Echokardiographische Untersuchung der linksatrialen Größe bei gesunden Katzen und Katzen mit linksventrikulärer Hypertrophie

Zusammenfassung

Gegenstand und Ziel: Die Größe des linken Vorhofs (LA) hat bei Katzen mit Kardiomyopathie sowohl diagnostische als auch prognostische Bedeutung und beeinflusst therapeutische Entscheidungen. Ziel dieser Arbeit war, die Größe des LA im zweidimensionalen (2-D) Echokardiogramm und im M-Mode bei gesunden Katzen und Katzen mit linksventrikulärer (LV) Hypertrophie zu quantifizieren und die Messmethoden miteinander zu vergleichen. Material und Methode: Insgesamt wurden 59 Katzen untersucht und in Gruppen eingeteilt. Die Kontrollgruppe bestand aus 26 gesunden Katzen und die Untersuchungsgruppen aus 33 Katzen mit hypertropher Kardiomyopathie (HCM) oder sekundärer LV Hypertrophie infolge arterieller Hypertension. Bei diesen Tieren erfolgte eine Unterteilung in asymptomatische und symptomatische Katzen. Fünf unterschiedliche echokardiographische Messmethoden fanden Anwendung. Das Verhältnis von Durchmesser des LA und Dimension der Aorta (LA/Ao) wurde aus dem M-Mode aus der langen und kurzen rechts-parasternalen Achse sowie aus der 2-D Kurzachse berechnet und Grenzwerte zur Diagnostik einer linksatrialen Vergrößerung ermittelt. Ergebnisse: In der Kontrollgruppe beeinflussten die Herzfrequenz, nicht jedoch die Körpermasse oder das Alter (p > 0,05) die Größe des LA. Eine linksatriale Vergrößerung konnte im Vergleich zur Gruppe der gesunden Katzen mit jeder angewandten Messmethode dargestellt werden (p < 0,004). Die Vergrößerung des LA wurde für jeden LA/Ao-Quotienten mit dem linksatrialen Durchmesser, gemessen in der 2-D langen Achse verglichen. Die Übereinstimung zwischen diesen Messmethoden war mittelmäßig bis moderat (Kappa = 0,39–0,57). Schlussfolgerung und klinische Relevanz: Diese Studie zeigt, dass eine Vergrößerung des LA bei der Katze durch unterschiedliche echokardiographische Messmethoden dargestellt werden kann. Die Grenzwerte der Methoden differieren, sodass die Ergebnisse der einzelnen Methoden nicht miteinander vergleichbar sind.

Summary

Objective: Left atrial (LA) enlargement has diagnostic and prognostic significance and impacts therapeutic decisions in cats with cardiomyopathy. The aim of this study was to quantify and compare LA dimensions obtained by two-dimensional (2-D) and M-mode echocardiography in healthy cats and cats with left ventricular (LV) hypertrophy. Material and methods: A total of 59 cats were examined and divided into different groups. The control group consisted of 26 healthy cats and the study group of 33 cats with hypertrophic cardiomyopathy (HCM) or secondary LV hypertrophy due to systemic hypertension. Cats of the study group were divided into asymptomatic and symptomatic animals. The assessment of LA size included five different echocardiographic methods of measurement. The LA/Ao-ratio (LA/Ao) was measured from right-parasternal long- and short-axis M-mode echocardiograms and 2-D echocardiogram from the short axis. Cutoff values to diagnose LA enlargement were established. Results: In the control group, LA size was influenced by heart rate but not by bodyweight and age. Cats with LV hypertrophy had greater LA dimensions as measured by each of the different methods (p < 0.004) compared to control cats. LA enlargement, based on two-dimensional LADs > 1.60 cm, was compared to each other method used to calculate LA/Ao and showed a fair to moderate agreement (Kappa 0.39–0.57). Conclusions and clinical relevance: It is concluded that LA enlargement in cats can be diagnosed using different 2-D and M-mode echocardiographic methods. As reference ranges of LA size obtained by use of different echocardiographic methods differ, results of studies using different methods for assessment of LA size assessment should not be compared with each other.

Schlüsselwörter

linker Vorhof - LA/AoVerhältnis - Echokardiographie - hypertrophe Kardiomyopathie - Referenzwerte - Katze

Key words

Left atrium - LA/Ao ratio - echocardiography - hypertrophic cardiomyopathy - reference values - cat

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