Résumé
BACKGROUND: Circadian rhythms have been described for acute myocardial infarction, sudden cardiac death, cerebrovascular disease, ischemic heart disease, and ventricular arrhythmia. Most of studies reported that the frequency of ventricular permature contractions(VPC's) shows a peak in day time. We tried to see that the circadian rhythm of VPC's in hypertension and ischemic heart disease(IHD) patients. And we will also studied the relationship between heart rate and frequencey of VPC's. METHOD: Twenty four hour holter monitoring was performed in hypertensive patients (N=23), ischemic heart disease patients(N=25), and normal control group(N=30). We tested the circadian pattern of VPC's and heart rates and the relationships of the frequency of VPC's and heart rates. RESULT: In hypertension group, a peak incidence of heart rate is between 5 and 8 P.M., in ischemic heart disease group, between 3 and 6 P.M.. In control group, the heart rate shows a peak beteen 1 and 3 P.M.. The frequency of VPC's in hypertension group shows the first peak between 4 and 10 P.M., and the second peak beteen 7 and 10 A.M.. In ischemic heart disease group, they show a peak between 2 and 8 P.M..In control group, there was no circadian variation for the frequency of VPC;s. Both in hypertension and IHD patients group, there was significant correlation between the frequency of VPC's and the heart rates. CONCLUSION: It seemed that VPC' were more frequently occurred in relation to the increase of heart rate in the afternoon, in hypertensive and ischemic heart disease patients.