Accuracy of percussion of the left cardiac border

The purpose of this study was to determine the accuracy of percussion of the left cardiac border. Sixty-six adult patients were studied. The left cardiac border as determined by percussion and marked with a calibrated lead marker was compared with that obtained by a chest X-ray. The error in locating the left cardiac border by percussion ranged from underestimating by 5.0 cm to overestimating by 5.5 cm. The mean absolute error was 1.6 cm (SD = 1.6 cm). In 74% (49/66) and 85% (56/66) of the patients the percussed border was within 1.0 and 2.0 cm, respectively, of that established by X-ray. In 24 of the 66 cases, a second examiner also independently percussed the left cardiac border. The differences between the location determined by the two observers ranged from 0 to 4 cm with a mean difference of 1.2 cm (SD = 1.0 cm).

Percussion can accurately locate the left cardiac border in the adult patient and is a reproducible technique.