Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

Background Heart rate variability (HRV) is known to be impaired in patients with congestive heart failure (CHF). Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincare plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincare plots incorporate autocovariance information and analysis of Poincare plots for various lags can provide interesting insights into the autonomic control of the heart.