[Several-day arterial pressure and heart rate monitoring in patients with paroxysmal atrial fibrillation].

Patient N presented with a well-apparent abnormality of chronological structure of heart beat biorhythms despite the absence of subjective complaints throughout the six-month long observation period. It was shown that AP peaks were associated with a significant decrease of circadian index (CI), i.e. the development of a rigid daily heart contraction rhythm. The reduction of CI as a specific indicator of stability of the daily cardiac contraction rhythm gave evidence of altered vegetative regulation of cardiac function during hypertension. Rigidity of the daily heart contraction rhythm increased with increasing severity of the disease. Smoothing of the circadian rhythm profile suggests depletion of adaptive reserve and the development of the "denervated" heart phenomenon. Cardioversion created a tendency towards normalization of circadian index.