Hernesniemi JA, Sipilä K, Tikkakoski A, et al. - Among 3,776 patients without pacemakers undergoing first maximal or submaximal exercise testing with cycle ergometer in a prospective clinical investigation (the Finnish Cardiovascular Study), researchers focused on if an association of cardiorespiratory fitness (CRF) and heart rate recovery (HRR) with the risk of sudden cardiac death (SCD) was independent of left ventricular ejection fraction (LVEF). Participants were observed until December 2013. By achieving maximal work level, the estimation of CRF in metabolic equivalents was done. The attenuation in heart rate 1 minute following maximal exertion defined HRR. Irrespective of LVEF, a significant association of CRF and HRR with SCD risk was seen.