Is warm-up in angina ischaemic preconditioning?

are then able to continue exertion with few or no symptoms but, unlike warm-up angina, without an intervening period of rest. Some of these phenomena have been recognised for centuries2 but they now receive less attention because of effective anti-angina treatment and changes in investigative techniques. For example treadmill exercise testing does not allow rest and imposes incremental increases in effort which make the walk through effect less likely. Only about 1 in 5 patients report symptoms of warm-up angina.' Objective testing in recent studies showed that at least 75% of unselected patients with angina had an enhanced performance on second effort.47 In these studies exercise performance on second effort was on average 125% of that on first effort, but there was considerable individual variability. Not surprisingly those individuals who derived the greatest benefit from first effort were those with a history of warm-up