  We have advanced a point-process based framework for the regulation of heart
beats by the autonomous nervous system and analyzed the model with and without
feedback. The model without feedback was found amenable to several analytical
results that help develop an intuition about the way the heart interacts with
the nervous system. However, in reality, feedback, baroreflex and chemoreflex
controls are important to model healthy and unhealthy scenarios for the heart.
Based on the Hurst exponent as an index of health of the heart we show how the
state of the nervous system may tune it in health and disease. Monte Carlo
simulation is used to generate RR interval series of the Electrocardiogram
(ECG) for different sympathetic and parasympathetic nerve excitations.
