6 Unravelling the mechanisms of mental stress vs exercise induced myocardial ischaemia

Background Mental stress (MS) triggers myocardial ischaemia at cardiac workloads that are lower than those that cause exercise-induced ischaemia in the same patient. Methods Intracoronary pressure and flow velocity data were acquired from 15 CAD (FFR 70% stenosis) patients and 11 controls during MS (mental arithmetic, stroop test). 7 CAD patients and 5 controls also underwent cycle ergometer exercise stress (ES). Coronary flow average peak velocity (APV), microvascular resistance (MR) and Buckberg index (BI) were calculated. Results At peak MS rate pressure product (RPP), a marker of myocardial oxygen demand, increased by 4418 ± 2353mmHg.bpm (p = 0 Conclusion A paradoxical rise in MR does occur in response to MS that is not seen with ES at similar workloads. This abnormal endothelial response correlates with the extent of atherosclerosis in the vessel.