[Arrhythmias and chronobiology].

The cyclical changes in biological events have seldom been studied by cardiologists. No complete systematic method of study has ever been applied to them. It is, however, certain that the circadian rhythms play a very important role in cardiac patients. This can be seen to be so in the arrhythmias. In a preliminary report, the authors give several examples of this concept; they have obtained their material by using a computerised magnetic tape recording of the electrocardiogram during a 24 hour period.