Comparative examination of percussional and echocardiographic determination of the cardiac dullness area in healthy horses.

Since percussion started to be a method forgotten and not trusted by many practitioners, the aim of the study was to demonstrate whether this procedure could deliver exact data if done accurately and by a practised examiner. The trial presented here included 31 healthy warm-blooded horses. Percussion of the area of cardiac dullness and then echocardiographic imaging of the same region were performed. To obtain the relevant measurement points, the 4th and 5th intercostal spaces (ICS) were used on the left and the 4th ICS on the right side. On the left side, the dorsal border of cardiac dullness was determined in the 4th ICS (1st point). Then the ventral border of the cardiac dullness was determined at the same place (2nd point). This was followed by the examination of the same points in the 5th ICS (3rd and 4th points). The following step was to measure the distance of these points from the ventral border of the thorax, and also that between the 2nd and the 4th points. On the right side the same procedure was used in the 4th ICS only. Mean values/standard errors (in cm) of absolute values of differences between percussional and echocardiographic measurements were as follow. Left side, 4th ICS, dorsal border: 0.8/0.1; ventral border: 0.7/0.1; 5th ICS, dorsal border: 0.8/0.1, ventral border: 0.9/0.2; right side, 4th ICS, dorsal border: 0.8/0.2; ventral border: 0.7/0.1. Due to the close correlation between the results of the two techniques, it is reasonable to consider cardiac percussion as an integrated part of the physical examination.