Assessment of circadian rhythm of blood pressure and heart rate in ambulatory patients.

Blood pressure recorded telemetrically over 24 h revealed a distinct circadian rhythm, in good accordance with the results of other investigators, measuring intra-arterially, but show much higher amplitudes and earlier acrophases as obtained by indirect blood pressure measurements. Telemetry which allowed measurements when subjects were sleeping proved to be an appropriate tool for the assessment of circadian rhythms of blood pressure and heart rate.