Echocardiography in the Domestic Cat

Echocardiographic examinations were performed on 25 normal healthy cats placed in left lateral recumbency. The cats were representative of serveral breeds, consisted of 12 males and 13 females, and weighed between 2 and 6.5 kg. Twelve measurements from the echocardiograms of each cat were made for the purpose of compiling a small data base (reference values). These measurements included wall thicknesses, luminal dimensions, and contractile indices. Left ventricular wall thickness averaged 0.37 +/- 0.08 cm, and the septal wall thickness averaged 0.45 +/- 0.09 cm. The average left ventricular lumen in diastole was 1.48 +/- 0.26 cm, and in systole, it was 0.88 +/- 0.24 cm, which resulted in an average shortening fraction of 41 +/- 7.3%. Velocity of circumferential shortening, an index of contractility, averaged 2.86 +/- 0.78 cm. In eight additional cats, both ventricles were catheterized for echographic chamber identification and then cineangiographic procedures. Then these cats were euthanatized, and postmortem measurements were compared with echocardiographic and cineangiographic measurements. According to the three methods of determining wall thickness, differences were less than 15%, where the range of deviations was between 0 and 0.5 mm and the average deviation was -0.01 +/- 0.26 mm.