[An analysis of precision and accuracy of the phonocardiogram exercise test]

Phonocardiogram exercise testing (PCGET) is a recently developed method to evaluate cardiac contractility and the cardiac reserve of patients with heart disease and of healthy subjects. In order to test the reliability of PCGET method, the present author conducted a study on its precision and accuracy. Thirty volunteers underwent PCGET. When different examiners measured the S1 amplitude in the same cardiac cycle of the same subject, the data obtained by examiner A were: x +/- s = 5.05 +/- 0.0451; the data obtained by examiner B were: x +/- s = 4.95 +/- 0.0346, F = 1.699, P > 0.05. When different examiners measured the same cardiac cycle of the same subject, the data obtained by examiner A were: x +/- s = 0.789 +/- 0.0018; the data obtained by examiner B were: x +/- s = 0.787 +/- 0.0017, F = 1.167, P > 0.05. The results suggest that PCGET is a nonivasive, convenient, and inexpensive technique to quantitatively evaluate cardiac reserve for abnormal or normal persons.