A computerized system for the analysis of the carotid pulse and apexcardiogram

A computer program for the on-line analysis of the carotid pulse (CP) and of the apexcardiogram (ACG) is described. The program measures the absolute and the heart rate-corrected time intervals, the time intervals ratios, the amplitude absolute values, the quantitative ACG (DA/Dt), the ejection fraction and the circumferential fiber shortening velocity, according to Antani. Normalized amplitude and angular ACG items are also calculated. 80 normal subjects were examined to evaluate the reliability of the computer measurements in comparison with the manual measurements and to establish normal computerized values. No significant differences resulted in the comparison of the manual and computerized measurements. The normal computerized values are quite similar to those reported in the literature. The systolic time intervals (STI) were derived from the CP/phonocardiogram recording and directly from the ACG, utilizing the second peak of the first ACG derivative as marker of the onset of the ejection period. The left ventricular ejection time was 286.36 +/- 14 and 282.35 +/- 21.80 (no significant difference) and the pre-ejection period 87 +/- 14 and 93.16 +/- 23.16 (no significant) utilizing the CP/phonocardiogram and the ACG respectively. The results demonstrate a good reliability of the computer system and the usefulness of the system in the direct estimate of the STI from the ACG.