Echocardiography and pathology of left ventricular "false tendons".

The anatomic incidence of left ventricular false tendons has been determined in 100 hearts obtained from consecutive autopsies on patients who had a wide variety of cardiac conditions. In this series, an anomalous band was found in 34 cases. A retrospective two-dimensional (2D) echocardiographic study was able to identify false tendons in only 18 percent of cases with anatomic evidence of them, indicating 2 mm as the limit of resolution of 2D echocardiography even with appropriate projections. Finally, the histologic examination has shown false tendons to contain conduction tissue and thus it is assumed to be intracavitary radiations of the bundle of His. This last consideration introduces new physical and electrophysiologic implications.