Heart rate recovery after orthostatic challenge and cardiopulmonary exercise testing in older individuals: prospective multicentre observational cohort study oleh Aaron James, David Bruce, Nicholas Tetlow, Amour B.U. Patel, Ethel Black, Nicole Whitehead, Anna Ratcliff, Alice Jamie Humphreys, Neil MacDonald, Gayle McDonnell, Ravishankar Raobaikady, Jeeveththaa Thirugnanasambanthar, Jeuela I. Ravindran, Nicole Whitehead, Gary Minto, Tom E.F. Abbott, Shaman Jhanji, Don Milliken, Gareth L. Ackland