The effect of the gravitation of the moon on acute myocardial infarction

A number of studies have reported a daily and yearly variation in the occurrence of acute myocardial infarction (AMI) [ , ]. It has been shown that the circadian variation of AMI is the result of an increase in the incidence of plaque rupture during the morning hours [ ]. These studies have shown a relation between the solar motion and the occurrence of AMI. Less information is available regarding the effect of the moon on coronary artery disease. Previous reports have shown lunar phases do not relate to the occurrence of AMI [ , ]. The period it takes the moon to orbit around the earth and the period of the phase of the moon are different. These periods are referred to as the sidereal month and synodic month, respectively. One sidereal month is 27.32 days, and after that time, the moon has returned to the same point in the heavens. The synodic month is 29.53 days, the time after which the moon returns to exactly the same position relative to the sun. The moon moves in an easterly direction relative to the earth, by 360°/29.53 = 12.2° each day, and relative to the earth, by 360°/27.32 = 13.2°. The difference between the sidereal and synodic daily motion of the moon is equal to the daily motion of the sun. This becomes immediately clear if we consider that the daily motion is nothing other than the angular velocity in astronomical units. A previous report has shown that a blind man has a circadian rhythm based on the motion of the moon [ ]. As well as the sun, the moon may control our biological clock. The study of the timing and activity at occurrence of AMI may provide clues to preventive measures. There have, however, been few studies concerning the gravitation of the moon. The aim of this study was to investigate the relation between the occurrence of AMI and the gravitation of the moon.