Patent ID: 7409241

Claim:
An active implantable medical device, including: means for collecting an endocardiac acceleration parameter of a patient; means for analyzing said collected endocardiac acceleration signal including means for determining a first peak endocardiac acceleration (PEA I) corresponding to a phase of isovolumic ventricular contraction in a given cardiac cycle and a second peak endocardiac acceleration (PEA II) corresponding to a phase of isovolumic ventricular relaxation in said given cardiac cycle, and means for determining a heart rate of a patient; means for calculating a long-term average and a short-term average of the values of the first peaks of endocardiac acceleration (PEA I) collected at the time of the phase of isovolumic ventricular contraction during a plurality of successive cycles; means for calculating a long-term average and a short-term average of the values of the second peaks of endocardiac acceleration (PEA II) collected at the time of the phase of isovolumic ventricular contraction collected during a plurality of successive cycles; means for calculating a long-term average and a short-term average of the values of heart rate; means for delivering at an output a data representative of sympathico-vagal activity of the patient, wherein said data representative of sympathico-vagal activity comprises said calculated long-term and short-term averages of said first peak, second peak, and heart rate; and means for detecting a risk of syncope when the short-term average of the values of the second peaks of endocardiac acceleration (PEA II) is less than the long-term average of the values of the second peaks of endocardiac acceleration (PEA II) and the short-term average of the values of heart rate is greater than the long-term average of the values of heart rate.