Measurement of the total transverse diameter of the heart by direct percussion

1. 1. A study comparing the total transverse cardiac diameters as obtained by direct percussion with the measurements on teleroentgenogram is presented. 2. 2. A discussion of the possible sources of error in both methods of examination is included. 3. 3. Of 333 examinations of 305 men, percussion measurements in 74 per cent were within plus or minus 10 per cent of the teleroentgenographic figures; 88 per cent were within plus or minus 15 per cent. In 58 per cent, percussion figures were within 1.0 cm. of the teleroentgenographic measurements. 4. 4. Fifty-five comparative examinations of forty-five women gave similar results. 5. 5. Direct percussion of the total transverse cardiac diameters appears to be of decided value in men.