Evaluation of respiratory influences on left ventricular function parameters extracted from echocardiographic acoustic quantification

This study was designed to assess, using the echocardiographic acoustic qua ntification technique, the influence of respiration on left ventricular (LV ) function and its modifications connected with the ageing process, quantif ying in a non-invasive way the respiratory contribution to the LV volume va riability An automated algorithm is applied to extract the beat-to-beat mea surements of LV function parameters from the LV volume signal, obtained fro m recordings lasting a few minutes. Mean values, amount of variability and spectral content were studied in a population of 17 normal young (mean age 25 +/- 1 years) and 12 normal old (mean age 64 +/- 2 years) subjects. Mean values of the beat-to-beat measurements of LV function parameters were able to point out alterations connected with the ageing process in peak filling rate, peak atrial filling rate and peak ejection rare. Spectral analysis, applied to the extracted variability series, displayed a predominance of th e high-frequency (HF) component corresponding to respiration in all LV func tion parameters; moreover, age related changes of HF variability were obser ved in peak ejection rate. The HF power spectrum component of beat-to-beat series extracted from the LV signal can provide a non-invasive assessment o f the fluctuations in ventricular parameters associated with respiration.