Echocardiographic assessment of feline false tendons and their relationship with focal thickening of the left ventricle.

BACKGROUND

False tendons (FTs) are string-like structures in the left ventricle. A FT might produce focal thickening at its insertion region of the left ventricle, which could be mistaken for focal hypertrophic cardiomyopathy.

OBJECTIVES

To perform a prospective, echocardiographic follow-up examination of feline FTs and compare the wall thickness at the FT insertion region and a normal region without FTs at both examinations.

ANIMALS: One hundred twenty-eight cats with one or multiple FTs without other cardiac abnormalities or systemic disease.

METHODS

Measurements of the interventricular septum at end-diastole at a region with and without FT insertion were performed using two-dimensional echocardiography at both examinations and compared statistically using a Student's t-test.

RESULTS

The follow-up interval ranged from 5 to 110 months (mean, 33 months). Myocardial wall segments with FT insertions were significantly thicker compared with neighboring wall regions in the long axis, but not in the short-axis views obtained. Comparing the wall thickness of follow-up examinations with the initial examination, revealed a significant growth of both FT and non-FT segments. However, differences in growth between the FT region and region without FTs were not statistically different.

CONCLUSIONS AND CLINICAL

IMPORTANCE

Many normal cats have FTs, associated with focal thickening compared with neighboring regions. This thickening can increase over time, proportionate to growth in other (non-FT) segments. The association of such thickening with an FT and the absence of disproportionate growth in this segment over time suggests that these segments are simply thicker related to FT insertion.