determined by the values that are obtained from a large numbers of diseased dogs.

Show MeSH
Related in: MedlinePlus