Selective quantification of cardiac sympathetic and parasympathetic nervous function based on the heart rate baroreflex impulse response

We introduce an improved technique for selectively quantifying cardiac sympathetic and parasympathetic nervous function based on the identification of the heart rate (HR) baroreflex impulse response from non-invasive cardio-respiratory measurements. We have tested the technique with respect to 24 humans breathing randomly or spontaneously under selective pharmacological autonomic blockade. Our results show that the technique performs much better than traditional HR power spectral indices in terms of predicting the known drug effects and is effective during spontaneous breathing.