Heart-rate spectral analysis: a noninvasive probe of cardiovascular regulation in critically ill children with heart disease.

Children may die suddenly and unexpectedly following cardiac surgery, even while receiving intensive medical care, when current noninvasive and invasive monitoring techniques fail to warn us of an impending problem. This report examines the efficacy of heart-rate spectral analysis, a noninvasive method that quantitates the beat-to-beat fluctuations in heart rate, in characterizing and tracking cardiovascular regulatory status. A total of 45 heart-rate fluctuation studies, performed on selected patients, at the bedside, using heart-rate spectral analysis, were retrospectively correlated with clinical events. The spectral pattern of 18 patients who sustained a cardiac arrest differed significantly from the others in the study group (p less than 0.0001).