Left ventricular ejection time measured by finger-tip plethysmography in healthy young Japanese. Its correction for...

Finger-tip plethysmograms were recorded photoelectrically on 200 young males and females each. The relation between the left ventricular ejection time (ET) and the preceding heart rate (HR) and a method for correcting ET for the heart rate were studied. The values calculated by the formula ET/S-S or ET/square root S-S varied with the HR, so these formulae cannot be used for correcting the ET for HR. Thus from the relationship between ET and HR, a formula for converting the measured ET to the ET at an HR OF 70, I.E. ETc, was deduced. ETc equals ET + HR - 70. This formula can be used for both sexes of Japanese juveniles and the values obtained by it can be directly compared, irrespective of the HR.