McIntyre WF, et al. - Researchers sought to determine the risks for stroke and death according to atrial fibrillation (AF) patterns found in the Manitoba Follow-Up Study which included 3,983 originally healthy men who have been followed with routine examinations since 1948. The following patterns of AF were identified: free of AF; newly-diagnosed; intermittent AF – in sinus; intermittent AF – in AF; and sustained AF. In order to estimate the risks, they created adjusted Cox proportional hazards models with time-dependent covariates. Stroke and death were associated with sustained and newly-diagnosed AF vs men free of AF. An association of intermittent AF with death, but not with stroke, was also observed. Overall, the associated risks of stroke and death have been shown to differ considerably with rhythm classification on serial ECGs in the longitudinal analysis of patterns of AF evolving over time.