Circadian pattern of cardiovascular and cerebrovascular diseases in geriatric population.

ABSTRACT

OBJECTIVES: Over last 13 years various studies have been done to evaluate the circadian pattern in cardiovascular and cerebrovascular diseases in adults and the existence of such variation in Indian population also has been demonstrated. The data on this variation in geriatric patients does not exist. METHODS: We undertook this prospective observational study at Government Medical College and Hospital, Chandigarh to evaluate the circadian variation in disorders like acute myocardial infarction (AMI), unstable angina (USA), non Q wave MI (non QMI), cerebrovascular accidents (strokes, both ischemic and hemorrhagic) and transient ischemic attacks (TIA). OBSERVATIONS We studied 158 patients (56.98% males and 43.02% females), mean age was 69 +/- 4 years. 34.17% each had AMI and CVA, 22.78% and USA and 7.59% had NON Q MI, only two patients in our study group had TIAs. We divided 24 hours into four equal quarters each for analysis. RESULTS: We observed that maximum episodes were seen during the period between 6 am till 12 noon 58/158 (36.71%) and a second peak was seen during 6 pm and 12 midnight when 40/158 events were recorded (25.31%). The least number of episodes were seen during the period between 12 midnight till 6 am 22/158 (13.92%). Similar peaking of events was noted for acute myocardial infarction but only one peak was seen for unstable angina. For cerebrovascular accidents two similar peaks were noted between 6 am till 12 noon and 12 noon till 6 pm. CONCLUSIONS: Our study population (geriatric patients) shows the presence of a definitive circadian variation with two comparable peaks. One during the morning hours (6 am-12 noon) and another peak between 6 pm and 12 midnight in patients having acute coronary diseases. In cerebrovascular accidents patients too, similar peaks were noted between 6 am till 12 noon and 12 noon till 6 pm.