I have measured out my life with coffee spoons…
T.S. Eliot, The Love Song of J. Alfred Prufrock
In this issue of JAMA Internal Medicine, Kim and colleagues2 investigate the association between coffee consumption and risk of tachyarrhythmia through a longitudinal prospective cohort study, coupled with a mendelian randomization analysis related to caffeine metabolism, and tests for an interaction between coffee, caffeine metabolism, and arrhythmic risk. Rhythms of interest included atrial fibrillation (AF), atrial flutter, (nonspecified) supraventricular tachycardia, ventricular tachycardia, and atrial and ventricular ectopy. The sample included nearly 400 000 select participants in UK Biobank, a unique database containing health and genetic information.